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Author SHA1 Message Date
Kumar Kartikeya Dwivedi
c00d738e16 bpf: Revert "bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"
This patch reverts commit
cb4158ce8e ("bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"). The
patch was well-intended and meant to be as a stop-gap fixing branch
prediction when the pointer may actually be NULL at runtime. Eventually,
it was supposed to be replaced by an automated script or compiler pass
detecting possibly NULL arguments and marking them accordingly.

However, it caused two main issues observed for production programs and
failed to preserve backwards compatibility. First, programs relied on
the verifier not exploring == NULL branch when pointer is not NULL, thus
they started failing with a 'dereference of scalar' error.  Next,
allowing raw_tp arguments to be modified surfaced the warning in the
verifier that warns against reg->off when PTR_MAYBE_NULL is set.

More information, context, and discusson on both problems is available
in [0]. Overall, this approach had several shortcomings, and the fixes
would further complicate the verifier's logic, and the entire masking
scheme would have to be removed eventually anyway.

Hence, revert the patch in preparation of a better fix avoiding these
issues to replace this commit.

  [0]: https://lore.kernel.org/bpf/20241206161053.809580-1-memxor@gmail.com

Reported-by: Manu Bretelle <chantra@meta.com>
Fixes: cb4158ce8e ("bpf: Mark raw_tp arguments with PTR_MAYBE_NULL")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241213221929.3495062-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-13 16:24:53 -08:00
Jann Horn
7d0d673627 bpf: Fix theoretical prog_array UAF in __uprobe_perf_func()
Currently, the pointer stored in call->prog_array is loaded in
__uprobe_perf_func(), with no RCU annotation and no immediately visible
RCU protection, so it looks as if the loaded pointer can immediately be
dangling.
Later, bpf_prog_run_array_uprobe() starts a RCU-trace read-side critical
section, but this is too late. It then uses rcu_dereference_check(), but
this use of rcu_dereference_check() does not actually dereference anything.

Fix it by aligning the semantics to bpf_prog_run_array(): Let the caller
provide rcu_read_lock_trace() protection and then load call->prog_array
with rcu_dereference_check().

This issue seems to be theoretical: I don't know of any way to reach this
code without having handle_swbp() further up the stack, which is already
holding a rcu_read_lock_trace() lock, so where we take
rcu_read_lock_trace() in __uprobe_perf_func()/bpf_prog_run_array_uprobe()
doesn't actually have any effect.

Fixes: 8c7dcb84e3 ("bpf: implement sleepable uprobes by chaining gps")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241210-bpf-fix-uprobe-uaf-v4-1-5fc8959b2b74@google.com
2024-12-10 13:06:51 -08:00
Eduard Zingerman
81f6d0530b bpf: check changes_pkt_data property for extension programs
When processing calls to global sub-programs, verifier decides whether
to invalidate all packet pointers in current state depending on the
changes_pkt_data property of the global sub-program.

Because of this, an extension program replacing a global sub-program
must be compatible with changes_pkt_data property of the sub-program
being replaced.

This commit:
- adds changes_pkt_data flag to struct bpf_prog_aux:
  - this flag is set in check_cfg() for main sub-program;
  - in jit_subprogs() for other sub-programs;
- modifies bpf_check_attach_btf_id() to check changes_pkt_data flag;
- moves call to check_attach_btf_id() after the call to check_cfg(),
  because it needs changes_pkt_data flag to be set:

    bpf_check:
      ...                             ...
    - check_attach_btf_id             resolve_pseudo_ldimm64
      resolve_pseudo_ldimm64   -->    bpf_prog_is_offloaded
      bpf_prog_is_offloaded           check_cfg
      check_cfg                     + check_attach_btf_id
      ...                             ...

The following fields are set by check_attach_btf_id():
- env->ops
- prog->aux->attach_btf_trace
- prog->aux->attach_func_name
- prog->aux->attach_func_proto
- prog->aux->dst_trampoline
- prog->aux->mod
- prog->aux->saved_dst_attach_type
- prog->aux->saved_dst_prog_type
- prog->expected_attach_type

Neither of these fields are used by resolve_pseudo_ldimm64() or
bpf_prog_offload_verifier_prep() (for netronome and netdevsim
drivers), so the reordering is safe.

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241210041100.1898468-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-10 10:24:57 -08:00
Linus Torvalds
06afb0f361 tracing updates for v6.13:
- Addition of faultable tracepoints
 
   There's a tracepoint attached to both a system call entry and exit. This
   location is known to allow page faults. The tracepoints are called under
   an rcu_read_lock() which does not allow faults that can sleep. This limits
   the ability of tracepoint handlers to page fault in user space system call
   parameters. Now these tracepoints have been made "faultable", allowing the
   callbacks to fault in user space parameters and record them.
 
   Note, only the infrastructure has been implemented. The consumers (perf,
   ftrace, BPF) now need to have their code modified to allow faults.
 
 - Fix up of BPF code for the tracepoint faultable logic
 
 - Update tracepoints to use the new static branch API
 
 - Remove trace_*_rcuidle() variants and the SRCU protection they used
 
 - Remove unused TRACE_EVENT_FL_FILTERED logic
 
 - Replace strncpy() with strscpy() and memcpy()
 
 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()
 
 - Fix perf events to not duplicate samples when tracing is enabled
 
 - Replace atomic64_add_return(1, counter) with atomic64_inc_return(counter)
 
 - Make stack trace buffer 4K instead of PAGE_SIZE
 
 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used
 
 - Get the true return address for function tracer when function graph tracer
   is also running.
 
   When function_graph trace is running along with function tracer,
   the parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.
 
 - Remove (un)regfunc pointers out of tracepoint structure
 
 - Added last minute bug fix for setting pending modules in stack function
   filter.
 
   echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
 
   Would cause a kernel NULL dereference.
 
 - Minor clean ups
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Merge tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field->field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
2024-11-22 13:27:01 -08:00
Xu Kuohai
7c8ce4ffb6 bpf: Add kernel symbol for struct_ops trampoline
Without kernel symbols for struct_ops trampoline, the unwinder may
produce unexpected stacktraces.

For example, the x86 ORC and FP unwinders check if an IP is in kernel
text by verifying the presence of the IP's kernel symbol. When a
struct_ops trampoline address is encountered, the unwinder stops due
to the absence of symbol, resulting in an incomplete stacktrace that
consists only of direct and indirect child functions called from the
trampoline.

The arm64 unwinder is another example. While the arm64 unwinder can
proceed across a struct_ops trampoline address, the corresponding
symbol name is displayed as "unknown", which is confusing.

Thus, add kernel symbol for struct_ops trampoline. The name is
bpf__<struct_ops_name>_<member_name>, where <struct_ops_name> is the
type name of the struct_ops, and <member_name> is the name of
the member that the trampoline is linked to.

Below is a comparison of stacktraces captured on x86 by perf record,
before and after this patch.

Before:
ffffffff8116545d __lock_acquire+0xad ([kernel.kallsyms])
ffffffff81167fcc lock_acquire+0xcc ([kernel.kallsyms])
ffffffff813088f4 __bpf_prog_enter+0x34 ([kernel.kallsyms])

After:
ffffffff811656bd __lock_acquire+0x30d ([kernel.kallsyms])
ffffffff81167fcc lock_acquire+0xcc ([kernel.kallsyms])
ffffffff81309024 __bpf_prog_enter+0x34 ([kernel.kallsyms])
ffffffffc000d7e9 bpf__tcp_congestion_ops_cong_avoid+0x3e ([kernel.kallsyms])
ffffffff81f250a5 tcp_ack+0x10d5 ([kernel.kallsyms])
ffffffff81f27c66 tcp_rcv_established+0x3b6 ([kernel.kallsyms])
ffffffff81f3ad03 tcp_v4_do_rcv+0x193 ([kernel.kallsyms])
ffffffff81d65a18 __release_sock+0xd8 ([kernel.kallsyms])
ffffffff81d65af4 release_sock+0x34 ([kernel.kallsyms])
ffffffff81f15c4b tcp_sendmsg+0x3b ([kernel.kallsyms])
ffffffff81f663d7 inet_sendmsg+0x47 ([kernel.kallsyms])
ffffffff81d5ab40 sock_write_iter+0x160 ([kernel.kallsyms])
ffffffff8149c67b vfs_write+0x3fb ([kernel.kallsyms])
ffffffff8149caf6 ksys_write+0xc6 ([kernel.kallsyms])
ffffffff8149cb5d __x64_sys_write+0x1d ([kernel.kallsyms])
ffffffff81009200 x64_sys_call+0x1d30 ([kernel.kallsyms])
ffffffff82232d28 do_syscall_64+0x68 ([kernel.kallsyms])
ffffffff8240012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms])

Fixes: 85d33df357 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112145849.3436772-4-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12 17:13:46 -08:00
Yonghong Song
5bd36da1e3 bpf: Support private stack for struct_ops progs
For struct_ops progs, whether a particular prog uses private stack
depends on prog->aux->priv_stack_requested setting before actual
insn-level verification for that prog. One particular implementation
is to piggyback on struct_ops->check_member(). The next patch has
an example for this. The struct_ops->check_member() sets
prog->aux->priv_stack_requested to be true which enables private stack
usage.

The struct_ops prog follows the same rule as kprobe/tracing progs after
function bpf_enable_priv_stack(). For example, even a struct_ops prog
requests private stack, it could still use normal kernel stack if
the stack size is small (< 64 bytes).

Similar to tracing progs, nested same cpu same prog run will be skipped.
A field (recursion_detected()) is added to bpf_prog_aux structure.
If bpf_prog->aux->recursion_detected is implemented by the struct_ops
subsystem and nested same cpu/prog happens, the function will be
triggered to report an error, collect related info, etc.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112163933.2224962-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12 16:26:25 -08:00
Yonghong Song
7d1cd70d4b bpf, x86: Support private stack in jit
Private stack is allocated in function bpf_int_jit_compile() with
alignment 8. Private stack allocation size includes the stack size
determined by verifier and additional space to protect stack overflow
and underflow. See below an illustration:
  ---> memory address increasing
  [8 bytes to protect overflow] [normal stack] [8 bytes to protect underflow]
If overflow/underflow is detected, kernel messages will be
emited in dmesg like
  BPF private stack overflow/underflow detected for prog Fx
  BPF Private stack overflow/underflow detected for prog bpf_prog_a41699c234a1567a_subprog1x
Those messages are generated when I made some changes to jitted code
to intentially cause overflow for some progs.

For the jited prog, The x86 register 9 (X86_REG_R9) is used to replace
bpf frame register (BPF_REG_10). The private stack is used per
subprog per cpu. The X86_REG_R9 is saved and restored around every
func call (not including tailcall) to maintain correctness of
X86_REG_R9.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112163922.2224385-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12 16:26:24 -08:00
Yonghong Song
e00931c025 bpf: Enable private stack for eligible subprogs
If private stack is used by any subprog, set that subprog
prog->aux->jits_use_priv_stack to be true so later jit can allocate
private stack for that subprog properly.

Also set env->prog->aux->jits_use_priv_stack to be true if
any subprog uses private stack. This is a use case for a
single main prog (no subprogs) to use private stack, and
also a use case for later struct-ops progs where
env->prog->aux->jits_use_priv_stack will enable recursion
check if any subprog uses private stack.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112163912.2224007-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12 16:26:24 -08:00
Menglong Dong
213a695297 bpf: Replace the document for PTR_TO_BTF_ID_OR_NULL
Commit c25b2ae136 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX |
PTR_MAYBE_NULL") moved the fields around and misplaced the
documentation for "PTR_TO_BTF_ID_OR_NULL". So, let's replace it in the
proper place.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111124911.1436911-1-dongml2@chinatelecom.cn
2024-11-11 20:12:58 -08:00
Kumar Kartikeya Dwivedi
cb4158ce8e bpf: Mark raw_tp arguments with PTR_MAYBE_NULL
Arguments to a raw tracepoint are tagged as trusted, which carries the
semantics that the pointer will be non-NULL.  However, in certain cases,
a raw tracepoint argument may end up being NULL. More context about this
issue is available in [0].

Thus, there is a discrepancy between the reality, that raw_tp arguments
can actually be NULL, and the verifier's knowledge, that they are never
NULL, causing explicit NULL checks to be deleted, and accesses to such
pointers potentially crashing the kernel.

To fix this, mark raw_tp arguments as PTR_MAYBE_NULL, and then special
case the dereference and pointer arithmetic to permit it, and allow
passing them into helpers/kfuncs; these exceptions are made for raw_tp
programs only. Ensure that we don't do this when ref_obj_id > 0, as in
that case this is an acquired object and doesn't need such adjustment.

The reason we do mask_raw_tp_trusted_reg logic is because other will
recheck in places whether the register is a trusted_reg, and then
consider our register as untrusted when detecting the presence of the
PTR_MAYBE_NULL flag.

To allow safe dereference, we enable PROBE_MEM marking when we see loads
into trusted pointers with PTR_MAYBE_NULL.

While trusted raw_tp arguments can also be passed into helpers or kfuncs
where such broken assumption may cause issues, a future patch set will
tackle their case separately, as PTR_TO_BTF_ID (without PTR_TRUSTED) can
already be passed into helpers and causes similar problems. Thus, they
are left alone for now.

It is possible that these checks also permit passing non-raw_tp args
that are trusted PTR_TO_BTF_ID with null marking. In such a case,
allowing dereference when pointer is NULL expands allowed behavior, so
won't regress existing programs, and the case of passing these into
helpers is the same as above and will be dealt with later.

Also update the failure case in tp_btf_nullable selftest to capture the
new behavior, as the verifier will no longer cause an error when
directly dereference a raw tracepoint argument marked as __nullable.

  [0]: https://lore.kernel.org/bpf/ZrCZS6nisraEqehw@jlelli-thinkpadt14gen4.remote.csb

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Fixes: 3f00c52393 ("bpf: Allow trusted pointers to be passed to KF_TRUSTED_ARGS kfuncs")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241104171959.2938862-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-04 11:37:36 -08:00
Andrii Nakryiko
61c6fefa92 bpf: decouple BPF link/attach hook and BPF program sleepable semantics
BPF link's lifecycle protection scheme depends on both BPF hook and BPF
program. If *either* of those require RCU Tasks Trace GP, then we need
to go through a chain of GPs before putting BPF program refcount and
deallocating BPF link memory.

This patch adds bpf_link-specific sleepable flag, which can be set to
true even if underlying BPF program is not sleepable itself. If either
link->sleepable or link->prog->sleepable is true, we'll go through
a chain of RCU Tasks Trace GP and RCU GP before putting BPF program and
freeing memory.

This will be used to protect BPF link for sleepable (faultable) raw
tracepoints in the next patch.

Link: https://lore.kernel.org/20241101181754.782341-2-andrii@kernel.org
Tested-by: Jordan Rife <jrife@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-01 14:39:07 -04:00
Alexei Starovoitov
bfa7b5c98b Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:

include/linux/bpf.h
include/uapi/linux/bpf.h
kernel/bpf/btf.c
kernel/bpf/helpers.c
kernel/bpf/syscall.c
kernel/bpf/verifier.c
kernel/trace/bpf_trace.c
mm/slab_common.c
tools/include/uapi/linux/bpf.h
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/all/20241024215724.60017-1-daniel@iogearbox.net/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 18:47:28 -07:00
Martin KaFai Lau
ba512b00e5 bpf: Add uptr support in the map_value of the task local storage.
This patch adds uptr support in the map_value of the task local storage.

struct map_value {
	struct user_data __uptr *uptr;
};

struct {
	__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
	__uint(map_flags, BPF_F_NO_PREALLOC);
	__type(key, int);
	__type(value, struct value_type);
} datamap SEC(".maps");

A new bpf_obj_pin_uptrs() is added to pin the user page and
also stores the kernel address back to the uptr for the
bpf prog to use later. It currently does not support
the uptr pointing to a user struct across two pages.
It also excludes PageHighMem support to keep it simple.
As of now, the 32bit bpf jit is missing other more crucial bpf
features. For example, many important bpf features depend on
bpf kfunc now but so far only one arch (x86-32) supports it
which was added by me as an example when kfunc was first
introduced to bpf.

The uptr can only be stored to the task local storage by the
syscall update_elem. Meaning the uptr will not be considered
if it is provided by the bpf prog through
bpf_task_storage_get(BPF_LOCAL_STORAGE_GET_F_CREATE).
This is enforced by only calling
bpf_local_storage_update(swap_uptrs==true) in
bpf_pid_task_storage_update_elem. Everywhere else will
have swap_uptrs==false.

This will pump down to bpf_selem_alloc(swap_uptrs==true). It is
the only case that bpf_selem_alloc() will take the uptr value when
updating the newly allocated selem. bpf_obj_swap_uptrs() is added
to swap the uptr between the SDATA(selem)->data and the user provided
map_value in "void *value". bpf_obj_swap_uptrs() makes the
SDATA(selem)->data takes the ownership of the uptr and the user space
provided map_value will have NULL in the uptr.

The bpf_obj_unpin_uptrs() is called after map->ops->map_update_elem()
returning error. If the map->ops->map_update_elem has reached
a state that the local storage has taken the uptr ownership,
the bpf_obj_unpin_uptrs() will be a no op because the uptr
is NULL. A "__"bpf_obj_unpin_uptrs is added to make this
error path unpin easier such that it does not have to check
the map->record is NULL or not.

BPF_F_LOCK is not supported when the map_value has uptr.
This can be revisited later if there is a use case. A similar
swap_uptrs idea can be considered.

The final bit is to do unpin_user_page in the bpf_obj_free_fields().
The earlier patch has ensured that the bpf_obj_free_fields() has
gone through the rcu gp when needed.

Cc: linux-mm@kvack.org
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/r/20241023234759.860539-7-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 10:25:59 -07:00
Kui-Feng Lee
1cb80d9e93 bpf: Support __uptr type tag in BTF
This patch introduces the "__uptr" type tag to BTF. It is to define
a pointer pointing to the user space memory. This patch adds BTF
logic to pass the "__uptr" type tag.

btf_find_kptr() is reused for the "__uptr" tag. The "__uptr" will only
be supported in the map_value of the task storage map. However,
btf_parse_struct_meta() also uses btf_find_kptr() but it is not
interested in "__uptr". This patch adds a "field_mask" argument
to btf_find_kptr() which will return BTF_FIELD_IGNORE if the
caller is not interested in a “__uptr” field.

btf_parse_kptr() is also reused to parse the uptr.
The btf_check_and_fixup_fields() is changed to do extra
checks on the uptr to ensure that its struct size is not larger
than PAGE_SIZE. It is not clear how a uptr pointing to a CO-RE
supported kernel struct will be used, so it is also not allowed now.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20241023234759.860539-2-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 10:25:58 -07:00
Daniel Borkmann
6fad274f06 bpf: Add MEM_WRITE attribute
Add a MEM_WRITE attribute for BPF helper functions which can be used in
bpf_func_proto to annotate an argument type in order to let the verifier
know that the helper writes into the memory passed as an argument. In
the past MEM_UNINIT has been (ab)used for this function, but the latter
merely tells the verifier that the passed memory can be uninitialized.

There have been bugs with overloading the latter but aside from that
there are also cases where the passed memory is read + written which
currently cannot be expressed, see also 4b3786a6c5 ("bpf: Zero former
ARG_PTR_TO_{LONG,INT} args in case of error").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-22 15:42:56 -07:00
Leon Hwang
d6083f040d bpf: Prevent tailcall infinite loop caused by freplace
There is a potential infinite loop issue that can occur when using a
combination of tail calls and freplace.

In an upcoming selftest, the attach target for entry_freplace of
tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in
entry_freplace leads to entry_tc. This results in an infinite loop:

entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc.

The problem arises because the tail_call_cnt in entry_freplace resets to
zero each time entry_freplace is executed, causing the tail call mechanism
to never terminate, eventually leading to a kernel panic.

To fix this issue, the solution is twofold:

1. Prevent updating a program extended by an freplace program to a
   prog_array map.
2. Prevent extending a program that is already part of a prog_array map
   with an freplace program.

This ensures that:

* If a program or its subprogram has been extended by an freplace program,
  it can no longer be updated to a prog_array map.
* If a program has been added to a prog_array map, neither it nor its
  subprograms can be extended by an freplace program.

Moreover, an extension program should not be tailcalled. As such, return
-EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a
prog_array map.

Additionally, fix a minor code style issue by replacing eight spaces with a
tab for proper formatting.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20241015150207.70264-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16 09:21:18 -07:00
Linus Torvalds
fa8380a06b bpf-next-6.12-struct-fd
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Merge tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf 'struct fd' updates from Alexei Starovoitov:
 "This includes struct_fd BPF changes from Al and Andrii"

* tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  bpf: convert bpf_token_create() to CLASS(fd, ...)
  security,bpf: constify struct path in bpf_token_create() LSM hook
  bpf: more trivial fdget() conversions
  bpf: trivial conversions for fdget()
  bpf: switch maps to CLASS(fd, ...)
  bpf: factor out fetching bpf_map from FD and adding it to used_maps list
  bpf: switch fdget_raw() uses to CLASS(fd_raw, ...)
  bpf: convert __bpf_prog_get() to CLASS(fd, ...)
2024-09-24 14:54:26 -07:00
Daniel Borkmann
32556ce93b bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.

In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.

The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.

However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).

MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val.

Fixes: 57c3bb725a ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types")
Reported-by: Lonial Con <kongln9170@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240913191754.13290-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13 13:17:55 -07:00
Andrii Nakryiko
d4dd9775ec bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpers
Add sleepable implementations of bpf_get_stack() and
bpf_get_task_stack() helpers and allow them to be used from sleepable
BPF program (e.g., sleepable uprobes).

Note, the stack trace IPs capturing itself is not sleepable (that would
need to be a separate project), only build ID fetching is sleepable and
thus more reliable, as it will wait for data to be paged in, if
necessary. For that we make use of sleepable build_id_parse()
implementation.

Now that build ID related internals in kernel/bpf/stackmap.c can be used
both in sleepable and non-sleepable contexts, we need to add additional
rcu_read_lock()/rcu_read_unlock() protection around fetching
perf_callchain_entry, but with the refactoring in previous commit it's
now pretty straightforward. We make sure to do rcu_read_unlock (in
sleepable mode only) right before stack_map_get_build_id_offset() call
which can sleep. By that time we don't have any more use of
perf_callchain_entry.

Note, bpf_get_task_stack() will fail for user mode if task != current.
And for kernel mode build ID are irrelevant. So in that sense adding
sleepable bpf_get_task_stack() implementation is a no-op. It feel right
to wire this up for symmetry and completeness, but I'm open to just
dropping it until we support `user && crosstask` condition.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240829174232.3133883-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11 09:58:31 -07:00
Martin KaFai Lau
169c31761c bpf: Add gen_epilogue to bpf_verifier_ops
This patch adds a .gen_epilogue to the bpf_verifier_ops. It is similar
to the existing .gen_prologue. Instead of allowing a subsystem
to run code at the beginning of a bpf prog, it allows the subsystem
to run code just before the bpf prog exit.

One of the use case is to allow the upcoming bpf qdisc to ensure that
the skb->dev is the same as the qdisc->dev_queue->dev. The bpf qdisc
struct_ops implementation could either fix it up or drop the skb.
Another use case could be in bpf_tcp_ca.c to enforce snd_cwnd
has sane value (e.g. non zero).

The epilogue can do the useful thing (like checking skb->dev) if it
can access the bpf prog's ctx. Unlike prologue, r1 may not hold the
ctx pointer. This patch saves the r1 in the stack if the .gen_epilogue
has returned some instructions in the "epilogue_buf".

The existing .gen_prologue is done in convert_ctx_accesses().
The new .gen_epilogue is done in the convert_ctx_accesses() also.
When it sees the (BPF_JMP | BPF_EXIT) instruction, it will be patched
with the earlier generated "epilogue_buf". The epilogue patching is
only done for the main prog.

Only one epilogue will be patched to the main program. When the
bpf prog has multiple BPF_EXIT instructions, a BPF_JA is used
to goto the earlier patched epilogue. Majority of the archs
support (BPF_JMP32 | BPF_JA): x86, arm, s390, risv64, loongarch,
powerpc and arc. This patch keeps it simple and always
use (BPF_JMP32 | BPF_JA). A new macro BPF_JMP32_A is added to
generate the (BPF_JMP32 | BPF_JA) insn.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240829210833.388152-4-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-29 18:15:45 -07:00
Dave Marchevsky
d59232afb0 bpf: Rename ARG_PTR_TO_KPTR -> ARG_KPTR_XCHG_DEST
ARG_PTR_TO_KPTR is currently only used by the bpf_kptr_xchg helper.
Although it limits reg types for that helper's first arg to
PTR_TO_MAP_VALUE, any arbitrary mapval won't do: further custom
verification logic ensures that the mapval reg being xchgd-into is
pointing to a kptr field. If this is not the case, it's not safe to xchg
into that reg's pointee.

Let's rename the bpf_arg_type to more accurately describe the fairly
specific expectations that this arg type encodes.

This is a nonfunctional change.

Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Link: https://lore.kernel.org/r/20240813212424.2871455-4-amery.hung@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-23 11:39:33 -07:00
Eduard Zingerman
ae010757a5 bpf: rename nocsr -> bpf_fastcall in verifier
Attribute used by LLVM implementation of the feature had been changed
from no_caller_saved_registers to bpf_fastcall (see [1]).
This commit replaces references to nocsr by references to bpf_fastcall
to keep LLVM and Kernel parts in sync.

[1] https://github.com/llvm/llvm-project/pull/105417

Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240822084112.3257995-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-22 08:35:20 -07:00
Matteo Croce
7f6287417b bpf: Allow bpf_current_task_under_cgroup() with BPF_CGROUP_*
The helper bpf_current_task_under_cgroup() currently is only allowed for
tracing programs, allow its usage also in the BPF_CGROUP_* program types.

Move the code from kernel/trace/bpf_trace.c to kernel/bpf/helpers.c,
so it compiles also without CONFIG_BPF_EVENTS.

This will be used in systemd-networkd to monitor the sysctl writes,
and filter it's own writes from others:
https://github.com/systemd/systemd/pull/32212

Signed-off-by: Matteo Croce <teknoraver@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240819162805.78235-3-technoboy85@gmail.com
2024-08-19 15:25:30 -07:00
Al Viro
55f325958c bpf: switch maps to CLASS(fd, ...)
Calling conventions for __bpf_map_get() would be more convenient
if it left fpdut() on failure to callers.  Makes for simpler logics
in the callers.

	Among other things, the proof of memory safety no longer has to
rely upon file->private_data never being ERR_PTR(...) for bpffs files.
Original calling conventions made it impossible for the caller to tell
whether __bpf_map_get() has returned ERR_PTR(-EINVAL) because it has found
the file not be a bpf map one (in which case it would've done fdput())
or because it found that ERR_PTR(-EINVAL) in file->private_data of a
bpf map file (in which case fdput() would _not_ have been done).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-08-13 15:58:17 -07:00
Eduard Zingerman
5b5f51bff1 bpf: no_caller_saved_registers attribute for helper calls
GCC and LLVM define a no_caller_saved_registers function attribute.
This attribute means that function scratches only some of
the caller saved registers defined by ABI.
For BPF the set of such registers could be defined as follows:
- R0 is scratched only if function is non-void;
- R1-R5 are scratched only if corresponding parameter type is defined
  in the function prototype.

This commit introduces flag bpf_func_prot->allow_nocsr.
If this flag is set for some helper function, verifier assumes that
it follows no_caller_saved_registers calling convention.

The contract between kernel and clang allows to simultaneously use
such functions and maintain backwards compatibility with old
kernels that don't understand no_caller_saved_registers calls
(nocsr for short):

- clang generates a simple pattern for nocsr calls, e.g.:

    r1 = 1;
    r2 = 2;
    *(u64 *)(r10 - 8)  = r1;
    *(u64 *)(r10 - 16) = r2;
    call %[to_be_inlined]
    r2 = *(u64 *)(r10 - 16);
    r1 = *(u64 *)(r10 - 8);
    r0 = r1;
    r0 += r2;
    exit;

- kernel removes unnecessary spills and fills, if called function is
  inlined by verifier or current JIT (with assumption that patch
  inserted by verifier or JIT honors nocsr contract, e.g. does not
  scratch r3-r5 for the example above), e.g. the code above would be
  transformed to:

    r1 = 1;
    r2 = 2;
    call %[to_be_inlined]
    r0 = r1;
    r0 += r2;
    exit;

Technically, the transformation is split into the following phases:
- function mark_nocsr_patterns(), called from bpf_check()
  searches and marks potential patterns in instruction auxiliary data;
- upon stack read or write access,
  function check_nocsr_stack_contract() is used to verify if
  stack offsets, presumably reserved for nocsr patterns, are used
  only from those patterns;
- function remove_nocsr_spills_fills(), called from bpf_check(),
  applies the rewrite for valid patterns.

See comment in mark_nocsr_pattern_for_call() for more details.

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 15:05:05 -07:00
Yonghong Song
92de36080c bpf: Fail verification for sign-extension of packet data/data_end/data_meta
syzbot reported a kernel crash due to
  commit 1f1e864b65 ("bpf: Handle sign-extenstin ctx member accesses").
The reason is due to sign-extension of 32-bit load for
packet data/data_end/data_meta uapi field.

The original code looks like:
        r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
        r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */
        r0 = r2
        r0 += 8
        if r3 > r0 goto +1
        ...
Note that __sk_buff->data load has 32-bit sign extension.

After verification and convert_ctx_accesses(), the final asm code looks like:
        r2 = *(u64 *)(r1 +208)
        r2 = (s32)r2
        r3 = *(u64 *)(r1 +80)
        r0 = r2
        r0 += 8
        if r3 > r0 goto pc+1
        ...
Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid
which may cause runtime failure.

Currently, in C code, typically we have
        void *data = (void *)(long)skb->data;
        void *data_end = (void *)(long)skb->data_end;
        ...
and it will generate
        r2 = *(u64 *)(r1 +208)
        r3 = *(u64 *)(r1 +80)
        r0 = r2
        r0 += 8
        if r3 > r0 goto pc+1

If we allow sign-extension,
        void *data = (void *)(long)(int)skb->data;
        void *data_end = (void *)(long)skb->data_end;
        ...
the generated code looks like
        r2 = *(u64 *)(r1 +208)
        r2 <<= 32
        r2 s>>= 32
        r3 = *(u64 *)(r1 +80)
        r0 = r2
        r0 += 8
        if r3 > r0 goto pc+1
and this will cause verification failure since "r2 <<= 32" is not allowed
as "r2" is a packet pointer.

To fix this issue for case
  r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
this patch added additional checking in is_valid_access() callback
function for packet data/data_end/data_meta access. If those accesses
are with sign-extenstion, the verification will fail.

  [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/

Reported-by: syzbot+ad9ec60c8eaf69e6f99c@syzkaller.appspotmail.com
Fixes: 1f1e864b65 ("bpf: Handle sign-extenstin ctx member accesses")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723153439.2429035-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 15:05:05 -07:00
Xu Kuohai
28ead3eaab bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.

For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.

Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.

This patch adds restriction for tail call to prevent such bypasses.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-4-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 13:09:26 -07:00
Xu Kuohai
5d99e198be bpf, lsm: Add check for BPF LSM return value
A bpf prog returning a positive number attached to file_alloc_security
hook makes kernel panic.

This happens because file system can not filter out the positive number
returned by the LSM prog using IS_ERR, and misinterprets this positive
number as a file pointer.

Given that hook file_alloc_security never returned positive number
before the introduction of BPF LSM, and other BPF LSM hooks may
encounter similar issues, this patch adds LSM return value check
in verifier, to ensure no unexpected value is returned.

Fixes: 520b7aa00d ("bpf: lsm: Initialize the BPF LSM hooks")
Reported-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240719110059.797546-3-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 13:09:22 -07:00
Martin KaFai Lau
e42ac14180 bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubs
The bpf_tcp_ca struct_ops currently uses a "u32 unsupported_ops[]"
array to track which ops is not supported.

After cfi_stubs had been added, the function pointer in cfi_stubs is
also NULL for the unsupported ops. Thus, the "u32 unsupported_ops[]"
becomes redundant. This observation was originally brought up in the
bpf/cfi discussion:
https://lore.kernel.org/bpf/CAADnVQJoEkdjyCEJRPASjBw1QGsKYrF33QdMGc1RZa9b88bAEA@mail.gmail.com/

The recent bpf qdisc patch (https://lore.kernel.org/bpf/20240714175130.4051012-6-amery.hung@bytedance.com/)
also needs to specify quite many unsupported ops. It is a good time
to clean it up.

This patch removes the need of "u32 unsupported_ops[]" and tests for null-ness
in the cfi_stubs instead.

Testing the cfi_stubs is done in a new function bpf_struct_ops_supported().
The verifier will call bpf_struct_ops_supported() when loading the
struct_ops program. The ".check_member" is removed from the bpf_tcp_ca
in this patch. ".check_member" could still be useful for other subsytems
to enforce other restrictions (e.g. sched_ext checks for prog->sleepable).

To keep the same error return, ENOTSUPP is used.

Cc: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240722183049.2254692-2-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29 12:54:13 -07:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Suren Baghdasaryan
3b0ba54d5f mm: add comments for allocation helpers explaining why they are macros
A number of allocation helper functions were converted into macros to
account them at the call sites.  Add a comment for each converted
allocation helper explaining why it has to be a macro and why we typecast
the return value wherever required.  The patch also moves
acpi_os_acquire_object() closer to other allocation helpers to group them
together under the same comment.  The patch has no functional changes.

Link: https://lkml.kernel.org/r/20240703174225.3891393-1-surenb@google.com
Fixes: 2c321f3f70 ("mm: change inlined allocation helpers to account at the call site")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:20 -07:00
Johannes Weiner
3a3b7fec39 mm: remove CONFIG_MEMCG_KMEM
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab
tracking is enabled.  It has been default-enabled and equivalent to
CONFIG_MEMCG for almost a decade.  We've only grown more kernel memory
accounting sites since, and there is no imaginable cgroup usecase going
forward that wants to track user pages but not the multitude of
user-drivable kernel allocations.

Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Paolo Abeni
7b769adc26 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-08

The following pull-request contains BPF updates for your *net-next* tree.

We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).

The main changes are:

1) Support resilient split BTF which cuts down on duplication and makes BTF
   as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.

2) Add support for dumping kfunc prototypes from BTF which enables both detecting
   as well as dumping compilable prototypes for kfuncs, from Daniel Xu.

3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
   support for BPF exceptions, from Ilya Leoshkevich.

4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
   for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.

5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
   for skbs and add coverage along with it, from Vadim Fedorenko.

6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
   a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.

7) Extend the BPF verifier to track the delta between linked registers in order
   to better deal with recent LLVM code optimizations, from Alexei Starovoitov.

8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
   have been a pointer to the map value, from Benjamin Tissoires.

9) Extend BPF selftests to add regular expression support for test output matching
   and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.

10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
    iterates exactly once anyway, from Dan Carpenter.

11) Add the capability to offload the netfilter flowtable in XDP layer through
    kfuncs, from Florian Westphal & Lorenzo Bianconi.

12) Various cleanups in networking helpers in BPF selftests to shave off a few
    lines of open-coded functions on client/server handling, from Geliang Tang.

13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
    that x86 JIT does not need to implement detection, from Leon Hwang.

14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
    out-of-bounds memory access for dynpointers, from Matt Bobrowski.

15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
    it might lead to problems on 32-bit archs, from Jiri Olsa.

16) Enhance traffic validation and dynamic batch size support in xsk selftests,
    from Tushar Vyavahare.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
  selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
  selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
  bpf: helpers: fix bpf_wq_set_callback_impl signature
  libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
  selftests/bpf: Remove exceptions tests from DENYLIST.s390x
  s390/bpf: Implement exceptions
  s390/bpf: Change seen_reg to a mask
  bpf: Remove unnecessary loop in task_file_seq_get_next()
  riscv, bpf: Optimize stack usage of trampoline
  bpf, devmap: Add .map_alloc_check
  selftests/bpf: Remove arena tests from DENYLIST.s390x
  selftests/bpf: Add UAF tests for arena atomics
  selftests/bpf: Introduce __arena_global
  s390/bpf: Support arena atomics
  s390/bpf: Enable arena
  s390/bpf: Support address space cast instruction
  s390/bpf: Support BPF_PROBE_MEM32
  s390/bpf: Land on the next JITed instruction after exception
  s390/bpf: Introduce pre- and post- probe functions
  s390/bpf: Get rid of get_probe_mem_regno()
  ...
====================

Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-09 17:01:46 +02:00
Sebastian Andrzej Siewior
d839a73179 net: Optimize xdp_do_flush() with bpf_net_context infos.
Every NIC driver utilizing XDP should invoke xdp_do_flush() after
processing all packages. With the introduction of the bpf_net_context
logic the flush lists (for dev, CPU-map and xsk) are lazy initialized
only if used. However xdp_do_flush() tries to flush all three of them so
all three lists are always initialized and the likely empty lists are
"iterated".
Without the usage of XDP but with CONFIG_DEBUG_NET the lists are also
initialized due to xdp_do_check_flushed().

Jakub suggest to utilize the hints in bpf_net_context and avoid invoking
the flush function. This will also avoiding initializing the lists which
are otherwise unused.

Introduce bpf_net_ctx_get_all_used_flush_lists() to return the
individual list if not-empty. Use the logic in xdp_do_flush() and
xdp_do_check_flushed(). Remove the not needed .*_check_flush().

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-02 15:26:57 +02:00
Rafael Passos
ab224b9ef7 bpf: remove unused parameter in __bpf_free_used_btfs
Fixes a compiler warning. The __bpf_free_used_btfs function
was taking an extra unused struct bpf_prog_aux *aux param

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Link: https://lore.kernel.org/r/20240615022641.210320-3-rafael@rcpassos.me
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-20 19:50:26 -07:00
Daniel Xu
cce4c40b96 bpf: treewide: Align kfunc signatures to prog point-of-view
Previously, kfunc declarations in bpf_kfuncs.h (and others) used "user
facing" types for kfuncs prototypes while the actual kfunc definitions
used "kernel facing" types. More specifically: bpf_dynptr vs
bpf_dynptr_kern, __sk_buff vs sk_buff, and xdp_md vs xdp_buff.

It wasn't an issue before, as the verifier allows aliased types.
However, since we are now generating kfunc prototypes in vmlinux.h (in
addition to keeping bpf_kfuncs.h around), this conflict creates
compilation errors.

Fix this conflict by using "user facing" types in kfunc definitions.
This results in more casts, but otherwise has no additional runtime
cost.

Note, similar to 5b268d1ebc ("bpf: Have bpf_rdonly_cast() take a const
pointer"), we also make kfuncs take const arguments where appropriate in
order to make the kfunc more permissive.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/b58346a63a0e66bc9b7504da751b526b0b189a67.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:31 -07:00
Kui-Feng Lee
67c3e8353f bpf: export bpf_link_inc_not_zero.
bpf_link_inc_not_zero() will be used by kernel modules.  We will use it in
bpf_testmod.c later.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30 15:34:13 -07:00
Kui-Feng Lee
1adddc97aa bpf: support epoll from bpf struct_ops links.
Add epoll support to bpf struct_ops links to trigger EPOLLHUP event upon
detachment.

This patch implements the "poll" of the "struct file_operations" for BPF
links and introduces a new "poll" operator in the "struct bpf_link_ops". By
implementing "poll" of "struct bpf_link_ops" for the links of struct_ops,
the file descriptor of a struct_ops link can be added to an epoll file
descriptor to receive EPOLLHUP events.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-4-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30 15:34:13 -07:00
Kui-Feng Lee
73287fe228 bpf: pass bpf_struct_ops_link to callbacks in bpf_struct_ops.
Pass an additional pointer of bpf_struct_ops_link to callback function reg,
unreg, and update provided by subsystems defined in bpf_struct_ops. A
bpf_struct_ops_map can be registered for multiple links. Passing a pointer
of bpf_struct_ops_link helps subsystems to distinguish them.

This pointer will be used in the later patches to let the subsystem
initiate a detachment on a link that was registered to it previously.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-2-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30 15:34:13 -07:00
Linus Torvalds
61307b7be4 The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.  Notable
 series include:
 
 - Lucas Stach has provided some page-mapping
   cleanup/consolidation/maintainability work in the series "mm/treewide:
   Remove pXd_huge() API".
 
 - In the series "Allow migrate on protnone reference with
   MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
   MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
   test.
 
 - In their series "Memory allocation profiling" Kent Overstreet and
   Suren Baghdasaryan have contributed a means of determining (via
   /proc/allocinfo) whereabouts in the kernel memory is being allocated:
   number of calls and amount of memory.
 
 - Matthew Wilcox has provided the series "Various significant MM
   patches" which does a number of rather unrelated things, but in largely
   similar code sites.
 
 - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
   Weiner has fixed the page allocator's handling of migratetype requests,
   with resulting improvements in compaction efficiency.
 
 - In the series "make the hugetlb migration strategy consistent" Baolin
   Wang has fixed a hugetlb migration issue, which should improve hugetlb
   allocation reliability.
 
 - Liu Shixin has hit an I/O meltdown caused by readahead in a
   memory-tight memcg.  Addressed in the series "Fix I/O high when memory
   almost met memcg limit".
 
 - In the series "mm/filemap: optimize folio adding and splitting" Kairui
   Song has optimized pagecache insertion, yielding ~10% performance
   improvement in one test.
 
 - Baoquan He has cleaned up and consolidated the early zone
   initialization code in the series "mm/mm_init.c: refactor
   free_area_init_core()".
 
 - Baoquan has also redone some MM initializatio code in the series
   "mm/init: minor clean up and improvement".
 
 - MM helper cleanups from Christoph Hellwig in his series "remove
   follow_pfn".
 
 - More cleanups from Matthew Wilcox in the series "Various page->flags
   cleanups".
 
 - Vlastimil Babka has contributed maintainability improvements in the
   series "memcg_kmem hooks refactoring".
 
 - More folio conversions and cleanups in Matthew Wilcox's series
 
 	"Convert huge_zero_page to huge_zero_folio"
 	"khugepaged folio conversions"
 	"Remove page_idle and page_young wrappers"
 	"Use folio APIs in procfs"
 	"Clean up __folio_put()"
 	"Some cleanups for memory-failure"
 	"Remove page_mapping()"
 	"More folio compat code removal"
 
 - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
   functions to work on folis".
 
 - Code consolidation and cleanup work related to GUP's handling of
   hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
 
 - Rick Edgecombe has developed some fixes to stack guard gaps in the
   series "Cover a guard gap corner case".
 
 - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
   "mm/ksm: fix ksm exec support for prctl".
 
 - Baolin Wang has implemented NUMA balancing for multi-size THPs.  This
   is a simple first-cut implementation for now.  The series is "support
   multi-size THP numa balancing".
 
 - Cleanups to vma handling helper functions from Matthew Wilcox in the
   series "Unify vma_address and vma_pgoff_address".
 
 - Some selftests maintenance work from Dev Jain in the series
   "selftests/mm: mremap_test: Optimizations and style fixes".
 
 - Improvements to the swapping of multi-size THPs from Ryan Roberts in
   the series "Swap-out mTHP without splitting".
 
 - Kefeng Wang has significantly optimized the handling of arm64's
   permission page faults in the series
 
 	"arch/mm/fault: accelerate pagefault when badaccess"
 	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
 
 - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
   GUP-fast".
 
 - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
   use struct vm_fault".
 
 - selftests build fixes from John Hubbard in the series "Fix
   selftests/mm build without requiring "make headers"".
 
 - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
   series "Improved Memory Tier Creation for CPUless NUMA Nodes".  Fixes
   the initialization code so that migration between different memory types
   works as intended.
 
 - David Hildenbrand has improved follow_pte() and fixed an errant driver
   in the series "mm: follow_pte() improvements and acrn follow_pte()
   fixes".
 
 - David also did some cleanup work on large folio mapcounts in his
   series "mm: mapcount for large folios + page_mapcount() cleanups".
 
 - Folio conversions in KSM in Alex Shi's series "transfer page to folio
   in KSM".
 
 - Barry Song has added some sysfs stats for monitoring multi-size THP's
   in the series "mm: add per-order mTHP alloc and swpout counters".
 
 - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
   and limit checking cleanups".
 
 - Matthew Wilcox has been looking at buffer_head code and found the
   documentation to be lacking.  The series is "Improve buffer head
   documentation".
 
 - Multi-size THPs get more work, this time from Lance Yang.  His series
   "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
   the freeing of these things.
 
 - Kemeng Shi has added more userspace-visible writeback instrumentation
   in the series "Improve visibility of writeback".
 
 - Kemeng Shi then sent some maintenance work on top in the series "Fix
   and cleanups to page-writeback".
 
 - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
   series "Improve anon_vma scalability for anon VMAs".  Intel's test bot
   reported an improbable 3x improvement in one test.
 
 - SeongJae Park adds some DAMON feature work in the series
 
 	"mm/damon: add a DAMOS filter type for page granularity access recheck"
 	"selftests/damon: add DAMOS quota goal test"
 
 - Also some maintenance work in the series
 
 	"mm/damon/paddr: simplify page level access re-check for pageout"
 	"mm/damon: misc fixes and improvements"
 
 - David Hildenbrand has disabled some known-to-fail selftests ni the
   series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
 
 - memcg metadata storage optimizations from Shakeel Butt in "memcg:
   reduce memory consumption by memcg stats".
 
 - DAX fixes and maintenance work from Vishal Verma in the series
   "dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Jakub Kicinski
89de2db193 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-04-29

We've added 147 non-merge commits during the last 32 day(s) which contain
a total of 158 files changed, 9400 insertions(+), 2213 deletions(-).

The main changes are:

1) Add an internal-only BPF per-CPU instruction for resolving per-CPU
   memory addresses and implement support in x86 BPF JIT. This allows
   inlining per-CPU array and hashmap lookups
   and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko.

2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song.

3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
   atomics in bpf_arena which can be JITed as a single x86 instruction,
   from Alexei Starovoitov.

4) Add support for passing mark with bpf_fib_lookup helper,
   from Anton Protopopov.

5) Add a new bpf_wq API for deferring events and refactor sleepable
   bpf_timer code to keep common code where possible,
   from Benjamin Tissoires.

6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs
   to check when NULL is passed for non-NULLable parameters,
   from Eduard Zingerman.

7) Harden the BPF verifier's and/or/xor value tracking,
   from Harishankar Vishwanathan.

8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel
   crypto subsystem, from Vadim Fedorenko.

9) Various improvements to the BPF instruction set standardization doc,
   from Dave Thaler.

10) Extend libbpf APIs to partially consume items from the BPF ringbuffer,
    from Andrea Righi.

11) Bigger batch of BPF selftests refactoring to use common network helpers
    and to drop duplicate code, from Geliang Tang.

12) Support bpf_tail_call_static() helper for BPF programs with GCC 13,
    from Jose E. Marchesi.

13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled,
    from Kumar Kartikeya Dwivedi.

14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs,
    from David Vernet.

15) Extend the BPF verifier to allow different input maps for a given
    bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu.

16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions
    for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan.

17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison
    the stack memory, from Martin KaFai Lau.

18) Improve xsk selftest coverage with new tests on maximum and minimum
    hardware ring size configurations, from Tushar Vyavahare.

19) Various ReST man pages fixes as well as documentation and bash completion
    improvements for bpftool, from Rameez Rehman & Quentin Monnet.

20) Fix libbpf with regards to dumping subsequent char arrays,
    from Quentin Deslandes.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits)
  bpf, docs: Clarify PC use in instruction-set.rst
  bpf_helpers.h: Define bpf_tail_call_static when building with GCC
  bpf, docs: Add introduction for use in the ISA Internet Draft
  selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us
  bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args
  selftests/bpf: dummy_st_ops should reject 0 for non-nullable params
  bpf: check bpf_dummy_struct_ops program params for test runs
  selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops
  selftests/bpf: adjust dummy_st_ops_success to detect additional error
  bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
  selftests/bpf: Add ring_buffer__consume_n test.
  bpf: Add bpf_guard_preempt() convenience macro
  selftests: bpf: crypto: add benchmark for crypto functions
  selftests: bpf: crypto skcipher algo selftests
  bpf: crypto: add skcipher to bpf crypto
  bpf: make common crypto API for TC/XDP programs
  bpf: update the comment for BTF_FIELDS_MAX
  selftests/bpf: Fix wq test.
  selftests/bpf: Use make_sockaddr in test_sock_addr
  selftests/bpf: Use connect_to_addr in test_sock_addr
  ...
====================

Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-29 13:12:19 -07:00
Suren Baghdasaryan
2c321f3f70 mm: change inlined allocation helpers to account at the call site
Main goal of memory allocation profiling patchset is to provide accounting
that is cheap enough to run in production.  To achieve that we inject
counters using codetags at the allocation call sites to account every time
allocation is made.  This injection allows us to perform accounting
efficiently because injected counters are immediately available as opposed
to the alternative methods, such as using _RET_IP_, which would require
counter lookup and appropriate locking that makes accounting much more
expensive.  This method requires all allocation functions to inject
separate counters at their call sites so that their callers can be
individually accounted.  Counter injection is implemented by allocation
hooks which should wrap all allocation functions.

Inlined functions which perform allocations but do not use allocation
hooks are directly charged for the allocations they perform.  In most
cases these functions are just specialized allocation wrappers used from
multiple places to allocate objects of a specific type.  It would be more
useful to do the accounting at their call sites instead.  Instrument these
helpers to do accounting at the call site.  Simple inlined allocation
wrappers are converted directly into macros.  More complex allocators or
allocators with documentation are converted into _noprof versions and
allocation hooks are added.  This allows memory allocation profiling
mechanism to charge allocations to the callers of these functions.

Link: https://lkml.kernel.org/r/20240415020731.1152108-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Jan Kara <jack@suse.cz>		[jbd2]
Cc: Anna Schumaker <anna@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:59 -07:00
Vadim Fedorenko
3e1c6f3540 bpf: make common crypto API for TC/XDP programs
Add crypto API support to BPF to be able to decrypt or encrypt packets
in TC/XDP BPF programs. Special care should be taken for initialization
part of crypto algo because crypto alloc) doesn't work with preemtion
disabled, it can be run only in sleepable BPF program. Also async crypto
is not supported because of the very same issue - TC/XDP BPF programs
are not sleepable.

Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://lore.kernel.org/r/20240422225024.2847039-2-vadfed@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-24 16:01:10 -07:00
Haiyue Wang
95c07d5825 bpf: update the comment for BTF_FIELDS_MAX
The commit d56b63cf0c ("bpf: add support for bpf_wq user type")
changes the fields support number to 11, just sync the comment.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240424054526.8031-1-haiyue.wang@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-24 15:58:26 -07:00
Benjamin Tissoires
246331e3f1 bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps
Currently bpf_wq_cancel_and_free() is just a placeholder as there is
no memory allocation for bpf_wq just yet.

Again, duplication of the bpf_timer approach

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-9-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:25 -07:00
Benjamin Tissoires
d56b63cf0c bpf: add support for bpf_wq user type
Mostly a copy/paste from the bpf_timer API, without the initialization
and free, as they will be done in a separate patch.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-5-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Yonghong Song
699c23f02c bpf: Add bpf_link support for sk_msg and sk_skb progs
Add bpf_link support for sk_msg and sk_skb programs. We have an
internal request to support bpf_link for sk_msg programs so user
space can have a uniform handling with bpf_link based libbpf
APIs. Using bpf_link based libbpf API also has a benefit which
makes system robust by decoupling prog life cycle and
attachment life cycle.

Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043527.3737160-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10 19:52:25 -07:00
Jakub Kicinski
cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605b ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1 ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 18:01:07 -07:00
Andrii Nakryiko
1a80dbcb2d bpf: support deferring bpf_link dealloc to after RCU grace period
BPF link for some program types is passed as a "context" which can be
used by those BPF programs to look up additional information. E.g., for
multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values.

Because of this runtime dependency, when bpf_link refcnt drops to zero
there could still be active BPF programs running accessing link data.

This patch adds generic support to defer bpf_link dealloc callback to
after RCU GP, if requested. This is done by exposing two different
deallocation callbacks, one synchronous and one deferred. If deferred
one is provided, bpf_link_free() will schedule dealloc_deferred()
callback to happen after RCU GP.

BPF is using two flavors of RCU: "classic" non-sleepable one and RCU
tasks trace one. The latter is used when sleepable BPF programs are
used. bpf_link_free() accommodates that by checking underlying BPF
program's sleepable flag, and goes either through normal RCU GP only for
non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP
(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF
program is sleepable.

We use this for multi-kprobe and multi-uprobe links, which dereference
link during program run. We also preventively switch raw_tp link to use
deferred dealloc callback, as upcoming changes in bpf-next tree expose
raw_tp link data (specifically, cookie value) to BPF program at runtime
as well.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com
Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com
Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:47:45 -07:00
Andrii Nakryiko
68ca5d4eeb bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF
aware variants). This brings them up to part w.r.t. BPF cookie usage
with classic tracepoint and fentry/fexit programs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-4-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:34 -07:00