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kernel/include/linux/btf_ids.h
Nathan Chancellor 2d5bcdcda8 bpf: Increase size of BTF_ID_LIST without CONFIG_DEBUG_INFO_BTF again 
After commit 66e3a13e7c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr"),
clang builds without CONFIG_DEBUG_INFO_BTF warn:

  kernel/bpf/verifier.c:10298:24: warning: array index 16 is past the end of the array (that has type 'u32[16]' (aka 'unsigned int[16]')) [-Warray-bounds]
                                     meta.func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) {
                                                     ^                  ~~~~~~~~~~~~~~~~~~~~~~~~
  kernel/bpf/verifier.c:9150:1: note: array 'special_kfunc_list' declared here
  BTF_ID_LIST(special_kfunc_list)
  ^
  include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
  #define BTF_ID_LIST(name) static u32 __maybe_unused name[16];
                            ^
  1 warning generated.

A warning of this nature was previously addressed by
commit beb3d47d1d ("bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set")
but there have been new kfuncs added since then.

Quadruple the size of the CONFIG_DEBUG_INFO_BTF=n definition so that
this problem is unlikely to show up for some time.

Link: https://github.com/ClangBuiltLinux/linux/issues/1810
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230307-bpf-kfuncs-warray-bounds-v1-1-00ad3191f3a6@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-07 07:49:28 -08:00

271 lines
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BTF_IDS_H
#define _LINUX_BTF_IDS_H
struct btf_id_set {
u32 cnt;
u32 ids[];
};
struct btf_id_set8 {
u32 cnt;
u32 flags;
struct {
u32 id;
u32 flags;
} pairs[];
};
#ifdef CONFIG_DEBUG_INFO_BTF
#include <linux/compiler.h> /* for __PASTE */
#include <linux/compiler_attributes.h> /* for __maybe_unused */
/*
* Following macros help to define lists of BTF IDs placed
* in .BTF_ids section. They are initially filled with zeros
* (during compilation) and resolved later during the
* linking phase by resolve_btfids tool.
*
* Any change in list layout must be reflected in resolve_btfids
* tool logic.
*/
#define BTF_IDS_SECTION ".BTF_ids"
#define ____BTF_ID(symbol, word) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
".local " #symbol " ; \n" \
".type " #symbol ", STT_OBJECT; \n" \
".size " #symbol ", 4; \n" \
#symbol ": \n" \
".zero 4 \n" \
word \
".popsection; \n");
#define __BTF_ID(symbol, word) \
____BTF_ID(symbol, word)
#define __ID(prefix) \
__PASTE(prefix, __COUNTER__)
/*
* The BTF_ID defines unique symbol for each ID pointing
* to 4 zero bytes.
*/
#define BTF_ID(prefix, name) \
__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__), "")
#define ____BTF_ID_FLAGS(prefix, name, flags) \
__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__), ".long " #flags "\n")
#define __BTF_ID_FLAGS(prefix, name, flags, ...) \
____BTF_ID_FLAGS(prefix, name, flags)
#define BTF_ID_FLAGS(prefix, name, ...) \
__BTF_ID_FLAGS(prefix, name, ##__VA_ARGS__, 0)
/*
* The BTF_ID_LIST macro defines pure (unsorted) list
* of BTF IDs, with following layout:
*
* BTF_ID_LIST(list1)
* BTF_ID(type1, name1)
* BTF_ID(type2, name2)
*
* list1:
* __BTF_ID__type1__name1__1:
* .zero 4
* __BTF_ID__type2__name2__2:
* .zero 4
*
*/
#define __BTF_ID_LIST(name, scope) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
"." #scope " " #name "; \n" \
#name ":; \n" \
".popsection; \n");
#define BTF_ID_LIST(name) \
__BTF_ID_LIST(name, local) \
extern u32 name[];
#define BTF_ID_LIST_GLOBAL(name, n) \
__BTF_ID_LIST(name, globl)
/* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with
* a single entry.
*/
#define BTF_ID_LIST_SINGLE(name, prefix, typename) \
BTF_ID_LIST(name) \
BTF_ID(prefix, typename)
#define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) \
BTF_ID_LIST_GLOBAL(name, 1) \
BTF_ID(prefix, typename)
/*
* The BTF_ID_UNUSED macro defines 4 zero bytes.
* It's used when we want to define 'unused' entry
* in BTF_ID_LIST, like:
*
* BTF_ID_LIST(bpf_skb_output_btf_ids)
* BTF_ID(struct, sk_buff)
* BTF_ID_UNUSED
* BTF_ID(struct, task_struct)
*/
#define BTF_ID_UNUSED \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
".zero 4 \n" \
".popsection; \n");
/*
* The BTF_SET_START/END macros pair defines sorted list of
* BTF IDs plus its members count, with following layout:
*
* BTF_SET_START(list)
* BTF_ID(type1, name1)
* BTF_ID(type2, name2)
* BTF_SET_END(list)
*
* __BTF_ID__set__list:
* .zero 4
* list:
* __BTF_ID__type1__name1__3:
* .zero 4
* __BTF_ID__type2__name2__4:
* .zero 4
*
*/
#define __BTF_SET_START(name, scope) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
"." #scope " __BTF_ID__set__" #name "; \n" \
"__BTF_ID__set__" #name ":; \n" \
".zero 4 \n" \
".popsection; \n");
#define BTF_SET_START(name) \
__BTF_ID_LIST(name, local) \
__BTF_SET_START(name, local)
#define BTF_SET_START_GLOBAL(name) \
__BTF_ID_LIST(name, globl) \
__BTF_SET_START(name, globl)
#define BTF_SET_END(name) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
".size __BTF_ID__set__" #name ", .-" #name " \n" \
".popsection; \n"); \
extern struct btf_id_set name;
/*
* The BTF_SET8_START/END macros pair defines sorted list of
* BTF IDs and their flags plus its members count, with the
* following layout:
*
* BTF_SET8_START(list)
* BTF_ID_FLAGS(type1, name1, flags)
* BTF_ID_FLAGS(type2, name2, flags)
* BTF_SET8_END(list)
*
* __BTF_ID__set8__list:
* .zero 8
* list:
* __BTF_ID__type1__name1__3:
* .zero 4
* .word (1 << 0) | (1 << 2)
* __BTF_ID__type2__name2__5:
* .zero 4
* .word (1 << 3) | (1 << 1) | (1 << 2)
*
*/
#define __BTF_SET8_START(name, scope) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
"." #scope " __BTF_ID__set8__" #name "; \n" \
"__BTF_ID__set8__" #name ":; \n" \
".zero 8 \n" \
".popsection; \n");
#define BTF_SET8_START(name) \
__BTF_ID_LIST(name, local) \
__BTF_SET8_START(name, local)
#define BTF_SET8_END(name) \
asm( \
".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \
".size __BTF_ID__set8__" #name ", .-" #name " \n" \
".popsection; \n"); \
extern struct btf_id_set8 name;
#else
#define BTF_ID_LIST(name) static u32 __maybe_unused name[64];
#define BTF_ID(prefix, name)
#define BTF_ID_FLAGS(prefix, name, ...)
#define BTF_ID_UNUSED
#define BTF_ID_LIST_GLOBAL(name, n) u32 __maybe_unused name[n];
#define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 __maybe_unused name[1];
#define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) u32 __maybe_unused name[1];
#define BTF_SET_START(name) static struct btf_id_set __maybe_unused name = { 0 };
#define BTF_SET_START_GLOBAL(name) static struct btf_id_set __maybe_unused name = { 0 };
#define BTF_SET_END(name)
#define BTF_SET8_START(name) static struct btf_id_set8 __maybe_unused name = { 0 };
#define BTF_SET8_END(name)
#endif /* CONFIG_DEBUG_INFO_BTF */
#ifdef CONFIG_NET
/* Define a list of socket types which can be the argument for
* skc_to_*_sock() helpers. All these sockets should have
* sock_common as the first argument in its memory layout.
*/
#define BTF_SOCK_TYPE_xxx \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCKET, socket)
enum {
#define BTF_SOCK_TYPE(name, str) name,
BTF_SOCK_TYPE_xxx
#undef BTF_SOCK_TYPE
MAX_BTF_SOCK_TYPE,
};
extern u32 btf_sock_ids[];
#endif
#define BTF_TRACING_TYPE_xxx \
BTF_TRACING_TYPE(BTF_TRACING_TYPE_TASK, task_struct) \
BTF_TRACING_TYPE(BTF_TRACING_TYPE_FILE, file) \
BTF_TRACING_TYPE(BTF_TRACING_TYPE_VMA, vm_area_struct)
enum {
#define BTF_TRACING_TYPE(name, type) name,
BTF_TRACING_TYPE_xxx
#undef BTF_TRACING_TYPE
MAX_BTF_TRACING_TYPE,
};
extern u32 btf_tracing_ids[];
extern u32 bpf_cgroup_btf_id[];
extern u32 bpf_local_storage_map_btf_id[];
#endif
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