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riscv: entry: Convert to generic entry

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This patch converts riscv to use the generic entry infrastructure from
kernel/entry/*. The generic entry makes maintainers' work easier and
codes more elegant. Here are the changes:

 - More clear entry.S with handle_exception and ret_from_exception
 - Get rid of complex custom signal implementation
 - Move syscall procedure from assembly to C, which is much more
   readable.
 - Connect ret_from_fork & ret_from_kernel_thread to generic entry.
 - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
 - Use the standard preemption code instead of custom

Suggested-by: Huacai Chen <chenhuacai@kernel.org>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Yipeng Zou <zouyipeng@huawei.com>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Guo Ren 2023-02-21 22:30:18 -05:00 committed by Palmer Dabbelt
parent d0db02c628
commit f0bddf5058
No known key found for this signature in database
GPG key ID: 2E1319F35FBB1889
14 changed files with 210 additions and 315 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
arch/riscv/Kconfig
View file

@ -60,6 +60,7 @@ config RISCV
select GENERIC_ATOMIC64 if !64BIT select GENERIC_ATOMIC64 if !64BIT
select GENERIC_CLOCKEVENTS_BROADCAST if SMP select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select GENERIC_EARLY_IOREMAP select GENERIC_EARLY_IOREMAP
select GENERIC_ENTRY
select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
select GENERIC_IDLE_POLL_SETUP select GENERIC_IDLE_POLL_SETUP
select GENERIC_IOREMAP if MMU select GENERIC_IOREMAP if MMU

2
arch/riscv/include/asm/asm-prototypes.h
View file

@ -27,5 +27,7 @@ DECLARE_DO_ERROR_INFO(do_trap_break);
asmlinkage unsigned long get_overflow_stack(void); asmlinkage unsigned long get_overflow_stack(void);
asmlinkage void handle_bad_stack(struct pt_regs *regs); asmlinkage void handle_bad_stack(struct pt_regs *regs);
asmlinkage void do_page_fault(struct pt_regs *regs);
asmlinkage void do_irq(struct pt_regs *regs);
#endif /* _ASM_RISCV_PROTOTYPES_H */ #endif /* _ASM_RISCV_PROTOTYPES_H */

1
arch/riscv/include/asm/csr.h
View file

@ -40,7 +40,6 @@
#define SR_UXL _AC(0x300000000, UL) /* XLEN mask for U-mode */ #define SR_UXL _AC(0x300000000, UL) /* XLEN mask for U-mode */
#define SR_UXL_32 _AC(0x100000000, UL) /* XLEN = 32 for U-mode */ #define SR_UXL_32 _AC(0x100000000, UL) /* XLEN = 32 for U-mode */
#define SR_UXL_64 _AC(0x200000000, UL) /* XLEN = 64 for U-mode */ #define SR_UXL_64 _AC(0x200000000, UL) /* XLEN = 64 for U-mode */
#define SR_UXL_SHIFT 32
#endif #endif
/* SATP flags */ /* SATP flags */

11
arch/riscv/include/asm/entry-common.h Normal file
View file

@ -0,0 +1,11 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_RISCV_ENTRY_COMMON_H
#define _ASM_RISCV_ENTRY_COMMON_H
#include <asm/stacktrace.h>
void handle_page_fault(struct pt_regs *regs);
void handle_break(struct pt_regs *regs);
#endif /* _ASM_RISCV_ENTRY_COMMON_H */

10
arch/riscv/include/asm/ptrace.h
View file

@ -53,6 +53,9 @@ struct pt_regs {
unsigned long orig_a0; unsigned long orig_a0;
}; };
#define PTRACE_SYSEMU 0x1f
#define PTRACE_SYSEMU_SINGLESTEP 0x20
#ifdef CONFIG_64BIT #ifdef CONFIG_64BIT
#define REG_FMT "%016lx" #define REG_FMT "%016lx"
#else #else
@ -121,8 +124,6 @@ extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
unsigned long frame_pointer); unsigned long frame_pointer);
int do_syscall_trace_enter(struct pt_regs *regs);
void do_syscall_trace_exit(struct pt_regs *regs);
/** /**
* regs_get_register() - get register value from its offset * regs_get_register() - get register value from its offset
@ -172,6 +173,11 @@ static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
return 0; return 0;
} }
static inline int regs_irqs_disabled(struct pt_regs *regs)
{
return !(regs->status & SR_PIE);
}
#endif /* __ASSEMBLY__ */ #endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_PTRACE_H */ #endif /* _ASM_RISCV_PTRACE_H */

5
arch/riscv/include/asm/stacktrace.h
View file

@ -16,4 +16,9 @@ extern void notrace walk_stackframe(struct task_struct *task, struct pt_regs *re
extern void dump_backtrace(struct pt_regs *regs, struct task_struct *task, extern void dump_backtrace(struct pt_regs *regs, struct task_struct *task,
const char *loglvl); const char *loglvl);
static inline bool on_thread_stack(void)
{
return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
}
#endif /* _ASM_RISCV_STACKTRACE_H */ #endif /* _ASM_RISCV_STACKTRACE_H */

21
arch/riscv/include/asm/syscall.h
View file

@ -74,5 +74,26 @@ static inline int syscall_get_arch(struct task_struct *task)
#endif #endif
} }
typedef long (*syscall_t)(ulong, ulong, ulong, ulong, ulong, ulong, ulong);
static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
{
syscall_t fn;
#ifdef CONFIG_COMPAT
if ((regs->status & SR_UXL) == SR_UXL_32)
fn = compat_sys_call_table[syscall];
else
#endif
fn = sys_call_table[syscall];
regs->a0 = fn(regs->orig_a0, regs->a1, regs->a2,
regs->a3, regs->a4, regs->a5, regs->a6);
}
static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
{
return false;
}
asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t); asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
#endif /* _ASM_RISCV_SYSCALL_H */ #endif /* _ASM_RISCV_SYSCALL_H */

13
arch/riscv/include/asm/thread_info.h
View file

@ -67,6 +67,7 @@ struct thread_info {
long kernel_sp; /* Kernel stack pointer */ long kernel_sp; /* Kernel stack pointer */
long user_sp; /* User stack pointer */ long user_sp; /* User stack pointer */
int cpu; int cpu;
unsigned long syscall_work; /* SYSCALL_WORK_ flags */
}; };
/* /*
@ -89,26 +90,18 @@ struct thread_info {
* - pending work-to-be-done flags are in lowest half-word * - pending work-to-be-done flags are in lowest half-word
* - other flags in upper half-word(s) * - other flags in upper half-word(s)
*/ */
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */ #define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */ #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
#define TIF_MEMDIE 5 /* is terminating due to OOM killer */ #define TIF_MEMDIE 5 /* is terminating due to OOM killer */
#define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing */
#define TIF_SECCOMP 8 /* syscall secure computing */
#define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */ #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
#define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */ #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
#define TIF_32BIT 11 /* compat-mode 32bit process */ #define TIF_32BIT 11 /* compat-mode 32bit process */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
#define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_UPROBE (1 << TIF_UPROBE)
@ -116,8 +109,4 @@ struct thread_info {
(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \ (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_NOTIFY_SIGNAL | _TIF_UPROBE) _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
#define _TIF_SYSCALL_WORK \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT | \
_TIF_SECCOMP)
#endif /* _ASM_RISCV_THREAD_INFO_H */ #endif /* _ASM_RISCV_THREAD_INFO_H */

242
arch/riscv/kernel/entry.S
View file

@ -14,11 +14,7 @@
#include <asm/asm-offsets.h> #include <asm/asm-offsets.h>
#include <asm/errata_list.h> #include <asm/errata_list.h>
#if !IS_ENABLED(CONFIG_PREEMPTION) SYM_CODE_START(handle_exception)
.set resume_kernel, restore_all
#endif
ENTRY(handle_exception)
/* /*
* If coming from userspace, preserve the user thread pointer and load * If coming from userspace, preserve the user thread pointer and load
* the kernel thread pointer. If we came from the kernel, the scratch * the kernel thread pointer. If we came from the kernel, the scratch
@ -106,19 +102,8 @@ _save_context:
.option norelax .option norelax
la gp, __global_pointer$ la gp, __global_pointer$
.option pop .option pop
move a0, sp /* pt_regs */
#ifdef CONFIG_TRACE_IRQFLAGS la ra, ret_from_exception
call __trace_hardirqs_off
#endif
#ifdef CONFIG_CONTEXT_TRACKING_USER
/* If previous state is in user mode, call user_exit_callable(). */
li a0, SR_PP
and a0, s1, a0
bnez a0, skip_context_tracking
call user_exit_callable
skip_context_tracking:
#endif
/* /*
* MSB of cause differentiates between * MSB of cause differentiates between
@ -126,38 +111,13 @@ skip_context_tracking:
*/ */
bge s4, zero, 1f bge s4, zero, 1f
la ra, ret_from_exception
/* Handle interrupts */ /* Handle interrupts */
move a0, sp /* pt_regs */ tail do_irq
la a1, generic_handle_arch_irq
jr a1
1: 1:
/*
* Exceptions run with interrupts enabled or disabled depending on the
* state of SR_PIE in m/sstatus.
*/
andi t0, s1, SR_PIE
beqz t0, 1f
/* kprobes, entered via ebreak, must have interrupts disabled. */
li t0, EXC_BREAKPOINT
beq s4, t0, 1f
#ifdef CONFIG_TRACE_IRQFLAGS
call __trace_hardirqs_on
#endif
csrs CSR_STATUS, SR_IE
1:
la ra, ret_from_exception
/* Handle syscalls */
li t0, EXC_SYSCALL
beq s4, t0, handle_syscall
/* Handle other exceptions */ /* Handle other exceptions */
slli t0, s4, RISCV_LGPTR slli t0, s4, RISCV_LGPTR
la t1, excp_vect_table la t1, excp_vect_table
la t2, excp_vect_table_end la t2, excp_vect_table_end
move a0, sp /* pt_regs */
add t0, t1, t0 add t0, t1, t0
/* Check if exception code lies within bounds */ /* Check if exception code lies within bounds */
bgeu t0, t2, 1f bgeu t0, t2, 1f
@ -165,95 +125,17 @@ skip_context_tracking:
jr t0 jr t0
1: 1:
tail do_trap_unknown tail do_trap_unknown
SYM_CODE_END(handle_exception)
handle_syscall: /*
#ifdef CONFIG_RISCV_M_MODE * The ret_from_exception must be called with interrupt disabled. Here is the
/* * caller list:
* When running is M-Mode (no MMU config), MPIE does not get set. * - handle_exception
* As a result, we need to force enable interrupts here because * - ret_from_fork
* handle_exception did not do set SR_IE as it always sees SR_PIE * - ret_from_kernel_thread
* being cleared. */
*/
csrs CSR_STATUS, SR_IE
#endif
#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
/* Recover a0 - a7 for system calls */
REG_L a0, PT_A0(sp)
REG_L a1, PT_A1(sp)
REG_L a2, PT_A2(sp)
REG_L a3, PT_A3(sp)
REG_L a4, PT_A4(sp)
REG_L a5, PT_A5(sp)
REG_L a6, PT_A6(sp)
REG_L a7, PT_A7(sp)
#endif
/* save the initial A0 value (needed in signal handlers) */
REG_S a0, PT_ORIG_A0(sp)
/*
* Advance SEPC to avoid executing the original
* scall instruction on sret
*/
addi s2, s2, 0x4
REG_S s2, PT_EPC(sp)
/* Trace syscalls, but only if requested by the user. */
REG_L t0, TASK_TI_FLAGS(tp)
andi t0, t0, _TIF_SYSCALL_WORK
bnez t0, handle_syscall_trace_enter
check_syscall_nr:
/* Check to make sure we don't jump to a bogus syscall number. */
li t0, __NR_syscalls
la s0, sys_ni_syscall
/*
* Syscall number held in a7.
* If syscall number is above allowed value, redirect to ni_syscall.
*/
bgeu a7, t0, 3f
#ifdef CONFIG_COMPAT
REG_L s0, PT_STATUS(sp)
srli s0, s0, SR_UXL_SHIFT
andi s0, s0, (SR_UXL >> SR_UXL_SHIFT)
li t0, (SR_UXL_32 >> SR_UXL_SHIFT)
sub t0, s0, t0
bnez t0, 1f
/* Call compat_syscall */
la s0, compat_sys_call_table
j 2f
1:
#endif
/* Call syscall */
la s0, sys_call_table
2:
slli t0, a7, RISCV_LGPTR
add s0, s0, t0
REG_L s0, 0(s0)
3:
jalr s0
ret_from_syscall:
/* Set user a0 to kernel a0 */
REG_S a0, PT_A0(sp)
/*
* We didn't execute the actual syscall.
* Seccomp already set return value for the current task pt_regs.
* (If it was configured with SECCOMP_RET_ERRNO/TRACE)
*/
ret_from_syscall_rejected:
#ifdef CONFIG_DEBUG_RSEQ
move a0, sp
call rseq_syscall
#endif
/* Trace syscalls, but only if requested by the user. */
REG_L t0, TASK_TI_FLAGS(tp)
andi t0, t0, _TIF_SYSCALL_WORK
bnez t0, handle_syscall_trace_exit
SYM_CODE_START_NOALIGN(ret_from_exception) SYM_CODE_START_NOALIGN(ret_from_exception)
REG_L s0, PT_STATUS(sp) REG_L s0, PT_STATUS(sp)
csrc CSR_STATUS, SR_IE
#ifdef CONFIG_TRACE_IRQFLAGS
call __trace_hardirqs_off
#endif
#ifdef CONFIG_RISCV_M_MODE #ifdef CONFIG_RISCV_M_MODE
/* the MPP value is too large to be used as an immediate arg for addi */ /* the MPP value is too large to be used as an immediate arg for addi */
li t0, SR_MPP li t0, SR_MPP
@ -261,17 +143,7 @@ SYM_CODE_START_NOALIGN(ret_from_exception)
#else #else
andi s0, s0, SR_SPP andi s0, s0, SR_SPP
#endif #endif
bnez s0, resume_kernel bnez s0, 1f
SYM_CODE_END(ret_from_exception)
/* Interrupts must be disabled here so flags are checked atomically */
REG_L s0, TASK_TI_FLAGS(tp) /* current_thread_info->flags */
andi s1, s0, _TIF_WORK_MASK
bnez s1, resume_userspace_slow
resume_userspace:
#ifdef CONFIG_CONTEXT_TRACKING_USER
call user_enter_callable
#endif
/* Save unwound kernel stack pointer in thread_info */ /* Save unwound kernel stack pointer in thread_info */
addi s0, sp, PT_SIZE_ON_STACK addi s0, sp, PT_SIZE_ON_STACK
@ -282,18 +154,7 @@ resume_userspace:
* structures again. * structures again.
*/ */
csrw CSR_SCRATCH, tp csrw CSR_SCRATCH, tp
restore_all:
#ifdef CONFIG_TRACE_IRQFLAGS
REG_L s1, PT_STATUS(sp)
andi t0, s1, SR_PIE
beqz t0, 1f
call __trace_hardirqs_on
j 2f
1: 1:
call __trace_hardirqs_off
2:
#endif
REG_L a0, PT_STATUS(sp) REG_L a0, PT_STATUS(sp)
/* /*
* The current load reservation is effectively part of the processor's * The current load reservation is effectively part of the processor's
@ -356,47 +217,10 @@ restore_all:
#else #else
sret sret
#endif #endif
SYM_CODE_END(ret_from_exception)
#if IS_ENABLED(CONFIG_PREEMPTION)
resume_kernel:
REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
bnez s0, restore_all
REG_L s0, TASK_TI_FLAGS(tp)
andi s0, s0, _TIF_NEED_RESCHED
beqz s0, restore_all
call preempt_schedule_irq
j restore_all
#endif
resume_userspace_slow:
/* Enter slow path for supplementary processing */
move a0, sp /* pt_regs */
move a1, s0 /* current_thread_info->flags */
call do_work_pending
j resume_userspace
/* Slow paths for ptrace. */
handle_syscall_trace_enter:
move a0, sp
call do_syscall_trace_enter
move t0, a0
REG_L a0, PT_A0(sp)
REG_L a1, PT_A1(sp)
REG_L a2, PT_A2(sp)
REG_L a3, PT_A3(sp)
REG_L a4, PT_A4(sp)
REG_L a5, PT_A5(sp)
REG_L a6, PT_A6(sp)
REG_L a7, PT_A7(sp)
bnez t0, ret_from_syscall_rejected
j check_syscall_nr
handle_syscall_trace_exit:
move a0, sp
call do_syscall_trace_exit
j ret_from_exception
#ifdef CONFIG_VMAP_STACK #ifdef CONFIG_VMAP_STACK
handle_kernel_stack_overflow: SYM_CODE_START_LOCAL(handle_kernel_stack_overflow)
/* /*
* Takes the psuedo-spinlock for the shadow stack, in case multiple * Takes the psuedo-spinlock for the shadow stack, in case multiple
* harts are concurrently overflowing their kernel stacks. We could * harts are concurrently overflowing their kernel stacks. We could
@ -505,23 +329,25 @@ restore_caller_reg:
REG_S s5, PT_TP(sp) REG_S s5, PT_TP(sp)
move a0, sp move a0, sp
tail handle_bad_stack tail handle_bad_stack
SYM_CODE_END(handle_kernel_stack_overflow)
#endif #endif
END(handle_exception) SYM_CODE_START(ret_from_fork)
call schedule_tail
ENTRY(ret_from_fork) move a0, sp /* pt_regs */
la ra, ret_from_exception la ra, ret_from_exception
tail schedule_tail tail syscall_exit_to_user_mode
ENDPROC(ret_from_fork) SYM_CODE_END(ret_from_fork)
ENTRY(ret_from_kernel_thread) SYM_CODE_START(ret_from_kernel_thread)
call schedule_tail call schedule_tail
/* Call fn(arg) */ /* Call fn(arg) */
la ra, ret_from_exception
move a0, s1 move a0, s1
jr s0 jalr s0
ENDPROC(ret_from_kernel_thread) move a0, sp /* pt_regs */
la ra, ret_from_exception
tail syscall_exit_to_user_mode
SYM_CODE_END(ret_from_kernel_thread)
/* /*
* Integer register context switch * Integer register context switch
@ -533,7 +359,7 @@ ENDPROC(ret_from_kernel_thread)
* The value of a0 and a1 must be preserved by this function, as that's how * The value of a0 and a1 must be preserved by this function, as that's how
* arguments are passed to schedule_tail. * arguments are passed to schedule_tail.
*/ */
ENTRY(__switch_to) SYM_FUNC_START(__switch_to)
/* Save context into prev->thread */ /* Save context into prev->thread */
li a4, TASK_THREAD_RA li a4, TASK_THREAD_RA
add a3, a0, a4 add a3, a0, a4
@ -570,7 +396,7 @@ ENTRY(__switch_to)
/* The offset of thread_info in task_struct is zero. */ /* The offset of thread_info in task_struct is zero. */
move tp, a1 move tp, a1
ret ret
ENDPROC(__switch_to) SYM_FUNC_END(__switch_to)
#ifndef CONFIG_MMU #ifndef CONFIG_MMU
#define do_page_fault do_trap_unknown #define do_page_fault do_trap_unknown
@ -579,7 +405,7 @@ ENDPROC(__switch_to)
.section ".rodata" .section ".rodata"
.align LGREG .align LGREG
/* Exception vector table */ /* Exception vector table */
ENTRY(excp_vect_table) SYM_CODE_START(excp_vect_table)
RISCV_PTR do_trap_insn_misaligned RISCV_PTR do_trap_insn_misaligned
ALT_INSN_FAULT(RISCV_PTR do_trap_insn_fault) ALT_INSN_FAULT(RISCV_PTR do_trap_insn_fault)
RISCV_PTR do_trap_insn_illegal RISCV_PTR do_trap_insn_illegal
@ -588,7 +414,7 @@ ENTRY(excp_vect_table)
RISCV_PTR do_trap_load_fault RISCV_PTR do_trap_load_fault
RISCV_PTR do_trap_store_misaligned RISCV_PTR do_trap_store_misaligned
RISCV_PTR do_trap_store_fault RISCV_PTR do_trap_store_fault
RISCV_PTR do_trap_ecall_u /* system call, gets intercepted */ RISCV_PTR do_trap_ecall_u /* system call */
RISCV_PTR do_trap_ecall_s RISCV_PTR do_trap_ecall_s
RISCV_PTR do_trap_unknown RISCV_PTR do_trap_unknown
RISCV_PTR do_trap_ecall_m RISCV_PTR do_trap_ecall_m
@ -598,11 +424,11 @@ ENTRY(excp_vect_table)
RISCV_PTR do_trap_unknown RISCV_PTR do_trap_unknown
RISCV_PTR do_page_fault /* store page fault */ RISCV_PTR do_page_fault /* store page fault */
excp_vect_table_end: excp_vect_table_end:
END(excp_vect_table) SYM_CODE_END(excp_vect_table)
#ifndef CONFIG_MMU #ifndef CONFIG_MMU
ENTRY(__user_rt_sigreturn) SYM_CODE_START(__user_rt_sigreturn)
li a7, __NR_rt_sigreturn li a7, __NR_rt_sigreturn
scall scall
END(__user_rt_sigreturn) SYM_CODE_END(__user_rt_sigreturn)
#endif #endif

1
arch/riscv/kernel/head.h
View file

@ -10,7 +10,6 @@
extern atomic_t hart_lottery; extern atomic_t hart_lottery;
asmlinkage void do_page_fault(struct pt_regs *regs);
asmlinkage void __init setup_vm(uintptr_t dtb_pa); asmlinkage void __init setup_vm(uintptr_t dtb_pa);
#ifdef CONFIG_XIP_KERNEL #ifdef CONFIG_XIP_KERNEL
asmlinkage void __init __copy_data(void); asmlinkage void __init __copy_data(void);

43
arch/riscv/kernel/ptrace.c
View file

@ -19,9 +19,6 @@
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/sched/task_stack.h> #include <linux/sched/task_stack.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
enum riscv_regset { enum riscv_regset {
REGSET_X, REGSET_X,
#ifdef CONFIG_FPU #ifdef CONFIG_FPU
@ -228,46 +225,6 @@ long arch_ptrace(struct task_struct *child, long request,
return ret; return ret;
} }
/*
* Allows PTRACE_SYSCALL to work. These are called from entry.S in
* {handle,ret_from}_syscall.
*/
__visible int do_syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
if (ptrace_report_syscall_entry(regs))
return -1;
/*
* Do the secure computing after ptrace; failures should be fast.
* If this fails we might have return value in a0 from seccomp
* (via SECCOMP_RET_ERRNO/TRACE).
*/
if (secure_computing() == -1)
return -1;
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall_get_nr(current, regs));
#endif
audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
return 0;
}
__visible void do_syscall_trace_exit(struct pt_regs *regs)
{
audit_syscall_exit(regs);
if (test_thread_flag(TIF_SYSCALL_TRACE))
ptrace_report_syscall_exit(regs, 0);
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs_return_value(regs));
#endif
}
#ifdef CONFIG_COMPAT #ifdef CONFIG_COMPAT
static int compat_riscv_gpr_get(struct task_struct *target, static int compat_riscv_gpr_get(struct task_struct *target,
const struct user_regset *regset, const struct user_regset *regset,

29
arch/riscv/kernel/signal.c
View file

@ -12,6 +12,7 @@
#include <linux/syscalls.h> #include <linux/syscalls.h>
#include <linux/resume_user_mode.h> #include <linux/resume_user_mode.h>
#include <linux/linkage.h> #include <linux/linkage.h>
#include <linux/entry-common.h>
#include <asm/ucontext.h> #include <asm/ucontext.h>
#include <asm/vdso.h> #include <asm/vdso.h>
@ -274,7 +275,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
signal_setup_done(ret, ksig, 0); signal_setup_done(ret, ksig, 0);
} }
static void do_signal(struct pt_regs *regs) void arch_do_signal_or_restart(struct pt_regs *regs)
{ {
struct ksignal ksig; struct ksignal ksig;
@ -311,29 +312,3 @@ static void do_signal(struct pt_regs *regs)
*/ */
restore_saved_sigmask(); restore_saved_sigmask();
} }
/*
* Handle any pending work on the resume-to-userspace path, as indicated by
* _TIF_WORK_MASK. Entered from assembly with IRQs off.
*/
asmlinkage __visible void do_work_pending(struct pt_regs *regs,
unsigned long thread_info_flags)
{
do {
if (thread_info_flags & _TIF_NEED_RESCHED) {
schedule();
} else {
local_irq_enable();
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
/* Handle pending signal delivery */
if (thread_info_flags & (_TIF_SIGPENDING |
_TIF_NOTIFY_SIGNAL))
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME)
resume_user_mode_work(regs);
}
local_irq_disable();
thread_info_flags = read_thread_flags();
} while (thread_info_flags & _TIF_WORK_MASK);
}

140
arch/riscv/kernel/traps.c
View file

@ -17,12 +17,14 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/irq.h> #include <linux/irq.h>
#include <linux/kexec.h> #include <linux/kexec.h>
#include <linux/entry-common.h>
#include <asm/asm-prototypes.h> #include <asm/asm-prototypes.h>
#include <asm/bug.h> #include <asm/bug.h>
#include <asm/csr.h> #include <asm/csr.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <asm/ptrace.h> #include <asm/ptrace.h>
#include <asm/syscall.h>
#include <asm/thread_info.h> #include <asm/thread_info.h>
int show_unhandled_signals = 1; int show_unhandled_signals = 1;
@ -123,10 +125,18 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
#else #else
#define __trap_section noinstr #define __trap_section noinstr
#endif #endif
#define DO_ERROR_INFO(name, signo, code, str) \ #define DO_ERROR_INFO(name, signo, code, str) \
asmlinkage __visible __trap_section void name(struct pt_regs *regs) \ asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
{ \ { \
do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \ if (user_mode(regs)) { \
irqentry_enter_from_user_mode(regs); \
do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
irqentry_exit_to_user_mode(regs); \
} else { \
irqentry_state_t state = irqentry_nmi_enter(regs); \
do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
irqentry_nmi_exit(regs, state); \
} \
} }
DO_ERROR_INFO(do_trap_unknown, DO_ERROR_INFO(do_trap_unknown,
@ -148,26 +158,50 @@ DO_ERROR_INFO(do_trap_store_misaligned,
int handle_misaligned_load(struct pt_regs *regs); int handle_misaligned_load(struct pt_regs *regs);
int handle_misaligned_store(struct pt_regs *regs); int handle_misaligned_store(struct pt_regs *regs);
asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs) asmlinkage __visible __trap_section void do_trap_load_misaligned(struct pt_regs *regs)
{ {
if (!handle_misaligned_load(regs)) if (user_mode(regs)) {
return; irqentry_enter_from_user_mode(regs);
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - load address misaligned"); if (handle_misaligned_load(regs))
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - load address misaligned");
irqentry_exit_to_user_mode(regs);
} else {
irqentry_state_t state = irqentry_nmi_enter(regs);
if (handle_misaligned_load(regs))
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - load address misaligned");
irqentry_nmi_exit(regs, state);
}
} }
asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs) asmlinkage __visible __trap_section void do_trap_store_misaligned(struct pt_regs *regs)
{ {
if (!handle_misaligned_store(regs)) if (user_mode(regs)) {
return; irqentry_enter_from_user_mode(regs);
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - store (or AMO) address misaligned"); if (handle_misaligned_store(regs))
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - store (or AMO) address misaligned");
irqentry_exit_to_user_mode(regs);
} else {
irqentry_state_t state = irqentry_nmi_enter(regs);
if (handle_misaligned_store(regs))
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - store (or AMO) address misaligned");
irqentry_nmi_exit(regs, state);
}
} }
#endif #endif
DO_ERROR_INFO(do_trap_store_fault, DO_ERROR_INFO(do_trap_store_fault,
SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault"); SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
DO_ERROR_INFO(do_trap_ecall_u,
SIGILL, ILL_ILLTRP, "environment call from U-mode");
DO_ERROR_INFO(do_trap_ecall_s, DO_ERROR_INFO(do_trap_ecall_s,
SIGILL, ILL_ILLTRP, "environment call from S-mode"); SIGILL, ILL_ILLTRP, "environment call from S-mode");
DO_ERROR_INFO(do_trap_ecall_m, DO_ERROR_INFO(do_trap_ecall_m,
@ -183,7 +217,7 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
return GET_INSN_LENGTH(insn); return GET_INSN_LENGTH(insn);
} }
asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs) void handle_break(struct pt_regs *regs)
{ {
#ifdef CONFIG_KPROBES #ifdef CONFIG_KPROBES
if (kprobe_single_step_handler(regs)) if (kprobe_single_step_handler(regs))
@ -213,7 +247,77 @@ asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
else else
die(regs, "Kernel BUG"); die(regs, "Kernel BUG");
} }
NOKPROBE_SYMBOL(do_trap_break);
asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
{
if (user_mode(regs)) {
irqentry_enter_from_user_mode(regs);
handle_break(regs);
irqentry_exit_to_user_mode(regs);
} else {
irqentry_state_t state = irqentry_nmi_enter(regs);
handle_break(regs);
irqentry_nmi_exit(regs, state);
}
}
asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs)
{
if (user_mode(regs)) {
ulong syscall = regs->a7;
syscall = syscall_enter_from_user_mode(regs, syscall);
regs->epc += 4;
regs->orig_a0 = regs->a0;
if (syscall < NR_syscalls)
syscall_handler(regs, syscall);
else
regs->a0 = -ENOSYS;
syscall_exit_to_user_mode(regs);
} else {
irqentry_state_t state = irqentry_nmi_enter(regs);
do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->epc,
"Oops - environment call from U-mode");
irqentry_nmi_exit(regs, state);
}
}
#ifdef CONFIG_MMU
asmlinkage __visible noinstr void do_page_fault(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
handle_page_fault(regs);
local_irq_disable();
irqentry_exit(regs, state);
}
#endif
asmlinkage __visible noinstr void do_irq(struct pt_regs *regs)
{
struct pt_regs *old_regs;
irqentry_state_t state = irqentry_enter(regs);
irq_enter_rcu();
old_regs = set_irq_regs(regs);
handle_arch_irq(regs);
set_irq_regs(old_regs);
irq_exit_rcu();
irqentry_exit(regs, state);
}
#ifdef CONFIG_GENERIC_BUG #ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long pc) int is_valid_bugaddr(unsigned long pc)

6
arch/riscv/mm/fault.c
View file

@ -15,6 +15,7 @@
#include <linux/uaccess.h> #include <linux/uaccess.h>
#include <linux/kprobes.h> #include <linux/kprobes.h>
#include <linux/kfence.h> #include <linux/kfence.h>
#include <linux/entry-common.h>
#include <asm/ptrace.h> #include <asm/ptrace.h>
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
@ -204,7 +205,7 @@ static inline bool access_error(unsigned long cause, struct vm_area_struct *vma)
* This routine handles page faults. It determines the address and the * This routine handles page faults. It determines the address and the
* problem, and then passes it off to one of the appropriate routines. * problem, and then passes it off to one of the appropriate routines.
*/ */
asmlinkage void do_page_fault(struct pt_regs *regs) void handle_page_fault(struct pt_regs *regs)
{ {
struct task_struct *tsk; struct task_struct *tsk;
struct vm_area_struct *vma; struct vm_area_struct *vma;
@ -251,7 +252,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
} }
#endif #endif
/* Enable interrupts if they were enabled in the parent context. */ /* Enable interrupts if they were enabled in the parent context. */
if (likely(regs->status & SR_PIE)) if (!regs_irqs_disabled(regs))
local_irq_enable(); local_irq_enable();
/* /*
@ -356,4 +357,3 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
} }
return; return;
} }
NOKPROBE_SYMBOL(do_page_fault);