Refactor the syscall exit path to better match the generic entry framework. Specifically:
- Introduce `_TIF_SYSCALL_EXIT_WORK` to aggregate exit-time thread flags (trace, audit, tracepoint). - Rename `syscall_trace_exit()` to `arm64_syscall_exit_work()` to better reflect its role. - Move `rseq_syscall()` out of `arm64_syscall_exit_work()` and into `arm64_syscall_exit_to_user_mode_work()` so that it runs unconditionally on all exits, consistent with generic entry. - Gate `arm64_syscall_exit_work()` behind the new flag check, mirroring the generic entry exit's pattern. Gating audit on `_TIF_SYSCALL_AUDIT` is equivalent to the previous `audit_context()` check: the audit context and flag are statically allocated at fork and freed at exit, remaining stable throughout syscall execution. No functional changes intended. Cc: Mark Rutland <[email protected]> Cc: Will Deacon <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Ada Couprie Diaz <[email protected]> Reviewed-by: Linus Walleij <[email protected]> Signed-off-by: Jinjie Ruan <[email protected]> --- arch/arm64/include/asm/syscall.h | 8 ++++++-- arch/arm64/include/asm/thread_info.h | 3 +++ arch/arm64/kernel/ptrace.c | 5 +---- 3 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index 3e4672ab4a4f..7cc872fde019 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -8,6 +8,7 @@ #include <uapi/linux/audit.h> #include <linux/compat.h> #include <linux/err.h> +#include <linux/rseq.h> typedef long (*syscall_fn_t)(const struct pt_regs *regs); @@ -121,13 +122,16 @@ static inline int syscall_get_arch(struct task_struct *task) } int arm64_syscall_trace_enter(struct pt_regs *regs, unsigned long flags); -void syscall_trace_exit(struct pt_regs *regs, unsigned long flags); +void arm64_syscall_exit_work(struct pt_regs *regs, unsigned long flags); static __always_inline void arm64_syscall_exit_to_user_mode_work(struct pt_regs *regs) { unsigned long flags = read_thread_flags(); - syscall_trace_exit(regs, flags); + rseq_syscall(regs); + + if (unlikely(flags & _TIF_SYSCALL_EXIT_WORK) || flags & _TIF_SINGLESTEP) + arm64_syscall_exit_work(regs, flags); } #endif /* __ASM_SYSCALL_H */ diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 5d7fe3e153c8..56a2c9426a32 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -112,6 +112,9 @@ void arch_setup_new_exec(void); _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ _TIF_SYSCALL_EMU) +#define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ + _TIF_SYSCALL_TRACEPOINT) + #ifdef CONFIG_SHADOW_CALL_STACK #define INIT_SCS \ .scs_base = init_shadow_call_stack, \ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index ac90b05dbd11..610a79c1072b 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -28,7 +28,6 @@ #include <linux/hw_breakpoint.h> #include <linux/regset.h> #include <linux/elf.h> -#include <linux/rseq.h> #include <asm/compat.h> #include <asm/cpufeature.h> @@ -2507,12 +2506,10 @@ static inline bool report_single_step(unsigned long flags) return flags & _TIF_SINGLESTEP; } -void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) +void arm64_syscall_exit_work(struct pt_regs *regs, unsigned long flags) { bool step; - rseq_syscall(regs); - audit_syscall_exit(regs); if (flags & _TIF_SYSCALL_TRACEPOINT) -- 2.34.1
