The generic syscall entry code has the form: | syscall_trace_enter() | { | ptrace_report_syscall_entry() | } | | syscall_exit_work() | { | ptrace_report_syscall_exit() | } In preparation for moving arm64 over to the generic entry code, split report_syscall() to two separate enter and exit functions to align the structure of the arm64 code with syscall_trace_enter() and syscall_exit_work() from the generic entry code. No functional changes. Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- v8: - report_syscall_enter() -> report_syscall_entry(). - Add ptrace_save_reg() helper. --- arch/arm64/kernel/ptrace.c | 41 +++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 4b001121c72d..4532e9831856 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2317,9 +2317,10 @@ enum ptrace_syscall_dir { PTRACE_SYSCALL_EXIT, }; -static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) +static __always_inline unsigned long ptrace_save_reg(struct pt_regs *regs, + enum ptrace_syscall_dir dir, + int *regno) { - int regno; unsigned long saved_reg; /* @@ -2338,15 +2339,31 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) * - Syscall stops behave differently to seccomp and pseudo-step traps * (the latter do not nobble any registers). */ - regno = (is_compat_task() ? 12 : 7); - saved_reg = regs->regs[regno]; - regs->regs[regno] = dir; + *regno = (is_compat_task() ? 12 : 7); + saved_reg = regs->regs[*regno]; + regs->regs[*regno] = dir; - if (dir == PTRACE_SYSCALL_ENTER) { - if (ptrace_report_syscall_entry(regs)) - forget_syscall(regs); - regs->regs[regno] = saved_reg; - } else if (!test_thread_flag(TIF_SINGLESTEP)) { + return saved_reg; +} + +static void report_syscall_entry(struct pt_regs *regs) +{ + unsigned long saved_reg; + int regno; + + saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_ENTER, ®no); + if (ptrace_report_syscall_entry(regs)) + forget_syscall(regs); + regs->regs[regno] = saved_reg; +} + +static void report_syscall_exit(struct pt_regs *regs) +{ + unsigned long saved_reg; + int regno; + + saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_EXIT, ®no); + if (!test_thread_flag(TIF_SINGLESTEP)) { ptrace_report_syscall_exit(regs, 0); regs->regs[regno] = saved_reg; } else { @@ -2366,7 +2383,7 @@ int syscall_trace_enter(struct pt_regs *regs) unsigned long flags = read_thread_flags(); if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) { - report_syscall(regs, PTRACE_SYSCALL_ENTER); + report_syscall_entry(regs); if (flags & _TIF_SYSCALL_EMU) return NO_SYSCALL; } @@ -2394,7 +2411,7 @@ void syscall_trace_exit(struct pt_regs *regs) trace_sys_exit(regs, syscall_get_return_value(current, regs)); if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)) - report_syscall(regs, PTRACE_SYSCALL_EXIT); + report_syscall_exit(regs); rseq_syscall(regs); } -- 2.34.1