On 04/12/25 1:51 PM, Jinjie Ruan wrote:
The generic entry abort the syscall_trace_enter() sequence if ptrace_report_syscall_entry() errors out, but arm64 not.
As the ptrace_report_syscall_entry() comment said, the calling arch code should abort the system call and must prevent normal entry so no system call is made if ptrace_report_syscall_entry() return nonzero.
In preparation for moving arm64 over to the generic entry code, return early if ptrace_report_syscall_entry() encounters an error.
Signed-off-by: Jinjie Ruan ruanjinjie@huawei.com
arch/arm64/kernel/ptrace.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 4532e9831856..3926ce6aa268 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2346,15 +2346,18 @@ static __always_inline unsigned long ptrace_save_reg(struct pt_regs *regs, return saved_reg; } -static void report_syscall_entry(struct pt_regs *regs) +static int report_syscall_entry(struct pt_regs *regs) { unsigned long saved_reg;
- int regno;
- int regno, ret;
saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_ENTER, ®no);
- if (ptrace_report_syscall_entry(regs))
- ret = ptrace_report_syscall_entry(regs);
- if (ret) forget_syscall(regs); regs->regs[regno] = saved_reg;
- return ret;
} static void report_syscall_exit(struct pt_regs *regs) @@ -2381,10 +2384,11 @@ static void report_syscall_exit(struct pt_regs *regs) int syscall_trace_enter(struct pt_regs *regs) { unsigned long flags = read_thread_flags();
- int ret;
if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
report_syscall_entry(regs);if (flags & _TIF_SYSCALL_EMU)
ret = report_syscall_entry(regs);if (ret || (flags & _TIF_SYSCALL_EMU))
A small nit.
Could report_syscall_entry(regs) be checked directly in the 'if' conditional code block thus dropping new 'ret' altogether ?
return NO_SYSCALL;}