On Wed, Jun 08, 2022 at 05:24:46PM +0100, Francis Laniel wrote:
> This patch enables exeve*() to be traced with syscalls:sys_exit_execve
> tracepoint.
> Previous to it, by calling forget_syscall(), this tracepoint would not
> print its information as syscall is -1.
> So, this patch removes call to forget_syscall() and set regs->syscallno
> to its previous value.
>
> Signed-off-by: Francis Laniel <flaniel@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/arm64/include/asm/processor.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
> index 9e58749db21d..86eb0bfe3b38 100644
> --- a/arch/arm64/include/asm/processor.h
> +++ b/arch/arm64/include/asm/processor.h
> @@ -272,8 +272,9 @@ void tls_preserve_current_state(void);
>
> static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
> {
> + s32 previous_syscall = regs->syscallno;
> memset(regs, 0, sizeof(*regs));
> - forget_syscall(regs);
> + regs->syscallno = previous_syscall;
I'm still unsure about this. Even if we preserve the syscall number here,
won't all the arguments be reported as 0?
I also looked quickly at the 32-bit arch/arm/ code and it looks like the
same behaviour exists there (module CONFIG_BINFMT_ELF_FDPIC).
Will
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