Re: [PATCH v6 5/6] arm64: add SIGSYS siginfo for compat task

On 08/27/2014 02:55 AM, Will Deacon wrote:

On Thu, Aug 21, 2014 at 09:56:44AM +0100, AKASHI Takahiro wrote:

...

SIGSYS is primarily used in secure computing to notify tracer. This patch allows signal handler on compat task to get correct information with SA_SYSINFO specified when this signal is delivered.

Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org

arch/arm64/include/asm/compat.h | 7 +++++++ arch/arm64/kernel/signal32.c | 8 ++++++++ 2 files changed, 15 insertions(+)

diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h index 253e33b..c877915 100644 --- a/arch/arm64/include/asm/compat.h +++ b/arch/arm64/include/asm/compat.h @@ -205,6 +205,13 @@ typedef struct compat_siginfo { compat_long_t _band; /* POLL_IN, POLL_OUT, POLL_MSG */ int _fd; } _sigpoll;h

• /* SIGSYS */
  

• struct {
  

• 	compat_uptr_t _call_addr; /* calling user insn */
  

• 	int _syscall;	/* triggering system call number */
  

• 	unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
  

• } _sigsys;
  

  } _sifields; } compat_siginfo_t;

diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index 1b9ad02..aa550d6 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -186,6 +186,14 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) err |= __put_user(from->si_uid, &to->si_uid); err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr); break; +#ifdef __ARCH_SIGSYS

• case __SI_SYS:

• err |= __put_user((compat_uptr_t)(unsigned long)
  

• 		from->si_call_addr, &to->si_call_addr);
  

• err |= __put_user(from->si_syscall, &to->si_syscall);
  

• err |= __put_user(from->si_arch, &to->si_arch);
  

• break;
  

+#endif

I think you should drop this #ifdef. We care about whether arch/arm/ defines __ARCH_SIGSYS, not whether arm64 defines it (they both happen to define it anyway).

Thanks. Done

-Takahiro AKASHI

Will