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

[AKASHI Takahiro]

On 08/22/2014 02:54 AM, Kees Cook wrote:
> On Thu, Aug 21, 2014 at 3:56 AM, AKASHI Takahiro
> <takahiro.akashi@xxxxxxxxxx> 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.

typo: SA_SIGINFO

> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
>
> I'm unable to test this myself, but if you've got the test suite
> passing in compat mode, then this patch must be correct. :)

Thanks.
Actually I found this bug when I ran your test programs, TRAP.handler, on 32bit userland.

-Takahiro AKASHI


> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> -Kees
>
> > ---
> >   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;
> > +
> > +               /* 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
> >          default: /* this is just in case for now ... */
> >                  err |= __put_user(from->si_pid, &to->si_pid);
> >                  err |= __put_user(from->si_uid, &to->si_uid);
> > --
> > 1.7.9.5
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