arm64: add SIGSYS siginfo for compat task

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

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index 56de5aadede241e0464c42ebcc00284e616d82ac..3fb053fa6e981b40accf4180187dd0789edeb1f0 100644 (file)
--- 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 */
+                       compat_uint_t _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 1b9ad02837cfcafd4ecbc87f3e10aafe504ac0de..5a1ba6e80d4e20b6d95b0152d99e2ebca53e7424 100644 (file)
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -186,6 +186,12 @@ 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;
+       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;
        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);