signal: Unify and correct copy_siginfo_from_user32

The function copy_siginfo_from_user32 is used for two things, in ptrace
since the dawn of siginfo for arbirarily modifying a signal that
user space sees, and in sigqueueinfo to send a signal with arbirary
siginfo data.

Create a single copy of copy_siginfo_from_user32 that all architectures
share, and teach it to handle all of the cases in the siginfo union.

In the generic version of copy_siginfo_from_user32 ensure that all
of the fields in siginfo are initialized so that the siginfo structure
can be safely copied to userspace if necessary.

When copying the embedded sigval union copy the si_int member.  That
ensures the 32bit values passes through the kernel unchanged.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 0 insertions, 16 deletions

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index 54a6159b9cd8..8022bb4c65a5 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -123,22 +123,6 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
 	return err;
 }
 
-/* CAUTION: This is just a very minimalist implementation for the
- *          sake of compat_sys_rt_sigqueueinfo()
- */
-int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
-{
-	if (!access_ok(VERIFY_WRITE, from, sizeof(compat_siginfo_t)))
-		return -EFAULT;
-
-	if (copy_from_user(to, from, 3*sizeof(int)) ||
-	    copy_from_user(to->_sifields._pad, from->_sifields._pad,
-			   SI_PAD_SIZE))
-		return -EFAULT;
-
-	return 0;
-}
-
 /* Checks if the fp is valid.  We always build signal frames which are
  * 16-byte aligned, therefore we can always enforce that the restore
  * frame has that property as well.