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>

2 files changed, 0 insertions, 45 deletions

diff --git a/arch/parisc/kernel/signal32.c b/arch/parisc/kernel/signal32.c
index 41afa9cd1f55..558e32475c35 100644
--- a/arch/parisc/kernel/signal32.c
+++ b/arch/parisc/kernel/signal32.c
@@ -262,50 +262,6 @@ setup_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __
 }
 
 int
-copy_siginfo_from_user32 (siginfo_t *to, compat_siginfo_t __user *from)
-{
-	compat_uptr_t addr;
-	int err;
-
-	if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
-		return -EFAULT;
-
-	err = __get_user(to->si_signo, &from->si_signo);
-	err |= __get_user(to->si_errno, &from->si_errno);
-	err |= __get_user(to->si_code, &from->si_code);
-
-	if (to->si_code < 0)
-		err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
-	else {
-		switch (siginfo_layout(to->si_signo, to->si_code)) {
-		      case SIL_CHLD:
-			err |= __get_user(to->si_utime, &from->si_utime);
-			err |= __get_user(to->si_stime, &from->si_stime);
-			err |= __get_user(to->si_status, &from->si_status);
-		      default:
-		      case SIL_KILL:
-			err |= __get_user(to->si_pid, &from->si_pid);
-			err |= __get_user(to->si_uid, &from->si_uid);
-			break;
-		      case SIL_FAULT:
-			err |= __get_user(addr, &from->si_addr);
-			to->si_addr = compat_ptr(addr);
-			break;
-		      case SIL_POLL:
-			err |= __get_user(to->si_band, &from->si_band);
-			err |= __get_user(to->si_fd, &from->si_fd);
-			break;
-		      case SIL_RT:
-			err |= __get_user(to->si_pid, &from->si_pid);
-			err |= __get_user(to->si_uid, &from->si_uid);
-			err |= __get_user(to->si_int, &from->si_int);
-			break;
-		}
-	}
-	return err;
-}
-
-int
 copy_siginfo_to_user32 (compat_siginfo_t __user *to, const siginfo_t *from)
 {
 	compat_uptr_t addr;
diff --git a/arch/parisc/kernel/signal32.h b/arch/parisc/kernel/signal32.h
index 719e7417732c..d25858e4db63 100644
--- a/arch/parisc/kernel/signal32.h
+++ b/arch/parisc/kernel/signal32.h
@@ -35,7 +35,6 @@ struct compat_ucontext {
 /* ELF32 signal handling */
 
 int copy_siginfo_to_user32 (compat_siginfo_t __user *to, const siginfo_t *from);
-int copy_siginfo_from_user32 (siginfo_t *to, compat_siginfo_t __user *from);
 
 /* In a deft move of uber-hackery, we decide to carry the top half of all
  * 64-bit registers in a non-portable, non-ABI, hidden structure.