[PATCH 3.16 080/114] parisc: fix a bug when syscall number of tracee is __NR_Linux_syscalls

From: Ben Hutchings
Date: Mon Jun 13 2016 - 14:40:36 EST


3.16.36-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: "Dmitry V. Levin" <ldv@xxxxxxxxxxxx>

commit f0b22d1bb2a37a665a969e95785c75a4f49d1499 upstream.

Do not load one entry beyond the end of the syscall table when the
syscall number of a traced process equals to __NR_Linux_syscalls.
Similar bug with regular processes was fixed by commit 3bb457af4fa8
("[PARISC] Fix bug when syscall nr is __NR_Linux_syscalls").

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
Acked-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/parisc/kernel/syscall.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -342,7 +342,7 @@ tracesys_next:
stw %r21, -56(%r30) /* 6th argument */
#endif

- comiclr,>>= __NR_Linux_syscalls, %r20, %r0
+ comiclr,>> __NR_Linux_syscalls, %r20, %r0
b,n .Lsyscall_nosys

LDREGX %r20(%r19), %r19