[PATCH 3.12 030/100] s390/seccomp: fix error return for filtered system calls

[Jiri Slaby]

From: Jan Willeke <willeke@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit dc295880c6752076f8b94ba3885d0bfff09e3e82 upstream.

The syscall_set_return_value function of s390 negates the error argument
before storing the value to the return register gpr2. This is incorrect,
the seccomp code already passes the negative error value.
Store the unmodified error value to gpr2.

Signed-off-by: Jan Willeke <willeke@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 arch/s390/include/asm/syscall.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index cd29d2f4e4f3..749313b452ae 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -54,7 +54,7 @@ static inline void syscall_set_return_value(struct task_struct *task,
 					    struct pt_regs *regs,
 					    int error, long val)
 {
-	regs->gprs[2] = error ? -error : val;
+	regs->gprs[2] = error ? error : val;
 }
 
 static inline void syscall_get_arguments(struct task_struct *task,
-- 
2.9.3