[PATCH 3.12 36/72] MIPS: ptrace: Fix regs_return_value for kernel context

From	Jiri Slaby <jslaby@suse.cz>
Newsgroups	linux.kernel
Subject	[PATCH 3.12 36/72] MIPS: ptrace: Fix regs_return_value for kernel context
Date	2016-11-07 14:20 +0100
Message-ID	<sAS0a-3Aq-9@gated-at.bofh.it> (permalink)
References	<sARQt-3wK-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>

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

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

commit 74f1077b5b783e7bf4fa3007cefdc8dbd6c07518 upstream.

Currently regs_return_value always negates reg[2] if it determines
the syscall has failed, but when called in kernel context this check is
invalid and may result in returning a wrong value.

This fixes errors reported by CONFIG_KPROBES_SANITY_TEST

Fixes: d7e7528bcd45 ("Audit: push audit success and retcode into arch ptrace.h")
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14381/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/mips/include/asm/ptrace.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
index 5e6cd0947393..a288de2199d8 100644
--- a/arch/mips/include/asm/ptrace.h
+++ b/arch/mips/include/asm/ptrace.h
@@ -73,7 +73,7 @@ static inline int is_syscall_success(struct pt_regs *regs)
 
 static inline long regs_return_value(struct pt_regs *regs)
 {
-	if (is_syscall_success(regs))
+	if (is_syscall_success(regs) || !user_mode(regs))
 		return regs->regs[2];
 	else
 		return -regs->regs[2];
-- 
2.10.2

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH 3.12 36/72] MIPS: ptrace: Fix regs_return_value for kernel context Jiri Slaby <jslaby@suse.cz> - 2016-11-07 14:20 +0100

csiph-web