lkml.org 
[lkml]   [2019]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 037/107] powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

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

From: Diana Craciun <diana.craciun@nxp.com>

commit c28218d4abbf4f2035495334d8bfcba64bda4787 upstream.

Used barrier_nospec to sanitize the syscall table.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/entry_32.S | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -33,6 +33,7 @@
#include <asm/unistd.h>
#include <asm/ptrace.h>
#include <asm/export.h>
+#include <asm/barrier.h>

/*
* MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE.
@@ -358,6 +359,15 @@ syscall_dotrace_cont:
ori r10,r10,sys_call_table@l
slwi r0,r0,2
bge- 66f
+
+ barrier_nospec_asm
+ /*
+ * Prevent the load of the handler below (based on the user-passed
+ * system call number) being speculatively executed until the test
+ * against NR_syscalls and branch to .66f above has
+ * committed.
+ */
+
lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
mtlr r10
addi r9,r1,STACK_FRAME_OVERHEAD

\
 
 \ /
  Last update: 2019-04-01 19:57    [W:0.339 / U:54.664 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site