summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/entry_32.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
-rw-r--r--arch/powerpc/kernel/entry_32.S10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 370645687cc7..bdd88f9d7926 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -34,6 +34,7 @@
#include <asm/ftrace.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.
@@ -347,6 +348,15 @@ 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