summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/kprobes/opt.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/kprobes/opt.c')
-rw-r--r--arch/x86/kernel/kprobes/opt.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index e941136e24d8..203d398802a3 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -40,6 +40,7 @@
#include <asm/debugreg.h>
#include <asm/set_memory.h>
#include <asm/sections.h>
+#include <asm/nospec-branch.h>
#include "common.h"
@@ -203,7 +204,7 @@ static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real)
}
/* Check whether insn is indirect jump */
-static int insn_is_indirect_jump(struct insn *insn)
+static int __insn_is_indirect_jump(struct insn *insn)
{
return ((insn->opcode.bytes[0] == 0xff &&
(X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */
@@ -237,6 +238,26 @@ static int insn_jump_into_range(struct insn *insn, unsigned long start, int len)
return (start <= target && target <= start + len);
}
+static int insn_is_indirect_jump(struct insn *insn)
+{
+ int ret = __insn_is_indirect_jump(insn);
+
+#ifdef CONFIG_RETPOLINE
+ /*
+ * Jump to x86_indirect_thunk_* is treated as an indirect jump.
+ * Note that even with CONFIG_RETPOLINE=y, the kernel compiled with
+ * older gcc may use indirect jump. So we add this check instead of
+ * replace indirect-jump check.
+ */
+ if (!ret)
+ ret = insn_jump_into_range(insn,
+ (unsigned long)__indirect_thunk_start,
+ (unsigned long)__indirect_thunk_end -
+ (unsigned long)__indirect_thunk_start);
+#endif
+ return ret;
+}
+
/* Decode whole function to ensure any instructions don't jump into target */
static int can_optimize(unsigned long paddr)
{