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Subject[PATCH 04/11] x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
Date
From: Andi Kleen <ak@linux.intel.com>

Convert all indirect jumps in ftrace assembler code to use
non speculative sequences.

Based on code from David Woodhouse and Tim Chen

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/ftrace_32.S | 3 ++-
arch/x86/kernel/ftrace_64.S | 6 +++---
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index b6c6468e10bc..c0c10ba53375 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -8,6 +8,7 @@
#include <asm/segment.h>
#include <asm/export.h>
#include <asm/ftrace.h>
+#include <asm/jump-asm.h>

#ifdef CC_USING_FENTRY
# define function_hook __fentry__
@@ -241,5 +242,5 @@ return_to_handler:
movl %eax, %ecx
popl %edx
popl %eax
- jmp *%ecx
+ NOSPEC_JMP %ecx
#endif
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index c832291d948a..4814c4b30b8d 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -7,7 +7,7 @@
#include <asm/ptrace.h>
#include <asm/ftrace.h>
#include <asm/export.h>
-
+#include <asm/jump-asm.h>

.code64
.section .entry.text, "ax"
@@ -286,7 +286,7 @@ trace:
* ip and parent ip are used and the list function is called when
* function tracing is enabled.
*/
- call *ftrace_trace_function
+ NOSPEC_CALL ftrace_trace_function

restore_mcount_regs

@@ -329,5 +329,5 @@ GLOBAL(return_to_handler)
movq 8(%rsp), %rdx
movq (%rsp), %rax
addq $24, %rsp
- jmp *%rdi
+ NOSPEC_JMP %rdi
#endif
--
2.14.3
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