[3.11.y.z extended stable] Patch "ftrace/x86: Load ftrace_ops in parameter not the variable holding it" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ftrace/x86: Load ftrace_ops in parameter not the variable holding it

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 8790ff3f45811bc37aab3bb36cf1ec4449504e81 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt at goodmis.org>
Date: Wed, 13 Nov 2013 15:20:04 -0500
Subject: ftrace/x86: Load ftrace_ops in parameter not the variable holding it

commit 1739f09e33d8f66bf48ddbc3eca615574da6c4f6 upstream.

Function tracing callbacks expect to have the ftrace_ops that registered it
passed to them, not the address of the variable that holds the ftrace_ops
that registered it.

Use a mov instead of a lea to store the ftrace_ops into the parameter
of the function tracing callback.

Signed-off-by: Steven Rostedt <rostedt at goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt at hitachi.com>
Link: http://lkml.kernel.org/r/20131113152004.459787f9@gandalf.local.home
Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/kernel/entry_32.S | 4 ++--
 arch/x86/kernel/entry_64.S | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 2cfbc3a..bbc89cf 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1085,7 +1085,7 @@ ENTRY(ftrace_caller)
 	pushl $0	/* Pass NULL as regs pointer */
 	movl 4*4(%esp), %eax
 	movl 0x4(%ebp), %edx
-	leal function_trace_op, %ecx
+	movl function_trace_op, %ecx
 	subl $MCOUNT_INSN_SIZE, %eax

 .globl ftrace_call
@@ -1143,7 +1143,7 @@ ENTRY(ftrace_regs_caller)
 	movl 12*4(%esp), %eax	/* Load ip (1st parameter) */
 	subl $MCOUNT_INSN_SIZE, %eax	/* Adjust ip */
 	movl 0x4(%ebp), %edx	/* Load parent ip (2nd parameter) */
-	leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
+	movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
 	pushl %esp		/* Save pt_regs as 4th parameter */

 GLOBAL(ftrace_regs_call)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 1b69951..bcdb3ca 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -88,7 +88,7 @@ END(function_hook)
 	MCOUNT_SAVE_FRAME \skip

 	/* Load the ftrace_ops into the 3rd parameter */
-	leaq function_trace_op, %rdx
+	movq function_trace_op(%rip), %rdx

 	/* Load ip into the first parameter */
 	movq RIP(%rsp), %rdi
--
1.8.3.2