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

[Kamal Mostafa]

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-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.17.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 891a930637c2039d9d48708c7a769dd4b2ad3bf9 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: Kamal Mostafa <kamal 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 6ed91d9..1d7fdbe 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1113,7 +1113,7 @@ 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
@@ -1171,7 +1171,7 @@ 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 cb3c591..310b270 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