[lkml]   [2014]   [Jun]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 3.12 010/181] ftrace/x86: Call text_ip_addr() instead of the duplicated code
From: Petr Mladek <>

3.12-stable review patch. If anyone has any objections, please let me know.


commit 964f7b6b785651a75ef1cbad43a393ca52d4b4f7 upstream.

I just went over this when looking at some Xen-related ftrace initialization
problems. They were related to Xen code that is not upstream but this clean up
would make sense here.

I think that this was already the intention when text_ip_addr() was introduced
in the commit 87fbb2ac6073a703930 (ftrace/x86: Use breakpoints for converting
function graph caller). Anyway, better do it now before it shots people into
their leg ;-)


Signed-off-by: Petr Mladek <>
Signed-off-by: Steven Rostedt <>
Signed-off-by: Jiri Slaby <>
arch/x86/kernel/ftrace.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 1ffc32dbe450..f8ab203fb676 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -297,16 +297,7 @@ int ftrace_int3_handler(struct pt_regs *regs)

static int ftrace_write(unsigned long ip, const char *val, int size)
- /*
- * On x86_64, kernel text mappings are mapped read-only with
- * CONFIG_DEBUG_RODATA. So we use the kernel identity mapping instead
- * of the kernel text mapping to modify the kernel text.
- *
- * For 32bit kernels, these mappings are same and we can use
- * kernel identity mapping to modify code.
- */
- if (within(ip, (unsigned long)_text, (unsigned long)_etext))
- ip = (unsigned long)__va(__pa_symbol(ip));
+ ip = text_ip_addr(ip);

return probe_kernel_write((void *)ip, val, size);

 \ /
  Last update: 2014-06-30 15:21    [W:0.672 / U:7.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site