ftrace/x86: Call text_ip_addr() instead of the duplicated code

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 ;-)

Link: http://lkml.kernel.org/p/1401812601-2359-1-git-send-email-pmladek@suse.cz
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 89de3eaf8772fcd1f80161eddc730f4c44aad4e0..cbc4a91b131e6c0cac7feec577f8fc117f56c94f 100644 (file)
--- 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);
 
        if (probe_kernel_write((void *)ip, val, size))
                return -EPERM;