Commit 964f7b6b authored Jun 03, 2014 by Petr Mladek Committed by Steven Rostedt Jun 03, 2014

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 87fbb2ac (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>

parent e3172181

arch/x86/kernel/ftrace.c

+1 −10

Original line number	Diff line number	Diff line
		@@ -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;

Admin message