Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 010/181] ftrace/x86: Call text_ip_addr() instead of the duplicated code | Date | Mon, 30 Jun 2014 13:50:31 +0200 |
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From: Petr Mladek <pmladek@suse.cz>
3.12-stable review patch. If anyone has any objections, please let me know.
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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 ;-)
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> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- 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); } -- 2.0.0
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