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authorIngo Molnar <mingo@elte.hu>2009-02-22 18:12:01 +0100
committerIngo Molnar <mingo@elte.hu>2009-02-22 18:12:01 +0100
commitc478f8786973d6d7552c652ddad3f6fd86b5af28 (patch)
tree39967f4bb9a35d626584bd46f1acd916c6b5278d /arch/x86/kernel/ftrace.c
parent843adf2379c18ed9a1b7493ee208bfd5512732e0 (diff)
parent4377245aa93b65b6597e4b7bb460fb9abc48b56b (diff)
Merge branch 'tip/x86/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
Conflicts: include/linux/ftrace.h kernel/trace/ftrace.c
Diffstat (limited to 'arch/x86/kernel/ftrace.c')
-rw-r--r--arch/x86/kernel/ftrace.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index c2e057d9f88..3925ec0184b 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/list.h>
+#include <asm/cacheflush.h>
#include <asm/ftrace.h>
#include <linux/ftrace.h>
#include <asm/nops.h>
@@ -26,6 +27,18 @@
#ifdef CONFIG_DYNAMIC_FTRACE
+int ftrace_arch_code_modify_prepare(void)
+{
+ set_kernel_text_rw();
+ return 0;
+}
+
+int ftrace_arch_code_modify_post_process(void)
+{
+ set_kernel_text_ro();
+ return 0;
+}
+
union ftrace_code_union {
char code[MCOUNT_INSN_SIZE];
struct {
@@ -111,6 +124,10 @@ static void ftrace_mod_code(void)
*/
mod_code_status = probe_kernel_write(mod_code_ip, mod_code_newcode,
MCOUNT_INSN_SIZE);
+
+ /* if we fail, then kill any new writers */
+ if (mod_code_status)
+ mod_code_write = 0;
}
void ftrace_nmi_enter(void)