[PATCH] x86_64: Don't allow kprobes on __switch_to
kprobes cannot deal with the funny calling conventions when it
runs on a different stack when it returns. If someone wants
to instrument context switch they can add a probe to schedule()
instead.
Cc: jkenisto@us.ibm.com, prasanna@in.ibm.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 8ded407..22a05de 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -516,8 +516,10 @@
* This could still be optimized:
* - fold all the options into a flag word and test it with a single test.
* - could test fs/gs bitsliced
+ *
+ * Kprobes not supported here. Set the probe on schedule instead.
*/
-struct task_struct *
+__kprobes struct task_struct *
__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *prev = &prev_p->thread,
