kprobes: support kretprobe blacklist

Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.

This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-x86/kprobes_64.h b/include/asm-x86/kprobes_64.h
index 3f495e5308b1..53f4d8507354 100644
--- a/include/asm-x86/kprobes_64.h
+++ b/include/asm-x86/kprobes_64.h
@@ -42,6 +42,7 @@ typedef u8 kprobe_opcode_t;
         : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
 
 #define ARCH_SUPPORTS_KRETPROBES
+extern const int kretprobe_blacklist_size;
 
 void kretprobe_trampoline(void);
 extern void arch_remove_kprobe(struct kprobe *p);