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>

8 files changed, 16 insertions, 0 deletions

diff --git a/include/asm-avr32/kprobes.h b/include/asm-avr32/kprobes.h
index 0f3e636e6e4d..996cb656474e 100644
--- a/include/asm-avr32/kprobes.h
+++ b/include/asm-avr32/kprobes.h
@@ -17,6 +17,8 @@ typedef u16	kprobe_opcode_t;
 #define BREAKPOINT_INSTRUCTION	0xd673	/* breakpoint */
 #define MAX_INSN_SIZE		2
 
+#define kretprobe_blacklist_size 0
+
 #define arch_remove_kprobe(p)	do { } while (0)
 
 /* Architecture specific copy of original instruction */
diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h
index 6c79edf24d73..a93ce9ef07ff 100644
--- a/include/asm-ia64/kprobes.h
+++ b/include/asm-ia64/kprobes.h
@@ -83,6 +83,7 @@ struct kprobe_ctlblk {
 };
 
 #define ARCH_SUPPORTS_KRETPROBES
+#define kretprobe_blacklist_size 0
 
 #define SLOT0_OPCODE_SHIFT	(37)
 #define SLOT1_p1_OPCODE_SHIFT	(37 - (64-46))
diff --git a/include/asm-powerpc/kprobes.h b/include/asm-powerpc/kprobes.h
index c16973d5de62..afabad230dbb 100644
--- a/include/asm-powerpc/kprobes.h
+++ b/include/asm-powerpc/kprobes.h
@@ -82,6 +82,7 @@ typedef unsigned int kprobe_opcode_t;
 
 #define ARCH_SUPPORTS_KRETPROBES
 #define flush_insn_slot(p)	do { } while (0)
+#define kretprobe_blacklist_size 0
 
 void kretprobe_trampoline(void);
 extern void arch_remove_kprobe(struct kprobe *p);
diff --git a/include/asm-s390/kprobes.h b/include/asm-s390/kprobes.h
index 8bc67cc9ffd2..948db3d0d05c 100644
--- a/include/asm-s390/kprobes.h
+++ b/include/asm-s390/kprobes.h
@@ -47,6 +47,7 @@ typedef u16 kprobe_opcode_t;
 	: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
 
 #define ARCH_SUPPORTS_KRETPROBES
+#define kretprobe_blacklist_size 0
 
 #define KPROBE_SWAP_INST	0x10
 
diff --git a/include/asm-sparc64/kprobes.h b/include/asm-sparc64/kprobes.h
index a04145b77f96..5020eaf67c29 100644
--- a/include/asm-sparc64/kprobes.h
+++ b/include/asm-sparc64/kprobes.h
@@ -10,6 +10,8 @@ typedef u32 kprobe_opcode_t;
 #define BREAKPOINT_INSTRUCTION_2 0x91d02071 /* ta 0x71 */
 #define MAX_INSN_SIZE 2
 
+#define kretprobe_blacklist_size 0
+
 #define arch_remove_kprobe(p)	do {} while (0)
 
 #define flush_insn_slot(p)		\
diff --git a/include/asm-x86/kprobes_32.h b/include/asm-x86/kprobes_32.h
index f2489d07ce88..b772d5b38685 100644
--- a/include/asm-x86/kprobes_32.h
+++ b/include/asm-x86/kprobes_32.h
@@ -45,6 +45,8 @@ typedef u8 kprobe_opcode_t;
 #define ARCH_SUPPORTS_KRETPROBES
 #define flush_insn_slot(p)	do { } while (0)
 
+extern const int kretprobe_blacklist_size;
+
 void arch_remove_kprobe(struct kprobe *p);
 void kretprobe_trampoline(void);
 
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);
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 51464d12a4e5..81891581e89b 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -166,6 +166,12 @@ struct kretprobe_instance {
 	struct task_struct *task;
 };
 
+struct kretprobe_blackpoint {
+	const char *name;
+	void *addr;
+};
+extern struct kretprobe_blackpoint kretprobe_blacklist[];
+
 static inline void kretprobe_assert(struct kretprobe_instance *ri,
 	unsigned long orig_ret_address, unsigned long trampoline_address)
 {