Kprobes: indicate kretprobe support in Kconfig

Add CONFIG_HAVE_KRETPROBES to the arch/<arch>/Kconfig file for relevant
architectures with kprobes support.  This facilitates easy handling of
in-kernel modules (like samples/kprobes/kretprobe_example.c) that depend on
kretprobes being present in the kernel.

Thanks to Sam Ravnborg for helping make the patch more lean.

Per Mathieu's suggestion, added CONFIG_KRETPROBES and fixed up dependencies.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 3 insertions, 10 deletions

diff --git a/include/asm-arm/kprobes.h b/include/asm-arm/kprobes.h
index 4e7bd32..c042194 100644
--- a/include/asm-arm/kprobes.h
+++ b/include/asm-arm/kprobes.h
@@ -20,7 +20,6 @@
 #include <linux/ptrace.h>
 #include <linux/percpu.h>
 
-#define ARCH_SUPPORTS_KRETPROBES
 #define __ARCH_WANT_KPROBES_INSN_SLOT
 #define MAX_INSN_SIZE			2
 #define MAX_STACK_SIZE			64	/* 32 would probably be OK */
diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h
index a93ce9e..adbaba1 100644
--- a/include/asm-ia64/kprobes.h
+++ b/include/asm-ia64/kprobes.h
@@ -82,7 +82,6 @@ struct kprobe_ctlblk {
 	struct prev_kprobe prev_kprobe[ARCH_PREV_KPROBE_SZ];
 };
 
-#define ARCH_SUPPORTS_KRETPROBES
 #define kretprobe_blacklist_size 0
 
 #define SLOT0_OPCODE_SHIFT	(37)
diff --git a/include/asm-powerpc/kprobes.h b/include/asm-powerpc/kprobes.h
index afabad2..d0e7701 100644
--- a/include/asm-powerpc/kprobes.h
+++ b/include/asm-powerpc/kprobes.h
@@ -80,7 +80,6 @@ typedef unsigned int kprobe_opcode_t;
 #define is_trap(instr)	(IS_TW(instr) || IS_TWI(instr))
 #endif
 
-#define ARCH_SUPPORTS_KRETPROBES
 #define flush_insn_slot(p)	do { } while (0)
 #define kretprobe_blacklist_size 0
 
diff --git a/include/asm-s390/kprobes.h b/include/asm-s390/kprobes.h
index 948db3d..330f68c 100644
--- a/include/asm-s390/kprobes.h
+++ b/include/asm-s390/kprobes.h
@@ -46,7 +46,6 @@ typedef u16 kprobe_opcode_t;
 	? (MAX_STACK_SIZE) \
 	: (((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 7237dd8..5879d71 100644
--- a/include/asm-sparc64/kprobes.h
+++ b/include/asm-sparc64/kprobes.h
@@ -14,8 +14,6 @@ typedef u32 kprobe_opcode_t;
 
 #define arch_remove_kprobe(p)	do {} while (0)
 
-#define ARCH_SUPPORTS_KRETPROBES
-
 #define flush_insn_slot(p)		\
 do { 	flushi(&(p)->ainsn.insn[0]);	\
 	flushi(&(p)->ainsn.insn[1]);	\
diff --git a/include/asm-x86/kprobes.h b/include/asm-x86/kprobes.h
index 143476a..61ad7b5 100644
--- a/include/asm-x86/kprobes.h
+++ b/include/asm-x86/kprobes.h
@@ -42,7 +42,6 @@ typedef u8 kprobe_opcode_t;
 	: (((unsigned long)current_thread_info()) + THREAD_SIZE \
 	   - (unsigned long)(ADDR)))
 
-#define ARCH_SUPPORTS_KRETPROBES
 #define flush_insn_slot(p)	do { } while (0)
 
 extern const int kretprobe_blacklist_size;
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 4a6ce82..0f28486 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -125,11 +125,11 @@ struct jprobe {
 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
-#ifdef ARCH_SUPPORTS_KRETPROBES
+#ifdef CONFIG_KRETPROBES
 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
 				   struct pt_regs *regs);
 extern int arch_trampoline_kprobe(struct kprobe *p);
-#else /* ARCH_SUPPORTS_KRETPROBES */
+#else /* CONFIG_KRETPROBES */
 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
 					struct pt_regs *regs)
 {
@@ -138,7 +138,7 @@ static inline int arch_trampoline_kprobe(struct kprobe *p)
 {
 	return 0;
 }
-#endif /* ARCH_SUPPORTS_KRETPROBES */
+#endif /* CONFIG_KRETPROBES */
 /*
  * Function-return probe -
  * Note: