[PATCH] IA64: kprobe invalidate icache of jump buffer

Kprobe inserts breakpoint instruction in probepoint and then jumps to
instruction slot when breakpoint is hit, the instruction slot icache must
be consistent with dcache.  Here is the patch which invalidates instruction
slot icache area.

Without this patch, in some machines there will be fault when executing
instruction slot where icache content is inconsistent with dcache.

Signed-off-by: bibo,mao <bibo.mao@intel.com>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/kernel/kprobes.c

@@ -448,11 +448,20 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	return 0;
 }
 
+void __kprobes flush_insn_slot(struct kprobe *p)
+{
+	unsigned long arm_addr;
+
+	arm_addr = ((unsigned long)&p->opcode.bundle) & ~0xFULL;
+	flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+}
+
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
 	unsigned long addr = (unsigned long)p->addr;
 	unsigned long arm_addr = addr & ~0xFULL;
 
+	flush_insn_slot(p);
 	memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t));
 	flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
 }

include/asm-i386/kprobes.h

@@ -45,6 +45,7 @@ typedef u8 kprobe_opcode_t;
 #define JPROBE_ENTRY(pentry)	(kprobe_opcode_t *)pentry
 #define ARCH_SUPPORTS_KRETPROBES
 #define  ARCH_INACTIVE_KPROBE_COUNT 0
+#define flush_insn_slot(p)	do { } while (0)
 
 void arch_remove_kprobe(struct kprobe *p);
 void kretprobe_trampoline(void);

include/asm-ia64/kprobes.h

@@ -125,5 +125,6 @@ static inline void jprobe_return(void)
 }
 extern void invalidate_stacked_regs(void);
 extern void flush_register_stack(void);
+extern void flush_insn_slot(struct kprobe *p);
 
 #endif				/* _ASM_KPROBES_H */

include/asm-powerpc/kprobes.h

@@ -51,6 +51,7 @@ typedef unsigned int kprobe_opcode_t;
 
 #define ARCH_SUPPORTS_KRETPROBES
 #define  ARCH_INACTIVE_KPROBE_COUNT 1
+#define flush_insn_slot(p)	do { } while (0)
 
 void kretprobe_trampoline(void);
 extern void arch_remove_kprobe(struct kprobe *p);

include/asm-sparc64/kprobes.h

@@ -13,6 +13,7 @@ typedef u32 kprobe_opcode_t;
 #define JPROBE_ENTRY(pentry)	(kprobe_opcode_t *)pentry
 #define arch_remove_kprobe(p)	do {} while (0)
 #define  ARCH_INACTIVE_KPROBE_COUNT 0
+#define flush_insn_slot(p)	do { } while (0)
 
 /* Architecture specific copy of original instruction*/
 struct arch_specific_insn {

include/asm-x86_64/kprobes.h

@@ -47,6 +47,7 @@ typedef u8 kprobe_opcode_t;
 
 void kretprobe_trampoline(void);
 extern void arch_remove_kprobe(struct kprobe *p);
+#define flush_insn_slot(p)	do { } while (0)
 
 /* Architecture specific copy of original instruction*/
 struct arch_specific_insn {

kernel/kprobes.c

@@ -393,6 +393,7 @@ static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p)
 static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
 {
 	copy_kprobe(p, ap);
+	flush_insn_slot(ap);
 	ap->addr = p->addr;
 	ap->pre_handler = aggr_pre_handler;
 	ap->fault_handler = aggr_fault_handler;