[PATCH] Kprobes causes NX protection fault on i686 SMP

Fix a problem seen on i686 machine with NX support where the instruction
could not be single stepped because of NX bit set on the memory pages
allocated by kprobes module.  This patch provides allocation of instruction
solt so that the processor can execute the instruction from that location
similar to x86_64 architecture.  Thanks to Bibo and Masami for testing this
patch.

Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/include/asm-i386/kprobes.h b/include/asm-i386/kprobes.h
index 27cac050a60e..a0d2d74a7dda 100644
--- a/include/asm-i386/kprobes.h
+++ b/include/asm-i386/kprobes.h
@@ -27,6 +27,9 @@
 #include <linux/types.h>
 #include <linux/ptrace.h>
 
+#define  __ARCH_WANT_KPROBES_INSN_SLOT
+
+struct kprobe;
 struct pt_regs;
 
 typedef u8 kprobe_opcode_t;
@@ -40,14 +43,14 @@ typedef u8 kprobe_opcode_t;
 
 #define JPROBE_ENTRY(pentry)    (kprobe_opcode_t *)pentry
 #define ARCH_SUPPORTS_KRETPROBES
-#define arch_remove_kprobe(p)   do {} while (0)
 
+void arch_remove_kprobe(struct kprobe *p);
 void kretprobe_trampoline(void);
 
 /* Architecture specific copy of original instruction*/
 struct arch_specific_insn {
         /* copy of the original instruction */
-        kprobe_opcode_t insn[MAX_INSN_SIZE];
+        kprobe_opcode_t *insn;
 };
 
 struct prev_kprobe {