[PATCH] kprobes: fix bug when probed on task and isr functions

This patch fixes a race condition where in system used to hang or sometime
crash within minutes when kprobes are inserted on ISR routine and a task
routine.

The fix has been stress tested on i386, ia64, pp64 and on x86_64.  To
reproduce the problem insert kprobes on schedule() and do_IRQ() functions
and you should see hang or system crash.

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

2 files changed, 4 insertions, 0 deletions

diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h
index bf36a32e37e4..573a3574a24f 100644
--- a/include/asm-ia64/kprobes.h
+++ b/include/asm-ia64/kprobes.h
@@ -92,6 +92,7 @@ struct arch_specific_insn {
         kprobe_opcode_t insn;
  #define INST_FLAG_FIX_RELATIVE_IP_ADDR         1
  #define INST_FLAG_FIX_BRANCH_REG               2
+ #define INST_FLAG_BREAK_INST                   4
         unsigned long inst_flag;
         unsigned short target_br_reg;
 };
diff --git a/include/asm-ppc64/kprobes.h b/include/asm-ppc64/kprobes.h
index 0802919c3235..d9129d2b038e 100644
--- a/include/asm-ppc64/kprobes.h
+++ b/include/asm-ppc64/kprobes.h
@@ -42,6 +42,9 @@ typedef unsigned int kprobe_opcode_t;
 
 #define JPROBE_ENTRY(pentry)    (kprobe_opcode_t *)((func_descr_t *)pentry)
 
+#define is_trap(instr)  (IS_TW(instr) || IS_TD(instr) || \
+                        IS_TWI(instr) || IS_TDI(instr))
+
 #define ARCH_SUPPORTS_KRETPROBES
 void kretprobe_trampoline(void);