[patch 8/9] Text Edit Lock - kprobes i386

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

[-- Attachment #1: text-edit-lock-kprobes-i386.patch --]
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Kprobes can use the text edit lock to insure mutual exclusion when editing the
code.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andi Kleen <andi@firstfloor.org>
CC: prasanna@in.ibm.com
CC: ananth@in.ibm.com
CC: anil.s.keshavamurthy@intel.com
CC: davem@davemloft.net
---
 arch/i386/kernel/kprobes.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: linux-2.6-lttng/arch/i386/kernel/kprobes.c
===================================================================
--- linux-2.6-lttng.orig/arch/i386/kernel/kprobes.c	2007-08-10 13:47:25.000000000 -0400
+++ linux-2.6-lttng/arch/i386/kernel/kprobes.c	2007-08-10 13:49:21.000000000 -0400
@@ -170,12 +170,16 @@ int __kprobes arch_prepare_kprobe(struct
 
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
-	text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
+	kernel_text_mark_rw((unsigned long) p->addr, sizeof(kprobe_opcode_t));
+	*p->addr = BREAKPOINT_INSTRUCTION;
+	kernel_text_unmark((unsigned long) p->addr, sizeof(kprobe_opcode_t));
 }
 
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
 {
-	text_poke(p->addr, &p->opcode, 1);
+	kernel_text_mark_rw((unsigned long) p->addr, sizeof(kprobe_opcode_t));
+	*p->addr = p->opcode;
+	kernel_text_unmark((unsigned long) p->addr, sizeof(kprobe_opcode_t));
 }
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68