Use the mutual exclusion provided by the text edit lock in the kprobes code. It allows coherent manipulation of the kernel code by other subsystems. Signed-off-by: Mathieu Desnoyers Acked-by: Ananth N Mavinakayanahalli CC: prasanna@in.ibm.com CC: ananth@in.ibm.com CC: anil.s.keshavamurthy@intel.com CC: davem@davemloft.net --- kernel/kprobes.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) Index: linux-2.6-lttng/kernel/kprobes.c =================================================================== --- linux-2.6-lttng.orig/kernel/kprobes.c 2007-09-07 10:12:06.000000000 -0400 +++ linux-2.6-lttng/kernel/kprobes.c 2007-09-07 10:13:09.000000000 -0400 @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s goto out; } + kernel_text_lock(); ret = arch_prepare_kprobe(p); if (ret) - goto out; + goto out_unlock_text; INIT_HLIST_NODE(&p->hlist); hlist_add_head_rcu(&p->hlist, @@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s if (kprobe_enabled) arch_arm_kprobe(p); - +out_unlock_text: + kernel_text_unlock(); out: mutex_unlock(&kprobe_mutex); @@ -621,8 +624,11 @@ valid_p: * enabled - otherwise, the breakpoint would already have * been removed. We save on flushing icache. */ - if (kprobe_enabled) + if (kprobe_enabled) { + kernel_text_lock(); arch_disarm_kprobe(p); + kernel_text_unlock(); + } hlist_del_rcu(&old_p->hlist); cleanup_p = 1; } else { @@ -644,9 +650,7 @@ valid_p: list_del_rcu(&p->list); kfree(old_p); } - mutex_lock(&kprobe_mutex); arch_remove_kprobe(p); - mutex_unlock(&kprobe_mutex); } else { mutex_lock(&kprobe_mutex); if (p->break_handler) @@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro ri->rp = rp; ri->task = current; arch_prepare_kretprobe(ri, regs); - /* XXX(hch): why is there no hlist_move_head? */ hlist_del(&ri->uflist); hlist_add_head(&ri->uflist, &ri->rp->used_instances); @@ -940,8 +943,10 @@ static void __kprobes enable_all_kprobes for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; + kernel_text_lock(); hlist_for_each_entry_rcu(p, node, head, hlist) arch_arm_kprobe(p); + kernel_text_unlock(); } kprobe_enabled = true; @@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe printk(KERN_INFO "Kprobes globally disabled\n"); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; + kernel_text_lock(); hlist_for_each_entry_rcu(p, node, head, hlist) { if (!arch_trampoline_kprobe(p)) arch_disarm_kprobe(p); } + kernel_text_unlock(); } mutex_unlock(&kprobe_mutex); -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/