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authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2009-03-06 10:36:38 -0500
committerIngo Molnar <mingo@elte.hu>2009-03-06 16:49:00 +0100
commit4460fdad85becd569f11501ad5b91814814335ff (patch)
tree7c781d0131f6130498ee2a346c7e95eb9b9b869f /kernel/kprobes.c
parent0e39ac444636ff5be39b26f1cb56d79594654dda (diff)
downloadlinux-2.6.34-ux500-4460fdad85becd569f11501ad5b91814814335ff.tar.gz
tracing, Text Edit Lock - kprobes architecture independent support
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. Changelog: Move the kernel_text_lock/unlock out of the for loops. Use text_mutex directly instead of a function. Remove whitespace modifications. (note : kprobes_mutex is always taken outside of text_mutex) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> LKML-Reference: <49B14306.2080202@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 7ba8cd9845c..479d4d5672f 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -43,6 +43,7 @@
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/kdebug.h>
+#include <linux/memory.h>
#include <asm-generic/sections.h>
#include <asm/cacheflush.h>
@@ -699,9 +700,10 @@ int __kprobes register_kprobe(struct kprobe *p)
goto out;
}
+ mutex_lock(&text_mutex);
ret = arch_prepare_kprobe(p);
if (ret)
- goto out;
+ goto out_unlock_text;
INIT_HLIST_NODE(&p->hlist);
hlist_add_head_rcu(&p->hlist,
@@ -710,6 +712,8 @@ int __kprobes register_kprobe(struct kprobe *p)
if (kprobe_enabled)
arch_arm_kprobe(p);
+out_unlock_text:
+ mutex_unlock(&text_mutex);
out:
mutex_unlock(&kprobe_mutex);
@@ -746,8 +750,11 @@ valid_p:
* enabled and not gone - otherwise, the breakpoint would
* already have been removed. We save on flushing icache.
*/
- if (kprobe_enabled && !kprobe_gone(old_p))
+ if (kprobe_enabled && !kprobe_gone(old_p)) {
+ mutex_lock(&text_mutex);
arch_disarm_kprobe(p);
+ mutex_unlock(&text_mutex);
+ }
hlist_del_rcu(&old_p->hlist);
} else {
if (p->break_handler && !kprobe_gone(p))
@@ -1280,12 +1287,14 @@ static void __kprobes enable_all_kprobes(void)
if (kprobe_enabled)
goto already_enabled;
+ mutex_lock(&text_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
if (!kprobe_gone(p))
arch_arm_kprobe(p);
}
+ mutex_unlock(&text_mutex);
kprobe_enabled = true;
printk(KERN_INFO "Kprobes globally enabled\n");
@@ -1310,6 +1319,7 @@ static void __kprobes disable_all_kprobes(void)
kprobe_enabled = false;
printk(KERN_INFO "Kprobes globally disabled\n");
+ mutex_lock(&text_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist) {
@@ -1318,6 +1328,7 @@ static void __kprobes disable_all_kprobes(void)
}
}
+ mutex_unlock(&text_mutex);
mutex_unlock(&kprobe_mutex);
/* Allow all currently running kprobes to complete */
synchronize_sched();