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authorbibo mao <bibo_mao@linux.intel.com>2006-03-26 01:38:20 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-26 08:57:04 -0800
commitc6fd91f0bdcd294a0ae0ba2b2a7f7456ef4b7144 (patch)
tree1d095d1761a44118f101b2ce9697346ff168753a /kernel
parentc9becf58d935265919bf1cb348b2c04492c8949d (diff)
downloadop-kernel-dev-c6fd91f0bdcd294a0ae0ba2b2a7f7456ef4b7144.zip
op-kernel-dev-c6fd91f0bdcd294a0ae0ba2b2a7f7456ef4b7144.tar.gz
[PATCH] kretprobe instance recycled by parent process
When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kprobes.c10
-rw-r--r--kernel/sched.c9
2 files changed, 13 insertions, 6 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 1fb9f75..1156eb0 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -323,10 +323,10 @@ struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk)
}
/*
- * This function is called from exit_thread or flush_thread when task tk's
- * stack is being recycled so that we can recycle any function-return probe
- * instances associated with this task. These left over instances represent
- * probed functions that have been called but will never return.
+ * This function is called from finish_task_switch when task tk becomes dead,
+ * so that we can recycle any function-return probe instances associated
+ * with this task. These left over instances represent probed functions
+ * that have been called but will never return.
*/
void __kprobes kprobe_flush_task(struct task_struct *tk)
{
@@ -336,7 +336,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
unsigned long flags = 0;
spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(current);
+ head = kretprobe_inst_table_head(tk);
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
if (ri->task == tk)
recycle_rp_inst(ri);
diff --git a/kernel/sched.c b/kernel/sched.c
index 7ffaabd..78acdef 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -49,6 +49,7 @@
#include <linux/syscalls.h>
#include <linux/times.h>
#include <linux/acct.h>
+#include <linux/kprobes.h>
#include <asm/tlb.h>
#include <asm/unistd.h>
@@ -1546,8 +1547,14 @@ static inline void finish_task_switch(runqueue_t *rq, task_t *prev)
finish_lock_switch(rq, prev);
if (mm)
mmdrop(mm);
- if (unlikely(prev_task_flags & PF_DEAD))
+ if (unlikely(prev_task_flags & PF_DEAD)) {
+ /*
+ * Remove function-return probe instances associated with this
+ * task and put them back on the free list.
+ */
+ kprobe_flush_task(prev);
put_task_struct(prev);
+ }
}
/**
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