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authorFrederic Weisbecker <fweisbec@gmail.com>2008-11-23 06:22:56 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-23 09:17:26 +0100
commitf201ae2356c74bcae130b2177b3dca903ea98071 (patch)
treec4b1b43fbe0a4594cb86749b2e7098fe15eb86ba /kernel/fork.c
parenta0a70c735ef714fe1b6777b571630c3d50c7b008 (diff)
downloadop-kernel-dev-f201ae2356c74bcae130b2177b3dca903ea98071.zip
op-kernel-dev-f201ae2356c74bcae130b2177b3dca903ea98071.tar.gz
tracing/function-return-tracer: store return stack into task_struct and allocate it dynamically
Impact: use deeper function tracing depth safely Some tests showed that function return tracing needed a more deeper depth of function calls. But it could be unsafe to store these return addresses to the stack. So these arrays will now be allocated dynamically into task_struct of current only when the tracer is activated. Typical scheme when tracer is activated: - allocate a return stack for each task in global list. - fork: allocate the return stack for the newly created task - exit: free return stack of current - idle init: same as fork I chose a default depth of 50. I don't have overruns anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index ac62f43..d1eb30e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -47,6 +47,7 @@
#include <linux/mount.h>
#include <linux/audit.h>
#include <linux/memcontrol.h>
+#include <linux/ftrace.h>
#include <linux/profile.h>
#include <linux/rmap.h>
#include <linux/acct.h>
@@ -1269,6 +1270,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
total_forks++;
spin_unlock(&current->sighand->siglock);
write_unlock_irq(&tasklist_lock);
+#ifdef CONFIG_FUNCTION_RET_TRACER
+ ftrace_retfunc_init_task(p);
+#endif
proc_fork_connector(p);
cgroup_post_fork(p);
return p;
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