* Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
> On Mon, Nov 10, 2008 at 04:29:41PM +1100, Stephen Rothwell wrote:
> > Today's linux-next build (powerpc ppc64_defconfig) failed like this:
> >
> > fs/proc/base.c:2547: error: 'pid_stack' undeclared here (not in a function)
> >
> > Caused by an interaction of commits
> > 078e9901c02d4899db5b24f708b8dfbca8935891 ("stacktrace:
> > add /proc/<pid>/stack to dump task's stack trace") and
> > 35f0b5fd7fab907a1119eaa614d9b24e5e225755 ("stacktrace:
> > convert /proc/<pid>/stack to seqfiles") from the tip-core tree with commit
> > 5d8880e3e0fb96459c652ac5e1504b90c949b3b9 ("proc: remove '##' usage") from
> > the proc tree.
> >
> > The former added a new usage of INF (which the second converted to a
> > ONE). I added the following patch to the merge of the proc tree and can
> > carry it.
>
> Time to steal this /proc/*/stack from Ingo. :-)
Alexey, would you like to carry them for v2.6.29? They are in a
separate tree here, the pull coordinates are below.
Please preserve the sha1's (do not rebase/cherry-pick, etc.) so that i
can carry it too without causing confusion.
Ingo
------------------->
The core/stacktrace git tree can be pulled from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core/stacktrace
Thanks,
Ingo
------------------>
Ken Chen (2):
stacktrace: add /proc/<pid>/stack to dump task's stack trace
stacktrace: convert /proc/<pid>/stack to seqfiles
Documentation/filesystems/proc.txt | 1 +
fs/proc/base.c | 50 ++++++++++++++++++++++++++++++++++-
2 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index bcceb99..11f5b75 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -139,6 +139,7 @@ Table 1-1: Process specific entries in /proc
statm Process memory status information
status Process status in human readable form
wchan If CONFIG_KALLSYMS is set, a pre-decoded wchan
+ stack Report full stack trace, enable via CONFIG_STACKTRACE
smaps Extension based on maps, the rss size for each mapped file
..............................................................................
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 486cf3f..6d294a4 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -65,6 +65,7 @@
#include <linux/mm.h>
#include <linux/rcupdate.h>
#include <linux/kallsyms.h>
+#include <linux/stacktrace.h>
#include <linux/resource.h>
#include <linux/module.h>
#include <linux/mount.h>
@@ -130,6 +131,12 @@ struct pid_entry {
{ .proc_show = &proc_##OTYPE } )
/*
+ * buffer size used for proc read. See proc_info_read().
+ * 4K page size but our output routines use some slack for overruns
+ */
+#define PROC_BLOCK_SIZE (3*1024)
+
+/*
* Count the number of hardlinks for the pid_entry table, excluding the .
* and .. links.
*/
@@ -340,6 +347,44 @@ static int proc_pid_wchan(struct task_struct *task, char *buffer)
}
#endif /* CONFIG_KALLSYMS */
+#ifdef CONFIG_STACKTRACE
+
+#define MAX_STACK_TRACE_DEPTH 64
+
+static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ struct stack_trace trace;
+ unsigned long *entries;
+ int i;
+
+ entries = kmalloc(sizeof(*entries)*MAX_STACK_TRACE_DEPTH, GFP_KERNEL);
+ if (!entries)
+ return -ENOMEM;
+
+ trace.nr_entries = 0;
+ trace.max_entries = MAX_STACK_TRACE_DEPTH;
+ trace.entries = entries;
+ trace.skip = 0;
+
+ /*
+ * Protect against the task exiting (and deallocating its
+ * stack, etc.) while we save its backtrace:
+ */
+ read_lock(&tasklist_lock);
+ save_stack_trace_tsk(task, &trace);
+ read_unlock(&tasklist_lock);
+
+ for (i = 0; i < trace.nr_entries; i++) {
+ seq_printf(m, "[<%p>] %pS\n",
+ (void *)entries[i], (void *)entries[i]);
+ }
+ kfree(entries);
+
+ return 0;
+}
+#endif
+
#ifdef CONFIG_SCHEDSTATS
/*
* Provides /proc/PID/schedstat
@@ -688,8 +733,6 @@ static const struct file_operations proc_mountstats_operations = {
.release = mounts_release,
};
-#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
-
static ssize_t proc_info_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
@@ -2491,6 +2534,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_KALLSYMS
INF("wchan", S_IRUGO, pid_wchan),
#endif
+#ifdef CONFIG_STACKTRACE
+ ONE("stack", S_IRUSR, pid_stack),
+#endif
#ifdef CONFIG_SCHEDSTATS
INF("schedstat", S_IRUGO, pid_schedstat),
#endif
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