Subject: [folded-merged] kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4.patch removed from -mm tree
To: lizefan@xxxxxxxxxx,catalin.marinas@xxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Thu, 03 Apr 2014 14:01:33 -0700
The patch titled
Subject: kmemleak: allow freeing internal objects after kmemleak was disabled
has been removed from the -mm tree. Its filename was
kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4.patch
This patch was dropped because it was folded into kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled.patch
------------------------------------------------------
From: Li Zefan <lizefan@xxxxxxxxxx>
Subject: kmemleak: allow freeing internal objects after kmemleak was disabled
v4: rephrase the printk string.
v3: Catalin wasn't suggesting to use "off" handler, but he wants to be
able to read memory leaks even when kmemleak is explicitly disabled.
v2: use "off" handler instead of "clear" handler to do this, suggested
by Catalin.
Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/kmemleak.txt | 17 ++++++------
mm/kmemleak.c | 47 ++++++++++++++++++++---------------
2 files changed, 36 insertions(+), 28 deletions(-)
diff -puN Documentation/kmemleak.txt~kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4 Documentation/kmemleak.txt
--- a/Documentation/kmemleak.txt~kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4
+++ a/Documentation/kmemleak.txt
@@ -44,8 +44,7 @@ objects to be reported as orphan.
Memory scanning parameters can be modified at run-time by writing to the
/sys/kernel/debug/kmemleak file. The following parameters are supported:
- off - disable kmemleak, or free all kmemleak objects if kmemleak
- has been disabled due to fatal errors. (irreversible).
+ off - disable kmemleak (irreversible)
stack=on - enable the task stacks scanning (default)
stack=off - disable the tasks stacks scanning
scan=on - start the automatic memory scanning thread (default)
@@ -54,7 +53,8 @@ Memory scanning parameters can be modifi
(default 600, 0 to stop the automatic scanning)
scan - trigger a memory scan
clear - clear list of current memory leak suspects, done by
- marking all current reported unreferenced objects grey
+ marking all current reported unreferenced objects grey,
+ or free all kmemleak objects if kmemleak has been disabled.
dump=<addr> - dump information about the object found at <addr>
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
@@ -124,13 +124,14 @@ Then as usual to get your report with:
Freeing kmemleak internal objects
---------------------------------
-To allow access to previously found memory leaks even when an error fatal
-to kmemleak happens, internal kmemleak objects won't be freed in this case.
-Those objects may occupy a large part of physical memory.
+To allow access to previosuly found memory leaks after kmemleak has been
+disabled by the user or due to an fatal error, internal kmemleak objects
+won't be freed when kmemleak is disabled, and those objects may occupy
+a large part of physical memory.
-You can reclaim memory from those objects with:
+In this situation, you may reclaim memory with:
- # echo off > /sys/kernel/debug/kmemleak
+ # echo clear > /sys/kernel/debug/kmemleak
Kmemleak API
------------
diff -puN mm/kmemleak.c~kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4 mm/kmemleak.c
--- a/mm/kmemleak.c~kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled-v4
+++ a/mm/kmemleak.c
@@ -1600,6 +1600,8 @@ static void kmemleak_clear(void)
kmemleak_found_leaks = false;
}
+static void __kmemleak_do_cleanup(void);
+
/*
* File write operation to configure kmemleak at run-time. The following
* commands can be written to the /sys/kernel/debug/kmemleak file:
@@ -1612,7 +1614,8 @@ static void kmemleak_clear(void)
* disable it)
* scan - trigger a memory scan
* clear - mark all current reported unreferenced kmemleak objects as
- * grey to ignore printing them
+ * grey to ignore printing them, or free all kmemleak objects
+ * if kmemleak has been disabled.
* dump=... - dump information about the object found at the given address
*/
static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
@@ -1631,9 +1634,11 @@ static ssize_t kmemleak_write(struct fil
if (ret < 0)
return ret;
- if (strncmp(buf, "off", 3) == 0) {
- stop_scan_thread();
- kmemleak_disable();
+ if (strncmp(buf, "clear", 5) == 0) {
+ if (atomic_read(&kmemleak_enabled))
+ kmemleak_clear();
+ else
+ __kmemleak_do_cleanup();
goto out;
}
@@ -1642,7 +1647,9 @@ static ssize_t kmemleak_write(struct fil
goto out;
}
- if (strncmp(buf, "stack=on", 8) == 0)
+ if (strncmp(buf, "off", 3) == 0)
+ kmemleak_disable();
+ else if (strncmp(buf, "stack=on", 8) == 0)
kmemleak_stack_scan = 1;
else if (strncmp(buf, "stack=off", 9) == 0)
kmemleak_stack_scan = 0;
@@ -1663,8 +1670,6 @@ static ssize_t kmemleak_write(struct fil
}
} else if (strncmp(buf, "scan", 4) == 0)
kmemleak_scan();
- else if (strncmp(buf, "clear", 5) == 0)
- kmemleak_clear();
else if (strncmp(buf, "dump=", 5) == 0)
ret = dump_str_object_info(buf + 5);
else
@@ -1689,6 +1694,16 @@ static const struct file_operations kmem
.release = kmemleak_release,
};
+static void __kmemleak_do_cleanup(void)
+{
+ struct kmemleak_object *object;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list)
+ delete_object_full(object->pointer);
+ rcu_read_unlock();
+}
+
/*
* Stop the memory scanning thread and free the kmemleak internal objects if
* no previous scan thread (otherwise, kmemleak may still have some useful
@@ -1696,22 +1711,14 @@ static const struct file_operations kmem
*/
static void kmemleak_do_cleanup(struct work_struct *work)
{
- struct kmemleak_object *object;
-
mutex_lock(&scan_mutex);
stop_scan_thread();
- if (!kmemleak_found_leaks) {
- rcu_read_lock();
- list_for_each_entry_rcu(object, &object_list, object_list)
- delete_object_full(object->pointer);
- rcu_read_unlock();
- } else {
- pr_info("Disable kmemleak without freeing internal objects, "
- "so you may still check information on memory leak. "
- "You may reclaim memory by writing \"off\" to "
- "/sys/kernel/debug/kmemleak\n");
- }
+ if (!kmemleak_found_leaks)
+ __kmemleak_do_cleanup();
+ else
+ pr_info("Kmemleak disabled without freeing internal data. "
+ "Reclaim the memory with \"echo clear > /sys/kernel/debug/kmemleak\"\n");
mutex_unlock(&scan_mutex);
}
_
Patches currently in -mm which might be from lizefan@xxxxxxxxxx are
origin.patch
kmemleak-free-internal-objects-only-if-therere-no-leaks-to-be-reported.patch
kmemleak-allow-freeing-internal-objects-after-kmemleak-was-disabled.patch
kmemleak-remove-redundant-code.patch
kmemleak-change-some-global-variables-to-int.patch
kmemleak-change-some-global-variables-to-int-v4.patch
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