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* [PATCH 0/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate
@ 2013-11-21  1:40 Shuah Khan
  2013-11-21  1:40 ` [PATCH 1/2] " Shuah Khan
  2013-11-21  1:40 ` [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate Shuah Khan
  0 siblings, 2 replies; 6+ messages in thread
From: Shuah Khan @ 2013-11-21  1:40 UTC (permalink / raw)
  To: len.brown, pavel, rjw, gregkh, anton, dwmw2
  Cc: Shuah Khan, linux-pm, linux-kernel, shuahkhan

power_supply_register() calls device_init_wakeup() to register a wakeup
source before initializing dev_name. As a result, device_wakeup_enable()
end up registering wakeup source with a null name when wakeup_source_register()
gets called with dev_name(dev) which is null at the time.

device_wakeup_enable() uses dev_name(dev) as the wakeup source name.
When it gets called with a device with its name not yet set, ws structure
with ws->name = NULL gets created.

When kernel is booted with wakeup_source_activate enabled, it will panic
when the trace point code tries to dereference ws->name. Registering a
a wakeup source without a name should be possible.

This patch series fixes power_supply_register() to initialize the device name
prior to calling device_init_wakeup() and fixes wakeup_source_activate
tracepoint to check for null name and handle it gracefully by just using
"(no name)" as the name string for the source.

These two patches are not dependent, I left them as a series since the original
discussion started the fixes grouped in a series.

power_supply patch - no changes since series patch v1, other than including
Acked-by from Greg and Anton. Also added stable tag.

Second patch now is the fix to tracepoint code. This fix is definitely better
than adding WARN_ON to device_wakeup_enable(). It removes the dependency
between these two patches.

These patches can be applied independently with no ill effects. I included
the trace for the wakeup_source_activate trace output in the changelogs for
both patches.

Shuah Khan (2):
  power_supply: Fix Oops from NULL pointer dereference from
    wakeup_source_activate
  PM: Fix Oops from NULL pointer dereference in wakeup_source_activate

 drivers/power/power_supply_core.c | 12 ++++++------
 include/trace/events/power.h      |  6 ++++--
 2 files changed, 10 insertions(+), 8 deletions(-)

-- 
1.8.3.2


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 1/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate
  2013-11-21  1:40 [PATCH 0/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate Shuah Khan
@ 2013-11-21  1:40 ` " Shuah Khan
  2013-11-21  1:40 ` [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate Shuah Khan
  1 sibling, 0 replies; 6+ messages in thread
From: Shuah Khan @ 2013-11-21  1:40 UTC (permalink / raw)
  To: len.brown, pavel, rjw, gregkh, anton, dwmw2
  Cc: Shuah Khan, linux-pm, linux-kernel, shuahkhan, stable

power_supply_register() calls device_init_wakeup() to register a wakeup
source before initializing dev_name. As a result, device_wakeup_enable()
end up registering wakeup source with a null name when wakeup_source_register()
gets called with dev_name(dev) which is null at the time.

When kernel is booted with wakeup_source_activate enabled, it will panic
when the trace point code tries to dereference ws->name.

Fixed the problem by moving up the kobject_set_name() call prior to accesses
to dev_name(). Replaced kobject_set_name() with dev_set_name() which is the
right interface to be called from drivers. Fixed the call to device_del() prior
to device_add() in for wakeup_init_failed error handling code.

Trace after the change:

            bash-2023  [000] d...    88.069073: wakeup_source_activate: BAT1 state=0x20001
     kworker/0:1-38    [000] d...    88.069155: wakeup_source_deactivate: BAT1 state=0x30000

Oops message:
[  819.769934] device: 'BAT1': device_add
[  819.770078] PM: Adding info for No Bus:BAT1
[  819.770235] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  819.770435] IP: [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.770572] PGD 3efd90067 PUD 3eff61067 PMD 0
[  819.770716] Oops: 0000 [#1] SMP
[  819.770829] Modules linked in: arc4 iwldvm mac80211 x86_pkg_temp_thermal coretemp kvm_intel joydev i915 kvm uvcvideo ghash_clmulni_intel videobuf2_vmalloc aesni_intel videobuf2_memops videobuf2_core aes_x86_64 ablk_helper cryptd videodev iwlwifi lrw rfcomm gf128mul glue_helper bnep btusb media bluetooth parport_pc hid_generic ppdev snd_hda_codec_hdmi drm_kms_helper snd_hda_codec_realtek cfg80211 drm tpm_infineon samsung_laptop snd_hda_intel usbhid snd_hda_codec hid snd_hwdep snd_pcm microcode snd_page_alloc snd_timer psmouse i2c_algo_bit lpc_ich tpm_tis video wmi mac_hid serio_raw ext2 lp parport r8169 mii
[  819.771802] CPU: 0 PID: 2167 Comm: bash Not tainted 3.12.0+ #25
[  819.771876] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 900X3C/900X3D/900X4C/900X4D/SAMSUNG_NP1234567890, BIOS P03AAC 07/12/2012
[  819.772022] task: ffff88002e6ddcc0 ti: ffff8804015ca000 task.ti: ffff8804015ca000
[  819.772119] RIP: 0010:[<ffffffff813381c0>]  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.772242] RSP: 0018:ffff8804015cbc70  EFLAGS: 00010046
[  819.772310] RAX: 0000000000000003 RBX: ffff88040cfd6d40 RCX: 0000000000000018
[  819.772397] RDX: 0000000000020001 RSI: 0000000000000000 RDI: 0000000000000000
[  819.772484] RBP: ffff8804015cbcc0 R08: 0000000000000000 R09: ffff8803f0768d40
[  819.772570] R10: ffffea001033b800 R11: 0000000000000000 R12: ffffffff81c519c0
[  819.772656] R13: 0000000000020001 R14: 0000000000000000 R15: 0000000000020001
[  819.772744] FS:  00007ff98309b740(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000
[  819.772845] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  819.772917] CR2: 0000000000000000 CR3: 00000003f59dc000 CR4: 00000000001407f0
[  819.773001] Stack:
[  819.773030]  ffffffff81114003 ffff8804015cbcb0 0000000000000000 0000000000000046
[  819.773146]  ffff880409757a18 ffff8803f065a160 0000000000000000 0000000000020001
[  819.773273]  0000000000000000 0000000000000000 ffff8804015cbce8 ffffffff8143e388
[  819.773387] Call Trace:
[  819.773434]  [<ffffffff81114003>] ? ftrace_raw_event_wakeup_source+0x43/0xe0
[  819.773520]  [<ffffffff8143e388>] wakeup_source_report_event+0xb8/0xd0
[  819.773595]  [<ffffffff8143e3cd>] __pm_stay_awake+0x2d/0x50
[  819.773724]  [<ffffffff8153395c>] power_supply_changed+0x3c/0x90
[  819.773795]  [<ffffffff8153407c>] power_supply_register+0x18c/0x250
[  819.773869]  [<ffffffff813d8d18>] sysfs_add_battery+0x61/0x7b
[  819.773935]  [<ffffffff813d8d69>] battery_notify+0x37/0x3f
[  819.774001]  [<ffffffff816ccb7c>] notifier_call_chain+0x4c/0x70
[  819.774071]  [<ffffffff81073ded>] __blocking_notifier_call_chain+0x4d/0x70
[  819.774149]  [<ffffffff81073e26>] blocking_notifier_call_chain+0x16/0x20
[  819.774227]  [<ffffffff8109397a>] pm_notifier_call_chain+0x1a/0x40
[  819.774316]  [<ffffffff81095b66>] hibernate+0x66/0x1c0
[  819.774407]  [<ffffffff81093931>] state_store+0x71/0xa0
[  819.774507]  [<ffffffff81331d8f>] kobj_attr_store+0xf/0x20
[  819.774613]  [<ffffffff811f8618>] sysfs_write_file+0x128/0x1c0
[  819.774735]  [<ffffffff8118579d>] vfs_write+0xbd/0x1e0
[  819.774841]  [<ffffffff811861d9>] SyS_write+0x49/0xa0
[  819.774939]  [<ffffffff816d1052>] system_call_fastpath+0x16/0x1b
[  819.775055] Code: 89 f8 48 89 e5 f6 82 c0 a6 84 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 a6 84 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80
[  819.775760] RIP  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.775881]  RSP <ffff8804015cbc70>
[  819.775949] CR2: 0000000000000000
[  819.794175] ---[ end trace c4ef25127039952e ]---

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
---
 drivers/power/power_supply_core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 00e6672..557af94 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -511,6 +511,10 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	dev_set_drvdata(dev, psy);
 	psy->dev = dev;
 
+	rc = dev_set_name(dev, "%s", psy->name);
+	if (rc)
+		goto dev_set_name_failed;
+
 	INIT_WORK(&psy->changed_work, power_supply_changed_work);
 
 	rc = power_supply_check_supplies(psy);
@@ -524,10 +528,6 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	if (rc)
 		goto wakeup_init_failed;
 
-	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
-	if (rc)
-		goto kobject_set_name_failed;
-
 	rc = device_add(dev);
 	if (rc)
 		goto device_add_failed;
@@ -553,11 +553,11 @@ create_triggers_failed:
 register_cooler_failed:
 	psy_unregister_thermal(psy);
 register_thermal_failed:
-wakeup_init_failed:
 	device_del(dev);
-kobject_set_name_failed:
 device_add_failed:
+wakeup_init_failed:
 check_supplies_failed:
+dev_set_name_failed:
 	put_device(dev);
 success:
 	return rc;
-- 
1.8.3.2


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate
  2013-11-21  1:40 [PATCH 0/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate Shuah Khan
  2013-11-21  1:40 ` [PATCH 1/2] " Shuah Khan
@ 2013-11-21  1:40 ` Shuah Khan
  2013-11-21  2:01   ` Shuah Khan
  1 sibling, 1 reply; 6+ messages in thread
From: Shuah Khan @ 2013-11-21  1:40 UTC (permalink / raw)
  To: len.brown, pavel, rjw, gregkh, anton, dwmw2
  Cc: Shuah Khan, linux-pm, linux-kernel, shuahkhan, stable

power_supply_register() calls device_init_wakeup() to register a wakeup
source before initializing dev_name. As a result, device_wakeup_enable()
end up registering wakeup source with a null name when wakeup_source_register()
gets called with dev_name(dev) which is null at the time.

When kernel is booted with wakeup_source_activate enabled, it will panic
when the trace point code tries to dereference ws->name. Registering a
a wakeup source without a name should be possible.

Fix wakeup_source_activate tracepoint to check for null name and handle it
gracefully by just using "(no name)" as the name string for the source.

Fixes: commit 6791e36c4a40e8930e08669e60077eea6770c429

Trace after the change:
            bash-2008  [000] d...   610.307262: wakeup_source_activate: (no name) state=0x20001
     kworker/0:0-2000  [000] d...   610.307287: wakeup_source_deactivate: (no name) state=0x30000

Oops message:

[  819.769934] device: 'BAT1': device_add
[  819.770078] PM: Adding info for No Bus:BAT1
[  819.770235] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  819.770435] IP: [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.770572] PGD 3efd90067 PUD 3eff61067 PMD 0
[  819.770716] Oops: 0000 [#1] SMP
[  819.770829] Modules linked in: arc4 iwldvm mac80211 x86_pkg_temp_thermal coretemp kvm_intel joydev i915 kvm uvcvideo ghash_clmulni_intel videobuf2_vmalloc aesni_intel videobuf2_memops videobuf2_core aes_x86_64 ablk_helper cryptd videodev iwlwifi lrw rfcomm gf128mul glue_helper bnep btusb media bluetooth parport_pc hid_generic ppdev snd_hda_codec_hdmi drm_kms_helper snd_hda_codec_realtek cfg80211 drm tpm_infineon samsung_laptop snd_hda_intel usbhid snd_hda_codec hid snd_hwdep snd_pcm microcode snd_page_alloc snd_timer psmouse i2c_algo_bit lpc_ich tpm_tis video wmi mac_hid serio_raw ext2 lp parport r8169 mii
[  819.771802] CPU: 0 PID: 2167 Comm: bash Not tainted 3.12.0+ #25
[  819.771876] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 900X3C/900X3D/900X4C/900X4D/SAMSUNG_NP1234567890, BIOS P03AAC 07/12/2012
[  819.772022] task: ffff88002e6ddcc0 ti: ffff8804015ca000 task.ti: ffff8804015ca000
[  819.772119] RIP: 0010:[<ffffffff813381c0>]  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.772242] RSP: 0018:ffff8804015cbc70  EFLAGS: 00010046
[  819.772310] RAX: 0000000000000003 RBX: ffff88040cfd6d40 RCX: 0000000000000018
[  819.772397] RDX: 0000000000020001 RSI: 0000000000000000 RDI: 0000000000000000
[  819.772484] RBP: ffff8804015cbcc0 R08: 0000000000000000 R09: ffff8803f0768d40
[  819.772570] R10: ffffea001033b800 R11: 0000000000000000 R12: ffffffff81c519c0
[  819.772656] R13: 0000000000020001 R14: 0000000000000000 R15: 0000000000020001
[  819.772744] FS:  00007ff98309b740(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000
[  819.772845] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  819.772917] CR2: 0000000000000000 CR3: 00000003f59dc000 CR4: 00000000001407f0
[  819.773001] Stack:
[  819.773030]  ffffffff81114003 ffff8804015cbcb0 0000000000000000 0000000000000046
[  819.773146]  ffff880409757a18 ffff8803f065a160 0000000000000000 0000000000020001
[  819.773273]  0000000000000000 0000000000000000 ffff8804015cbce8 ffffffff8143e388
[  819.773387] Call Trace:
[  819.773434]  [<ffffffff81114003>] ? ftrace_raw_event_wakeup_source+0x43/0xe0
[  819.773520]  [<ffffffff8143e388>] wakeup_source_report_event+0xb8/0xd0
[  819.773595]  [<ffffffff8143e3cd>] __pm_stay_awake+0x2d/0x50
[  819.773724]  [<ffffffff8153395c>] power_supply_changed+0x3c/0x90
[  819.773795]  [<ffffffff8153407c>] power_supply_register+0x18c/0x250
[  819.773869]  [<ffffffff813d8d18>] sysfs_add_battery+0x61/0x7b
[  819.773935]  [<ffffffff813d8d69>] battery_notify+0x37/0x3f
[  819.774001]  [<ffffffff816ccb7c>] notifier_call_chain+0x4c/0x70
[  819.774071]  [<ffffffff81073ded>] __blocking_notifier_call_chain+0x4d/0x70
[  819.774149]  [<ffffffff81073e26>] blocking_notifier_call_chain+0x16/0x20
[  819.774227]  [<ffffffff8109397a>] pm_notifier_call_chain+0x1a/0x40
[  819.774316]  [<ffffffff81095b66>] hibernate+0x66/0x1c0
[  819.774407]  [<ffffffff81093931>] state_store+0x71/0xa0
[  819.774507]  [<ffffffff81331d8f>] kobj_attr_store+0xf/0x20
[  819.774613]  [<ffffffff811f8618>] sysfs_write_file+0x128/0x1c0
[  819.774735]  [<ffffffff8118579d>] vfs_write+0xbd/0x1e0
[  819.774841]  [<ffffffff811861d9>] SyS_write+0x49/0xa0
[  819.774939]  [<ffffffff816d1052>] system_call_fastpath+0x16/0x1b
[  819.775055] Code: 89 f8 48 89 e5 f6 82 c0 a6 84 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 a6 84 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80
[  819.775760] RIP  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.775881]  RSP <ffff8804015cbc70>
[  819.775949] CR2: 0000000000000000
[  819.794175] ---[ end trace c4ef25127039952e ]---

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Cc: stable@vger.kernel.org
---
 include/trace/events/power.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index cda100d..5ba545a 100644
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -110,12 +110,14 @@ DECLARE_EVENT_CLASS(wakeup_source,
 	TP_ARGS(name, state),
 
 	TP_STRUCT__entry(
-		__string(       name,           name            )
+		__string(name,  name ? name : "(no name)")
 		__field(        u64,            state           )
 	),
 
 	TP_fast_assign(
-		__assign_str(name, name);
+		const char *tname = name ? name : "(no name)";
+
+		__assign_str(name, tname);
 		__entry->state = state;
 	),
 
-- 
1.8.3.2


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate
  2013-11-21  1:40 ` [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate Shuah Khan
@ 2013-11-21  2:01   ` Shuah Khan
  2013-11-21  2:26     ` Steven Rostedt
  0 siblings, 1 reply; 6+ messages in thread
From: Shuah Khan @ 2013-11-21  2:01 UTC (permalink / raw)
  To: len.brown, pavel, rjw, gregkh, anton, dwmw2, rostedt, fweisbec,
	mingo, keun-o.park, paul.gortmaker
  Cc: Shuah Khan, linux-pm, linux-kernel, shuahkhan, stable

On 11/20/2013 06:40 PM, Shuah Khan wrote:
> power_supply_register() calls device_init_wakeup() to register a wakeup
> source before initializing dev_name. As a result, device_wakeup_enable()
> end up registering wakeup source with a null name when wakeup_source_register()
> gets called with dev_name(dev) which is null at the time.
>
> When kernel is booted with wakeup_source_activate enabled, it will panic
> when the trace point code tries to dereference ws->name. Registering a
> a wakeup source without a name should be possible.
>
> Fix wakeup_source_activate tracepoint to check for null name and handle it
> gracefully by just using "(no name)" as the name string for the source.
>
> Fixes: commit 6791e36c4a40e8930e08669e60077eea6770c429
>
> Trace after the change:
>              bash-2008  [000] d...   610.307262: wakeup_source_activate: (no name) state=0x20001
>       kworker/0:0-2000  [000] d...   610.307287: wakeup_source_deactivate: (no name) state=0x30000
>
> Oops message:
>
> [  819.769934] device: 'BAT1': device_add
> [  819.770078] PM: Adding info for No Bus:BAT1
> [  819.770235] BUG: unable to handle kernel NULL pointer dereference at           (null)
> [  819.770435] IP: [<ffffffff813381c0>] skip_spaces+0x30/0x30
> [  819.770572] PGD 3efd90067 PUD 3eff61067 PMD 0
> [  819.770716] Oops: 0000 [#1] SMP
> [  819.770829] Modules linked in: arc4 iwldvm mac80211 x86_pkg_temp_thermal coretemp kvm_intel joydev i915 kvm uvcvideo ghash_clmulni_intel videobuf2_vmalloc aesni_intel videobuf2_memops videobuf2_core aes_x86_64 ablk_helper cryptd videodev iwlwifi lrw rfcomm gf128mul glue_helper bnep btusb media bluetooth parport_pc hid_generic ppdev snd_hda_codec_hdmi drm_kms_helper snd_hda_codec_realtek cfg80211 drm tpm_infineon samsung_laptop snd_hda_intel usbhid snd_hda_codec hid snd_hwdep snd_pcm microcode snd_page_alloc snd_timer psmouse i2c_algo_bit lpc_ich tpm_tis video wmi mac_hid serio_raw ext2 lp parport r8169 mii
> [  819.771802] CPU: 0 PID: 2167 Comm: bash Not tainted 3.12.0+ #25
> [  819.771876] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 900X3C/900X3D/900X4C/900X4D/SAMSUNG_NP1234567890, BIOS P03AAC 07/12/2012
> [  819.772022] task: ffff88002e6ddcc0 ti: ffff8804015ca000 task.ti: ffff8804015ca000
> [  819.772119] RIP: 0010:[<ffffffff813381c0>]  [<ffffffff813381c0>] skip_spaces+0x30/0x30
> [  819.772242] RSP: 0018:ffff8804015cbc70  EFLAGS: 00010046
> [  819.772310] RAX: 0000000000000003 RBX: ffff88040cfd6d40 RCX: 0000000000000018
> [  819.772397] RDX: 0000000000020001 RSI: 0000000000000000 RDI: 0000000000000000
> [  819.772484] RBP: ffff8804015cbcc0 R08: 0000000000000000 R09: ffff8803f0768d40
> [  819.772570] R10: ffffea001033b800 R11: 0000000000000000 R12: ffffffff81c519c0
> [  819.772656] R13: 0000000000020001 R14: 0000000000000000 R15: 0000000000020001
> [  819.772744] FS:  00007ff98309b740(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000
> [  819.772845] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  819.772917] CR2: 0000000000000000 CR3: 00000003f59dc000 CR4: 00000000001407f0
> [  819.773001] Stack:
> [  819.773030]  ffffffff81114003 ffff8804015cbcb0 0000000000000000 0000000000000046
> [  819.773146]  ffff880409757a18 ffff8803f065a160 0000000000000000 0000000000020001
> [  819.773273]  0000000000000000 0000000000000000 ffff8804015cbce8 ffffffff8143e388
> [  819.773387] Call Trace:
> [  819.773434]  [<ffffffff81114003>] ? ftrace_raw_event_wakeup_source+0x43/0xe0
> [  819.773520]  [<ffffffff8143e388>] wakeup_source_report_event+0xb8/0xd0
> [  819.773595]  [<ffffffff8143e3cd>] __pm_stay_awake+0x2d/0x50
> [  819.773724]  [<ffffffff8153395c>] power_supply_changed+0x3c/0x90
> [  819.773795]  [<ffffffff8153407c>] power_supply_register+0x18c/0x250
> [  819.773869]  [<ffffffff813d8d18>] sysfs_add_battery+0x61/0x7b
> [  819.773935]  [<ffffffff813d8d69>] battery_notify+0x37/0x3f
> [  819.774001]  [<ffffffff816ccb7c>] notifier_call_chain+0x4c/0x70
> [  819.774071]  [<ffffffff81073ded>] __blocking_notifier_call_chain+0x4d/0x70
> [  819.774149]  [<ffffffff81073e26>] blocking_notifier_call_chain+0x16/0x20
> [  819.774227]  [<ffffffff8109397a>] pm_notifier_call_chain+0x1a/0x40
> [  819.774316]  [<ffffffff81095b66>] hibernate+0x66/0x1c0
> [  819.774407]  [<ffffffff81093931>] state_store+0x71/0xa0
> [  819.774507]  [<ffffffff81331d8f>] kobj_attr_store+0xf/0x20
> [  819.774613]  [<ffffffff811f8618>] sysfs_write_file+0x128/0x1c0
> [  819.774735]  [<ffffffff8118579d>] vfs_write+0xbd/0x1e0
> [  819.774841]  [<ffffffff811861d9>] SyS_write+0x49/0xa0
> [  819.774939]  [<ffffffff816d1052>] system_call_fastpath+0x16/0x1b
> [  819.775055] Code: 89 f8 48 89 e5 f6 82 c0 a6 84 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 a6 84 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80
> [  819.775760] RIP  [<ffffffff813381c0>] skip_spaces+0x30/0x30
> [  819.775881]  RSP <ffff8804015cbc70>
> [  819.775949] CR2: 0000000000000000
> [  819.794175] ---[ end trace c4ef25127039952e ]---
>
> Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
> Cc: stable@vger.kernel.org
> ---
>   include/trace/events/power.h | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> index cda100d..5ba545a 100644
> --- a/include/trace/events/power.h
> +++ b/include/trace/events/power.h
> @@ -110,12 +110,14 @@ DECLARE_EVENT_CLASS(wakeup_source,
>   	TP_ARGS(name, state),
>
>   	TP_STRUCT__entry(
> -		__string(       name,           name            )
> +		__string(name,  name ? name : "(no name)")
>   		__field(        u64,            state           )
>   	),
>
>   	TP_fast_assign(
> -		__assign_str(name, name);
> +		const char *tname = name ? name : "(no name)";
> +
> +		__assign_str(name, tname);
>   		__entry->state = state;
>   	),
>
>

Adding tracing maintainers.

-- 
Shuah Khan
Senior Linux Kernel Developer - Open Source Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com | (970) 672-0658

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate
  2013-11-21  2:01   ` Shuah Khan
@ 2013-11-21  2:26     ` Steven Rostedt
  2013-11-21 18:02       ` Shuah Khan
  0 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2013-11-21  2:26 UTC (permalink / raw)
  To: shuah.kh
  Cc: len.brown, pavel, rjw, gregkh, anton, dwmw2, fweisbec, mingo,
	keun-o.park, paul.gortmaker, linux-pm, linux-kernel, shuahkhan,
	stable

On Wed, 20 Nov 2013 19:01:22 -0700
Shuah Khan <shuah.kh@samsung.com> wrote:

> On 11/20/2013 06:40 PM, Shuah Khan wrote:

> > ---
> >   include/trace/events/power.h | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> > index cda100d..5ba545a 100644
> > --- a/include/trace/events/power.h
> > +++ b/include/trace/events/power.h
> > @@ -110,12 +110,14 @@ DECLARE_EVENT_CLASS(wakeup_source,
> >   	TP_ARGS(name, state),
> >
> >   	TP_STRUCT__entry(
> > -		__string(       name,           name            )
> > +		__string(name,  name ? name : "(no name)")
> >   		__field(        u64,            state           )
> >   	),
> >
> >   	TP_fast_assign(
> > -		__assign_str(name, name);
> > +		const char *tname = name ? name : "(no name)";
> > +
> > +		__assign_str(name, tname);
> >   		__entry->state = state;
> >   	),
> >
> >
> 
> Adding tracing maintainers.

Thanks!

This is one solution, but what about just making the tracing facility a
bit more robust for everyone. Following what glibc printf() does when
it is passed a NULL, does this patch fix it too?

-- Steve

(haven't even compile tested this)

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 52594b2..bdac88c 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -372,7 +372,8 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 	__data_size += (len) * sizeof(type);
 
 #undef __string
-#define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)
+#define __string(item, src) __dynamic_array(char, item,			\
+				    strlen((src) ? (src) : "(null)") + 1)
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -501,7 +502,7 @@ static inline notrace int ftrace_get_offsets_##call(			\
 
 #undef __assign_str
 #define __assign_str(dst, src)						\
-	strcpy(__get_str(dst), src);
+	strcpy(__get_str(dst), (src) ? (src) : "(null)");
 
 #undef TP_fast_assign
 #define TP_fast_assign(args...) args


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate
  2013-11-21  2:26     ` Steven Rostedt
@ 2013-11-21 18:02       ` Shuah Khan
  0 siblings, 0 replies; 6+ messages in thread
From: Shuah Khan @ 2013-11-21 18:02 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: len.brown, pavel, rjw, gregkh, anton, dwmw2, fweisbec, mingo,
	keun-o.park, paul.gortmaker, linux-pm, linux-kernel, shuahkhan,
	stable, Shuah Khan

On 11/20/2013 07:26 PM, Steven Rostedt wrote:
> On Wed, 20 Nov 2013 19:01:22 -0700
> Shuah Khan <shuah.kh@samsung.com> wrote:
>
>> On 11/20/2013 06:40 PM, Shuah Khan wrote:
>
>>> ---
>>>    include/trace/events/power.h | 6 ++++--
>>>    1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
>>> index cda100d..5ba545a 100644
>>> --- a/include/trace/events/power.h
>>> +++ b/include/trace/events/power.h
>>> @@ -110,12 +110,14 @@ DECLARE_EVENT_CLASS(wakeup_source,
>>>    	TP_ARGS(name, state),
>>>
>>>    	TP_STRUCT__entry(
>>> -		__string(       name,           name            )
>>> +		__string(name,  name ? name : "(no name)")
>>>    		__field(        u64,            state           )
>>>    	),
>>>
>>>    	TP_fast_assign(
>>> -		__assign_str(name, name);
>>> +		const char *tname = name ? name : "(no name)";
>>> +
>>> +		__assign_str(name, tname);
>>>    		__entry->state = state;
>>>    	),
>>>
>>>
>>
>> Adding tracing maintainers.
>
> Thanks!
>
> This is one solution, but what about just making the tracing facility a
> bit more robust for everyone. Following what glibc printf() does when
> it is passed a NULL, does this patch fix it too?
>

Why not? I am working to get the code compiling now. Will let you know 
if this works.

-- Shuah


-- 
Shuah Khan
Senior Linux Kernel Developer - Open Source Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com | (970) 672-0658

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, back to index

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-11-21  1:40 [PATCH 0/2] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate Shuah Khan
2013-11-21  1:40 ` [PATCH 1/2] " Shuah Khan
2013-11-21  1:40 ` [PATCH 2/2] PM: Fix Oops from NULL pointer dereference in wakeup_source_activate Shuah Khan
2013-11-21  2:01   ` Shuah Khan
2013-11-21  2:26     ` Steven Rostedt
2013-11-21 18:02       ` Shuah Khan

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