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
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
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
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
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
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