Steven Rostedt (Red Hat) 1bfdf02fc0 tracing: Allow events to have NULL strings ... commit 4e58e54754 upstream. If an TRACE_EVENT() uses __assign_str() or __get_str on a NULL pointer then the following oops will happen: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c127a17b>] strlen+0x10/0x1a *pde = 00000000 ^M Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.13.0-rc1-test+ #2 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006^M task: f5cde9f0 ti: f5e5e000 task.ti: f5e5e000 EIP: 0060:[<c127a17b>] EFLAGS: 00210046 CPU: 1 EIP is at strlen+0x10/0x1a EAX: 00000000 EBX: c2472da8 ECX: ffffffff EDX: c2472da8 ESI: c1c5e5fc EDI: 00000000 EBP: f5e5fe84 ESP: f5e5fe80 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 CR0: 8005003b CR2: 00000000 CR3: 01f32000 CR4: 000007d0 Stack: f5f18b90 f5e5feb8 c10687a8 0759004f 00000005 00000005 00000005 00200046 00000002 00000000 c1082a93 f56c7e28 c2472da8 c1082a93 f5e5fee4 c106bc61^M 00000000 c1082a93 00000000 00000000 00000001 00200046 00200082 00000000 Call Trace: [<c10687a8>] ftrace_raw_event_lock+0x39/0xc0 [<c1082a93>] ? ktime_get+0x29/0x69 [<c1082a93>] ? ktime_get+0x29/0x69 [<c106bc61>] lock_release+0x57/0x1a5 [<c1082a93>] ? ktime_get+0x29/0x69 [<c10824dd>] read_seqcount_begin.constprop.7+0x4d/0x75 [<c1082a93>] ? ktime_get+0x29/0x69^M [<c1082a93>] ktime_get+0x29/0x69 [<c108a46a>] __tick_nohz_idle_enter+0x1e/0x426 [<c10690e8>] ? lock_release_holdtime.part.19+0x48/0x4d [<c10bc184>] ? time_hardirqs_off+0xe/0x28 [<c1068c82>] ? trace_hardirqs_off_caller+0x3f/0xaf [<c108a8cb>] tick_nohz_idle_enter+0x59/0x62 [<c1079242>] cpu_startup_entry+0x64/0x192 [<c102299c>] start_secondary+0x277/0x27c Code: 90 89 c6 89 d0 88 c4 ac 38 e0 74 09 84 c0 75 f7 be 01 00 00 00 89 f0 48 5e 5d c3 55 89 e5 57 66 66 66 66 90 83 c9 ff 89 c7 31 c0 <f2> ae f7 d1 8d 41 ff 5f 5d c3 55 89 e5 57 66 66 66 66 90 31 ff EIP: [<c127a17b>] strlen+0x10/0x1a SS:ESP 0068:f5e5fe80 CR2: 0000000000000000 ---[ end trace 01bc47bf519ec1b2 ]--- New tracepoints have been added that have allowed for NULL pointers being assigned to strings. To fix this, change the TRACE_EVENT() code to check for NULL and if it is, it will assign "(null)" to it instead (similar to what glibc printf does). Reported-by: Shuah Khan <shuah.kh@samsung.com> Reported-by: Jovi Zhangwei <jovi.zhangwei@gmail.com> Link: http://lkml.kernel.org/r/CAGdX0WFeEuy+DtpsJzyzn0343qEEjLX97+o1VREFkUEhndC+5Q@mail.gmail.com Link: http://lkml.kernel.org/r/528D6972.9010702@samsung.com Fixes: 9cbf117662 ("tracing/events: provide string with undefined size support") Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-12-04 10:57:17 -08:00
..
acpi	ACPI / hotplug: Fix conflicted PCI bridge notify handlers	2013-12-04 10:57:04 -08:00
asm-generic	mm: Fix generic hugetlb pte check return type.	2013-10-13 16:08:33 -07:00
clocksource	ARM: late Exynos multiplatform changes	2013-05-07 11:28:42 -07:00
crypto	crypto: sha512 - Expose generic sha512 routine to be callable from other modules	2013-04-25 21:00:57 +08:00
drm	Merge branch 'drm-radeon-sun-hainan' of git://people.freedesktop.org/~airlied/linux	2013-05-21 08:50:57 -07:00
dt-bindings	ARM: dt: create a DT header for the GIC	2013-04-05 12:23:24 -06:00
keys
linux	audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent audit_names record	2013-12-04 10:57:03 -08:00
math-emu
media	media: v4l2: added missing mutex.h include to v4l2-ctrls.h	2013-09-26 17:18:26 -07:00
memory
misc
net	ipv6: reset dst.expires value when clearing expire flag	2013-11-20 12:27:46 -08:00
pcmcia	pcmcia/ds.h: introduce helper for pcmcia_driver module boilerplate	2013-03-15 12:26:03 -07:00
ras
rdma
rxrpc
scsi	Merge branch 'postmerge' into for-linus	2013-05-10 07:54:01 -07:00
sound	ALSA: compress: fix drain calls blocking other compress functions (v6)	2013-11-29 11:11:45 -08:00
target	iscsi-target: Fix iscsit_sequence_cmd reject handling for iser	2013-08-04 16:51:17 +08:00
trace	tracing: Allow events to have NULL strings	2013-12-04 10:57:17 -08:00
uapi	perf: Fix perf ring buffer memory ordering	2013-11-20 12:27:47 -08:00
video	Merge branch 'fbdev-3.10-fixes' of git://gitorious.org/linux-omap-dss2/linux into linux-fbdev/for-3.10-fixes	2013-05-29 17:00:34 +08:00
xen	xenbus: delay xenbus frontend resume if xenstored is not running	2013-05-29 09:04:19 -04:00
Kbuild	UAPI: remove empty Kbuild files	2013-04-30 17:04:09 -07:00