- 15 12月, 2017 1 次提交
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由 Steven Rostedt (VMware) 提交于
The stack tracer records a stack dump whenever it sees a stack usage that is more than what it ever saw before. This can happen at any function that is being traced. If it happens when the CPU is going idle (or other strange locations), RCU may not be watching, and in this case, the recording of the stack trace will trigger a warning. There's been lots of efforts to make hacks to allow stack tracing to proceed even if RCU is not watching, but this only causes more issues to appear. Simply do not trace a stack if RCU is not watching. It probably isn't a bad stack anyway. Acked-by: N"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 02 11月, 2017 1 次提交
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由 Greg Kroah-Hartman 提交于
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org> Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 25 10月, 2017 1 次提交
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由 Mark Rutland 提交于
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 9月, 2017 1 次提交
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由 Steven Rostedt (VMware) 提交于
Currently the stack tracer calls rcu_irq_enter() to make sure RCU is watching when it records a stack trace. But if the stack tracer is triggered while tracing inside of a rcu_irq_enter(), calling rcu_irq_enter() unconditionally can be problematic. The reason for having rcu_irq_enter() in the first place has been fixed from within the saving of the stack trace code, and there's no reason for doing it in the stack tracer itself. Just remove it. Cc: stable@vger.kernel.org Fixes: 0be964be ("module: Sanitize RCU usage and locking") Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Suggested-by: N"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 12 7月, 2017 1 次提交
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由 Steven Rostedt (VMware) 提交于
The "stack_trace_filter" file only makes sense if DYNAMIC_FTRACE is configured in. If it is not, then the user can not filter any functions. Not only that, the open function causes warnings when DYNAMIC_FTRACE is not set. Link: http://lkml.kernel.org/r/20170710110521.600806-1-arnd@arndb.deReported-by: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 29 6月, 2017 1 次提交
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由 Steven Rostedt (VMware) 提交于
When doing the following command: # echo ":mod:kvm_intel" > /sys/kernel/tracing/stack_trace_filter it triggered a crash. This happened with the clean up of probes. It required all callers to the regex function (doing ftrace filtering) to have ops->private be a pointer to a trace_array. But for the stack tracer, that is not the case. Allow for the ops->private to be NULL, and change the function command callbacks to handle the trace_array pointer being NULL as well. Fixes: d2afd57a ("tracing/ftrace: Allow instances to have their own function probes") Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 11 4月, 2017 4 次提交
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由 Steven Rostedt (VMware) 提交于
Tracing uses rcu_irq_enter() as a way to make sure that RCU is watching when it needs to use rcu_read_lock() and friends. This is because tracing can happen as RCU is about to enter user space, or about to go idle, and RCU does not watch for RCU read side critical sections as it makes the transition. There is a small location within the RCU infrastructure that rcu_irq_enter() itself will not work. If tracing were to occur in that section it will break if it tries to use rcu_irq_enter(). Originally, this happens with the stack_tracer, because it will call save_stack_trace when it encounters stack usage that is greater than any stack usage it had encountered previously. There was a case where that happened in the RCU section where rcu_irq_enter() did not work, and lockdep complained loudly about it. To fix it, stack tracing added a call to be disabled and RCU would disable stack tracing during the critical section that rcu_irq_enter() was inoperable. This solution worked, but there are other cases that use rcu_irq_enter() and it would be a good idea to let RCU give a way to let others know that rcu_irq_enter() will not work. For example, in trace events. Another helpful aspect of this change is that it also moves the per cpu variable called in the RCU critical section into a cache locale along with other RCU per cpu variables used in that same location. I'm keeping the stack_trace_disable() code, as that still could be used in the future by places that really need to disable it. And since it's only a static inline, it wont take up any kernel text if it is not used. Link: http://lkml.kernel.org/r/20170405093207.404f8deb@gandalf.local.homeAcked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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由 Steven Rostedt (VMware) 提交于
In order to eliminate a function call, make "trace_active" into "disable_stack_tracer" and convert stack_tracer_disable() and friends into static inline functions. Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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由 Steven Rostedt (VMware) 提交于
There are certain parts of the kernel that cannot let stack tracing proceed (namely in RCU), because the stack tracer uses RCU, and parts of RCU internals cannot handle having RCU read side locks taken. Add stack_tracer_disable() and stack_tracer_enable() functions to let RCU stop stack tracing on the current CPU when it is in those critical sections. Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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由 Steven Rostedt (VMware) 提交于
The updates to the trace_active per cpu variable can be updated with the __this_cpu_*() functions as it only gets updated on the CPU that the variable is on. Thanks to Paul McKenney for suggesting __this_cpu_* instead of this_cpu_*. Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
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- 10 3月, 2017 1 次提交
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由 Masahiro Yamada 提交于
Fix typos and add the following to the scripts/spelling.txt: overide||override While we are here, fix the doubled "address" in the touched line Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt. Also, fix the comment block style in the touched hunks in drivers/media/dvb-frontends/drx39xyj/drx_driver.h. Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 02 3月, 2017 1 次提交
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由 Ingo Molnar 提交于
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 20 2月, 2016 1 次提交
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由 Yang Shi 提交于
When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled", the below KASAN warning is triggered: BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8 Read of size 8 by task ksoftirqd/4/29 page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x0() page dumped because: kasan: bad access detected CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129 Hardware name: Freescale Layerscape 2085a RDB Board (DT) Call trace: [<ffffffc000091300>] dump_backtrace+0x0/0x3a0 [<ffffffc0000916c4>] show_stack+0x24/0x30 [<ffffffc0009bbd78>] dump_stack+0xd8/0x168 [<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920 [<ffffffc000421688>] kasan_report+0x70/0xb8 [<ffffffc00041f7f0>] __asan_load8+0x60/0x78 [<ffffffc0002e05c4>] check_stack+0x344/0x848 [<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370 [<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590 [<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14 [<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8 [<ffffffc000089864>] __switch_to+0x34/0x218 [<ffffffc0011e089c>] __schedule+0x3ac/0x15b8 [<ffffffc0011e1f6c>] schedule+0x5c/0x178 [<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960 [<ffffffc00015b518>] kthread+0x1d8/0x2b0 [<ffffffc0000874d0>] ret_from_fork+0x10/0x40 Memory state around the buggy address: ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4 ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 ^ ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 The stacker tracer traverses the whole kernel stack when saving the max stack trace. It may touch the stack red zones to cause the warning. So, just disable the instrumentation to silence the warning. Link: http://lkml.kernel.org/r/1455309960-18930-1-git-send-email-yang.shi@linaro.orgSigned-off-by: NYang Shi <yang.shi@linaro.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 30 1月, 2016 1 次提交
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由 Steven Rostedt 提交于
When a max stack trace is discovered, the stack dump is saved. In order to not record the overhead of the stack tracer, the ip of the traced function is looked for within the dump. The trace is started from the location of that function. But if for some reason the ip is not found, the entire stack trace is then truncated. That's not very useful. Instead, print everything if the ip of the traced function is not found within the trace. This issue showed up on s390. Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home Fixes: 72ac426a ("tracing: Clean up stack tracing and fix fentry updates") Cc: stable@vger.kernel.org # v4.3+ Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Tested-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 04 11月, 2015 2 次提交
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由 Steven Rostedt (Red Hat) 提交于
Now that max_stack_lock is a global variable, it requires a naming convention that is unlikely to collide. Rename it to the same naming convention that the other stack_trace variables have. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 AKASHI Takahiro 提交于
A stack frame may be used in a different way depending on cpu architecture. Thus it is not always appropriate to slurp the stack contents, as current check_stack() does, in order to calcurate a stack index (height) at a given function call. At least not on arm64. In addition, there is a possibility that we will mistakenly detect a stale stack frame which has not been overwritten. This patch makes check_stack() a weak function so as to later implement arch-specific version. Link: http://lkml.kernel.org/r/1446182741-31019-5-git-send-email-takahiro.akashi@linaro.orgSigned-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 21 10月, 2015 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
The code in stack tracer should not be executed within an NMI as it grabs spinlocks and stack tracing an NMI gives the possibility of causing a deadlock. Although this is safe on x86_64, because it does not perform stack traces when the task struct stack is not in use (interrupts and NMIs), it may be an issue for NMIs on i386 and other archs that use the same stack as the NMI. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 20 10月, 2015 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
The stack tracer was triggering the WARN_ON() in module.c: static void module_assert_mutex_or_preempt(void) { #ifdef CONFIG_LOCKDEP if (unlikely(!debug_locks)) return; WARN_ON(!rcu_read_lock_sched_held() && !lockdep_is_held(&module_mutex)); #endif } The reason is that the stack tracer traces all function calls, and some of those calls happen while exiting or entering user space and idle. Some of these functions are called after RCU had already stopped watching, as RCU does not watch userspace or idle CPUs. If a max stack is hit, then the save_stack_trace() is called, which will check module addresses and call module_assert_mutex_or_preempt(), and then trigger the warning. Sad part is, the warning itself will also do a stack trace and tigger the same warning. That probably should be fixed. The warning was added by 0be964be "module: Sanitize RCU usage and locking" but this bug has probably been around longer. But it's unlikely to cause much harm, but the new warning causes the system to lock up. Cc: stable@vger.kernel.org # 4.2+ Cc: Peter Zijlstra <peterz@infradead.org> Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 21 7月, 2015 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
Akashi Takahiro was porting the stack tracer to arm64 and found some issues with it. One was that it repeats the top function, due to the stack frame added by the mcount caller and added by itself. This was added when fentry came in, and before fentry created its own stack frame. But x86's fentry now creates its own stack frame, and there's no need to insert the function again. This also cleans up the code a bit, where it doesn't need to do something special for fentry, and doesn't include insertion of a duplicate entry for the called function being traced. Link: http://lkml.kernel.org/r/55A646EE.6030402@linaro.orgSome-suggestions-by: NJungseok Lee <jungseoklee85@gmail.com> Some-suggestions-by: NMark Rutland <mark.rutland@arm.com> Reported-by: NAKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 16 4月, 2015 1 次提交
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由 Joe Perches 提交于
The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Miscellanea: o Remove unused return value from trace_lookup_stack Signed-off-by: NJoe Perches <joe@perches.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 1月, 2015 2 次提交
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由 Steven Rostedt (Red Hat) 提交于
tracing_init_dentry() will soon return NULL as a valid pointer for the top level tracing directroy. NULL can not be used as an error value. Instead, switch to ERR_PTR() and check the return status with IS_ERR(). Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
The creation of tracing files and directories is for the most part encapsulated in helper functions in trace.c. Other files do not need to include debugfs.h or fs.h, as they may have needed to in the past. Remove them from the files that do not need them. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 19 9月, 2014 2 次提交
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由 Aaron Tomlin 提交于
This facility is used in a few places so let's introduce a helper function to improve code readability. Signed-off-by: NAaron Tomlin <atomlin@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dzickus@redhat.com Cc: bmr@redhat.com Cc: jcastillo@redhat.com Cc: oleg@redhat.com Cc: riel@redhat.com Cc: prarit@redhat.com Cc: jgh@redhat.com Cc: minchan@kernel.org Cc: mpe@ellerman.id.au Cc: tglx@linutronix.de Cc: hannes@cmpxchg.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1410527779-8133-3-git-send-email-atomlin@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Aaron Tomlin 提交于
Tasks get their end of stack set to STACK_END_MAGIC with the aim to catch stack overruns. Currently this feature does not apply to init_task. This patch removes this restriction. Note that a similar patch was posted by Prarit Bhargava some time ago but was never merged: http://marc.info/?l=linux-kernel&m=127144305403241&w=2Signed-off-by: NAaron Tomlin <atomlin@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NMichael Ellerman <mpe@ellerman.id.au> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dzickus@redhat.com Cc: bmr@redhat.com Cc: jcastillo@redhat.com Cc: jgh@redhat.com Cc: minchan@kernel.org Cc: tglx@linutronix.de Cc: hannes@cmpxchg.org Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1410527779-8133-2-git-send-email-atomlin@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 03 6月, 2014 1 次提交
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由 Minchan Kim 提交于
While I played with my own feature(ex, something on the way to reclaim), the kernel would easily oops. I guessed that the reason had to do with stack overflow and wanted to prove it. I discovered the stack tracer which proved to be very useful for me but the kernel would oops before my user program gather the information via "watch cat /sys/kernel/debug/tracing/stack_trace" so I couldn't get any message from that. What I needed was to have the stack tracer emit the kernel stack usage before it does the oops so I could find what was hogging the stack. This patch shows the callstack of max stack usage right before an oops so we can find a culprit. So, the result is as follows. [ 1116.522206] init: lightdm main process (1246) terminated with status 1 [ 1119.922916] init: failsafe-x main process (1272) terminated with status 1 [ 3887.728131] kworker/u24:1 (6637) used greatest stack depth: 256 bytes left [ 6397.629227] cc1 (9554) used greatest stack depth: 128 bytes left [ 7174.467392] Depth Size Location (47 entries) [ 7174.467392] ----- ---- -------- [ 7174.467785] 0) 7248 256 get_page_from_freelist+0xa7/0x920 [ 7174.468506] 1) 6992 352 __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469224] 2) 6640 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 3) 6632 168 new_slab+0x2c5/0x370 [ 7174.469413] 4) 6464 8 __slab_alloc+0x3a9/0x501 [ 7174.469413] 5) 6456 80 __kmalloc+0x1cb/0x200 [ 7174.469413] 6) 6376 376 vring_add_indirect+0x36/0x200 [ 7174.469413] 7) 6000 144 virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] 8) 5856 288 __virtblk_add_req+0xda/0x1b0 [ 7174.469413] 9) 5568 96 virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] 10) 5472 128 __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] 11) 5344 16 blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] 12) 5328 96 blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] 13) 5232 112 blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] 14) 5120 112 blk_flush_plug_list+0xc7/0x220 [ 7174.469413] 15) 5008 64 io_schedule_timeout+0x88/0x100 [ 7174.469413] 16) 4944 128 mempool_alloc+0x145/0x170 [ 7174.469413] 17) 4816 96 bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] 18) 4720 48 get_swap_bio+0x30/0x90 [ 7174.469413] 19) 4672 160 __swap_writepage+0x150/0x230 [ 7174.469413] 20) 4512 32 swap_writepage+0x42/0x90 [ 7174.469413] 21) 4480 320 shrink_page_list+0x676/0xa80 [ 7174.469413] 22) 4160 208 shrink_inactive_list+0x262/0x4e0 [ 7174.469413] 23) 3952 304 shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] 24) 3648 80 shrink_zone+0x3f/0x110 [ 7174.469413] 25) 3568 128 do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] 26) 3440 208 try_to_free_pages+0xf7/0x1e0 [ 7174.469413] 27) 3232 352 __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] 28) 2880 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 29) 2872 200 __page_cache_alloc+0x13f/0x160 [ 7174.469413] 30) 2672 80 find_or_create_page+0x4c/0xb0 [ 7174.469413] 31) 2592 80 ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] 32) 2512 176 ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] 33) 2336 128 ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] 34) 2208 256 ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] 35) 1952 160 ext4_map_blocks+0x325/0x530 [ 7174.469413] 36) 1792 384 ext4_writepages+0x6d1/0xce0 [ 7174.469413] 37) 1408 16 do_writepages+0x23/0x40 [ 7174.469413] 38) 1392 96 __writeback_single_inode+0x45/0x2e0 [ 7174.469413] 39) 1296 176 writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] 40) 1120 80 __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] 41) 1040 160 wb_writeback+0x29b/0x350 [ 7174.469413] 42) 880 208 bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] 43) 672 144 process_one_work+0x1d2/0x570 [ 7174.469413] 44) 528 112 worker_thread+0x116/0x370 [ 7174.469413] 45) 416 240 kthread+0xf3/0x110 [ 7174.469413] 46) 176 176 ret_from_fork+0x7c/0xb0 [ 7174.469413] ------------[ cut here ]------------ [ 7174.469413] kernel BUG at kernel/trace/trace_stack.c:174! [ 7174.469413] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 7174.469413] Dumping ftrace buffer: [ 7174.469413] (ftrace buffer empty) [ 7174.469413] Modules linked in: [ 7174.469413] CPU: 0 PID: 440 Comm: kworker/u24:0 Not tainted 3.14.0+ #212 [ 7174.469413] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 7174.469413] Workqueue: writeback bdi_writeback_workfn (flush-253:0) [ 7174.469413] task: ffff880034170000 ti: ffff880029518000 task.ti: ffff880029518000 [ 7174.469413] RIP: 0010:[<ffffffff8112336e>] [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP: 0000:ffff880029518290 EFLAGS: 00010046 [ 7174.469413] RAX: 0000000000000030 RBX: 000000000000002f RCX: 0000000000000000 [ 7174.469413] RDX: 0000000000000000 RSI: 000000000000002f RDI: ffffffff810b7159 [ 7174.469413] RBP: ffff8800295182f0 R08: ffffffffffffffff R09: 0000000000000000 [ 7174.469413] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff82768dfc [ 7174.469413] R13: 000000000000f2e8 R14: ffff8800295182b8 R15: 00000000000000f8 [ 7174.469413] FS: 0000000000000000(0000) GS:ffff880037c00000(0000) knlGS:0000000000000000 [ 7174.469413] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 7174.469413] CR2: 00002acd0b994000 CR3: 0000000001c0b000 CR4: 00000000000006f0 [ 7174.469413] Stack: [ 7174.469413] 0000000000000000 ffffffff8114fdb7 0000000000000087 0000000000001c50 [ 7174.469413] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 7174.469413] 0000000000000002 ffff880034170000 ffff880034171028 0000000000000000 [ 7174.469413] Call Trace: [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff816eee3f>] ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff810a23fa>] ? __bfs+0x11a/0x270 [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff8119092f>] ? alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff811507fd>] __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469413] [<ffffffff810a4de6>] ? check_irq_usage+0x96/0xe0 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81199cd5>] ? new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff81199cd5>] new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff816db002>] __slab_alloc+0x3a9/0x501 [ 7174.469413] [<ffffffff8119af8b>] ? __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8119af8b>] __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141de10>] ? vring_add_indirect+0x200/0x200 [ 7174.469413] [<ffffffff8141dc46>] vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141e402>] virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] [<ffffffff8148e35a>] __virtblk_add_req+0xda/0x1b0 [ 7174.469413] [<ffffffff8148e503>] virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] [<ffffffff8134aa0f>] __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] [<ffffffff8134b0d5>] blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] [<ffffffff8134b7bb>] blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] [<ffffffff8134be5b>] blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] [<ffffffff81342237>] blk_flush_plug_list+0xc7/0x220 [ 7174.469413] [<ffffffff816e60ef>] ? _raw_spin_unlock_irqrestore+0x3f/0x70 [ 7174.469413] [<ffffffff816e16e8>] io_schedule_timeout+0x88/0x100 [ 7174.469413] [<ffffffff816e1665>] ? io_schedule_timeout+0x5/0x100 [ 7174.469413] [<ffffffff81149415>] mempool_alloc+0x145/0x170 [ 7174.469413] [<ffffffff8109baf0>] ? __init_waitqueue_head+0x60/0x60 [ 7174.469413] [<ffffffff811e246b>] bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184110>] get_swap_bio+0x30/0x90 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184660>] __swap_writepage+0x150/0x230 [ 7174.469413] [<ffffffff810ab405>] ? do_raw_spin_unlock+0x5/0xa0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184515>] ? __swap_writepage+0x5/0x230 [ 7174.469413] [<ffffffff81184782>] swap_writepage+0x42/0x90 [ 7174.469413] [<ffffffff8115ae96>] shrink_page_list+0x676/0xa80 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115b872>] shrink_inactive_list+0x262/0x4e0 [ 7174.469413] [<ffffffff8115c1c1>] shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] [<ffffffff8115c4bf>] shrink_zone+0x3f/0x110 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115c9e6>] do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] [<ffffffff8115cf47>] try_to_free_pages+0xf7/0x1e0 [ 7174.469413] [<ffffffff81150db3>] __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81145c0f>] ? __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81145c0f>] __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81146c6c>] find_or_create_page+0x4c/0xb0 [ 7174.469413] [<ffffffff811463e5>] ? find_get_page+0x5/0x130 [ 7174.469413] [<ffffffff812837b9>] ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] [<ffffffff81284c07>] ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] [<ffffffff81281070>] ? ext4_mb_use_preallocated+0x40/0x360 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81287eb8>] ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] [<ffffffff8127d83b>] ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] [<ffffffff8124e6d5>] ext4_map_blocks+0x325/0x530 [ 7174.469413] [<ffffffff81253871>] ext4_writepages+0x6d1/0xce0 [ 7174.469413] [<ffffffff812531a0>] ? ext4_journalled_write_end+0x330/0x330 [ 7174.469413] [<ffffffff811539b3>] do_writepages+0x23/0x40 [ 7174.469413] [<ffffffff811d2365>] __writeback_single_inode+0x45/0x2e0 [ 7174.469413] [<ffffffff811d36ed>] writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] [<ffffffff811d39de>] __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] [<ffffffff811d40bb>] wb_writeback+0x29b/0x350 [ 7174.469413] [<ffffffff81057c3d>] ? __local_bh_enable_ip+0x6d/0xd0 [ 7174.469413] [<ffffffff811d6e9c>] bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81070672>] process_one_work+0x1d2/0x570 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81071bb6>] worker_thread+0x116/0x370 [ 7174.469413] [<ffffffff81071aa0>] ? manage_workers.isra.19+0x2e0/0x2e0 [ 7174.469413] [<ffffffff81078e53>] kthread+0xf3/0x110 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] [<ffffffff816ef0ec>] ret_from_fork+0x7c/0xb0 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] Code: c0 49 bc fc 8d 76 82 ff ff ff ff e8 44 5a 5b 00 31 f6 8b 05 95 2b b3 00 48 39 c6 7d 0e 4c 8b 04 f5 20 5f c5 81 49 83 f8 ff 75 11 <0f> 0b 48 63 05 71 5a 64 01 48 29 c3 e9 d0 fd ff ff 48 8d 5e 01 [ 7174.469413] RIP [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP <ffff880029518290> [ 7174.469413] ---[ end trace c97d325b36b718f3 ]--- Link: http://lkml.kernel.org/p/1401683592-1651-1-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 25 4月, 2014 1 次提交
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由 Jiaxing Wang 提交于
When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cnSigned-off-by: NJiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 24 3月, 2014 1 次提交
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由 Aaron Tomlin 提交于
It is difficult to detect a stack overrun when it actually occurs. We have observed that this type of corruption is often silent and can go unnoticed. Once the corrupted region is examined, the outcome is undefined and often results in sporadic system crashes. When the stack tracing feature is enabled, let's check for this condition and take appropriate action. Note: init_task doesn't get its stack end location set to STACK_END_MAGIC. Link: http://lkml.kernel.org/r/1395669837-30209-1-git-send-email-atomlin@redhat.comSigned-off-by: NAaron Tomlin <atomlin@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 03 1月, 2014 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
Trace event triggers added a lseek that uses the ftrace_filter_lseek() function. Unfortunately, when function tracing is not configured in that function is not defined and the kernel fails to build. This is the second time that function was added to a file ops and it broke the build due to requiring special config dependencies. Make a generic tracing_lseek() that all the tracing utilities may use. Also, modify the old ftrace_filter_lseek() to return 0 instead of 1 on WRONLY. Not sure why it was a 1 as that does not make sense. This also changes the old tracing_seek() to modify the file pos pointer on WRONLY as well. Reported-by: Nkbuild test robot <fengguang.wu@intel.com> Tested-by: NTom Zanussi <tom.zanussi@linux.intel.com> Acked-by: NTom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 13 4月, 2013 2 次提交
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由 Namhyung Kim 提交于
Check return value and bail out if it's NULL. Link: http://lkml.kernel.org/r/1365553093-10180-2-git-send-email-namhyung@kernel.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: NNamhyung Kim <namhyung@kernel.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Namhyung Kim 提交于
Currently set_ftrace_pid and set_graph_function files use seq_lseek for their fops. However seq_open() is called only for FMODE_READ in the fops->open() so that if an user tries to seek one of those file when she open it for writing, it sees NULL seq_file and then panic. It can be easily reproduced with following command: $ cd /sys/kernel/debug/tracing $ echo 1234 | sudo tee -a set_ftrace_pid In this example, GNU coreutils' tee opens the file with fopen(, "a") and then the fopen() internally calls lseek(). Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@kernel.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: NNamhyung Kim <namhyung@kernel.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 15 3月, 2013 3 次提交
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由 Steven Rostedt (Red Hat) 提交于
Currently, the depth reported in the stack tracer stack_trace file does not match the stack_max_size file. This is because the stack_max_size includes the overhead of stack tracer itself while the depth does not. The first time a max is triggered, a calculation is not performed that figures out the overhead of the stack tracer and subtracts it from the stack_max_size variable. The overhead is stored and is subtracted from the reported stack size for comparing for a new max. Now the stack_max_size corresponds to the reported depth: # cat stack_max_size 4640 # cat stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 4640 32 _raw_spin_lock+0x18/0x24 1) 4608 112 ____cache_alloc+0xb7/0x22d 2) 4496 80 kmem_cache_alloc+0x63/0x12f 3) 4416 16 mempool_alloc_slab+0x15/0x17 [...] While testing against and older gcc on x86 that uses mcount instead of fentry, I found that pasing in ip + MCOUNT_INSN_SIZE let the stack trace show one more function deep which was missing before. Cc: stable@vger.kernel.org Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
When gcc 4.6 on x86 is used, the function tracer will use the new option -mfentry which does a call to "fentry" at every function instead of "mcount". The significance of this is that fentry is called as the first operation of the function instead of the mcount usage of being called after the stack. This causes the stack tracer to show some bogus results for the size of the last function traced, as well as showing "ftrace_call" instead of the function. This is due to the stack frame not being set up by the function that is about to be traced. # cat stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 4824 216 ftrace_call+0x5/0x2f 1) 4608 112 ____cache_alloc+0xb7/0x22d 2) 4496 80 kmem_cache_alloc+0x63/0x12f The 216 size for ftrace_call includes both the ftrace_call stack (which includes the saving of registers it does), as well as the stack size of the parent. To fix this, if CC_USING_FENTRY is defined, then the stack_tracer will reserve the first item in stack_dump_trace[] array when calling save_stack_trace(), and it will fill it in with the parent ip. Then the code will look for the parent pointer on the stack and give the real size of the parent's stack pointer: # cat stack_trace Depth Size Location (14 entries) ----- ---- -------- 0) 2640 48 update_group_power+0x26/0x187 1) 2592 224 update_sd_lb_stats+0x2a5/0x4ac 2) 2368 160 find_busiest_group+0x31/0x1f1 3) 2208 256 load_balance+0xd9/0x662 I'm Cc'ing stable, although it's not urgent, as it only shows bogus size for item #0, the rest of the trace is legit. It should still be corrected in previous stable releases. Cc: stable@vger.kernel.org Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
Use the stack of stack_trace_call() instead of check_stack() as the test pointer for max stack size. It makes it a bit cleaner and a little more accurate. Adding stable, as a later fix depends on this patch. Cc: stable@vger.kernel.org Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 20 11月, 2012 1 次提交
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由 Anton Vorontsov 提交于
It seems that 'ftrace_enabled' flag should not be used inside the tracer functions. The ftrace core is using this flag for internal purposes, and the flag wasn't meant to be used in tracers' runtime checks. stack tracer is the only tracer that abusing the flag. So stop it from serving as a bad example. Also, there is a local 'stack_trace_disabled' flag in the stack tracer, which is never updated; so it can be removed as well. Link: http://lkml.kernel.org/r/1342637761-9655-1-git-send-email-anton.vorontsov@linaro.orgSigned-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 31 7月, 2012 1 次提交
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由 Steven Rostedt 提交于
As more users of the function tracer utility are being added, they do not always add the necessary recursion protection. To protect from function recursion due to tracing, if the callback ftrace_ops does not specifically specify that it protects against recursion (by setting the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be called by the mcount trampoline which adds recursion protection. If the flag is set, then the function will be called directly with no extra protection. Note, the list operation is called if more than one function callback is registered, or if the arch does not support all of the function tracer features. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 20 7月, 2012 2 次提交
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由 Steven Rostedt 提交于
Return as the 4th paramater to the function tracer callback the pt_regs. Later patches that implement regs passing for the architectures will require having the ftrace_ops set the SAVE_REGS flag, which will tell the arch to take the time to pass a full set of pt_regs to the ftrace_ops callback function. If the arch does not support it then it should pass NULL. If an arch can pass full regs, then it should define: ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1 Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.orgReviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt 提交于
Currently the function trace callback receives only the ip and parent_ip of the function that it traced. It would be more powerful to also return the ops that registered the function as well. This allows the same function to act differently depending on what ftrace_ops registered it. Link: http://lkml.kernel.org/r/20120612225424.267254552@goodmis.orgReviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 21 12月, 2011 2 次提交
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由 Steven Rostedt 提交于
Add stacktrace_filter= to the kernel command line that lets the user pick specific functions to check the stack on. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt 提交于
The stack_tracer is used to look at every function and check if the current stack is bigger than the last recorded max stack size. When a new max is found, then it saves that stack off. Currently the stack tracer is limited by the global_ops of the function tracer. As the stack tracer has nothing to do with the ftrace function tracer, except that it uses it as its internal engine, the stack tracer should have its own list. A new file is added to the tracing debugfs directory called: stack_trace_filter that can be used to select which functions you want to check the stack on. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 15 6月, 2011 1 次提交
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由 Peter Huewe 提交于
This patch replaces the code for getting an unsigned long from a userspace buffer by a simple call to kstroul_from_user. This makes it easier to read and less error prone. Signed-off-by: NPeter Huewe <peterhuewe@gmx.de> Link: http://lkml.kernel.org/r/1307476707-14762-1-git-send-email-peterhuewe@gmx.deSigned-off-by: NSteven Rostedt <rostedt@goodmis.org>
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