- 18 Jul, 2014 1 commit
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Steven Rostedt (Red Hat) authored
ftrace_stop() is going away as it disables parts of function tracing that affects users that should not be affected. But ftrace_graph_stop() is built on ftrace_stop(). Here's another example of killing all of function tracing because something went wrong with function graph tracing. Instead of disabling all users of function tracing on function graph error, disable only function graph tracing. To do this, the arch code must call ftrace_graph_is_dead() before it implements function graph. Link: http://lkml.kernel.org/r/53C8D874.9090601@monstr.euTested-by:
Michal Simek <monstr@monstr.eu> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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- 17 Jul, 2014 5 commits
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Steven Rostedt (Red Hat) authored
ftrace_stop() is going away as it disables parts of function tracing that affects users that should not be affected. But ftrace_graph_stop() is built on ftrace_stop(). Here's another example of killing all of function tracing because something went wrong with function graph tracing. Instead of disabling all users of function tracing on function graph error, disable only function graph tracing. To do this, the arch code must call ftrace_graph_is_dead() before it implements function graph. Link: http://lkml.kernel.org/r/53C54D18.3020602@zytor.comAcked-by:
H. Peter Anvin <hpa@linux.intel.com> Reviewed-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by:
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Steven Rostedt (Red Hat) authored
ftrace_stop() is going away as it disables parts of function tracing that affects users that should not be affected. But ftrace_graph_stop() is built on ftrace_stop(). Here's another example of killing all of function tracing because something went wrong with function graph tracing. Instead of disabling all users of function tracing on function graph error, disable only function graph tracing. A new function is created called ftrace_graph_is_dead(). This is called in strategic paths to prevent function graph from doing more harm and allowing at least a warning to be printed before the system crashes. NOTE: ftrace_stop() is still used until all the archs are converted over to use ftrace_graph_is_dead(). After that, ftrace_stop() will be removed. Reviewed-by:
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Steven Rostedt (Red Hat) authored
ftrace_stop() and ftrace_start() were added to the suspend and hibernate process because there was some function within the work flow that caused the system to reboot if it was traced. This function has recently been found (restore_processor_state()). Now there's no reason to disable function tracing while we are going into suspend or hibernate, which means that being able to trace this will help tremendously in debugging any issues with suspend or hibernate. This also means that the ftrace_stop/start() functions can be removed and simplify the function tracing code a bit. Link: http://lkml.kernel.org/r/1518201.VD9cU33jRU@vostro.rjw.lanAcked-by:
"Rafael J. Wysocki" <rjw@rjwysocki.net> Reviewed-by:
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Steven Rostedt (Red Hat) authored
ftrace_stop() is used to stop function tracing during suspend and resume which removes a lot of possible debugging opportunities with tracing. The reason was that some function in the resume path was causing a triple fault if it were to be traced. The issue I found was that doing something as simple as calling smp_processor_id() would reboot the box! When function tracing was first created I didn't have a good way to figure out what function was having issues, or it looked to be multiple ones. To fix it, we just created a big hammer approach to the problem which was to add a flag in the mcount trampoline that could be checked and not call the traced functions. Lately I developed better ways to find problem functions and I can bisect down to see what function is causing the issue. I removed the flag that stopped tracing and proceeded to find the problem function and it ended up being restore_processor_state(). This function makes sense as when the CPU comes back online from a suspend it calls this function to set up registers, amongst them the GS register, which stores things such as what CPU the processor is (if you call smp_processor_id() without this set up properly, it would fault). By making restore_processor_state() notrace, the system can suspend and resume without the need of the big hammer tracing to stop. Link: http://lkml.kernel.org/r/3577662.BSnUZfboWb@vostro.rjw.lanAcked-by:
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Steven Rostedt (Red Hat) authored
The function graph trampoline is called from the function trampoline and both do a save and restore of registers. The save of registers done by the function trampoline when only the function graph tracer is running is a waste of CPU cycles. As the function graph tracer trampoline in x86 is dependent from the function trampoline, we can call it directly when a function is only being traced by the function graph trampoline. Acked-by:
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- 16 Jul, 2014 1 commit
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Steven Rostedt (Red Hat) authored
Currently if an arch supports function graph tracing, the core code will just assign the function graph trampoline to the function graph addr that gets called. But as the old method for function graph tracing always calls the function trampoline first and that calls the function graph trampoline, some archs may have the function graph trampoline dependent on operations that were done in the function trampoline. This causes function graph tracer to break on those archs. Instead of having the default be to set the function graph ftrace_ops to the function graph trampoline, have it instead just set it to zero which will keep it from jumping to a trampoline that is not set up to be jumped directly too. Link: http://lkml.kernel.org/r/53BED155.9040607@nvidia.comReported-by:
Tuomas Tynkkynen <ttynkkynen@nvidia.com> Tested-by:
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- 09 Jul, 2014 1 commit
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Steven Rostedt (Red Hat) authored
Needed 099ed151 "tracing: Remove ftrace_stop/start() from reading the trace file" for the removal of ftrace_start/stop().
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- 01 Jul, 2014 19 commits
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Steven Rostedt (Red Hat) authored
Disabling reading and writing to the trace file should not be able to disable all function tracing callbacks. There's other users today (like kprobes and perf). Reading a trace file should not stop those from happening. Cc: stable@vger.kernel.org # 3.0+ Reviewed-by:
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Namhyung Kim authored
It was missing the description of set_graph_notrace file. Add it. Link: http://lkml.kernel.org/p/1402590233-22321-5-git-send-email-namhyung@kernel.orgSigned-off-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
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Namhyung Kim authored
When there's no entry in set_ftrace_notrace, it'll print nothing, but it's better to print something like below like set_graph_notrace does: #### no functions disabled #### Link: http://lkml.kernel.org/p/1402644246-4649-1-git-send-email-namhyung@kernel.orgReported-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by:
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Namhyung Kim authored
When there's no entry in set_graph_notrace, it'll print below message #### all functions enabled #### While this is technically correct, it's better to print like below: #### no functions disabled #### Link: http://lkml.kernel.org/p/1402590233-22321-3-git-send-email-namhyung@kernel.orgReported-by:
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Namhyung Kim authored
The ftrace_graph_notrace option is for specifying notrace filter for function graph tracer at boot time. It can be altered after boot using set_graph_notrace file on the debugfs. Link: http://lkml.kernel.org/p/1402590233-22321-2-git-send-email-namhyung@kernel.orgSigned-off-by:
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Fabian Frederick authored
Convert pr_warning to standard pr_warn Define pr_fmt(fmt) fmt to avoid any future default fmt definition Link: http://lkml.kernel.org/p/1402141388-21144-1-git-send-email-fabf@skynet.beSigned-off-by:
Fabian Frederick <fabf@skynet.be> Signed-off-by:
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Namhyung Kim authored
When a filter file is open for writing and O_TRUNC is set, there's no need to copy and free the filter entries. Link: http://lkml.kernel.org/p/1402474014-28655-2-git-send-email-namhyung@kernel.orgSigned-off-by:
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Namhyung Kim authored
As struct ftrace_page is managed in a single linked list, it should free from the start page. Link: http://lkml.kernel.org/p/1402474014-28655-1-git-send-email-namhyung@kernel.orgSigned-off-by:
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Namhyung Kim authored
It seems like it's a leftover from commit 4104d326 ("ftrace: Remove global function list and call function directly"). As it isn't updated at all, checking its value is meaningless. Let's get rid of it. Link: http://lkml.kernel.org/p/1402584972-17824-1-git-send-email-namhyung@kernel.orgSigned-off-by:
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Steven Rostedt (Red Hat) authored
There's several locations in the kernel that open code the calculation of the next location in the trace_seq buffer. This is usually done with p->buffer + p->len Instead of having this open coded, supply a helper function in the header to do it for them. This function is called trace_seq_buffer_ptr(). Link: http://lkml.kernel.org/p/20140626220129.452783019@goodmis.orgAcked-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
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Fabian Frederick authored
This fixes checkpatch warning: "WARNING: debugfs_remove(NULL) is safe this check is probably not required" Link: http://lkml.kernel.org/p/1403802871-8599-1-git-send-email-fabf@skynet.beSigned-off-by:
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Steven Rostedt (Red Hat) authored
trace_seq_reserve() has no users in the kernel, it just wastes space. Remove it. Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: -
Steven Rostedt (Red Hat) authored
Currently trace_seq_putmem_hex() can only take as a parameter a pointer to something that is 8 bytes or less, otherwise it will overflow the buffer. This is protected by a macro that encompasses the call to trace_seq_putmem_hex() that has a BUILD_BUG_ON() for the variable before it is passed in. This is not very robust and if trace_seq_putmem_hex() ever gets used outside that macro it will cause issues. Instead of only being able to produce a hex output of memory that is for a single word, change it to be more robust and allow any size input. Signed-off-by: -
Steven Rostedt (Red Hat) authored
For using trace_seq_*() functions in NMI context, I posted a patch to move it to the lib/ directory. This caused Andrew Morton to take a look at the code. He went through and gave a lot of comments about missing kernel doc, inconsistent types for the save variable, mix match of EXPORT_SYMBOL_GPL() and EXPORT_SYMBOL() as well as missing EXPORT_SYMBOL*()s. There were a few comments about the way variables were being compared (int vs uint). All these were good review comments and should be implemented regardless of if trace_seq.c should be moved to lib/ or not. Signed-off-by: -
Steven Rostedt (Red Hat) authored
The trace_seq_*() functions are a nice utility that allows users to manipulate buffers with printf() like formats. It has its own trace_seq.h header in include/linux and should be in its own file. Being tied with trace_output.c is rather awkward. Signed-off-by: -
Masami Hiramatsu authored
Simplify ftrace_hash_disable/enable path in ftrace_hash_move for hardening the process if the memory allocation failed. Link: http://lkml.kernel.org/p/20140617110442.15167.81076.stgit@kbuild-fedora.novalocalSigned-off-by:
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Zhao Hongjiang authored
Strings should be copied with strlcpy instead of strncpy when they will later be printed via %s. This guarantees that they terminate with a NUL '\0' character and do not run pass the end of the allocated string. This is only for sample code, but it should stil represent a good role model. Link: http://lkml.kernel.org/p/51C2E204.1080501@huawei.comSigned-off-by:
Zhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by:
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Steven Rostedt (Red Hat) authored
The enabled_functions is used to help debug the dynamic function tracing. Adding what trampolines are attached to files is useful for debugging. Signed-off-by: -
Steven Rostedt (Red Hat) authored
Function graph tracing is a bit different than the function tracers, as it is processed after either the ftrace_caller or ftrace_regs_caller and we only have one place to modify the jump to ftrace_graph_caller, the jump needs to happen after the restore of registeres. The function graph tracer is dependent on the function tracer, where even if the function graph tracing is going on by itself, the save and restore of registers is still done for function tracing regardless of if function tracing is happening, before it calls the function graph code. If there's no function tracing happening, it is possible to just call the function graph tracer directly, and avoid the wasted effort to save and restore regs for function tracing. This requires adding new flags to the dyn_ftrace records: FTRACE_FL_TRAMP FTRACE_FL_TRAMP_EN The first is set if the count for the record is one, and the ftrace_ops associated to that record has its own trampoline. That way the mcount code can call that trampoline directly. In the future, trampolines can be added to arbitrary ftrace_ops, where you can have two or more ftrace_ops registered to ftrace (like kprobes and perf) and if they are not tracing the same functions, then instead of doing a loop to check all registered ftrace_ops against their hashes, just call the ftrace_ops trampoline directly, which would call the registered ftrace_ops function directly. Without this patch perf showed: 0.05% hackbench [kernel.kallsyms] [k] ftrace_caller 0.05% hackbench [kernel.kallsyms] [k] arch_local_irq_save 0.05% hackbench [kernel.kallsyms] [k] native_sched_clock 0.04% hackbench [kernel.kallsyms] [k] __buffer_unlock_commit 0.04% hackbench [kernel.kallsyms] [k] preempt_trace 0.04% hackbench [kernel.kallsyms] [k] prepare_ftrace_return 0.04% hackbench [kernel.kallsyms] [k] __this_cpu_preempt_check 0.04% hackbench [kernel.kallsyms] [k] ftrace_graph_caller See that the ftrace_caller took up more time than the ftrace_graph_caller did. With this patch: 0.05% hackbench [kernel.kallsyms] [k] __buffer_unlock_commit 0.04% hackbench [kernel.kallsyms] [k] call_filter_check_discard 0.04% hackbench [kernel.kallsyms] [k] ftrace_graph_caller 0.04% hackbench [kernel.kallsyms] [k] sched_clock The ftrace_caller is no where to be found and ftrace_graph_caller still takes up the same percentage. Signed-off-by:
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- 30 Jun, 2014 7 commits
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Oleg Nesterov authored
The usage of uprobe_buffer_enable() added by dcad1a20 is very wrong, 1. uprobe_buffer_enable() and uprobe_buffer_disable() are not balanced, _enable() should be called only if !enabled. 2. If uprobe_buffer_enable() fails probe_event_enable() should clear tp.flags and free event_file_link. 3. If uprobe_register() fails it should do uprobe_buffer_disable(). Link: http://lkml.kernel.org/p/20140627170146.GA18332@redhat.comAcked-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Oleg Nesterov authored
I do not know why dd9fa555 "tracing/uprobes: Move argument fetching to uprobe_dispatcher()" added the UPROBE_HANDLER_REMOVE, but it looks wrong. OK, perhaps it makes sense to avoid store_trace_args() if the tracee is nacked by uprobe_perf_filter(). But then we should kill the same code in uprobe_perf_func() and unify the TRACE/PROFILE filtering (we need to do this anyway to mix perf/ftrace). Until then this code actually adds the pessimization because uprobe_perf_filter() will be called twice and return T in likely case. Link: http://lkml.kernel.org/p/20140627170143.GA18329@redhat.comAcked-by:
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Oleg Nesterov authored
Add WARN_ON's into uprobe_unregister() and uprobe_apply() to ensure that nobody tries to play with the dead uprobe/consumer. This helps to catch the bugs like the one fixed by the previous patch. In the longer term we should fix this poorly designed interface. uprobe_register() should return "struct uprobe *" which should be passed to apply/unregister. Plus other semantic changes, see the changelog in commit 41ccba02. Link: http://lkml.kernel.org/p/20140627170140.GA18322@redhat.comAcked-by:
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Oleg Nesterov authored
This reverts commit 43fe9891. This patch is very wrong. Firstly, this change leads to unbalanced uprobe_unregister(). Just for example, # perf probe -x /lib/libc.so.6 syscall # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable # perf record -e probe_libc:syscall whatever after that uprobe is dead (unregistered) but the user of ftrace/perf can't know this, and it looks as if nobody hits this probe. This would be easy to fix, but there are other reasons why it is not simple to mix ftrace and perf. If nothing else, they can't share the same ->consumer.filter. This is fixable too, but probably we need to fix the poorly designed uprobe_register() interface first. At least "register" and "apply" should be clearly separated. Link: http://lkml.kernel.org/p/20140627170136.GA18319@redhat.com Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com> Cc: stable@vger.kernel.org # v3.14 Acked-by:
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Steven Rostedt (Red Hat) authored
The ftrace dynamic record has a flags element that also has a counter. Instead of hard coding "rec->flags & ~FTRACE_FL_MASK" all over the place. Use a macro instead. Signed-off-by: -
Steven Rostedt (Red Hat) authored
As new flags will be added to the ftrace dynamic record, and since the flags field is also a counter, converting the numbers used to do the shifting and masking into a set of macros where we only need to deal with the max bit count of the counter and the number of bits for the flags will prevent mistakes in the future. Dealing with only two numbers is much easier than updating all the macros that deal with shifting and masking. Signed-off-by: -
Steven Rostedt (Red Hat) authored
When registering a function callback for the function tracer, the ops can specify if it wants to save full regs (like an interrupt would) for each function that it traces, or if it does not care about regs and just wants to have the fastest return possible. Once a ops has registered a function, if other ops register that function they all will receive the regs too. That's because it does the work once, it does it for everyone. Now if the ops wanting regs unregisters the function so that there's only ops left that do not care about regs, those ops will still continue getting regs and going through the work for it on that function. This is because the disabling of the rec counter only sees the ops registered, and does not see the ops that are still attached, and does not know if the current ops that are still attached want regs or not. To play it safe, it just keeps regs being processed until no function is registered anymore. Instead of doing that, check the ops that are still registered for that function and if none want regs for it anymore, then disable the processing of regs. Signed-off-by:
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- 29 Jun, 2014 6 commits
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Linus Torvalds authored
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git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds authored
Pull ARM fixes from Russell King: "Another round of ARM fixes. The largest change here is the L2 changes to work around problems for the Armada 37x/380 devices, where most of the size comes down to comments rather than code. The other significant fix here is for the ptrace code, to ensure that rewritten syscalls work as intended. This was pointed out by Kees Cook, but Will Deacon reworked the patch to be more elegant. The remainder are fairly trivial changes" * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: 8087/1: ptrace: reload syscall number after secure_computing() check ARM: 8086/1: Set memblock limit for nommu ARM: 8085/1: sa1100: collie: add top boot mtd partition ARM: 8084/1: sa1100: collie: revert back to cfi_probe ARM: 8080/1: mcpm.h: remove unused variable declaration ARM: 8076/1: mm: add support for HW coherent systems in PL310 cache
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Randy Dunlap authored
Note that I don't maintain Documentation/ABI/, Documentation/devicetree/, or the language translation files. Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Dan Carpenter authored
These days most people use git to send patches so I have added a section about that. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Will Deacon authored
On the syscall tracing path, we call out to secure_computing() to allow seccomp to check the syscall number being attempted. As part of this, a SIGTRAP may be sent to the tracer and the syscall could be re-written by a subsequent SET_SYSCALL ptrace request. Unfortunately, this new syscall is ignored by the current code unless TIF_SYSCALL_TRACE is also set on the current thread. This patch slightly reworks the enter path of the syscall tracing code so that we always reload the syscall number from current_thread_info()->syscall after the potential ptrace traps. Acked-by:
Kees Cook <keescook@chromium.org> Tested-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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Laura Abbott authored
Commit 1c2f87c2 (ARM: 8025/1: Get rid of meminfo) changed find_limits to use memblock_get_current_limit for calculating the max_low pfn. nommu targets never actually set a limit on memblock though which means memblock_get_current_limit will just return the default value. Set the memblock_limit to be the end of DDR to make sure bounds are calculated correctly. Signed-off-by:
Laura Abbott <lauraa@codeaurora.org> Signed-off-by:
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