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2011-10-31kernel: Add <linux/module.h> to files using it implicitlyPaul Gortmaker1-0/+1
These files are doing things like module_put and try_module_get so they need to call out the module.h for explicit inclusion, rather than getting it via <linux/device.h> which we ideally want to remove the module.h inclusion from. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-11tracing: Warn on output if the function tracer was found corruptedSteven Rostedt1-0/+8
As the function tracer is very intrusive, lots of self checks are performed on the tracer and if something is found to be strange it will shut itself down keeping it from corrupting the rest of the kernel. This shutdown may still allow functions to be traced, as the tracing only stops new modifications from happening. Trying to stop the function tracer itself can cause more harm as it requires code modification. Although a WARN_ON() is executed, a user may not notice it. To help the user see that something isn't right with the tracing of the system a big warning is added to the output of the tracer that lets the user know that their data may be incomplete. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-21Merge branch 'tip/perf/core' of ↵Ingo Molnar1-21/+74
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2011-07-21Merge branch 'perf/urgent' into perf/coreIngo Molnar1-11/+31
Merge reason: pick up the latest fixes - they won't make v3.0. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14ftrace: Fix regression where ftrace breaks when modules are loadedSteven Rostedt1-2/+28
Enabling function tracer to trace all functions, then load a module and then disable function tracing will cause ftrace to fail. This can also happen by enabling function tracing on the command line: ftrace=function and during boot up, modules are loaded, then you disable function tracing with 'echo nop > current_tracer' you will trigger a bug in ftrace that will shut itself down. The reason is, the new ftrace code keeps ref counts of all ftrace_ops that are registered for tracing. When one or more ftrace_ops are registered, all the records that represent the functions that the ftrace_ops will trace have a ref count incremented. If this ref count is not zero, when the code modification runs, that function will be enabled for tracing. If the ref count is zero, that function will be disabled from tracing. To make sure the accounting was working, FTRACE_WARN_ON()s were added to updating of the ref counts. If the ref count hits its max (> 2^30 ftrace_ops added), or if the ref count goes below zero, a FTRACE_WARN_ON() is triggered which disables all modification of code. Since it is common for ftrace_ops to trace all functions in the kernel, instead of creating > 20,000 hash items for the ftrace_ops, the hash count is just set to zero, and it represents that the ftrace_ops is to trace all functions. This is where the issues arrise. If you enable function tracing to trace all functions, and then add a module, the modules function records do not get the ref count updated. When the function tracer is disabled, all function records ref counts are subtracted. Since the modules never had their ref counts incremented, they go below zero and the FTRACE_WARN_ON() is triggered. The solution to this is rather simple. When modules are loaded, and their functions are added to the the ftrace pool, look to see if any ftrace_ops are registered that trace all functions. And for those, update the ref count for the module function records. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13ftrace: Fix dynamic selftest failure on some archsSteven Rostedt1-0/+26
Archs that do not implement CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST, will fail the dynamic ftrace selftest. The function tracer has a quick 'off' variable that will prevent the call back functions from being called. This variable is called function_trace_stop. In x86, this is implemented directly in the mcount assembly, but for other archs, an intermediate function is used called ftrace_test_stop_func(). In dynamic ftrace, the function pointer variable ftrace_trace_function is used to update the caller code in the mcount caller. But for archs that do not have CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST set, it only calls ftrace_test_stop_func() instead, which in turn calls __ftrace_trace_function. When more than one ftrace_ops is registered, the function it calls is ftrace_ops_list_func(), which will iterate over all registered ftrace_ops and call the callbacks that have their hash matching. The issue happens when two ftrace_ops are registered for different functions and one is then unregistered. The __ftrace_trace_function is then pointed to the remaining ftrace_ops callback function directly. This mean it will be called for all functions that were registered to trace by both ftrace_ops that were registered. This is not an issue for archs with CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST, because the update of ftrace_trace_function doesn't happen until after all functions have been updated, and then the mcount caller is updated. But for those archs that do use the ftrace_test_stop_func(), the update is immediate. The dynamic selftest fails because it hits this situation, and the ftrace_ops that it registers fails to only trace what it was suppose to and instead traces all other functions. The solution is to delay the setting of __ftrace_trace_function until after all the functions have been updated according to the registered ftrace_ops. Also, function_trace_stop is set during the update to prevent function tracing from calling code that is caused by the function tracer itself. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13ftrace: Update filter when tracing enabled in set_ftrace_filter()Steven Rostedt1-0/+4
Currently, if set_ftrace_filter() is called when the ftrace_ops is active, the function filters will not be updated. They will only be updated when tracing is disabled and re-enabled. Update the functions immediately during set_ftrace_filter(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13ftrace: Balance records when updating the hashSteven Rostedt1-16/+33
Whenever the hash of the ftrace_ops is updated, the record counts must be balance. This requires disabling the records that are set in the original hash, and then enabling the records that are set in the updated hash. Moving the update into ftrace_hash_move() removes the bug where the hash was updated but the records were not, which results in ftrace triggering a warning and disabling itself because the ftrace_ops filter is updated while the ftrace_ops was registered, and then the failure happens when the ftrace_ops is unregistered. The current code will not trigger this bug, but new code will. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-07ftrace: Do not disable interrupts for modules in mcount updateSteven Rostedt1-5/+11
When I mounted an NFS directory, it caused several modules to be loaded. At the time I was running the preemptirqsoff tracer, and it showed the following output: # tracer: preemptirqsoff # # preemptirqsoff latency trace v1.1.5 on 2.6.33.9-rt30-mrg-test # -------------------------------------------------------------------- # latency: 1177 us, #4/4, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: modprobe-19370 (uid:0 nice:0 policy:0 rt_prio:0) # ----------------- # => started at: ftrace_module_notify # => ended at: ftrace_module_notify # # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| /_--=> lock-depth # |||||/ delay # cmd pid |||||| time | caller # \ / |||||| \ | / modprobe-19370 3d.... 0us!: ftrace_process_locs <-ftrace_module_notify modprobe-19370 3d.... 1176us : ftrace_process_locs <-ftrace_module_notify modprobe-19370 3d.... 1178us : trace_hardirqs_on <-ftrace_module_notify modprobe-19370 3d.... 1178us : <stack trace> => ftrace_process_locs => ftrace_module_notify => notifier_call_chain => __blocking_notifier_call_chain => blocking_notifier_call_chain => sys_init_module => system_call_fastpath That's over 1ms that interrupts are disabled on a Real-Time kernel! Looking at the cause (being the ftrace author helped), I found that the interrupts are disabled before the code modification of mcounts into nops. The interrupts only need to be disabled on start up around this code, not when modules are being loaded. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-07ftrace: Fix regression of :mod:module function enablingSteven Rostedt1-9/+3
The new code that allows different utilities to pick and choose what functions they trace broke the :mod: hook that allows users to trace only functions of a particular module. The reason is that the :mod: hook bypasses the hash that is setup to allow individual users to trace their own functions and uses the global hash directly. But if the global hash has not been set up, it will cause a bug: echo '*:mod:radeon' > /sys/kernel/debug/set_ftrace_filter produces: [drm:drm_mode_getfb] *ERROR* invalid framebuffer id [drm:radeon_crtc_page_flip] *ERROR* failed to reserve new rbo buffer before flip BUG: unable to handle kernel paging request at ffffffff8160ec90 IP: [<ffffffff810d9136>] add_hash_entry+0x66/0xd0 PGD 1a05067 PUD 1a09063 PMD 80000000016001e1 Oops: 0003 [#1] SMP Jul 7 04:02:28 phyllis kernel: [55303.858604] CPU 1 Modules linked in: cryptd aes_x86_64 aes_generic binfmt_misc rfcomm bnep ip6table_filter hid radeon r8169 ahci libahci mii ttm drm_kms_helper drm video i2c_algo_bit intel_agp intel_gtt Pid: 10344, comm: bash Tainted: G WC 3.0.0-rc5 #1 Dell Inc. Inspiron N5010/0YXXJJ RIP: 0010:[<ffffffff810d9136>] [<ffffffff810d9136>] add_hash_entry+0x66/0xd0 RSP: 0018:ffff88003a96bda8 EFLAGS: 00010246 RAX: ffff8801301735c0 RBX: ffffffff8160ec80 RCX: 0000000000306ee0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880137c92940 RBP: ffff88003a96bdb8 R08: ffff880137c95680 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81c9df78 R13: ffff8801153d1000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f329c18a700(0000) GS:ffff880137c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff8160ec90 CR3: 000000003002b000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process bash (pid: 10344, threadinfo ffff88003a96a000, task ffff88012fcfc470) Stack: 0000000000000fd0 00000000000000fc ffff88003a96be38 ffffffff810d92f5 ffff88011c4c4e00 ffff880000000000 000000000b69f4d0 ffffffff8160ec80 ffff8800300e6f06 0000000081130295 0000000000000282 ffff8800300e6f00 Call Trace: [<ffffffff810d92f5>] match_records+0x155/0x1b0 [<ffffffff810d940c>] ftrace_mod_callback+0xbc/0x100 [<ffffffff810dafdf>] ftrace_regex_write+0x16f/0x210 [<ffffffff810db09f>] ftrace_filter_write+0xf/0x20 [<ffffffff81166e48>] vfs_write+0xc8/0x190 [<ffffffff81167001>] sys_write+0x51/0x90 [<ffffffff815c7e02>] system_call_fastpath+0x16/0x1b Code: 48 8b 33 31 d2 48 85 f6 75 33 49 89 d4 4c 03 63 08 49 8b 14 24 48 85 d2 48 89 10 74 04 48 89 42 08 49 89 04 24 4c 89 60 08 31 d2 RIP [<ffffffff810d9136>] add_hash_entry+0x66/0xd0 RSP <ffff88003a96bda8> CR2: ffffffff8160ec90 ---[ end trace a5d031828efdd88e ]--- Reported-by: Brian Marete <marete@toshnix.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-05Merge branch 'tip/perf/core-2' of ↵Ingo Molnar1-16/+4
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2011-06-14tracing: Convert to kstrtoul_from_userPeter Huewe1-11/+2
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: Peter Huewe <peterhuewe@gmx.de> Link: http://lkml.kernel.org/r/1307476707-14762-1-git-send-email-peterhuewe@gmx.de Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-06-14ftrace: Fixed an include coding style issuePaul McQuade1-5/+2
Removed <asm/ftrace.h> because <linux/ftrace.h> was already declared. Braces of struct's coding style fixed. Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul McQuade <tungstentide@gmail.com> Link: http://lkml.kernel.org/r/4DE59711.3090900@gmail.com Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-06-07ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqsSteven Rostedt1-0/+7
Revert the commit that removed the disabling of interrupts around the initial modifying of mcount callers to nops, and update the comment. The original comment was outdated and stated that the interrupts were being disabled to prevent kstop machine, which was required with the old ftrace daemon, but was no longer the case. What the comment failed to mention was that interrupts needed to be disabled to keep interrupts from preempting the modifying of the code and then executing the code that was partially modified. Revert the commit and update the comment. Reported-by: Richard W.M. Jones <rjones@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-06-06ftrace: Fix possible undefined return codeGuoWen Li1-1/+1
kernel/trace/ftrace.c: In function 'ftrace_regex_write.clone.15': kernel/trace/ftrace.c:2743:6: warning: 'ret' may be used uninitialized in this function Signed-off-by: GuoWen Li <guowen.li.linux@gmail.com> Link: http://lkml.kernel.org/r/201106011918.47939.guowen.li.linux@gmail.com Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-25ftrace: Add internal recursive checksSteven Rostedt1-1/+12
Witold reported a reboot caused by the selftests of the dynamic function tracer. He sent me a config and I used ktest to do a config_bisect on it (as my config did not cause the crash). It pointed out that the problem config was CONFIG_PROVE_RCU. What happened was that if multiple callbacks are attached to the function tracer, we iterate a list of callbacks. Because the list is managed by synchronize_sched() and preempt_disable, the access to the pointers uses rcu_dereference_raw(). When PROVE_RCU is enabled, the rcu_dereference_raw() calls some debugging functions, which happen to be traced. The tracing of the debug function would then call rcu_dereference_raw() which would then call the debug function and then... well you get the idea. I first wrote two different patches to solve this bug. 1) add a __rcu_dereference_raw() that would not do any checks. 2) add notrace to the offending debug functions. Both of these patches worked. Talking with Paul McKenney on IRC, he suggested to add recursion detection instead. This seemed to be a better solution, so I decided to implement it. As the task_struct already has a trace_recursion to detect recursion in the ring buffer, and that has a very small number it allows, I decided to use that same variable to add flags that can detect the recursion inside the infrastructure of the function tracer. I plan to change it so that the task struct bit can be checked in mcount, but as that requires changes to all archs, I will hold that off to the next merge window. Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1306348063.1465.116.camel@gandalf.stny.rr.com Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-25ftrace: Set ops->flag to enabled even on static function tracingSteven Rostedt1-1/+5
When dynamic ftrace is not configured, the ops->flags still needs to have its FTRACE_OPS_FL_ENABLED bit set in ftrace_startup(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-25ftrace: Have ftrace_startup() return failure codeSteven Rostedt1-6/+8
The register_ftrace_function() returns an error code on failure except if the call to ftrace_startup() fails. Add a error return to ftrace_startup() if it fails to start, allowing register_ftrace_funtion() to return a proper error value. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Modify ftrace_set_filter/notrace to take opsSteven Rostedt1-2/+44
Since users of the function tracer can now pick and choose which functions they want to trace agnostically from other users of the function tracer, we need to pass the ops struct to the ftrace_set_filter() functions. The functions ftrace_set_global_filter() and ftrace_set_global_notrace() is added to keep the old filter functions which are used to modify the generic function tracers. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Allow dynamically allocated function tracersSteven Rostedt1-7/+30
Now that functions may be selected individually, it only makes sense that we should allow dynamically allocated trace structures to be traced. This will allow perf to allocate a ftrace_ops structure at runtime and use it to pick and choose which functions that structure will trace. Note, a dynamically allocated ftrace_ops will always be called indirectly instead of being called directly from the mcount in entry.S. This is because there's no safe way to prevent mcount from being preempted before calling the function, unless we modify every entry.S to do so (not likely). Thus, dynamically allocated functions will now be called by the ftrace_ops_list_func() that loops through the ops that are allocated if there are more than one op allocated at a time. This loop is protected with a preempt_disable. To determine if an ftrace_ops structure is allocated or not, a new util function was added to the kernel/extable.c called core_kernel_data(), which returns 1 if the address is between _sdata and _edata. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Implement separate user function filteringSteven Rostedt1-38/+155
ftrace_ops that are registered to trace functions can now be agnostic to each other in respect to what functions they trace. Each ops has their own hash of the functions they want to trace and a hash to what they do not want to trace. A empty hash for the functions they want to trace denotes all functions should be traced that are not in the notrace hash. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Free hash with call_rcu_sched()Steven Rostedt1-27/+28
When a hash is modified and might be in use, we need to perform a schedule RCU operation on it, as the hashes will soon be used directly in the function tracer callback. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Have global_ops store the functions that are to be tracedSteven Rostedt1-16/+53
This is a step towards each ops structure defining its own set of functions to trace. As the current code with pid's and such are specific to the global_ops, it is restructured to be used with the global ops. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Add ops parameter to ftrace_startup/shutdown functionsSteven Rostedt1-14/+14
In order to allow different ops to enable different functions, the ftrace_startup() and ftrace_shutdown() functions need the ops parameter passed to them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Add enabled_functions fileSteven Rostedt1-2/+49
Add the enabled_functions file that is used to show all the functions that have been enabled for tracing as well as their ref counts. This helps seeing if any function has been registered and what functions are being traced. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Use counters to enable functions to traceSteven Rostedt1-16/+142
Every function has its own record that stores the instruction pointer and flags for the function to be traced. There are only two flags: enabled and free. The enabled flag states that tracing for the function has been enabled (actively traced), and the free flag states that the record no longer points to a function and can be used by new functions (loaded modules). These flags are now moved to the MSB of the flags (actually just the top 32bits). The rest of the bits (30 bits) are now used as a ref counter. Everytime a tracer register functions to trace, those functions will have its counter incremented. When tracing is enabled, to determine if a function should be traced, the counter is examined, and if it is non-zero it is set to trace. When a ftrace_ops is registered to trace functions, its hashes are examined. If the ftrace_ops filter_hash count is zero, then all functions are set to be traced, otherwise only the functions in the hash are to be traced. The exception to this is if a function is also in the ftrace_ops notrace_hash. Then that function's counter is not incremented for this ftrace_ops. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Separate hash allocation and assignmentSteven Rostedt1-42/+233
When filtering, allocate a hash to insert the function records. After the filtering is complete, assign it to the ftrace_ops structure. This allows the ftrace_ops structure to have a much smaller array of hash buckets instead of wasting a lot of memory. A read only empty_hash is created to be the minimum size that any ftrace_ops can point to. When a new hash is created, it has the following steps: o Allocate a default hash. o Walk the function records assigning the filtered records to the hash o Allocate a new hash with the appropriate size buckets o Move the entries from the default hash to the new hash. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Create a global_ops to hold the filter and notrace hashesSteven Rostedt1-19/+46
Combine the filter and notrace hashes to be accessed by a single entity, the global_ops. The global_ops is a ftrace_ops structure that is passed to different functions that can read or modify the filtering of the function tracer. The ftrace_ops structure was modified to hold a filter and notrace hashes so that later patches may allow each ftrace_ops to have its own set of rules to what functions may be filtered. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Use hash instead for FTRACE_FL_FILTERSteven Rostedt1-82/+69
When multiple users are allowed to have their own set of functions to trace, having the FTRACE_FL_FILTER flag will not be enough to handle the accounting of those users. Each user will need their own set of functions. Replace the FTRACE_FL_FILTER with a filter_hash instead. This is temporary until the rest of the function filtering accounting gets in. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Replace FTRACE_FL_NOTRACE flag with a hash of ignored functionsSteven Rostedt1-26/+150
To prepare for the accounting system that will allow multiple users of the function tracer, having the FTRACE_FL_NOTRACE as a flag in the dyn_trace record does not make sense. All ftrace_ops will soon have a hash of functions they should trace and not trace. By making a global hash of functions not to trace makes this easier for the transition. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-01Merge branch 'tip/perf/core' of ↵Ingo Molnar1-209/+138
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2011-04-29ftrace: Consolidate the function match routines for normal and modsSteven Rostedt1-62/+36
The code used for matching functions is almost identical between normal selecting of functions and using the :mod: feature of set_ftrace_notrace. Consolidate the two users into one function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Consolidate updating of ftrace_trace_functionSteven Rostedt1-61/+34
There are three locations that perform almost identical functions in order to update the ftrace_trace_function (the ftrace function variable that gets called by mcount). Consolidate these into a single function called update_ftrace_function(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Move record update for normal and modules into a separate functionSteven Rostedt1-8/+11
The updating of a function record is moved to a single function. This will allow us to add specific changes in one location for both modules and kernel functions. Later patches will determine if the function record itself needs to be updated (which enables the mcount caller), or just the ftrace_ops needs the update. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Remove FTRACE_FL_CONVERTED flagSteven Rostedt1-8/+4
Since we disable all function tracer processing if we detect that a modification of a instruction had failed, we do not need to track that the record has failed. No more ftrace processing is allowed, and the FTRACE_FL_CONVERTED flag is pointless. The FTRACE_FL_CONVERTED flag was used to denote records that were successfully converted from mcount calls into nops. But if a single record fails, all of ftrace is disabled. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Remove FTRACE_FL_FAILED flagSteven Rostedt1-29/+47
Since we disable all function tracer processing if we detect that a modification of a instruction had failed, we do not need to track that the record has failed. No more ftrace processing is allowed, and the FTRACE_FL_FAILED flag is pointless. Removing this flag simplifies some of the code, but some ftrace_disabled checks needed to be added or move around a little. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Remove failures fileSteven Rostedt1-37/+2
The failures file in the debugfs tracing directory would list the functions that failed to convert when the old dead ftrace daemon tried to update code but failed. Since this code is now dead along with the daemon the failures file is useless. Remove it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Remove unnecessary disabling of irqsSteven Rostedt1-4/+0
The disabling of interrupts around ftrace_update_code() was used to protect against the evil ftrace daemon from years past. But that daemon has long been killed. It is safe to keep interrupts enabled while updating the initial mcount into nops. The ftrace_mutex is also held which keeps other users at bay. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Make FTRACE_WARN_ON() work in if conditionSteven Rostedt1-6/+10
Let FTRACE_WARN_ON() be used as a stand alone statement or inside a conditional: if (FTRACE_WARN_ON(x)) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29ftrace: Only update the function code on write to filter filesSteven Rostedt1-5/+7
If function tracing is enabled, a read of the filter files will cause the call to stop_machine to update the function trace sites. It should only call stop_machine on write. Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-31Fix common misspellingsLucas De Marchi1-2/+2
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-22tracing: Fix set_ftrace_filter probe function displayJiri Olsa1-2/+1
If one or more function probes (like traceon) are enabled, and there's no other function filter, the first probe func is skipped (which one depends on the position in the hash). $ echo sys_open:traceon sys_close:traceon > ./set_ftrace_filter $ cat set_ftrace_filter #### all functions enabled #### sys_close:traceon:unlimited $ The reason was, that in the case of no other function filter, the func_pos was not properly updated before calling t_hash_start. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1297874134-7008-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-11ftrace: Fix memory leak with function graph and cpu hotplugSteven Rostedt1-7/+45
When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stable Tree <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds1-0/+2
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-18tracing/trivial: Remove cast from void*matt mooney1-2/+2
Unnecessary cast from void* in assignment. Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann1-0/+2
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-09-15Merge branch 'tip/perf/core' of ↵Ingo Molnar1-29/+78
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2010-09-14tracing: Remove leftover FTRACE_ENABLE/DISABLE_MCOUNT enumsSteven Rostedt1-14/+4
The enums for FTRACE_ENABLE_MCOUNT and FTRACE_DISABLE_MCOUNT were used as commands to ftrace_run_update_code(). But these commands were used by the old nasty ftrace daemon that has long been slain. This is a clean up patch to remove the references to these enums and simplify the code a little. Reported-by: Wu Zhangjin <wuzhangjin@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-14tracing: Fix reading of set_ftrace_filter across listsSteven Rostedt1-3/+3
If we do: # cd /sys/kernel/debug # echo 'do_IRQ:traceon schedule:traceon sys_write:traceon' > \ set_ftrace_filter # cat set_ftrace_filter We get the following output: #### all functions enabled #### sys_write:traceon:unlimited schedule:traceon:unlimited do_IRQ:traceon:unlimited This outputs two lists. One is the fact that all functions are currently enabled for function tracing, the other has three probed functions, which happen to have 'traceon' as their commands. Currently, when reading the first list (functions enabled) the seq_file code will receive a "NULL" from the t_next() function causing it to exit early. This makes "read()" from userspace stop reading the code at this boarder. Although read is allowed to do this, some (broken) applications might consider this an end of file and stop early. This patch adds the start of the second list to t_next() when it finishes the first list. It is a simple change and gives the set_ftrace_filter file nicer reading ability. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-14tracing: Keep track of set_ftrace_filter position and allow lseek againSteven Rostedt1-8/+26
This patch keeps track of the index within the elements of set_ftrace_filter and if the position goes backwards, it nicely resets and starts from the beginning again. This allows for lseek and pread to work properly now. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>