- 07 Mar, 2014 17 commits
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Petr Mladek authored
Ftrace modifies function calls using Int3 breakpoints on x86. The breakpoints are handled only when the patching is in progress. If something goes wrong, there is a recovery code that removes the breakpoints. If this fails, the system might get silently rebooted when a remaining break is not handled or an invalid instruction is proceed. We should BUG() when the breakpoint could not be removed. Otherwise, the system silently crashes when the function finishes the Int3 handler is disabled. Note that we need to modify remove_breakpoint() to return non-zero value only when there is an error. The return value was ignored before, so it does not cause any troubles. Link: http://lkml.kernel.org/r/1393258342-29978-4-git-send-email-pmladek@suse.czSigned-off-by:
Petr Mladek <pmladek@suse.cz> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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Petr Mladek authored
We should print some warning and kill ftrace functionality when the ftrace function is not set correctly. Otherwise, ftrace might do crazy things without an explanation. The error value has been ignored so far. Note that an error that happens during updating all the traced calls is handled in ftrace_replace_code(). We print more details about the particular failing address via ftrace_bug() there. Link: http://lkml.kernel.org/r/1393258342-29978-3-git-send-email-pmladek@suse.czSigned-off-by:
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Jiri Slaby authored
The 'freelist' member was introduced to 'struct dyn_ftrace' in commit ee000b7f (tracing: use union for multi-usages field), but the use of this member was later removed in 32082309 (ftrace: Remove usage of "freed" records). Remove also the 'freelist' member now. Link: http://lkml.kernel.org/r/1393268401-24379-5-git-send-email-jslaby@suse.czSigned-off-by:
Jiri Slaby <jslaby@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by:
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Jiri Slaby authored
As the data parameter is not really used by any ftrace_dyn_arch_init, remove that from ftrace_dyn_arch_init. This also removes the addr local variable from ftrace_init which is now unused. Note the documentation was imprecise as it did not suggest to set (*data) to 0. Link: http://lkml.kernel.org/r/1393268401-24379-4-git-send-email-jslaby@suse.cz Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-arch@vger.kernel.org Signed-off-by:
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Jiri Slaby authored
No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any way, it just sets the value to 0. And this is used as a return value in the caller -- ftrace_init, which just checks the retval against zero. Note there is also "return 0" in every ftrace_dyn_arch_init. So it is enough to check the retval and remove all the indirect sets of data on all archs. Link: http://lkml.kernel.org/r/1393268401-24379-3-git-send-email-jslaby@suse.cz Cc: linux-arch@vger.kernel.org Signed-off-by:
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Jiri Slaby authored
The function used to do allocations some time ago. This no longer happens and it only checks the count and prints some info. This patch inlines the body to the only caller. There are two reasons: * the name of the function was misleading * it's clear what is going on in ftrace_init now Link: http://lkml.kernel.org/r/1393268401-24379-2-git-send-email-jslaby@suse.czSigned-off-by:
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Jiri Slaby authored
Some of them can be local to functions, so make them local and pass them as parameters where needed: * __start_mcount_loc+__stop_mcount_loc are local to ftrace_init * ftrace_new_pgs -> new_pgs/start_pg * ftrace_update_cnt -> local update_cnt in ftrace_update_code Link: http://lkml.kernel.org/r/1393268401-24379-1-git-send-email-jslaby@suse.czSigned-off-by:
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Filipe Brandenburger authored
Use a temporary variable to store the expansion of the len expression. If the evaluation is expensive, this commit will ensure it is evaluated only once inside ftrace_get_offsets_<call>. Link: http://lkml.kernel.org/r/1393651938-16418-3-git-send-email-filbranden@google.comSigned-off-by:
Filipe Brandenburger <filbranden@google.com> Signed-off-by:
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Filipe Brandenburger authored
This fixes expansion of the len argument in __dynamic_array macros. The previous code from commit 7d536cb3 would not fully evaluate the expression before multiplying its result by the size of the type. This went unnoticed because the length stored in the high 16 bits of the offset (which is the one that was broken here) is only used by filter_pred_strloc which only acts on strings for which the size of the type is 1. Link: http://lkml.kernel.org/r/1393651938-16418-2-git-send-email-filbranden@google.comSigned-off-by:
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Steven Rostedt (Red Hat) authored
There's nothing in the module.h header that requires tracepoint.h to be included, and there may be cases that tracepoint.h may need to include module.h, which will cause recursive header issues. But module.h requires seeing HAVE_JUMP_LABEL which is set in jump_label.h which it just coincidentally gets from tracepoint.h. Link: http://lkml.kernel.org/r/20140307084712.5c68641a@gandalf.local.homeAcked-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Steven Rostedt (Red Hat) authored
The trace event headers are required to include tracepoint.h. The only reason they worked now is because module.h included tracepoint.h, and that will soon change. Link: http://lkml.kernel.org/r/20140226190644.591040764@goodmis.org Fixes: 7b2a2d4a "mm: migrate: Add a tracepoint for migrate_pages" Acked-by:
Mel Gorman <mgorman@suse.de> Signed-off-by:
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Steven Rostedt (Red Hat) authored
The trace event headers are required to include tracepoint.h. The only reason they worked now is because module.h included tracepoint.h, and that will soon change. Link: http://lkml.kernel.org/r/20140226190644.442886305@goodmis.org Fixes: 455b2864 "writeback: Initial tracing support" Cc: Dave Chinner <dchinner@redhat.com> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by:
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Steven Rostedt authored
Tracepoints were made to allow enabling a tracepoint in a module before that module was loaded. When a tracepoint is enabled and it does not exist, the name is stored and will be enabled when the tracepoint is created. The problem with this approach is that when a tracepoint is enabled when it expects to be there, it gives no warning that it does not exist. To add salt to the wound, if a module is added and sets the FORCED flag, which can happen if it isn't signed properly, the tracepoint code will not enabled the tracepoints, but they will be created in the debugfs system! When a user goes to enable the tracepoint, the tracepoint code will not see it existing and will think it is to be enabled later AND WILL NOT GIVE A WARNING. The tracing will look like it succeeded but will actually be doing nothing. This will cause lots of confusion and headaches for developers trying to figure out why they are not seeing their tracepoints. Link: http://lkml.kernel.org/r/20140213154507.4040fb06@gandalf.local.homeReported-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reported-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Steven Rostedt authored
The functions that assign the contents for the ftrace events are defined by the TRACE_EVENT() macros. Each event has its own unique way to assign data to its buffer. When you have over 500 events, that means there's 500 functions assigning data uniquely for each event (not really that many, as DECLARE_EVENT_CLASS() and multiple DEFINE_EVENT()s will only need a single function). By making helper functions in the core kernel to do some of the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux 12959102 1913504 9785344 24657950 178401e /tmp/vmlinux.patched That's a total of 28288 bytes, which comes down to 56 bytes per event. Link: http://lkml.kernel.org/r/20120810034708.370808175@goodmis.orgSigned-off-by:
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Steven Rostedt authored
The code that shows array fields for events is defined for all events. This can add up quite a bit when you have over 500 events. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux.patched That's a total of 3556 bytes, which comes down to 7 bytes per event. Although it's not much, this code is just called at initialization of the events. Link: http://lkml.kernel.org/r/20120810034708.084036335@goodmis.orgSigned-off-by:
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Steven Rostedt authored
The code for trace events to format the raw recorded event data into human readable format in the 'trace' file is repeated for every event in the system. When you have over 500 events, this can add up quite a bit. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12991007 1913568 9785344 24689919 178bcff /tmp/vmlinux.orig 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux.patched Note, this version does not save as much as the version of this patch I had a few years ago. That is because in the mean time, commit f71130de ("tracing: Add a helper function for event print functions") did a lot of the work my original patch did. But this change helps slightly, and is part of a larger clean up to reduce the size much further. Link: http://lkml.kernel.org/r/20120810034707.378538034@goodmis.org Cc: Li Zefan <lizefan@huawei.com> Signed-off-by:
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Steven Rostedt (Red Hat) authored
Having ftrace_write() return -EPERM on failure, as that's what the callers return, then we can clean up the code a bit. That is, instead of: if (ftrace_write(...)) return -EPERM; return 0; or if (ftrace_write(...)) { ret = -EPERM; goto_out; } We can instead have: return ftrace_write(...); or ret = ftrace_write(...); if (ret) goto out; Signed-off-by:
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- 04 Mar, 2014 3 commits
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Steven Rostedt (Red Hat) authored
No reason to allocate tp_module structures for modules that have no tracepoints. This just wastes memory. Fixes: b75ef8b4 "Tracepoint: Dissociate from module mutex" Acked-by:
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Petr Mladek authored
If a failure occurs while modifying ftrace function, it bails out and will remove the tracepoints to be back to what the code originally was. There is missing the final sync run across the CPUs after the fix up is done and before the ftrace int3 handler flag is reset. Here's the description of the problem: CPU0 CPU1 ---- ---- remove_breakpoint(); modifying_ftrace_code = 0; [still sees breakpoint] <takes trap> [sees modifying_ftrace_code as zero] [no breakpoint handler] [goto failed case] [trap exception - kernel breakpoint, no handler] BUG() Link: http://lkml.kernel.org/r/1393258342-29978-2-git-send-email-pmladek@suse.cz Fixes: 8a4d0a68 "ftrace: Use breakpoint method to update ftrace caller" Acked-by:
Frederic Weisbecker <fweisbec@gmail.com> Acked-by:
H. Peter Anvin <hpa@linux.intel.com> Signed-off-by:
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Steven Rostedt (Red Hat) authored
If a failure occurs while enabling a trace, it bails out and will remove the tracepoints to be back to what the code originally was. But the fix up had some bugs in it. By injecting a failure in the code, the fix up ran to completion, but shortly afterward the system rebooted. There was two bugs here. The first was that there was no final sync run across the CPUs after the fix up was done, and before the ftrace int3 handler flag was reset. That means that other CPUs could still see the breakpoint and trigger on it long after the flag was cleared, and the int3 handler would think it was a spurious interrupt. Worse yet, the int3 handler could hit other breakpoints because the ftrace int3 handler flag would have prevented the int3 handler from going further. Here's a description of the issue: CPU0 CPU1 ---- ---- remove_breakpoint(); modifying_ftrace_code = 0; [still sees breakpoint] <takes trap> [sees modifying_ftrace_code as zero] [no breakpoint handler] [goto failed case] [trap exception - kernel breakpoint, no handler] BUG() The second bug was that the removal of the breakpoints required the "within()" logic updates instead of accessing the ip address directly. As the kernel text is mapped read-only when CONFIG_DEBUG_RODATA is set, and the removal of the breakpoint is a modification of the kernel text. The ftrace_write() includes the "within()" logic, where as, the probe_kernel_write() does not. This prevented the breakpoint from being removed at all. Link: http://lkml.kernel.org/r/1392650573-3390-1-git-send-email-pmladek@suse.czReported-by:
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- 20 Feb, 2014 18 commits
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Steven Rostedt (Red Hat) authored
The ENABLED flag needs to be cleared when a ftrace_ops is unregistered otherwise it wont be able to be registered again. This is only for static tracing and does not affect DYNAMIC_FTRACE at all. Signed-off-by: -
Steven Rostedt authored
Being able to change the trace clock at boot can be advantageous if you need a better source of when things happen across CPUs. The default trace clock is the fastest, but it uses local clocks which may not be synced across CPUs and it does not let you know when events took place with respect to events on other CPUs. The global trace clock can help in this case, and if you do not care about timings, the counter "clock" is the best, as that is just a simple atomic counter that is incremented for every event. Usage is to add "trace_clock=counter" on the kernel command line. You can replace counter with "global" or any of the clocks listed in /sys/kernel/debug/tracing/trace_clock Suggested-by:
Thomas Gleixner <tglx@linutronix.de> Tested-by:
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Namhyung Kim authored
It seems there's no reason to prevent mixed used of ftrace and perf for a single uprobe event. At least the kprobes already support it. Link: http://lkml.kernel.org/r/1389946120-19610-6-git-send-email-namhyung@kernel.orgReviewed-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
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Namhyung Kim authored
Add support for event triggering to uprobes. This is same as kprobes support added by Tom (plus cleanup by Steven). Link: http://lkml.kernel.org/r/1389946120-19610-5-git-send-email-namhyung@kernel.orgReviewed-by:
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zhangwei(Jovi) authored
Support multi-buffer on uprobe-based dynamic events by using ftrace_event_file. This patch is based kprobe-based dynamic events multibuffer support work initially, commited by Masami(commit 41a7dd42), but revised as below: Oleg changed the kprobe-based multibuffer design from array-pointers of ftrace_event_file into simple list, so this patch also change to the list design. rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func, to synchronize with ftrace_event_file list add and delete. Even though we allow multi-uprobes instances now, but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive in probe_event_enable currently, this means we cannot allow one user is using uprobe-tracer, and another user is using perf-probe on same uprobe concurrently. (Perhaps this will be fix in future, kprobe don't have this limitation now) Link: http://lkml.kernel.org/r/1389946120-19610-4-git-send-email-namhyung@kernel.orgReviewed-by:
Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by:
zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by:
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Namhyung Kim authored
A single uprobe event might serve different users like ftrace and perf. And this is especially important for upcoming multi buffer support. But in this case it'll fetch (same) data from userspace multiple times. So move it to the beginning of the dispatcher function and reuse it for each users. Link: http://lkml.kernel.org/r/1389946120-19610-3-git-send-email-namhyung@kernel.orgReviewed-by:
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Namhyung Kim authored
The uprobe_{trace,perf}_print functions are misnomers since what they do is not printing. There's also a real print function named print_uprobe_event() so they'll only increase confusion IMHO. Rename them with double underscores to follow convention of kprobe. Link: http://lkml.kernel.org/r/1389946120-19610-2-git-send-email-namhyung@kernel.orgReviewed-by: -
Steven Rostedt (Red Hat) authored
Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance directories to let users filter of functions to trace for the given instance. Signed-off-by: -
Steven Rostedt (Red Hat) authored
In preparation for having the function tracing instances be able to filter on functions, the generic filter functions must first be converted to take in the global_ops as a parameter. Signed-off-by: -
Steven Rostedt (Red Hat) authored
Allow instances (sub-buffers) to enable function tracing. Each instance will have its own function tracing capability. For now, instances will not have function stack tracing, or will they be able to pick and choose what functions they can trace. Picking and choosing their own functions will come later. Signed-off-by: -
Steven Rostedt (Red Hat) authored
As tracers will soon be used by instances, the tracer enabled field needs to be converted to a counter instead of a boolean. This counter is protected by the trace_types_lock mutex. Signed-off-by: -
Steven Rostedt (Red Hat) authored
When an instance is about to be deleted, make sure the tracer is set to nop. If it isn't reset the tracer and set it to the nop tracer, otherwise memory leaks and bad pointers may result. Signed-off-by: -
Steven Rostedt (Red Hat) authored
If global_ops function is being called directly, instead of the global_ops list function, set the global_ops private to be the same as the ops private that's being called directly. Signed-off-by: -
Steven Rostedt (Red Hat) authored
Passing data to the function callback was originally done by adding the ftrace_ops in another structure, and using the container_of() to get the field. But this adds a bit more complexity than it is worth, and adding a simple .private field to ftrace_ops makes things a lot easier. But be warned, the .private data should not be freed once it is used unless the ftrace_ops itself has gone through the necessary freeing routines. A simple synchronize_sched() is not enough as functions can be traced that are called outside the view of RCU and all its concoctions. Signed-off-by: -
Steven Rostedt (Red Hat) authored
Currently, only the top level instance can have tracing options. Signed-off-by: -
Steven Rostedt (Red Hat) authored
Currently the tracers (function, function_graph, irqsoff, etc) can only be used by the top level tracing directory (not for instances). This sets up the infrastructure to allow instances to be able to run a separate tracer apart from the what the top level tracing is doing. As tracers need to adapt for being used by instances, the tracers must flag if they can be used by instances or not. Currently only the 'nop' tracer can be used by all instances. Signed-off-by: -
Steven Rostedt (Red Hat) authored
As options (flags) may affect instances instead of being global the flag_changed() callbacks need to receive the trace_array descriptor of the instance they will be modifying. Signed-off-by: -
Steven Rostedt (Red Hat) authored
As options (flags) may affect instances instead of being global the set_flag() callbacks need to receive the trace_array descriptor of the instance they will be modifying. Signed-off-by:
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- 16 Feb, 2014 2 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds authored
Pull btrfs fixes from Chris Mason: "We have a small collection of fixes in my for-linus branch. The big thing that stands out is a revert of a new ioctl. Users haven't shipped yet in btrfs-progs, and Dave Sterba found a better way to export the information" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: use right clone root offset for compressed extents btrfs: fix null pointer deference at btrfs_sysfs_add_one+0x105 Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol Btrfs: fix max_inline mount option Btrfs: fix a lockdep warning when cleaning up aborted transaction Revert "btrfs: add ioctl to export size of global metadata reservation"
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