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2014-01-23tracing: Fix formatting of trace README fileSteven Rostedt (Red Hat)
Fix the formatting of the README file in the trace debugfs to fit in an 80 character window. Also add a comment about the event trigger counter with regards to traceon and traceoff. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-22tracing/README: Add event file usage to tracing mini-HOWTOTom Zanussi
It would be useful to have a cheat-sheet for everything under tracing/events/ alongside the existing text describing the other files in the tracing/ dir. Add short descriptions of the directories and files under events/ along with examples, similar to the existing text for the other files in tracing/. Also clean up a few minor alignment problems noticed when adding the new text. Link: http://lkml.kernel.org/r/1389993104.3040.445.camel@empanada Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-19tracing: Fix buggered tee(2) on tracing_pipeAl Viro
In kernel/trace/trace.c we have this: static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { __free_page(buf->page); } static const struct pipe_buf_operations tracing_pipe_buf_ops = { .can_merge = 0, .map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, .confirm = generic_pipe_buf_confirm, .release = tracing_pipe_buf_release, .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; with void generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { page_cache_get(buf->page); } and I don't see anything that would've prevented tee(2) called on the pipe that got stuff spliced into it from that sucker. ->ops->get() will be called, then buf gets copied into target pipe's ->bufs[] and eventually readers get to both copies of the buffer. With get_page(page) look at that page __free_page(page) look at that page __free_page(page) which is not a good thing, to put it mildly. AFAICS, that ought to use the normal generic_pipe_buf_release() (aka page_cache_release(buf->page)), shouldn't it? [ SDR - As trace_pipe just allocates the page with alloc_page(GFP_KERNEL), and doesn't do anything special with it (no LRU logic). The __free_page() should be fine, as it wont actually free a page with reference count. Maybe there's a chance to leak memory? Anyway, This change is at a minimum good for being symmetric with generic_pipe_buf_get, it is fine to add. ] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [ SDR - Removed no longer used tracing_pipe_buf_release ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-14tracing: Have trace buffer point back to trace_arraySteven Rostedt (Red Hat)
The trace buffer has a descriptor pointer that goes back to the trace array. But it was never assigned. Luckily, nothing uses it (yet), but it will in the future. Although nothing currently uses this, if any of the new features get backported to older kernels, and because this is such a simple change, I'm marking it for stable too. Cc: stable@vger.kernel.org # v3.10+ Fixes: 12883efb670c "tracing: Consolidate max_tr into main trace_array structure" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-13ftrace: Fix synchronization location disabling and freeing ftrace_opsSteven Rostedt (Red Hat)
The synchronization needed after ftrace_ops are unregistered must happen after the callback is disabled from becing called by functions. The current location happens after the function is being removed from the internal lists, but not after the function callbacks were disabled, leaving the functions susceptible of being called after their callbacks are freed. This affects perf and any externel users of function tracing (LTTng and SystemTap). Cc: stable@vger.kernel.org # 3.0+ Fixes: cdbe61bfe704 "ftrace: Allow dynamically allocated function tracers" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-13ftrace: Have function graph only trace based on global_ops filtersSteven Rostedt (Red Hat)
Doing some different tests, I discovered that function graph tracing, when filtered via the set_ftrace_filter and set_ftrace_notrace files, does not always keep with them if another function ftrace_ops is registered to trace functions. The reason is that function graph just happens to trace all functions that the function tracer enables. When there was only one user of function tracing, the function graph tracer did not need to worry about being called by functions that it did not want to trace. But now that there are other users, this becomes a problem. For example, one just needs to do the following: # cd /sys/kernel/debug/tracing # echo schedule > set_ftrace_filter # echo function_graph > current_tracer # cat trace [..] 0) | schedule() { ------------------------------------------ 0) <idle>-0 => rcu_pre-7 ------------------------------------------ 0) ! 2980.314 us | } 0) | schedule() { ------------------------------------------ 0) rcu_pre-7 => <idle>-0 ------------------------------------------ 0) + 20.701 us | } # echo 1 > /proc/sys/kernel/stack_tracer_enabled # cat trace [..] 1) + 20.825 us | } 1) + 21.651 us | } 1) + 30.924 us | } /* SyS_ioctl */ 1) | do_page_fault() { 1) | __do_page_fault() { 1) 0.274 us | down_read_trylock(); 1) 0.098 us | find_vma(); 1) | handle_mm_fault() { 1) | _raw_spin_lock() { 1) 0.102 us | preempt_count_add(); 1) 0.097 us | do_raw_spin_lock(); 1) 2.173 us | } 1) | do_wp_page() { 1) 0.079 us | vm_normal_page(); 1) 0.086 us | reuse_swap_page(); 1) 0.076 us | page_move_anon_rmap(); 1) | unlock_page() { 1) 0.082 us | page_waitqueue(); 1) 0.086 us | __wake_up_bit(); 1) 1.801 us | } 1) 0.075 us | ptep_set_access_flags(); 1) | _raw_spin_unlock() { 1) 0.098 us | do_raw_spin_unlock(); 1) 0.105 us | preempt_count_sub(); 1) 1.884 us | } 1) 9.149 us | } 1) + 13.083 us | } 1) 0.146 us | up_read(); When the stack tracer was enabled, it enabled all functions to be traced, which now the function graph tracer also traces. This is a side effect that should not occur. To fix this a test is added when the function tracing is changed, as well as when the graph tracer is enabled, to see if anything other than the ftrace global_ops function tracer is enabled. If so, then the graph tracer calls a test trampoline that will look at the function that is being traced and compare it with the filters defined by the global_ops. As an optimization, if there's no other function tracers registered, or if the only registered function tracers also use the global ops, the function graph infrastructure will call the registered function graph callback directly and not go through the test trampoline. Cc: stable@vger.kernel.org # 3.3+ Fixes: d2d45c7a03a2 "tracing: Have stack_tracer use a separate list of functions" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-09ftrace: Synchronize setting function_trace_op with ftrace_trace_functionSteven Rostedt (Red Hat)
ftrace_trace_function is a variable that holds what function will be called directly by the assembly code (mcount). If just a single function is registered and it handles recursion itself, then the assembly will call that function directly without any helper function. It also passes in the ftrace_op that was registered with the callback. The ftrace_op to send is stored in the function_trace_op variable. The ftrace_trace_function and function_trace_op needs to be coordinated such that the called callback wont be called with the wrong ftrace_op, otherwise bad things can happen if it expected a different op. Luckily, there's no callback that doesn't use the helper functions that requires this. But there soon will be and this needs to be fixed. Use a set_function_trace_op to store the ftrace_op to set the function_trace_op to when it is safe to do so (during the update function within the breakpoint or stop machine calls). Or if dynamic ftrace is not being used (static tracing) then we have to do a bit more synchronization when the ftrace_trace_function is set as that takes affect immediately (as oppose to dynamic ftrace doing it with the modification of the trampoline). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-09tracing: Show available event triggers when no trigger is setSteven Rostedt (Red Hat)
Currently there's no way to know what triggers exist on a kernel without looking at the source of the kernel or randomly trying out triggers. Instead of creating another file in the debugfs system, simply show what available triggers are there when cat'ing the trigger file when it has no events: [root /sys/kernel/debug/tracing]# cat events/sched/sched_switch/trigger # Available triggers: # traceon traceoff snapshot stacktrace enable_event disable_event This stays consistent with other debugfs files where meta data like this is always proceeded with a '#' at the start of the line so that tools can strip these out. Link: http://lkml.kernel.org/r/20140107103548.0a84536d@gandalf.local.home Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-09tracing: Consolidate event trigger codeSteven Rostedt (Red Hat)
The event trigger code that checks for callback triggers before and after recording of an event has lots of flags checks. This code is duplicated throughout the ftrace events, kprobes and system calls. They all do the exact same checks against the event flags. Added helper functions ftrace_trigger_soft_disabled(), event_trigger_unlock_commit() and event_trigger_unlock_commit_regs() that consolidated the code and these are used instead. Link: http://lkml.kernel.org/r/20140106222703.5e7dbba2@gandalf.local.home Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-09tracing: Fix counter for traceon/off event triggersSteven Rostedt (Red Hat)
The counters for the traceon and traceoff are only suppose to decrement when the trigger enables or disables tracing. It is not suppose to decrement every time the event is hit. Only decrement the counter if the trigger actually did something. Link: http://lkml.kernel.org/r/20140106223124.0e5fd0b4@gandalf.local.home Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-06tracing: Remove double-underscore naming in syscall trigger invocationsTom Zanussi
There's no reason to use double-underscores for any variable name in ftrace_syscall_enter()/exit(), since those functions aren't generated and there's no need to avoid namespace collisions as with the event macros, which is where the original invocation code came from. Link: http://lkml.kernel.org/r/0b489c9d1f7ee315cff60fa0e4c2b433ade8ae0d.1389036657.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-06tracing/kprobes: Add trace event trigger invocationsTom Zanussi
Add code to the kprobe/kretprobe event functions that will invoke any event triggers associated with a probe's ftrace_event_file. The code to do this is very similar to the invocation code already used to invoke the triggers associated with static events and essentially replaces the existing soft-disable checks with a superset that preserves the original behavior but adds the bits needed to support event triggers. Link: http://lkml.kernel.org/r/f2d49f157b608070045fdb26c9564d5a05a5a7d0.1389036657.git.tom.zanussi@linux.intel.com Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-03tracing/probes: Fix build break on !CONFIG_KPROBE_EVENTNamhyung Kim
When kprobe-based dynamic event tracer is not enabled, it caused following build error: kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8dd): undefined reference to `fetch_symbol_u8' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8e9): undefined reference to `fetch_symbol_u16' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8f5): undefined reference to `fetch_symbol_u32' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c901): undefined reference to `fetch_symbol_u64' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c909): undefined reference to `fetch_symbol_string' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c913): undefined reference to `fetch_symbol_string_size' ... It was due to the fetch methods are referred from CHECK_FETCH_FUNCS macro and since it was only defined in trace_kprobe.c. Move NULL definition of such fetch functions to the header file. Note, it also requires CONFIG_BRANCH_PROFILING enabled to trigger this failure as well. This is because the "fetch_symbol_*" variables are referenced in a "else if" statement that will only call update_symbol_cache(), which is a static inline stub function when CONFIG_KPROBE_EVENT is not enabled. gcc is smart enough to optimize this "else if" out and that also removes the code that references the undefined variables. But when BRANCH_PROFILING is enabled, it fools gcc into keeping the if statement around and thus references the undefined symbols and fails to build. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-02tracing/uprobes: Add @+file_offset fetch methodNamhyung Kim
Enable to fetch data from a file offset. Currently it only supports fetching from same binary uprobe set. It'll translate the file offset to a proper virtual address in the process. The syntax is "@+OFFSET" as it does similar to normal memory fetching (@ADDR) which does no address translation. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02uprobes: Allocate ->utask before handler_chain() for tracing handlersOleg Nesterov
uprobe_trace_print() and uprobe_perf_print() need to pass the additional info to call_fetch() methods, currently there is no simple way to do this. current->utask looks like a natural place to hold this info, but we need to allocate it before handler_chain(). This is a bit unfortunate, perhaps we will find a better solution later, but this is simple and should work right now. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Add support for full argument access methodsNamhyung Kim
Enable to fetch other types of argument for the uprobes. IOW, we can access stack, memory, deref, bitfield and retval from uprobes now. The format for the argument types are same as kprobes (but @SYMBOL type is not supported for uprobes), i.e: @ADDR : Fetch memory at ADDR $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address $retval : Fetch return value +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address Note that the retval only can be used with uretprobes. Original-patch-by: Hyeoncheol Lee <cheol.lee@lge.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Fetch args before reserving a ring bufferNamhyung Kim
Fetching from user space should be done in a non-atomic context. So use a per-cpu buffer and copy its content to the ring buffer atomically. Note that we can migrate during accessing user memory thus use a per-cpu mutex to protect concurrent accesses. This is needed since we'll be able to fetch args from an user memory which can be swapped out. Before that uprobes could fetch args from registers only which saved in a kernel space. While at it, use __get_data_size() and store_trace_args() to reduce code duplication. And add struct uprobe_cpu_buffer and its helpers as suggested by Oleg. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Pass 'is_return' to traceprobe_parse_probe_arg()Namhyung Kim
Currently uprobes don't pass is_return to the argument parser so that it cannot make use of "$retval" fetch method since it only works for return probes. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Implement 'memory' fetch method for uprobesNamhyung Kim
Use separate method to fetch from memory. Move existing functions to trace_kprobe.c and make them static. Also add new memory fetch implementation for uprobes. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Add fetch{,_size} member into deref fetch methodHyeoncheol Lee
The deref fetch methods access a memory region but it assumes that it's a kernel memory since uprobes does not support them. Add ->fetch and ->fetch_size member in order to provide a proper access methods for supporting uprobes. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com> [namhyung@kernel.org: Split original patch into pieces as requested] Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Move 'symbol' fetch method to kprobesNamhyung Kim
Move existing functions to trace_kprobe.c and add NULL entries to the uprobes fetch type table. I don't make them static since some generic routines like update/free_XXX_fetch_param() require pointers to the functions. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Implement 'stack' fetch method for uprobesNamhyung Kim
Use separate method to fetch from stack. Move existing functions to trace_kprobe.c and make them static. Also add new stack fetch implementation for uprobes. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Split [ku]probes_fetch_type_tableNamhyung Kim
Use separate fetch_type_table for kprobes and uprobes. It currently shares all fetch methods but some of them will be implemented differently later. This is not to break build if [ku]probes is configured alone (like !CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT). So I added '__weak' to the table declaration so that it can be safely omitted when it configured out. Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Move fetch function helpers to trace_probe.hNamhyung Kim
Move fetch function helper macros/functions to the header file and make them external. This is preparation of supporting uprobe fetch table in next patch. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Integrate duplicate set_print_fmt()Namhyung Kim
The set_print_fmt() functions are implemented almost same for [ku]probes. Move it to a common place and get rid of the duplication. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/kprobes: Move common functions to trace_probe.hNamhyung Kim
The __get_data_size() and store_trace_args() will be used by uprobes too. Move them to a common location. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Convert to struct trace_probeNamhyung Kim
Convert struct trace_uprobe to make use of the common trace_probe structure. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/kprobes: Factor out struct trace_probeNamhyung Kim
There are functions that can be shared to both of kprobes and uprobes. Separate common data structure to struct trace_probe and use it from the shared functions. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/probes: Fix basic print type functionsNamhyung Kim
The print format of s32 type was "ld" and it's casted to "long". So it turned out to print 4294967295 for "-1" on 64-bit systems. Not sure whether it worked well on 32-bit systems. Anyway, it doesn't need to have cast argument at all since it already casted using type pointer - just get rid of it. Thanks to Oleg for pointing that out. And print 0x prefix for unsigned type as it shows hex numbers. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Fix documentation of uprobe registration syntaxNamhyung Kim
The uprobe syntax requires an offset after a file path not a symbol. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing: Fix rcu handling of event_trigger_data filter fieldSteven Rostedt (Red Hat)
The filter field of the event_trigger_data structure is protected under RCU sched locks. It was not annotated as such, and after doing so, sparse pointed out several locations that required fix ups. Reported-by: kbuild test robot <fengguang.wu@intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-02tracing: Add generic tracing_lseek() functionSteven Rostedt (Red Hat)
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: kbuild test robot <fengguang.wu@intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Add and use generic set_trigger_filter() implementationTom Zanussi
Add a generic event_command.set_trigger_filter() op implementation and have the current set of trigger commands use it - this essentially gives them all support for filters. Syntactically, filters are supported by adding 'if <filter>' just after the command, in which case only events matching the filter will invoke the trigger. For example, to add a filter to an enable/disable_event command: echo 'enable_event:system:event if common_pid == 999' > \ .../othersys/otherevent/trigger The above command will only enable the system:event event if the common_pid field in the othersys:otherevent event is 999. As another example, to add a filter to a stacktrace command: echo 'stacktrace if common_pid == 999' > \ .../somesys/someevent/trigger The above command will only trigger a stacktrace if the common_pid field in the event is 999. The filter syntax is the same as that described in the 'Event filtering' section of Documentation/trace/events.txt. Because triggers can now use filters, the trigger-invoking logic needs to be moved in those cases - e.g. for ftrace_raw_event_calls, if a trigger has a filter associated with it, the trigger invocation now needs to happen after the { assign; } part of the call, in order for the trigger condition to be tested. There's still a SOFT_DISABLED-only check at the top of e.g. the ftrace_raw_events function, so when an event is soft disabled but not because of the presence of a trigger, the original SOFT_DISABLED behavior remains unchanged. There's also a bit of trickiness in that some triggers need to avoid being invoked while an event is currently in the process of being logged, since the trigger may itself log data into the trace buffer. Thus we make sure the current event is committed before invoking those triggers. To do that, we split the trigger invocation in two - the first part (event_triggers_call()) checks the filter using the current trace record; if a command has the post_trigger flag set, it sets a bit for itself in the return value, otherwise it directly invoks the trigger. Once all commands have been either invoked or set their return flag, event_triggers_call() returns. The current record is then either committed or discarded; if any commands have deferred their triggers, those commands are finally invoked following the close of the current event by event_triggers_post_call(). To simplify the above and make it more efficient, the TRIGGER_COND bit is introduced, which is set only if a soft-disabled trigger needs to use the log record for filter testing or needs to wait until the current log record is closed. The syscall event invocation code is also changed in analogous ways. Because event triggers need to be able to create and free filters, this also adds a couple external wrappers for the existing create_filter and free_filter functions, which are too generic to be made extern functions themselves. Link: http://lkml.kernel.org/r/7164930759d8719ef460357f143d995406e4eead.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Move ftrace_event_file() out of DYNAMIC_FTRACE ifdefSteven Rostedt (Red Hat)
Now that event triggers use ftrace_event_file(), it needs to be outside the #ifdef CONFIG_DYNAMIC_FTRACE, as it can now be used when that is not defined. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Add 'enable_event' and 'disable_event' event trigger commandsTom Zanussi
Add 'enable_event' and 'disable_event' event_command commands. enable_event and disable_event event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'enable_event' and 'disable_event' ftrace function commands, but instead of writing to the set_ftrace_filter file, the enable_event and disable_event triggers are written to the per-event 'trigger' files: echo 'enable_event:system:event' > .../othersys/otherevent/trigger echo 'disable_event:system:event' > .../othersys/otherevent/trigger The above commands will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger Where N is the number of times the command will be invoked. The above commands will will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit, but only N times. This also makes the find_event_file() helper function extern, since it's useful to use from other places, such as the event triggers code, so make it accessible. Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Add 'stacktrace' event trigger commandTom Zanussi
Add 'stacktrace' event_command. stacktrace event triggers are added by the user via this command in a similar way and using practically the same syntax as the analogous 'stacktrace' ftrace function command, but instead of writing to the set_ftrace_filter file, the stacktrace event trigger is written to the per-event 'trigger' files: echo 'stacktrace' > .../tracing/events/somesys/someevent/trigger The above command will turn on stacktraces for someevent i.e. whenever someevent is hit, a stacktrace will be logged. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'stacktrace:N' > .../tracing/events/somesys/someevent/trigger Where N is the number of times the command will be invoked. The above command will log N stacktraces for someevent i.e. whenever someevent is hit N times, a stacktrace will be logged. Link: http://lkml.kernel.org/r/0c30c008a0828c660aa0e1bbd3255cf179ed5c30.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Add 'snapshot' event trigger commandTom Zanussi
Add 'snapshot' event_command. snapshot event triggers are added by the user via this command in a similar way and using practically the same syntax as the analogous 'snapshot' ftrace function command, but instead of writing to the set_ftrace_filter file, the snapshot event trigger is written to the per-event 'trigger' files: echo 'snapshot' > .../somesys/someevent/trigger The above command will turn on snapshots for someevent i.e. whenever someevent is hit, a snapshot will be done. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'snapshot:N' > .../somesys/someevent/trigger Where N is the number of times the command will be invoked. The above command will snapshot N times for someevent i.e. whenever someevent is hit N times, a snapshot will be done. Also adds a new tracing_alloc_snapshot() function - the existing tracing_snapshot_alloc() function is a special version of tracing_snapshot() that also does the snapshot allocation - the snapshot triggers would like to be able to do just the allocation but not take a snapshot; the existing tracing_snapshot_alloc() in turn now also calls tracing_alloc_snapshot() underneath to do that allocation. Link: http://lkml.kernel.org/r/c9524dd07ce01f9dcbd59011290e0a8d5b47d7ad.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> [ fix up from kbuild test robot <fengguang.wu@intel.com report ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-20tracing: Add 'traceon' and 'traceoff' event trigger commandsTom Zanussi
Add 'traceon' and 'traceoff' event_command commands. traceon and traceoff event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'traceon' and 'traceoff' ftrace function commands, but instead of writing to the set_ftrace_filter file, the traceon and traceoff triggers are written to the per-event 'trigger' files: echo 'traceon' > .../tracing/events/somesys/someevent/trigger echo 'traceoff' > .../tracing/events/somesys/someevent/trigger The above command will turn tracing on or off whenever someevent is hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'traceon:N' > .../tracing/events/somesys/someevent/trigger echo 'traceoff:N' > .../tracing/events/somesys/someevent/trigger Where N is the number of times the command will be invoked. The above commands will will turn tracing on or off whenever someevent is hit, but only N times. Some common register/unregister_trigger() implementations of the event_command reg()/unreg() callbacks are also provided, which add and remove trigger instances to the per-event list of triggers, and arm/disarm them as appropriate. event_trigger_callback() is a general-purpose event_command func() implementation that orchestrates command parsing and registration for most normal commands. Most event commands will use these, but some will override and possibly reuse them. The event_trigger_init(), event_trigger_free(), and event_trigger_print() functions are meant to be common implementations of the event_trigger_ops init(), free(), and print() ops, respectively. Most trigger_ops implementations will use these, but some will override and possibly reuse them. Link: http://lkml.kernel.org/r/00a52816703b98d2072947478dd6e2d70cde5197.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-20tracing: Add basic event trigger frameworkTom Zanussi
Add a 'trigger' file for each trace event, enabling 'trace event triggers' to be set for trace events. 'trace event triggers' are patterned after the existing 'ftrace function triggers' implementation except that triggers are written to per-event 'trigger' files instead of to a single file such as the 'set_ftrace_filter' used for ftrace function triggers. The implementation is meant to be entirely separate from ftrace function triggers, in order to keep the respective implementations relatively simple and to allow them to diverge. The event trigger functionality is built on top of SOFT_DISABLE functionality. It adds a TRIGGER_MODE bit to the ftrace_event_file flags which is checked when any trace event fires. Triggers set for a particular event need to be checked regardless of whether that event is actually enabled or not - getting an event to fire even if it's not enabled is what's already implemented by SOFT_DISABLE mode, so trigger mode directly reuses that. Event trigger essentially inherit the soft disable logic in __ftrace_event_enable_disable() while adding a bit of logic and trigger reference counting via tm_ref on top of that in a new trace_event_trigger_enable_disable() function. Because the base __ftrace_event_enable_disable() code now needs to be invoked from outside trace_events.c, a wrapper is also added for those usages. The triggers for an event are actually invoked via a new function, event_triggers_call(), and code is also added to invoke them for ftrace_raw_event calls as well as syscall events. The main part of the patch creates a new trace_events_trigger.c file to contain the trace event triggers implementation. The standard open, read, and release file operations are implemented here. The open() implementation sets up for the various open modes of the 'trigger' file. It creates and attaches the trigger iterator and sets up the command parser. If opened for reading set up the trigger seq_ops. The read() implementation parses the event trigger written to the 'trigger' file, looks up the trigger command, and passes it along to that event_command's func() implementation for command-specific processing. The release() implementation does whatever cleanup is needed to release the 'trigger' file, like releasing the parser and trigger iterator, etc. A couple of functions for event command registration and unregistration are added, along with a list to add them to and a mutex to protect them, as well as an (initially empty) registration function to add the set of commands that will be added by future commits, and call to it from the trace event initialization code. also added are a couple trigger-specific data structures needed for these implementations such as a trigger iterator and a struct for trigger-specific data. A couple structs consisting mostly of function meant to be implemented in command-specific ways, event_command and event_trigger_ops, are used by the generic event trigger command implementations. They're being put into trace.h alongside the other trace_event data structures and functions, in the expectation that they'll be needed in several trace_event-related files such as trace_events_trigger.c and trace_events.c. The event_command.func() function is meant to be called by the trigger parsing code in order to add a trigger instance to the corresponding event. It essentially coordinates adding a live trigger instance to the event, and arming the triggering the event. Every event_command func() implementation essentially does the same thing for any command: - choose ops - use the value of param to choose either a number or count version of event_trigger_ops specific to the command - do the register or unregister of those ops - associate a filter, if specified, with the triggering event The reg() and unreg() ops allow command-specific implementations for event_trigger_op registration and unregistration, and the get_trigger_ops() op allows command-specific event_trigger_ops selection to be parameterized. When a trigger instance is added, the reg() op essentially adds that trigger to the triggering event and arms it, while unreg() does the opposite. The set_filter() function is used to associate a filter with the trigger - if the command doesn't specify a set_filter() implementation, the command will ignore filters. Each command has an associated trigger_type, which serves double duty, both as a unique identifier for the command as well as a value that can be used for setting a trigger mode bit during trigger invocation. The signature of func() adds a pointer to the event_command struct, used to invoke those functions, along with a command_data param that can be passed to the reg/unreg functions. This allows func() implementations to use command-specific blobs and supports code re-use. The event_trigger_ops.func() command corrsponds to the trigger 'probe' function that gets called when the triggering event is actually invoked. The other functions are used to list the trigger when needed, along with a couple mundane book-keeping functions. This also moves event_file_data() into trace.h so it can be used outside of trace_events.c. Link: http://lkml.kernel.org/r/316d95061accdee070aac8e5750afba0192fa5b9.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Idea-by: Steve Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-15Merge tag 'pci-v3.13-fixes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI device hotplug - Move device_del() from pci_stop_dev() to pci_destroy_dev() (Rafael Wysocki) Host bridge drivers - Update maintainers for DesignWare, i.MX6, Armada, R-Car (Bjorn Helgaas) - mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin (Jason Gunthorpe) Miscellaneous - Avoid unnecessary CPU switch when calling .probe() (Alexander Duyck) - Revert "workqueue: allow work_on_cpu() to be called recursively" (Bjorn Helgaas) - Disable Bus Master only on kexec reboot (Khalid Aziz) - Omit PCI ID macro strings to shorten quirk names for LTO (Michal Marek)" * tag 'pci-v3.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: MAINTAINERS: Add DesignWare, i.MX6, Armada, R-Car PCI host maintainers PCI: Disable Bus Master only on kexec reboot PCI: mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin PCI: Omit PCI ID macro strings to shorten quirk names PCI: Move device_del() from pci_stop_dev() to pci_destroy_dev() Revert "workqueue: allow work_on_cpu() to be called recursively" PCI: Avoid unnecessary CPU switch when calling driver .probe() method
2013-12-12Merge tag 'keys-devel-20131210' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull misc keyrings fixes from David Howells: "These break down into five sets: - A patch to error handling in the big_key type for huge payloads. If the payload is larger than the "low limit" and the backing store allocation fails, then big_key_instantiate() doesn't clear the payload pointers in the key, assuming them to have been previously cleared - but only one of them is. Unfortunately, the garbage collector still calls big_key_destroy() when sees one of the pointers with a weird value in it (and not NULL) which it then tries to clean up. - Three patches to fix the keyring type: * A patch to fix the hash function to correctly divide keyrings off from keys in the topology of the tree inside the associative array. This is only a problem if searching through nested keyrings - and only if the hash function incorrectly puts the a keyring outside of the 0 branch of the root node. * A patch to fix keyrings' use of the associative array. The __key_link_begin() function initially passes a NULL key pointer to assoc_array_insert() on the basis that it's holding a place in the tree whilst it does more allocation and stuff. This is only a problem when a node contains 16 keys that match at that level and we want to add an also matching 17th. This should easily be manufactured with a keyring full of keyrings (without chucking any other sort of key into the mix) - except for (a) above which makes it on average adding the 65th keyring. * A patch to fix searching down through nested keyrings, where any keyring in the set has more than 16 keyrings and none of the first keyrings we look through has a match (before the tree iteration needs to step to a more distal node). Test in keyutils test suite: http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=8b4ae963ed92523aea18dfbb8cab3f4979e13bd1 - A patch to fix the big_key type's use of a shmem file as its backing store causing audit messages and LSM check failures. This is done by setting S_PRIVATE on the file to avoid LSM checks on the file (access to the shmem file goes through the keyctl() interface and so is gated by the LSM that way). This isn't normally a problem if a key is used by the context that generated it - and it's currently only used by libkrb5. Test in keyutils test suite: http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=d9a53cbab42c293962f2f78f7190253fc73bd32e - A patch to add a generated file to .gitignore. - A patch to fix the alignment of the system certificate data such that it it works on s390. As I understand it, on the S390 arch, symbols must be 2-byte aligned because loading the address discards the least-significant bit" * tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: KEYS: correct alignment of system_certificate_list content in assembly file Ignore generated file kernel/x509_certificate_list security: shmem: implement kernel private shmem inodes KEYS: Fix searching of nested keyrings KEYS: Fix multiple key add into associative array KEYS: Fix the keyring hash function KEYS: Pre-clear struct key on allocation
2013-12-12futex: move user address verification up to common codeLinus Torvalds
When debugging the read-only hugepage case, I was confused by the fact that get_futex_key() did an access_ok() only for the non-shared futex case, since the user address checking really isn't in any way specific to the private key handling. Now, it turns out that the shared key handling does effectively do the equivalent checks inside get_user_pages_fast() (it doesn't actually check the address range on x86, but does check the page protections for being a user page). So it wasn't actually a bug, but the fact that we treat the address differently for private and shared futexes threw me for a loop. Just move the check up, so that it gets done for both cases. Also, use the 'rw' parameter for the type, even if it doesn't actually matter any more (it's a historical artifact of the old racy i386 "page faults from kernel space don't check write protections"). Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12futex: fix handling of read-only-mapped hugepagesLinus Torvalds
The hugepage code had the exact same bug that regular pages had in commit 7485d0d3758e ("futexes: Remove rw parameter from get_futex_key()"). The regular page case was fixed by commit 9ea71503a8ed ("futex: Fix regression with read only mappings"), but the transparent hugepage case (added in a5b338f2b0b1: "thp: update futex compound knowledge") case remained broken. Found by Dave Jones and his trinity tool. Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Cc: stable@kernel.org # v2.6.38+ Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mel Gorman <mgorman@suse.de> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-10KEYS: correct alignment of system_certificate_list content in assembly fileHendrik Brueckner
Apart from data-type specific alignment constraints, there are also architecture-specific alignment requirements. For example, on s390 symbols must be on even addresses implying a 2-byte alignment. If the system_certificate_list_end symbol is on an odd address and if this address is loaded, the least-significant bit is ignored. As a result, the load_system_certificate_list() fails to load the certificates because of a wrong certificate length calculation. To be safe, align system_certificate_list on an 8-byte boundary. Also improve the length calculation of the system_certificate_list content. Introduce a system_certificate_list_size (8-byte aligned because of unsigned long) variable that stores the length. Let the linker calculate this size by introducing a start and end label for the certificate content. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com>
2013-12-10Ignore generated file kernel/x509_certificate_listRusty Russell
$ git status # On branch pending-rebases # Untracked files: # (use "git add <file>..." to include in what will be committed) # # kernel/x509_certificate_list nothing added to commit but untracked files present (use "git add" to track) $ Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com>
2013-12-07PCI: Disable Bus Master only on kexec rebootKhalid Aziz
Add a flag to tell the PCI subsystem that kernel is shutting down in preparation to kexec a kernel. Add code in PCI subsystem to use this flag to clear Bus Master bit on PCI devices only in case of kexec reboot. This fixes a power-off problem on Acer Aspire V5-573G and likely other machines and avoids any other issues caused by clearing Bus Master bit on PCI devices in normal shutdown path. The problem was introduced by b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown"). This patch is based on discussion at http://marc.info/?l=linux-pci&m=138425645204355&w=2 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861 Reported-by: Chang Liu <cl91tp@gmail.com> Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: stable@vger.kernel.org # v3.5+
2013-12-06Merge tag 'trace-fixes-3.13-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "A regression showed up that there's a large delay when enabling all events. This was prevalent when FTRACE_SELFTEST was enabled which enables all events several times, and caused the system bootup to pause for over a minute. This was tracked down to an addition of a synchronize_sched() performed when system call tracepoints are unregistered. The synchronize_sched() is needed between the unregistering of the system call tracepoint and a deletion of a tracing instance buffer. But placing the synchronize_sched() in the unreg of *every* system call tracepoint is a bit overboard. A single synchronize_sched() before the deletion of the instance is sufficient" * tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Only run synchronize_sched() at instance deletion time
2013-12-05tracing: Only run synchronize_sched() at instance deletion timeSteven Rostedt
It has been reported that boot up with FTRACE_SELFTEST enabled can take a very long time. There can be stalls of over a minute. This was tracked down to the synchronize_sched() called when a system call event is disabled. As the self tests enable and disable thousands of events, this makes the synchronize_sched() get called thousands of times. The synchornize_sched() was added with d562aff93bfb53 "tracing: Add support for SOFT_DISABLE to syscall events" which caused this regression (added in 3.13-rc1). The synchronize_sched() is to protect against the events being accessed when a tracer instance is being deleted. When an instance is being deleted all the events associated to it are unregistered. The synchronize_sched() makes sure that no more users are running when it finishes. Instead of calling synchronize_sched() for all syscall events, we only need to call it once, after the events are unregistered and before the instance is deleted. The event_mutex is held during this action to prevent new users from enabling events. Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.home Reported-by: Petr Mladek <pmladek@suse.cz> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Petr Mladek <pmladek@suse.cz> Tested-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-04Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: - timekeeping: Cure a subtle drift issue on GENERIC_TIME_VSYSCALL_OLD - nohz: Make CONFIG_NO_HZ=n and nohz=off command line option behave the same way. Fixes a long standing load accounting wreckage. - clocksource/ARM: Kconfig update to avoid ARM=n wreckage - clocksource/ARM: Fixlets for the AT91 and SH clocksource/clockevents - Trivial documentation update and kzalloc conversion from akpms pile * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off time: Fix 1ns/tick drift w/ GENERIC_TIME_VSYSCALL_OLD clocksource: arm_arch_timer: Hide eventstream Kconfig on non-ARM clocksource: sh_tmu: Add clk_prepare/unprepare support clocksource: sh_tmu: Release clock when sh_tmu_register() fails clocksource: sh_mtu2: Add clk_prepare/unprepare support clocksource: sh_mtu2: Release clock when sh_mtu2_register() fails ARM: at91: rm9200: switch back to clockevents_config_and_register tick: Document tick_do_timer_cpu timer: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) NOHZ: Check for nohz active instead of nohz enabled
2013-12-02Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: - Correction of fuzzy and fragile IRQ_RETVAL macro - IRQ related resume fix affecting only XEN - ARM/GIC fix for chained GIC controllers * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: Gic: fix boot for chained gics irq: Enable all irqs unconditionally in irq_resume genirq: Correct fuzzy and fragile IRQ_RETVAL() definition