linux/kernel/trace/trace_functions_graph.c, branch v4.9

Merge tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-10-06T18:48:41Z

Pull tracing updates from Steven Rostedt: "This release cycle is rather small. Just a few fixes to tracing. The big change is the addition of the hwlat tracer. It not only detects SMIs, but also other latency that's caused by the hardware. I have detected some latency from large boxes having bus contention" * tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Call traceoff trigger after event is recorded ftrace/scripts: Add helper script to bisect function tracing problem functions tracing: Have max_latency be defined for HWLAT_TRACER as well tracing: Add NMI tracing in hwlat detector tracing: Have hwlat trace migrate across tracing_cpumask CPUs tracing: Add documentation for hwlat_detector tracer tracing: Added hardware latency tracer ftrace: Access ret_stack->subtime only in the function profiler function_graph: Handle TRACE_BPUTS in print_graph_comment tracing/uprobe: Drop isdigit() check in create_trace_uprobe

ftrace: Access ret_stack->subtime only in the function profiler

2016-09-01T16:19:40Z

The subtime is used only for function profiler with function graph tracer enabled. Move the definition of subtime under CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the initialization of subtime into the graph entry callback. Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org Cc: Ingo Molnar Cc: Josh Poimboeuf Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt

function_graph: Handle TRACE_BPUTS in print_graph_comment

2016-09-01T15:19:55Z

It missed to handle TRACE_BPUTS so messages recorded by trace_bputs() will be shown with symbol info unnecessarily. You can see it with the trace_printk sample code: # cd /sys/kernel/tracing/ # echo sys_sync > set_graph_function # echo 1 > options/sym-offset # echo function_graph > current_tracer Note that the sys_sync filter was there to prevent recording other functions and the sym-offset option was needed since the first message was called from a module init function so kallsyms doesn't have the symbol and omitted in the output. # cd ~/build/kernel # insmod samples/trace_printk/trace-printk.ko # cd - # head trace Before: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 1) | /* 0xffffffffa0002000: This is a static string that will use trace_bputs */ 1) | /* This is a dynamic string that will use trace_puts */ 1) | /* trace_printk_irq_work+0x5/0x7b [trace_printk]: (irq) This is a static string that will use trace_bputs */ 1) | /* (irq) This is a dynamic string that will use trace_puts */ 1) | /* (irq) This is a static string that will use trace_bprintk() */ 1) | /* (irq) This is a dynamic string that will use trace_printk */ After: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 1) | /* This is a static string that will use trace_bputs */ 1) | /* This is a dynamic string that will use trace_puts */ 1) | /* (irq) This is a static string that will use trace_bputs */ 1) | /* (irq) This is a dynamic string that will use trace_puts */ 1) | /* (irq) This is a static string that will use trace_bprintk() */ 1) | /* (irq) This is a dynamic string that will use trace_printk */ Link: http://lkml.kernel.org/r/20160901024354.13720-1-namhyung@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt

ftrace: Add ftrace_graph_ret_addr() stack unwinding helpers

2016-08-24T10:15:14Z

When function graph tracing is enabled for a function, ftrace modifies the stack by replacing the original return address with the address of a hook function (return_to_handler). Stack unwinders need a way to get the original return address. Add an arch-independent helper function for that named ftrace_graph_ret_addr(). This adds two variations of the function: one depends on HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, and the other relies on an index state variable. The former is recommended because, in some cases, the latter can cause problems when the unwinder skips stack frames. It can get out of sync with the ret_stack index and wrong addresses can be reported for the stack trace. Once all arches have been ported to use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, we can get rid of the distinction. Signed-off-by: Josh Poimboeuf Acked-by: Steven Rostedt Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/36bd90f762fc5e5af3929e3797a68a64906421cf.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

ftrace: Add return address pointer to ftrace_ret_stack

2016-08-24T10:15:14Z

Storing this value will help prevent unwinders from getting out of sync with the function graph tracer ret_stack. Now instead of needing a stateful iterator, they can compare the return address pointer to find the right ret_stack entry. Note that an array of 50 ftrace_ret_stack structs is allocated for every task. So when an arch implements this, it will add either 200 or 400 bytes of memory usage per task (depending on whether it's a 32-bit or 64-bit platform). Signed-off-by: Josh Poimboeuf Acked-by: Steven Rostedt Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

ftrace: Only allocate the ret_stack 'fp' field when needed

2016-08-24T10:15:14Z

This saves some memory when HAVE_FUNCTION_GRAPH_FP_TEST isn't defined. On x86_64 with newer versions of gcc which have -mfentry, it saves 400 bytes per task. Signed-off-by: Josh Poimboeuf Acked-by: Steven Rostedt Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/5c7747d9ea7b5cb47ef0a8ce8a6cea6bf7aa94bf.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

ftrace: Remove CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST from config

2016-08-24T10:15:13Z

Make HAVE_FUNCTION_GRAPH_FP_TEST a normal define, independent from kconfig. This removes some config file pollution and simplifies the checking for the fp test. Suggested-by: Steven Rostedt Signed-off-by: Josh Poimboeuf Acked-by: Steven Rostedt Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/2c4e5f05054d6d367f702fd153af7a0109dd5c81.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

tracing/function_graph: Fix filters for function_graph threshold

2016-06-27T17:29:24Z

Function graph tracer currently ignores filters if tracing_thresh is set. For example, even if set_ftrace_pid is set, then its ignored if tracing_thresh set, resulting in all processes being traced. To fix this, we reuse the same entry function as when tracing_thresh is not set and do everything as in the regular case except for writing the function entry to the ring buffer. Link: http://lkml.kernel.org/r/1466228694-2677-1-git-send-email-agnel.joel@gmail.com Cc: Frederic Weisbecker Cc: Ingo Molnar Signed-off-by: Joel Fernandes Signed-off-by: Steven Rostedt

ftrace: Have set_ftrace_pid use the bitmap like events do

2016-06-20T13:54:19Z

Convert set_ftrace_pid to use the bitmap like set_event_pid does. This allows for instances to use the pid filtering as well, and will allow for function-fork option to set if the children of a traced function should be traced or not. Signed-off-by: Steven Rostedt

arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

2016-03-25T23:37:42Z

KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to so that the users don't need to pull in . Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko Acked-by: Steven Rostedt Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrey Konovalov Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Konstantin Serebryany Cc: Dmitry Chernenkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds