kernel/linux.git/include/trace/trace_events.h, branch v6.6.132

tracing/ftrace: disable preemption in syscall probe

2024-12-14T19:00:10+00:00

[ Upstream commit 13d750c2c03e9861e15268574ed2c239cca9c9d5 ] In preparation for allowing system call enter/exit instrumentation to handle page faults, make sure that ftrace can handle this change by explicitly disabling preemption within the ftrace system call tracepoint probes to respect the current expectations within ftrace ring buffer code. This change does not yet allow ftrace to take page faults per se within its probe, but allows its existing probes to adapt to the upcoming change. Cc: Michael Jeanson Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Alexei Starovoitov Cc: Yonghong Song Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Andrii Nakryiko Cc: bpf@vger.kernel.org Cc: Joel Fernandes Link: https://lore.kernel.org/20241009010718.2050182-3-mathieu.desnoyers@efficios.com Acked-by: Masami Hiramatsu (Google) Signed-off-by: Mathieu Desnoyers Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

tracing: Rename the staging files for trace_events

2022-04-02T12:40:04+00:00

When looking for implementation of different phases of the creation of the TRACE_EVENT() macro, it is pretty useless when all helper macro redefinitions are in files labeled "stageX_defines.h". Rename them to state which phase the files are for. For instance, when looking for the defines that are used to create the event fields, seeing "stage4_event_fields.h" gives the developer a good idea that the defines are in that file. Signed-off-by: Steven Rostedt (Google)

tracing: Move the defines to create TRACE_EVENTS into their own files

2022-03-11T16:49:23+00:00

In an effort to add custom event macros that can be used to create your own custom events based on existing tracepoints, move the defines of the special macros used in TRACE_EVENT() into their own files such that they can be reused for TRACE_CUSTOM_EVENT(). Link: https://lkml.kernel.org/r/20220303220625.553406495@goodmis.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Joel Fernandes Cc: Peter Zijlstra Cc: Masami Hiramatsu Cc: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing/perf: Avoid -Warray-bounds warning for __rel_loc macro

2022-01-28T00:15:45+00:00

As done for trace_events.h, also fix the __rel_loc macro in perf.h, which silences the -Warray-bounds warning: In file included from ./include/linux/string.h:253, from ./include/linux/bitmap.h:11, from ./include/linux/cpumask.h:12, from ./include/linux/mm_types_task.h:14, from ./include/linux/mm_types.h:5, from ./include/linux/buildid.h:5, from ./include/linux/module.h:14, from samples/trace_events/trace-events-sample.c:2: In function '__fortify_strcpy', inlined from 'perf_trace_foo_rel_loc' at samples/trace_events/./trace-events-sample.h:519:1: ./include/linux/fortify-string.h:47:33: warning: '__builtin_strcpy' offset 12 is out of the bounds [ 0, 4] [-Warray-bounds] 47 | #define __underlying_strcpy __builtin_strcpy | ^ ./include/linux/fortify-string.h:445:24: note: in expansion of macro '__underlying_strcpy' 445 | return __underlying_strcpy(p, q); | ^~~~~~~~~~~~~~~~~~~ Also make __data struct member a proper flexible array to avoid future problems. Link: https://lkml.kernel.org/r/20220125220037.2738923-1-keescook@chromium.org Cc: Steven Rostedt Cc: Masami Hiramatsu Fixes: 55de2c0b5610c ("tracing: Add '__rel_loc' using trace event macros") Reported-by: Stephen Rothwell Signed-off-by: Kees Cook Signed-off-by: Steven Rostedt (Google)

tracing: Avoid -Warray-bounds warning for __rel_loc macro

2022-01-28T00:15:45+00:00

Since -Warray-bounds checks the destination size from the type of given pointer, __assign_rel_str() macro gets warned because it passes the pointer to the 'u32' field instead of 'trace_event_raw_*' data structure. Pass the data address calculated from the 'trace_event_raw_*' instead of 'u32' __rel_loc field. Link: https://lkml.kernel.org/r/20220125233154.dac280ed36944c0c2fe6f3ac@kernel.org Cc: Stephen Rothwell Cc: Kees Cook Signed-off-by: Masami Hiramatsu [ This did not fix the warning, but is still a nice clean up ] Signed-off-by: Steven Rostedt (Google)

tracing: Add '__rel_loc' using trace event macros

2021-12-06T20:37:21+00:00

Add '__rel_loc' using trace event macros. These macros are usually not used in the kernel, except for testing purpose. This also add "rel_" variant of macros for dynamic_array string, and bitmask. Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.stgit@devnote2 Cc: Beau Belgrave Cc: Namhyung Kim Cc: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Add trace_event helper macros __string_len() and __assign_str_len()

2021-08-17T15:47:52+00:00

There's a few cases that a string that is to be recorded in a trace event, does not have a terminating 'nul' character, and instead, the tracepoint passes in the length of the string to record. Add two helper macros to the trace event code that lets this work easier, than tricks with "%.*s" logic. __string_len() which is similar to __string() for declaration, but takes a length argument. __assign_str_len() which is similar to __assign_str() for assiging the string, but it too takes a length argument. Note, the TRACE_EVENT() macro will allocate the location on the ring buffer to 'len + 1', that will be used to store the string into. It is a requirement that the 'len' used for this is a most the length of the string being recorded. This string can still use __get_str() just like strings created with __string() can use to retrieve the string. Link: https://lore.kernel.org/linux-nfs/20210513105018.7539996a@gandalf.local.home/ Tested-by: Chuck Lever Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Chuck Lever

trace: Add __print_ns_to_secs() and __print_ns_without_secs() helpers

2021-06-25T22:26:12+00:00

To have nanosecond output displayed in a more human readable format, its nicer to convert it to a seconds format (XXX.YYYYYYYYY). The problem is that to do so, the numbers must be divided by NSEC_PER_SEC, and moded too. But as these numbers are 64 bit, this can not be done simply with '/' and '%' operators, but must use do_div() instead. Instead of performing the expensive do_div() in the hot path of the tracepoint, it is more efficient to perform it during the output phase. But passing in do_div() can confuse the parser, and do_div() doesn't work exactly like a normal C function. It modifies the number in place, and we don't want to modify the actual values in the ring buffer. Two helper functions are now created: __print_ns_to_secs() and __print_ns_without_secs() They both take a value of nanoseconds, and the former will return that number divided by NSEC_PER_SEC, and the latter will mod it with NSEC_PER_SEC giving a way to print a nice human readable format: __print_fmt("time=%llu.%09u", __print_ns_to_secs(REC->nsec_val), __print_ns_without_secs(REC->nsec_val)) Link: https://lkml.kernel.org/r/e503b903045496c4ccde52843e1e318b422f7a56.1624372313.git.bristot@redhat.com Cc: Phil Auld Cc: Sebastian Andrzej Siewior Cc: Kate Carcia Cc: Jonathan Corbet Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Alexandre Chartre Cc: Clark Willaims Cc: John Kacur Cc: Juri Lelli Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Steven Rostedt Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (VMware)

tracing: Update the stage 3 of trace event macro comment

2021-02-11T21:31:57+00:00

Update the comment of the 3rd stage of trace event macro expansion code. Now there are 2 macros makes different trace_raw_output_() functions. Link: https://lkml.kernel.org/r/160277371605.29307.8586817119278606720.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Show real address for trace event arguments

2021-02-11T21:31:57+00:00

To help debugging kernel, show real address for trace event arguments in tracefs/trace{,pipe} instead of hashed pointer value. Since ftrace human-readable format uses vsprintf(), all %p are translated to hash values instead of pointer address. However, when debugging the kernel, raw address value gives a hint when comparing with the memory mapping in the kernel. (Those are sometimes used with crash log, which is not hashed too) So converting %p with %px when calling trace_seq_printf(). Moreover, this is not improving the security because the tracefs can be used only by root user and the raw address values are readable from tracefs/percpu/cpu*/trace_pipe_raw file. Link: https://lkml.kernel.org/r/160277370703.29307.5134475491761971203.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)