aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/perf/scripts/python/export-to-postgresql.py (unfollow)
AgeCommit message (Collapse)AuthorFilesLines
2021-11-01tracing/osnoise: Split workload start from the tracer startDaniel Bristot de Oliveira1-23/+36
In preparation from supporting multiple trace instances, create workload start/stop specific functions. No functional change. Link: https://lkml.kernel.org/r/74b090971e9acdd13625be1c28ef3270d2275e77.1635702894.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-01tracing/osnoise: Improve comments about barrier need for NMI callbacksDaniel Bristot de Oliveira1-1/+7
trace_osnoise_callback_enabled is used by ftrace_nmi_enter/exit() to know when to call the NMI callback. The barrier is used to avoid having callbacks enabled before the resetting date during the start or to touch the values after stopping the tracer. Link: https://lkml.kernel.org/r/a413b8f14aa9312fbd1ba99f96225a8aed831053.1635702894.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-01tracing/osnoise: Do not follow tracing_cpumaskDaniel Bristot de Oliveira1-18/+6
In preparation to support multiple instances, decouple the osnoise/timelat workload from instance-specific tracing_cpumask. Different instances can have conflicting cpumasks, making osnoise workload management needlessly complex. Osnoise already has its global cpumask. I also thought about using the first instance mask, but the "first" instance could be removed before the others. This also fixes the problem that changing the tracing_mask was not re-starting the trace. Link: https://lkml.kernel.org/r/169a71bcc919ce3ab53ae6f9ca5cde57fffaf9c6.1635702894.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-29tracing/histogram: Fix semicolon.cocci warningskernel test robot1-1/+1
kernel/trace/trace_events_hist.c:6039:2-3: Unneeded semicolon Remove unneeded semicolon. Generated by: scripts/coccinelle/misc/semicolon.cocci Link: https://lkml.kernel.org/r/20211030005615.GA41257@3074f0d39c61 Fixes: c5eac6ee8bc5 ("tracing/histogram: Simplify handling of .sym-offset in expressions") CC: Kalesh Singh <kaleshsingh@google.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-28tracing/histogram: Fix documentation inline emphasis warningKalesh Singh1-1/+1
This fixes the warning: Documentation/trace/histogram.rst:1766: WARNING: Inline emphasis start-string without end-string The issue was caused by an unescaped '*' character. Link: https://lore.kernel.org/all/20211028170548.2597449-1-kaleshsingh@google.com/T/#m77da47432f5cc6521d4294ffdb9621949cc35d04 Link: https://lkml.kernel.org/r/20211028170548.2597449-1-kaleshsingh@google.com Fixes: 2d2f6d4b8ce7 ("tracing/histogram: Document expression arithmetic and constants") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker togetherRobin H. Johnson1-1/+1
Running endpoint security solutions like Sentinel1 that use perf-based tracing heavily lead to this repeated dump complaining about dockerd. The default value of 2048 is nowhere near not large enough. Using the prior patch "tracing: show size of requested buffer", we get "perf buffer not large enough, wanted 6644, have 6144", after repeated up-sizing (I did 2/4/6/8K). With 8K, the problem doesn't occur at all, so below is the trace for 6K. I'm wondering if this value should be selectable at boot time, but this is a good starting point. ``` ------------[ cut here ]------------ perf buffer not large enough, wanted 6644, have 6144 WARNING: CPU: 1 PID: 4997 at kernel/trace/trace_event_perf.c:402 perf_trace_buf_alloc+0x8c/0xa0 Modules linked in: [..] CPU: 1 PID: 4997 Comm: sh Tainted: G T 5.13.13-x86_64-00039-gb3959163488e #63 Hardware name: LENOVO 20KH002JUS/20KH002JUS, BIOS N23ET66W (1.41 ) 09/02/2019 RIP: 0010:perf_trace_buf_alloc+0x8c/0xa0 Code: 80 3d 43 97 d0 01 00 74 07 31 c0 5b 5d 41 5c c3 ba 00 18 00 00 89 ee 48 c7 c7 00 82 7d 91 c6 05 25 97 d0 01 01 e8 22 ee bc 00 <0f> 0b 31 c0 eb db 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 89 RSP: 0018:ffffb922026b7d58 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff9da5ee012000 RCX: 0000000000000027 RDX: ffff9da881657828 RSI: 0000000000000001 RDI: ffff9da881657820 RBP: 00000000000019f4 R08: 0000000000000000 R09: ffffb922026b7b80 R10: ffffb922026b7b78 R11: ffffffff91dda688 R12: 000000000000000f R13: ffff9da5ee012108 R14: ffff9da8816570a0 R15: ffffb922026b7e30 FS: 00007f420db1a080(0000) GS:ffff9da881640000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000060 CR3: 00000002504a8006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kprobe_perf_func+0x11e/0x270 ? do_execveat_common.isra.0+0x1/0x1c0 ? do_execveat_common.isra.0+0x5/0x1c0 kprobe_ftrace_handler+0x10e/0x1d0 0xffffffffc03aa0c8 ? do_execveat_common.isra.0+0x1/0x1c0 do_execveat_common.isra.0+0x5/0x1c0 __x64_sys_execve+0x33/0x40 do_syscall_64+0x6b/0xc0 ? do_syscall_64+0x11/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f420dc1db37 Code: ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 00 f7 d8 64 41 89 00 eb dc 0f 1f 84 00 00 00 00 00 b8 3b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 01 43 0f 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd4e8b4e38 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f420dc1db37 RDX: 0000564338d1e740 RSI: 0000564338d32d50 RDI: 0000564338d28f00 RBP: 0000564338d28f00 R08: 0000564338d32d50 R09: 0000000000000020 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000564338d28f00 R13: 0000564338d32d50 R14: 0000564338d1e740 R15: 0000564338d28c60 ---[ end trace 83ab3e8e16275e49 ]--- ``` Link: https://lkml.kernel.org/r/20210831043723.13481-2-robbat2@gentoo.org Signed-off-by: Robin H. Johnson <robbat2@gentoo.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27tracing: Show size of requested perf bufferRobin H. Johnson1-1/+2
If the perf buffer isn't large enough, provide a hint about how large it needs to be for whatever is running. Link: https://lkml.kernel.org/r/20210831043723.13481-1-robbat2@gentoo.org Signed-off-by: Robin H. Johnson <robbat2@gentoo.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27bootconfig: Initialize ret in xbc_parse_tree()Steven Rostedt (VMware)1-1/+1
The do while loop continues while ret is zero, but ret is never initialized. The check for ret in the loop at the while should always be initialized, but if an empty string were to be passed in, q would be NULL and p would be '\0', and it would break out of the loop without ever setting ret. Set ret to zero, and then xbc_verify_tree() would be called and catch that it is an empty tree and report the proper error. Link: https://lkml.kernel.org/r/20211027105753.6ab9da5f@gandalf.local.home Fixes: bdac5c2b243f ("bootconfig: Allocate xbc_data inside xbc_init()") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27ftrace: do CPU checking after preemption disabled王贇1-3/+3
With CONFIG_DEBUG_PREEMPT we observed reports like: BUG: using smp_processor_id() in preemptible caller is perf_ftrace_function_call+0x6f/0x2e0 CPU: 1 PID: 680 Comm: a.out Not tainted Call Trace: <TASK> dump_stack_lvl+0x8d/0xcf check_preemption_disabled+0x104/0x110 ? optimize_nops.isra.7+0x230/0x230 ? text_poke_bp_batch+0x9f/0x310 perf_ftrace_function_call+0x6f/0x2e0 ... __text_poke+0x5/0x620 text_poke_bp_batch+0x9f/0x310 This telling us the CPU could be changed after task is preempted, and the checking on CPU before preemption will be invalid. Since now ftrace_test_recursion_trylock() will help to disable the preemption, this patch just do the checking after trylock() to address the issue. Link: https://lkml.kernel.org/r/54880691-5fe2-33e7-d12f-1fa6136f5183@linux.alibaba.com CC: Steven Rostedt <rostedt@goodmis.org> Cc: Guo Ren <guoren@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Jisheng Zhang <jszhang@kernel.org> Reported-by: Abaci <abaci@linux.alibaba.com> Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27ftrace: disable preemption when recursion locked王贇9-32/+21
As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption properly, however currently this work is done outside of the function, which could be missing by mistake. And since the internal using of trace_test_and_set_recursion() and trace_clear_recursion() also require preemption disabled, we can just merge the logical. This patch will make sure the preemption has been disabled when trace_test_and_set_recursion() return bit >= 0, and trace_clear_recursion() will enable the preemption if previously enabled. Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com CC: Petr Mladek <pmladek@suse.com> Cc: Guo Ren <guoren@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Jisheng Zhang <jszhang@kernel.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: Miroslav Benes <mbenes@suse.cz> Reported-by: Abaci <abaci@linux.alibaba.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com> [ Removed extra line in comment - SDR ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/histogram: Document expression arithmetic and constantsKalesh Singh1-0/+14
Histogram expressions now support division, and multiplication in addition to the already supported subtraction and addition operators. Numeric constants can also be used in a hist trigger expressions or assigned to a variable and used by refernce in an expression. Link: https://lkml.kernel.org/r/20211025200852.3002369-9-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/histogram: Optimize division by a power of 2Kalesh Singh1-0/+4
The division is a slow operation. If the divisor is a power of 2, use a shift instead. Results were obtained using Android's version of perf (simpleperf[1]) as described below: 1. hist_field_div() is modified to call 2 test functions: test_hist_field_div_[not]_optimized(); passing them the same args. Use noinline and volatile to ensure these are not optimized out by the compiler. 2. Create a hist event trigger that uses division: events/kmem/rss_stat$ echo 'hist:keys=common_pid:x=size/<divisor>' >> trigger events/kmem/rss_stat$ echo 'hist:keys=common_pid:vals=$x' >> trigger 3. Run Android's lmkd_test[2] to generate rss_stat events, and record CPU samples with Android's simpleperf: simpleperf record -a --exclude-perf --post-unwind=yes -m 16384 -g -f 2000 -o perf.data == Results == Divisor is a power of 2 (divisor == 32): test_hist_field_div_not_optimized | 8,717,091 cpu-cycles test_hist_field_div_optimized | 1,643,137 cpu-cycles If the divisor is a power of 2, the optimized version is ~5.3x faster. Divisor is not a power of 2 (divisor == 33): test_hist_field_div_not_optimized | 4,444,324 cpu-cycles test_hist_field_div_optimized | 5,497,958 cpu-cycles If the divisor is not a power of 2, as expected, the optimized version is slightly slower (~24% slower). [1] https://android.googlesource.com/platform/system/extras/+/master/simpleperf/doc/README.md [2] https://cs.android.com/android/platform/superproject/+/master:system/memory/lmkd/tests/lmkd_test.cpp Link: https://lkml.kernel.org/r/20211025200852.3002369-7-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/histogram: Covert expr to const if both operands are constantsKalesh Singh1-30/+74
If both operands of a hist trigger expression are constants, convert the expression to a constant. This optimization avoids having to perform the same calculation multiple times and also saves on memory since the merged constants are represented by a single struct hist_field instead or multiple. Link: https://lkml.kernel.org/r/20211025200852.3002369-6-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/histogram: Simplify handling of .sym-offset in expressionsKalesh Singh1-26/+17
The '-' in .sym-offset can confuse the hist trigger arithmetic expression parsing. Simplify the handling of this by replacing the 'sym-offset' with 'symXoffset'. This allows us to correctly evaluate expressions where the user may have inadvertently added a .sym-offset modifier to one of the operands in an expression, instead of bailing out. In this case the .sym-offset has no effect on the evaluation of the expression. The only valid use of the .sym-offset is as a hist key modifier. Link: https://lkml.kernel.org/r/20211025200852.3002369-5-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing: Fix operator precedence for hist triggers expressionKalesh Singh1-70/+140
The current histogram expression evaluation logic evaluates the expression from right to left. This can lead to incorrect results if the operations are not associative (as is the case for subtraction and, the now added, division operators). e.g. 16-8-4-2 should be 2 not 10 --> 16-8-4-2 = ((16-8)-4)-2 64/8/4/2 should be 1 not 16 --> 64/8/4/2 = ((64/8)/4)/2 Division and multiplication are currently limited to single operation expression due to operator precedence support not yet implemented. Rework the expression parsing to support the correct evaluation of expressions containing operators of different precedences; and fix the associativity error by evaluating expressions with operators of the same precedence from left to right. Examples: (1) echo 'hist:keys=common_pid:a=8,b=4,c=2,d=1,w=$a-$b-$c-$d' \ >> event/trigger (2) echo 'hist:keys=common_pid:x=$a/$b/3/2' >> event/trigger (3) echo 'hist:keys=common_pid:y=$a+10/$c*1024' >> event/trigger (4) echo 'hist:keys=common_pid:z=$a/$b+$c*$d' >> event/trigger Link: https://lkml.kernel.org/r/20211025200852.3002369-4-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing: Add division and multiplication support for hist triggersKalesh Singh1-1/+71
Adds basic support for division and multiplication operations for hist trigger variable expressions. For simplicity this patch only supports, division and multiplication for a single operation expression (e.g. x=$a/$b), as currently expressions are always evaluated right to left. This can lead to some incorrect results: e.g. echo 'hist:keys=common_pid:x=8-4-2' >> event/trigger 8-4-2 should evaluate to 2 i.e. (8-4)-2 but currently x evaluate to 6 i.e. 8-(4-2) Multiplication and division in sub-expressions will work correctly, once correct operator precedence support is added (See next patch in this series). For the undefined case of division by 0, the histogram expression evaluates to (u64)(-1). Since this cannot be detected when the expression is created, it is the responsibility of the user to be aware and account for this possibility. Examples: echo 'hist:keys=common_pid:a=8,b=4,x=$a/$b' \ >> event/trigger echo 'hist:keys=common_pid:y=5*$b' \ >> event/trigger Link: https://lkml.kernel.org/r/20211025200852.3002369-3-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing: Add support for creating hist trigger variables from literalKalesh Singh1-1/+70
Currently hist trigger expressions don't support the use of numeric literals: e.g. echo 'hist:keys=common_pid:x=$y-1234' --> is not valid expression syntax Having the ability to use numeric constants in hist triggers supports a wider range of expressions for creating variables. Add support for creating trace event histogram variables from numeric literals. e.g. echo 'hist:keys=common_pid:x=1234,y=size-1024' >> event/trigger A negative numeric constant is created, using unary minus operator (parentheses are required). e.g. echo 'hist:keys=common_pid:z=-(2)' >> event/trigger Constants can be used with division/multiplication (added in the next patch in this series) to implement granularity filters for frequent trace events. For instance we can limit emitting the rss_stat trace event to when there is a 512KB cross over in the rss size: # Create a synthetic event to monitor instead of the high frequency # rss_stat event echo 'rss_stat_throttled unsigned int mm_id; unsigned int curr; int member; long size' >> tracing/synthetic_events # Create a hist trigger that emits the synthetic rss_stat_throttled # event only when the rss size crosses a 512KB boundary. echo 'hist:keys=keys=mm_id,member:bucket=size/0x80000:onchange($bucket) .rss_stat_throttled(mm_id,curr,member,size)' >> events/kmem/rss_stat/trigger A use case for using constants with addition/subtraction is not yet known, but for completeness the use of constants are supported for all operators. Link: https://lkml.kernel.org/r/20211025200852.3002369-2-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26selftests/ftrace: Stop tracing while reading the trace file by defaultMasami Hiramatsu2-1/+13
Stop tracing while reading the trace file by default, to prevent the test results while checking it and to avoid taking a long time to check the result. If there is any testcase which wants to test the tracing while reading the trace file, please override this setting inside the test case. This also recovers the pause-on-trace when clean it up. Link: https://lkml.kernel.org/r/163529053143.690749.15365238954175942026.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26MAINTAINERS: Update KPROBES and TRACING entriesTiezhu Yang1-1/+4
There is no git tree for KPROBES in MAINTAINERS, it is not convinent to rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, so add git tree and missing files for KPROBES, and also use linux-trace.git for TRACING to avoid confusing. Link: https://lkml.kernel.org/r/1635213091-24387-5-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26test_kprobes: Move it from kernel/ to lib/Tiezhu Yang3-1/+1
Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to let test_kprobes.c in lib/, just like other similar tests found in lib/. Link: https://lkml.kernel.org/r/1635213091-24387-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26docs, kprobes: Remove invalid URL and add new referenceTiezhu Yang1-1/+1
The following reference is invalid, remove it. https://www.ibm.com/developerworks/library/l-kprobes/index.html Add the following new reference "An introduction to KProbes": https://lwn.net/Articles/132196/ Link: https://lkml.kernel.org/r/1635213091-24387-3-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26samples/kretprobes: Fix return value if register_kretprobe() failedTiezhu Yang1-1/+1
Use the actual return value instead of always -1 if register_kretprobe() failed. E.g. without this patch: # insmod samples/kprobes/kretprobe_example.ko func=no_such_func insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Operation not permitted With this patch: # insmod samples/kprobes/kretprobe_example.ko func=no_such_func insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Unknown symbol in module Link: https://lkml.kernel.org/r/1635213091-24387-2-git-send-email-yangtiezhu@loongson.cn Fixes: 804defea1c02 ("Kprobes: move kprobe examples to samples/") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26lib/bootconfig: Fix the xbc_get_info kerneldocMasami Hiramatsu1-2/+2
Fix the kernel doc of xbc_get_info() to add '@' to the parameters. Link: https://lkml.kernel.org/r/163525086738.676803.15352231787913236933.stgit@devnote2 Fixes: e306220cb7b7 ("bootconfig: Add xbc_get_info() for the node information") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26kprobes: Add a test case for stacktrace from kretprobe handlerMasami Hiramatsu3-0/+171
Add a test case for stacktrace from kretprobe handler and nested kretprobe handlers. This test checks both of stack trace inside kretprobe handler and stack trace from pt_regs. Those stack trace must include actual function return address instead of kretprobe trampoline. The nested kretprobe stacktrace test checks whether the unwinder can correctly unwind the call frame on the stack which has been modified by the kretprobe. Since the stacktrace on kretprobe is correctly fixed only on x86, this introduces a meta kconfig ARCH_CORRECT_STACKTRACE_ON_KRETPROBE which tells user that the stacktrace on kretprobe is correct or not. The test results will be shown like below; TAP version 14 1..1 # Subtest: kprobes_test 1..6 ok 1 - test_kprobe ok 2 - test_kprobes ok 3 - test_kretprobe ok 4 - test_kretprobes ok 5 - test_stacktrace_on_kretprobe ok 6 - test_stacktrace_on_nested_kretprobe # kprobes_test: pass:6 fail:0 skip:0 total:6 # Totals: pass:6 fail:0 skip:0 total:6 ok 1 - kprobes_test Link: https://lkml.kernel.org/r/163516211244.604541.18350507860972214415.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26lib/bootconfig: Make xbc_alloc_mem() and xbc_free_mem() as __init functionMasami Hiramatsu1-2/+2
Since the xbc_alloc_mem() and xbc_free_mem() are used from the __init functions and memblock_alloc() is __init function, make them __init functions too. Link: https://lkml.kernel.org/r/163515075747.547467.5746167540626712819.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 4ee1b4cac236 ("bootconfig: Cleanup dummy headers in tools/bootconfig") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26ftrace/sh: Add arch_ftrace_ops_list_func stub to have compressed image still linkSteven Rostedt (VMware)1-0/+3
Using the linker script to fix an issue where some archs call the function tracer with just the ip (instruction pointer) and pip (parent instruction pointer) where as more up to date archs also pass in the associated ftrace_ops and the ftrace_regs pointer, the generic code will be called either with two parameters or four. To avoid any C undefined behavior of calling two parameters to four or four to two parameter function, two functions are created, where a preprocessor macro uses the one that matches the architecture. As the function pointers for them may be different, a typecast is used. But this triggers issues with newer compilers that will fail due to -Werror. A linker trick is now used to map the generic function to the function that is used (note the generic function is only used to set the default function callback). The linker trick defines ftrace_ops_list_func (the generic function) to arch_ftrace_ops_list_func (the arch defined one). Link: https://lore.kernel.org/all/20200617165616.52241bde@oasis.local.home/ But this fails sh arch because their linker script is included in their compressed image that does not define arch_ftrace_ops_list_func at all sh4-linux-ld:arch/sh/boot/compressed/../../kernel/vmlinux.lds:32: undefined symbol `arch_ftrace_ops_list_func' referenced in expression Included a stub by that name in the misc.c to allow the code to compile and link, even though it's not used. This is similar to what was done for ftrace_stub: b83b43ffc6e4b ("fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub") Link: https://lkml.kernel.org/r/20211021221627.5d7270de@rorschach.local.home Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: linux-sh@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/hwlat: Make some internal symbols staticWang ShaoBo1-2/+2
The sparse tool complains as follows: kernel/trace/trace_hwlat.c:82:27: warning: symbol 'hwlat_single_cpu_data' was not declared. Should it be static? kernel/trace/trace_hwlat.c:83:1: warning: symbol '__pcpu_scope_hwlat_per_cpu_data' was not declared. Should it be static? This symbol is not used outside of trace_hwlat.c, so this commit marks it static. Link: https://lkml.kernel.org/r/20211021035225.1050685-1-bobo.shaobowang@huawei.com Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing: Fix missing trace_boot_init_histograms kstrdup NULL checksMathieu Desnoyers1-0/+4
trace_boot_init_histograms misses NULL pointer checks for kstrdup failure. Link: https://lkml.kernel.org/r/20211015195550.22742-1-mathieu.desnoyers@efficios.com Fixes: 64dc7f6958ef5 ("tracing/boot: Show correct histogram error command") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25trace/timerlat: Add migrate-disabled field to the timerlat headerDaniel Bristot de Oliveira1-5/+6
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing output," the migrate disabled field is also printed in the !PREEMPR_RT kernel config. While this information was added to the vast majority of tracers, osnoise and timerlat were not updated (because they are new tracers). Fix timerlat header by adding the information about migrate disabled. Link: https://lkml.kernel.org/r/bc0c234ab49946cdd63effa6584e1d5e8662cb44.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 54357f0c9149 ("tracing: Add migrate-disabled counter to tracing output.") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25trace/osnoise: Add migrate-disabled field to the osnoise headerDaniel Bristot de Oliveira1-7/+7
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing output," the migrate disabled field is also printed in the !PREEMPR_RT kernel config. While this information was added to the vast majority of tracers, osnoise and timerlat were not updated (because they are new tracers). Fix osnoise header by adding the information about migrate disabled. Link: https://lkml.kernel.org/r/9cb3d54e29e0588dbba12e81486bd8a09adcd8ca.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 54357f0c9149 ("tracing: Add migrate-disabled counter to tracing output.") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25tracing/doc: Fix typos on the timerlat tracer documentationDaniel Bristot de Oliveira1-12/+12
Fixes a series of typos in the timerlat doc. Link: https://lkml.kernel.org/r/d3763eb376603890baab908141de6660ba18fff8.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: a955d7eac177 ("trace: Add timerlat tracer") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25trace/osnoise: Fix an ifdef commentDaniel Bristot de Oliveira1-1/+1
s/CONFIG_OSNOISE_TRAECR/CONFIG_OSNOISE_TRACER/ No functional changes. Link: https://lkml.kernel.org/r/33924a16f6e5559ce24952ca7d62561604bfd94a.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25perf/core: allow ftrace for functions in kernel/event/core.cSong Liu1-5/+0
It is useful to trace functions in kernel/event/core.c. Allow ftrace for them by removing $(CC_FLAGS_FTRACE) from Makefile. Link: https://lkml.kernel.org/r/20211006210732.2826289-1-songliubraving@fb.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25tools/latency-collector: Use correct size when writing queue_full_warningViktor Rosendahl1-1/+1
queue_full_warning is a pointer, so it is wrong to use sizeof to calculate the number of characters of the string it points to. The effect is that we only print out the first few characters of the warning string. The correct way is to use strlen(). We don't need to add 1 to the strlen() because we don't want to write the terminating null character to stdout. Link: https://lkml.kernel.org/r/20211019160701.15587-1-Viktor.Rosendahl@bmw.de Link: https://lore.kernel.org/r/8fd4bb65ef3da67feac9ce3258cdbe9824752cf1.1629198502.git.jing.yangyang@zte.com.cn Link: https://lore.kernel.org/r/20211012025424.180781-1-davidcomponentone@gmail.com Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25ftrace: Make ftrace_profile_pages_init staticchongjiapeng1-1/+1
This symbol is not used outside of ftrace.c, so marks it static. Fixes the following sparse warning: kernel/trace/ftrace.c:579:5: warning: symbol 'ftrace_profile_pages_init' was not declared. Should it be static? Link: https://lkml.kernel.org/r/1634640534-18280-1-git-send-email-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Fixes: cafb168a1c92 ("tracing: make the function profiler per cpu") Signed-off-by: chongjiapeng <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22ARM: Recover kretprobe modified return address in stacktraceMasami Hiramatsu4-0/+28
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, arm unwinder shows it instead of the correct return address. This finds the correct return address from the per-task kretprobe_instances list and verify it is in between the caller fp and callee fp. Note that this supports both GCC and clang if CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=n. For the ARM unwinder, this is still not working correctly. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22ARM: kprobes: Make a frame pointer on __kretprobe_trampolineMasami Hiramatsu1-4/+24
Currently kretprobe on ARM just fills r0-r11 of pt_regs, but that is not enough for the stacktrace. Moreover, from the user kretprobe handler, stacktrace needs a frame pointer on the __kretprobe_trampoline. This adds a frame pointer on __kretprobe_trampoline for both gcc and clang case. Those have different frame pointer so we need different but similar stack on pt_regs. Gcc makes the frame pointer (fp) to point the 'pc' address of the {fp, ip (=sp), lr, pc}, this means {r11, r13, r14, r15}. Thus if we save the r11 (fp) on pt_regs->r12, we can make this set on the end of pt_regs. On the other hand, Clang makes the frame pointer to point the 'fp' address of {fp, lr} on stack. Since the next to the pt_regs->lr is pt_regs->sp, I reused the pair of pt_regs->fp and pt_regs->ip. So this stores the 'lr' on pt_regs->ip and make the fp to point pt_regs->fp. For both cases, saves __kretprobe_trampoline address to pt_regs->lr, so that the stack tracer can identify this frame pointer has been made by the __kretprobe_trampoline. Note that if the CONFIG_FRAME_POINTER is not set, this keeps fp as is. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22ARM: clang: Do not rely on lr register for stacktraceMasami Hiramatsu1-2/+1
Currently the stacktrace on clang compiled arm kernel uses the 'lr' register to find the first frame address from pt_regs. However, that is wrong after calling another function, because the 'lr' register is used by 'bl' instruction and never be recovered. As same as gcc arm kernel, directly use the frame pointer (r11) of the pt_regs to find the first frame address. Note that this fixes kretprobe stacktrace issue only with CONFIG_UNWINDER_FRAME_POINTER=y. For the CONFIG_UNWINDER_ARM, we need another fix. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22arm64: Recover kretprobe modified return address in stacktraceMasami Hiramatsu3-0/+12
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, stack unwinder shows it instead of the correct return address. This checks whether the next return address is the __kretprobe_trampoline(), and if so, try to find the correct return address from the kretprobe instance list. For this purpose this adds 'kr_cur' loop cursor to memorize the current kretprobe instance. With this fix, now arm64 can enable CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the kprobe self tests. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22arm64: kprobes: Make a frame pointer on __kretprobe_trampolineMasami Hiramatsu1-0/+4
Make a frame pointer (make the x29 register points the address of pt_regs->regs[29]) on __kretprobe_trampoline. This frame pointer will be used by the stacktracer when it is called from the kretprobe handlers. In this case, the stack tracer will unwind stack to trampoline_probe_handler() and find the next frame pointer in the stack frame of the __kretprobe_trampoline(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22arm64: kprobes: Record frame pointer with kretprobe instanceMasami Hiramatsu1-2/+2
Record the frame pointer instead of stack address with kretprobe instance as the identifier on the instance list. Since arm64 always enable CONFIG_FRAME_POINTER, we can use the actual frame pointer (x29). This will allow the stacktrace code to find the original return address from the FP alone. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-22x86/unwind: Compile kretprobe fixup code only if CONFIG_KRETPROBES=yMasami Hiramatsu1-0/+6
Compile kretprobe related stacktrace entry recovery code and unwind_state::kr_cur field only when CONFIG_KRETPROBES=y. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21kprobes: convert tests to kunitSven Schnelle3-167/+61
This converts the kprobes testcases to use the kunit framework. It adds a dependency on CONFIG_KUNIT, and the output will change to TAP: TAP version 14 1..1 # Subtest: kprobes_test 1..4 random: crng init done ok 1 - test_kprobe ok 2 - test_kprobes ok 3 - test_kretprobe ok 4 - test_kretprobes ok 1 - kprobes_test Note that the kprobes testcases are no longer run immediately after kprobes initialization, but as a late initcall when kunit is initialized. kprobes itself is initialized with an early initcall, so the order is still correct. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21tracing: use %ps format string to print symbolsArnd Bergmann1-10/+5
clang started warning about excessive stack usage in hist_trigger_print_key() kernel/trace/trace_events_hist.c:4723:13: error: stack frame size (1336) exceeds limit (1024) in function 'hist_trigger_print_key' [-Werror,-Wframe-larger-than] The problem is that there are two 512-byte arrays on the stack if hist_trigger_stacktrace_print() gets inlined. I don't think this has changed in the past five years, but something probably changed the inlining decisions made by the compiler, so the problem is now made more obvious. Rather than printing the symbol names into separate buffers, it seems we can simply use the special %ps format string modifier to print the pointers symbolically and get rid of both buffers. Marking hist_trigger_stacktrace_print() would be a simpler way of avoiding the warning, but that would not address the excessive stack usage. Link: https://lkml.kernel.org/r/20211019153337.294790-1-arnd@kernel.org Fixes: 69a0200c2e25 ("tracing: Add hist trigger support for stacktraces as keys") Link: https://lore.kernel.org/all/20211015095704.49a99859@gandalf.local.home/ Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21tracing: Explain the trace recursion transition bit betterSteven Rostedt (VMware)1-2/+6
The current text of the explanation of the transition bit in the trace recursion protection is not very clear. Improve the text, so that when all the archs no longer have the issue of tracing between a start of a new (interrupt) context and updating the preempt_count to reflect the new context, that it may be removed. Link: https://lore.kernel.org/all/20211018220203.064a42ed@gandalf.local.home/ Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace/direct: Do not disable when switching direct callersSteven Rostedt (VMware)1-14/+20
Currently to switch a set of "multi" direct trampolines from one trampoline to another, a full shutdown of the current set needs to be done, followed by an update to what trampoline the direct callers would call, and then re-enabling the callers. This leaves a time when the functions will not be calling anything, and events may be missed. Instead, use a trick to allow all the functions with direct trampolines attached will always call either the new or old trampoline while the switch is happening. To do this, first attach a "dummy" callback via ftrace to all the functions that the current direct trampoline is attached to. This will cause the functions to call the "list func" instead of the direct trampoline. The list function will call the direct trampoline "helper" that will set the function it should call as it returns back to the ftrace trampoline. At this moment, the direct caller descriptor can safely update the direct call trampoline. The list function will pick either the new or old function (depending on the memory coherency model of the architecture). Now removing the dummy function from each of the locations of the direct trampoline caller, will put back the direct call, but now to the new trampoline. A better visual is: [ Changing direct call from my_direct_1 to my_direct_2 ] <traced_func>: call my_direct_1 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv <traced_func>: call ftrace_caller <ftrace_caller>: [..] call ftrace_ops_list_func ftrace_ops_list_func() { ops->func() -> direct_helper -> set rax to my_direct_1 or my_direct_2 } call rax (to either my_direct_1 or my_direct_2 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv <traced_func>: call my_direct_2 Link: https://lore.kernel.org/all/20211014162819.5c85618b@gandalf.local.home/ Acked-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace/samples: Add multi direct interface test moduleJiri Olsa2-0/+53
Adding simple module that uses multi direct interface: register_ftrace_direct_multi unregister_ftrace_direct_multi The init function registers trampoline for 2 functions, and exit function unregisters them. Link: https://lkml.kernel.org/r/20211008091336.33616-9-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add multi direct modify interfaceJiri Olsa2-0/+68
Adding interface to modify registered direct function for ftrace_ops. Adding following function: modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) The function changes the currently registered direct function for all attached functions. Link: https://lkml.kernel.org/r/20211008091336.33616-8-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add multi direct register/unregister interfaceJiri Olsa2-0/+153
Adding interface to register multiple direct functions within single call. Adding following functions: register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) The register_ftrace_direct_multi registers direct function (addr) with all functions in ops filter. The ops filter can be updated before with ftrace_set_filter_ip calls. All requested functions must not have direct function currently registered, otherwise register_ftrace_direct_multi will fail. The unregister_ftrace_direct_multi unregisters ops related direct functions. Link: https://lkml.kernel.org/r/20211008091336.33616-7-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add ftrace_add_rec_direct functionJiri Olsa1-27/+37
Factor out the code that adds (ip, addr) tuple to direct_functions hash in new ftrace_add_rec_direct function. It will be used in following patches. Link: https://lkml.kernel.org/r/20211008091336.33616-6-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>