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path: root/tools/perf/util/probe-finder.c
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2024-04-01bitops: make BYTES_TO_BITS() treewide-availableAlexander Lobakin
Avoid open-coding that simple expression each time by moving BYTES_TO_BITS() from the probes code to <linux/bitops.h> to export it to the rest of the kernel. Simplify the macro while at it. `BITS_PER_LONG / sizeof(long)` always equals to %BITS_PER_BYTE, regardless of the target architecture. Do the same for the tools ecosystem as well (incl. its version of bitops.h). The previous implementation had its implicit type of long, while the new one is int, so adjust the format literal accordingly in the perf code. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Acked-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-10perf probe: Convert to check dwarf_getcfi featureNamhyung Kim
Now it has a feature check for the dwarf_getcfi(), use it and convert the code to check HAVE_DWARF_CFI_SUPPORT definition. Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: linux-toolchains@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Link: https://lore.kernel.org/r/20231110000012.3538610-10-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-11-10perf tools: Add util/debuginfo.[ch] filesNamhyung Kim
Split debuginfo data structure and related functions into a separate file so that it can be used by other components than the probe-finder. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: linux-toolchains@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Link: https://lore.kernel.org/r/20231110000012.3538610-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-04-19perf probe: Add missing 0x prefix for addresses printed in hexadecimalArnaldo Carvalho de Melo
To fix this confusing warning: # perf probe -l Failed to find debug information for address 798240 probe_main:prometheus_new_counter__return (on github.com/prometheus/client_golang/prometheus.NewCounter%return in /home/acme/git/prometheus-uprobes/main with counter) # As that 798240 is printed with PRIx64 but has no letters, better print the 0x prefix to disambiguate. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/lkml/ZEBCyFu2GjTw6qOi@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-03perf probe: Fix to get declared file name from clang DWARF5Masami Hiramatsu (Google)
Fix to get the declared file name even if it uses file index 0 in DWARF5, using custom die_get_decl_file() function. Actually, the DWARF5 standard says file index 0 of the DW_AT_decl_file is invalid(1), but there is a discussion and maybe this will be updated [2]. Anyway, clang generates such DWARF5 file for the linux kernel. Thus it must be handled. Without this, 'perf probe' returns an error: $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Debuginfo analysis failed. Error: Failed to show lines. With this, it can handle the case correctly: $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 <vfs_read@$SRC_PATH/fs/read_write.c:10> 11 ret = rw_verify_area(READ, file, pos, count); 12 if (ret) return ret; [1] DWARF5 specification 2.14 says "The value 0 indicates that no source file has been specified.") [2] http://wiki.dwarfstd.org/index.php?title=DWARF5_Line_Table_File_Numbers) Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/166731052936.2100653.13380621874859467731.stgit@devnote3 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-03perf probe: Fix to avoid crashing if DW_AT_decl_file is NULLMasami Hiramatsu (Google)
Since clang generates DWARF5 which sets DW_AT_decl_file as 0, dwarf_decl_file() thinks that is invalid and returns NULL. In that case 'perf probe' SIGSEGVs because it doesn't expect a NULL decl_file. This adds a dwarf_decl_file() return value check to avoid such SEGV with clang generated DWARF5 info. Without this, 'perf probe' crashes: $ perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Segmentation fault $ With this, it just warns about it: $ perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Debuginfo analysis failed. Error: Failed to show lines. $ Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/166731051077.2100653.15626653369345128302.stgit@devnote3 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-18perf probe: Fix add event failure when running 32-bit perf in a 64-bit kernelYang Jihong
The "address" member of "struct probe_trace_point" uses long data type. If kernel is 64-bit and perf program is 32-bit, size of "address" variable is 32 bits. As a result, upper 32 bits of address read from kernel are truncated, an error occurs during address comparison in kprobe_warn_out_range(). Before: # perf probe -a schedule schedule is out of .text, skip it. Error: Failed to add events. Solution: Change data type of "address" variable to u64 and change corresponding address printing and value assignment. After: # perf.new.new probe -a schedule Added new event: probe:schedule (on schedule) You can now use it in all perf tools, such as: perf record -e probe:schedule -aR sleep 1 # perf probe -l probe:schedule (on schedule@kernel/sched/core.c) # perf record -e probe:schedule -aR sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.156 MB perf.data (1366 samples) ] # perf report --stdio # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 1K of event 'probe:schedule' # Event count (approx.): 1366 # # Overhead Command Shared Object Symbol # ........ ............... ................. ............ # 6.22% migration/0 [kernel.kallsyms] [k] schedule 6.22% migration/1 [kernel.kallsyms] [k] schedule 6.22% migration/2 [kernel.kallsyms] [k] schedule 6.22% migration/3 [kernel.kallsyms] [k] schedule 6.15% migration/10 [kernel.kallsyms] [k] schedule 6.15% migration/11 [kernel.kallsyms] [k] schedule 6.15% migration/12 [kernel.kallsyms] [k] schedule 6.15% migration/13 [kernel.kallsyms] [k] schedule 6.15% migration/14 [kernel.kallsyms] [k] schedule 6.15% migration/15 [kernel.kallsyms] [k] schedule 6.15% migration/4 [kernel.kallsyms] [k] schedule 6.15% migration/5 [kernel.kallsyms] [k] schedule 6.15% migration/6 [kernel.kallsyms] [k] schedule 6.15% migration/7 [kernel.kallsyms] [k] schedule 6.15% migration/8 [kernel.kallsyms] [k] schedule 6.15% migration/9 [kernel.kallsyms] [k] schedule 0.22% rcu_sched [kernel.kallsyms] [k] schedule ... # # (Cannot load tips.txt file, please install perf!) # Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Ian Rogers <irogers@google.com> Cc: Jianlin Lv <jianlin.lv@arm.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Li Huafei <lihuafei1@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lore.kernel.org/lkml/20210715063723.11926-1-yangjihong1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-07perf probe: Fix debuginfo__new() to enable build-id based debuginfoMasami Hiramatsu
Fix debuginfo__new() to set the build-id to dso before dso__read_binary_type_filename() so that it can find DSO_BINARY_TYPE__BUILDID_DEBUGINFO debuginfo correctly. However, this may not change the result, because elfutils (libdwfl) has its own debuginfo finder. With/without this patch, the perf probe correctly find the debuginfo file. This is just a failsafe and keep code's sanity (if you use dso__read_binary_type_filename(), you must set the build-id to the dso.) Reported-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Masami Hiramatsu <mhriamat@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Stefan Liebler <stli@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Link: http://lore.kernel.org/lkml/162532651863.393143.11692691321219235810.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-06-01perf probe: Fix NULL pointer dereference in convert_variable_location()Li Huafei
If we just check whether the variable can be converted, 'tvar' should be a null pointer. However, the null pointer check is missing in the 'Constant value' execution path. The following cases can trigger this problem: $ cat test.c #include <stdio.h> void main(void) { int a; const int b = 1; asm volatile("mov %1, %0" : "=r"(a): "i"(b)); printf("a: %d\n", a); } $ gcc test.c -o test -O -g $ sudo ./perf probe -x ./test -L "main" <main@/home/lhf/test.c:0> 0 void main(void) { 2 int a; const int b = 1; asm volatile("mov %1, %0" : "=r"(a): "i"(b)); 6 printf("a: %d\n", a); } $ sudo ./perf probe -x ./test -V "main:6" Segmentation fault The check on 'tvar' is added. If 'tavr' is a null pointer, we return 0 to indicate that the variable can be converted. Now, we can successfully show the variables that can be accessed. $ sudo ./perf probe -x ./test -V "main:6" Available variables at main:6 @<main+13> char* __fmt int a int b However, the variable 'b' cannot be tracked. $ sudo ./perf probe -x ./test -D "main:6 b" Failed to find the location of the 'b' variable at this address. Perhaps it has been optimized out. Use -V with the --range option to show 'b' location range. Error: Failed to add events. This is because __die_find_variable_cb() did not successfully match variable 'b', which has the DW_AT_const_value attribute instead of DW_AT_location. We added support for DW_AT_const_value in __die_find_variable_cb(). With this modification, we can successfully track the variable 'b'. $ sudo ./perf probe -x ./test -D "main:6 b" p:probe_test/main_L6 /home/lhf/test:0x1156 b=\1:s32 Fixes: 66f69b219716 ("perf probe: Support DW_AT_const_value constant value") Signed-off-by: Li Huafei <lihuafei1@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Jianlin Lv <jianlin.lv@arm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Yang Jihong <yangjihong1@huawei.com> Cc: Zhang Jinhao <zhangjinhao2@huawei.com> http://lore.kernel.org/lkml/20210601092750.169601-1-lihuafei1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-23perf tools: Fix various typos in commentsIngo Molnar
Fix ~124 single-word typos and a few spelling errors in the perf tooling code, accumulated over the years. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-02-08perf probe: Add protection to avoid endless loopJianlin Lv
if dwarf_offdie() returns NULL, the continue statement forces the next iteration of the loop without updating the 'off' variable. It will cause an endless loop in the process of traversing the compile unit. So add exception protection for looping CUs. Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: jianlin.lv@arm.com Link: http://lore.kernel.org/lkml/20210203145702.1219509-1-Jianlin.Lv@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-11-27perf probe: Change function definition check due to broken DWARFMasami Hiramatsu
Since some gcc generates a broken DWARF which lacks DW_AT_declaration attribute from the subprogram DIE of function prototype. (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97060) So, in addition to the DW_AT_declaration check, we also check the subprogram DIE has DW_AT_inline or actual entry pc. Committer testing: # cat /etc/fedora-release Fedora release 33 (Thirty Three) # Before: # perf test vfs_getname 78: Use vfs_getname probe to get syscall args filenames : FAILED! 79: Check open filename arg using perf trace + vfs_getname : FAILED! 81: Add vfs_getname probe to get syscall args filenames : FAILED! # After: # perf test vfs_getname 78: Use vfs_getname probe to get syscall args filenames : Ok 79: Check open filename arg using perf trace + vfs_getname : Ok 81: Add vfs_getname probe to get syscall args filenames : Ok # Reported-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Link: http://lore.kernel.org/lkml/160645613571.2824037.7441351537890235895.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-10-14perf tools: Pass build_id object to build_id__sprintf()Jiri Olsa
Passing build_id object to build_id__sprintf function, so it can operate with the proper size of build id. This will create proper md5 build id readable names, like following: a50e350e97c43b4708d09bcd85ebfff7 instead of: a50e350e97c43b4708d09bcd85ebfff700000000 Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20201013192441.1299447-5-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-09-18perf probe: Fall back to debuginfod query if debuginfo and source not found ↵Masami Hiramatsu
locally Since 'perf probe' heavily depends on debuginfo, debuginfod gives us many benefits on the 'perf probe' command on remote machine. Especially, this will be helpful for the embedded devices which will not have enough storage, or boot with a cross-build kernel whose source code is in the host machine. This will work as similar to commit c7a14fdcb3fa7736 ("perf build-ids: Fall back to debuginfod query if debuginfo not found") Tested with: (host) $ cd PATH/TO/KBUILD/DIR/ (host) $ debuginfod -F . ... (remote) # perf probe -L vfs_read Failed to find the path for the kernel: No such file or directory Error: Failed to show lines. (remote) # export DEBUGINFOD_URLS="http://$HOST_IP:8002/" (remote) # perf probe -L vfs_read <vfs_read@...> 0 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { 2 ssize_t ret; if (!(file->f_mode & FMODE_READ)) return -EBADF; 6 if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; 8 if (unlikely(!access_ok(buf, count))) return -EFAULT; 11 ret = rw_verify_area(READ, file, pos, count); 12 if (ret) return ret; if (count > MAX_RW_COUNT) ... (remote) # perf probe -a "vfs_read count" Added new event: probe:vfs_read (on vfs_read with count) (remote) # perf probe -l probe:vfs_read (on vfs_read@ksrc/linux/fs/read_write.c with count) Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Frank Ch. Eigler <fche@redhat.com> Cc: Aaron Merey <amerey@redhat.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Link: http://lore.kernel.org/lkml/160041610083.912668.13659563860278615846.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-17perf probe: Fix memory leakage when the probe point is not foundMasami Hiramatsu
Fix the memory leakage in debuginfo__find_trace_events() when the probe point is not found in the debuginfo. If there is no probe point found in the debuginfo, debuginfo__find_probes() will NOT return -ENOENT, but 0. Thus the caller of debuginfo__find_probes() must check the tf.ntevs and release the allocated memory for the array of struct probe_trace_event. The current code releases the memory only if the debuginfo__find_probes() hits an error but not checks tf.ntevs. In the result, the memory allocated on *tevs are not released if tf.ntevs == 0. This fixes the memory leakage by checking tf.ntevs == 0 in addition to ret < 0. Fixes: ff741783506c ("perf probe: Introduce debuginfo to encapsulate dwarf information") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/159438668346.62703.10887420400718492503.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-17perf probe: Fix wrong variable warning when the probe point is not foundMasami Hiramatsu
Fix a wrong "variable not found" warning when the probe point is not found in the debuginfo. Since the debuginfo__find_probes() can return 0 even if it does not find given probe point in the debuginfo, fill_empty_trace_arg() can be called with tf.ntevs == 0 and it can emit a wrong warning. To fix this, reject ntevs == 0 in fill_empty_trace_arg(). E.g. without this patch; # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di" Failed to find the location of the '%di' variable at this address. Perhaps it has been optimized out. Use -V with the --range option to show '%di' location range. Added new events: probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) You can now use it in all perf tools, such as: perf record -e probe_libc:memcpy -aR sleep 1 With this; # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di" Added new events: probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) You can now use it in all perf tools, such as: perf record -e probe_libc:memcpy -aR sleep 1 Fixes: cb4027308570 ("perf probe: Trace a magic number if variable is not found") Reported-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Andi Kleen <ak@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/159438667364.62703.2200642186798763202.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-05-28perf symbols: Fix debuginfo search for UbuntuAdrian Hunter
Reportedly, from 19.10 Ubuntu has begun mixing up the location of some debug symbol files, putting files expected to be in /usr/lib/debug/usr/lib into /usr/lib/debug/lib instead. Fix by adding another dso_binary_type. Example on Ubuntu 20.04 Before: $ perf record -e intel_pt//u uname Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.030 MB perf.data ] $ perf script --call-trace | head -5 uname 14003 [005] 15321.764958566: cbr: 42 freq: 4219 MHz (156%) uname 14003 [005] 15321.764958566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) 7f1e71cc4100 uname 14003 [005] 15321.764961566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) 7f1e71cc4df0 uname 14003 [005] 15321.764961900: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) 7f1e71cc4e18 uname 14003 [005] 15321.764963233: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) 7f1e71cc5128 After: $ perf script --call-trace | head -5 uname 14003 [005] 15321.764958566: cbr: 42 freq: 4219 MHz (156%) uname 14003 [005] 15321.764958566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) _start uname 14003 [005] 15321.764961566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) _dl_start uname 14003 [005] 15321.764961900: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) _dl_start uname 14003 [005] 15321.764963233: (/usr/lib/x86_64-linux-gnu/ld-2.31.so ) _dl_start Reported-by: Travis Downs <travis.downs@gmail.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/20200526155207.9172-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-03-09perf probe: Do not depend on dwfl_module_addrsym()Masami Hiramatsu
Do not depend on dwfl_module_addrsym() because it can fail on user-space shared libraries. Actually, same bug was fixed by commit 664fee3dc379 ("perf probe: Do not use dwfl_module_addrsym if dwarf_diename finds symbol name"), but commit 07d369857808 ("perf probe: Fix wrong address verification) reverted to get actual symbol address from symtab. This fixes it again by getting symbol address from DIE, and only if the DIE has only address range, it uses dwfl_module_addrsym(). Fixes: 07d369857808 ("perf probe: Fix wrong address verification) Reported-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Link: http://lore.kernel.org/lkml/158281812176.476.14164573830975116234.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-01-31perf probe: Add ustring support for perf probe commandThomas Richter
Kernel commit 88903c464321 ("tracing/probe: Add ustring type for user-space string") adds support for user-space strings when type 'ustring' is specified. Here is an example using sysfs command line interface for kprobes: Function to probe: struct filename * getname_flags(const char __user *filename, int flags, int *empty) Setup: # cd /sys/kernel/debug/tracing/ # echo 'p:tmr1 getname_flags +0(%r2):ustring' > kprobe_events # cat events/kprobes/tmr1/format | fgrep print print fmt: "(%lx) arg1=\"%s\"", REC->__probe_ip, REC->arg1 # echo 1 > events/kprobes/tmr1/enable # touch /tmp/111 # echo 0 > events/kprobes/tmr1/enable # cat trace|fgrep /tmp/111 touch-5846 [005] d..2 255520.717960: tmr1:\ (getname_flags+0x0/0x400) arg1="/tmp/111" Doing the same with the perf tool fails. Using type 'string' succeeds: # perf probe "vfs_getname=getname_flags:72 pathname=filename:string" Added new event: probe:vfs_getname (on getname_flags:72 with pathname=filename:string) .... # perf probe -d probe:vfs_getname Removed event: probe:vfs_getname However using type 'ustring' fails (output before): # perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring" Failed to write event: Invalid argument Error: Failed to add events. # Fix this by adding type 'ustring' in function convert_variable_type(). Using ustring succeeds (output after): # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring" Added new event: probe:vfs_getname (on getname_flags:72 with pathname=filename:ustring) You can now use it in all perf tools, such as: perf record -e probe:vfs_getname -aR sleep 1 # Note: This issue also exists on x86, it is not s390 specific. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: sumanthk@linux.ibm.com Link: http://lore.kernel.org/lkml/20200120132011.64698-2-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-22perf probe: Fix spelling mistake "addrees" -> "address"Colin Ian King
There is a spelling mistake in a pr_warning message. Fix it. Signed-off-by: Colin King <colin.king@canonical.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel-janitors@vger.kernel.org Link: http://lore.kernel.org/lkml/20191121092623.374896-1-colin.king@canonical.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-18perf probe: Trace a magic number if variable is not foundMasami Hiramatsu
Trace a magic number as immediate value if the target variable is not found at some probe points which is based on one probe event. This feature is good for the case if you trace a source code line with some local variables, which is compiled into several instructions and some of the variables are optimized out on some instructions. Even if so, with this feature, perf probe trace a magic number instead of such disappeared variables and fold those probes on one event. E.g. without this patch: # perf probe -D "pud_page_vaddr pud" Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. Failed to find 'pud' in this function. p:probe/pud_page_vaddr _text+23480787 pud=%ax:x64 p:probe/pud_page_vaddr _text+23808453 pud=%bp:x64 p:probe/pud_page_vaddr _text+23558082 pud=%ax:x64 p:probe/pud_page_vaddr _text+328373 pud=%r8:x64 p:probe/pud_page_vaddr _text+348448 pud=%bx:x64 p:probe/pud_page_vaddr _text+23816818 pud=%bx:x64 With this patch: # perf probe -D "pud_page_vaddr pud" | head spurious_kernel_fault is blacklisted function, skip it. vmalloc_fault is blacklisted function, skip it. p:probe/pud_page_vaddr _text+23480787 pud=%ax:x64 p:probe/pud_page_vaddr _text+149051 pud=\deade12d:x64 p:probe/pud_page_vaddr _text+23808453 pud=%bp:x64 p:probe/pud_page_vaddr _text+315926 pud=\deade12d:x64 p:probe/pud_page_vaddr _text+23807209 pud=\deade12d:x64 p:probe/pud_page_vaddr _text+23557365 pud=%ax:x64 p:probe/pud_page_vaddr _text+314097 pud=%di:x64 p:probe/pud_page_vaddr _text+314015 pud=\deade12d:x64 p:probe/pud_page_vaddr _text+313893 pud=\deade12d:x64 p:probe/pud_page_vaddr _text+324083 pud=\deade12d:x64 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Link: http://lore.kernel.org/lkml/157406476931.24476.6261475888681844285.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-18perf probe: Support DW_AT_const_value constant valueMasami Hiramatsu
Support DW_AT_const_value for variable assignment instead of location. Note that this requires ftrace supporting immediate value. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Link: http://lore.kernel.org/lkml/157406476012.24476.16096289871757175775.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-18perf probe: Do not show non representive lines by perf-probe -LMasami Hiramatsu
Since perf probe -L shows non representive lines, it can be mislead users where user can put probes. This prevents to show such non representive lines so that user can understand which lines user can probe. # perf probe -L kernel_read <kernel_read@/build/linux-pvZVvI/linux-5.0.0/fs/read_write.c:0> 0 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { 2 mm_segment_t old_fs; ssize_t result; old_fs = get_fs(); 6 set_fs(get_ds()); /* The cast to a user pointer is valid due to the set_fs() */ 8 result = vfs_read(file, (void __user *)buf, count, pos); 9 set_fs(old_fs); 10 return result; } EXPORT_SYMBOL(kernel_read); Committer testing: Before: # perf probe -L kernel_read <kernel_read@/usr/src/debug/kernel-5.3.fc30/linux-5.3.8-200.fc30.x86_64/fs/read_write.c:0> 0 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) 1 { 2 mm_segment_t old_fs; 3 ssize_t result; 5 old_fs = get_fs(); 6 set_fs(KERNEL_DS); /* The cast to a user pointer is valid due to the set_fs() */ 8 result = vfs_read(file, (void __user *)buf, count, pos); 9 set_fs(old_fs); 10 return result; } EXPORT_SYMBOL(kernel_read); # See the 1, 3, 5 lines? They shouldn't be there, after this patch: # perf probe -L kernel_read <kernel_read@/usr/src/debug/kernel-5.3.fc30/linux-5.3.8-200.fc30.x86_64/fs/read_write.c:0> 0 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { 2 mm_segment_t old_fs; ssize_t result; old_fs = get_fs(); 6 set_fs(KERNEL_DS); /* The cast to a user pointer is valid due to the set_fs() */ 8 result = vfs_read(file, (void __user *)buf, count, pos); 9 set_fs(old_fs); 10 return result; } EXPORT_SYMBOL(kernel_read); # Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Link: http://lore.kernel.org/lkml/157406473064.24476.2913278267727587314.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-18perf probe: Verify given line is a representive lineMasami Hiramatsu
Verify user given probe line is a representive line (which doesn't share the address with other lines or the line is the least line among the lines which shares same address), and if not, it shows what is the representive line. Without this fix, user can put a probe on the lines which is not a a representive line. But since this is not a representive line, perf probe -l shows a representive line number instead of user given line number. e.g. (put kernel_read:3, but listed as kernel_read:2) # perf probe -a kernel_read:3 Added new event: probe:kernel_read (on kernel_read:3) You can now use it in all perf tools, such as: perf record -e probe:kernel_read -aR sleep 1 # perf probe -l probe:kernel_read (on kernel_read:2@linux-5.0.0/fs/read_write.c) With this fix, perf probe doesn't allow user to put a probe on a representive line, and tell what is the representive line. # perf probe -a kernel_read:3 This line is sharing the addrees with other lines. Please try to probe at kernel_read:2 instead. Error: Failed to add events. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Link: http://lore.kernel.org/lkml/157406472071.24476.14915451439785001021.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-07perf probe: Skip overlapped location on searching variablesMasami Hiramatsu
Since debuginfo__find_probes() callback function can be called with the location which already passed, the callback function must filter out such overlapped locations. add_probe_trace_event() has already done it by commit 1a375ae7659a ("perf probe: Skip same probe address for a given line"), but add_available_vars() doesn't. Thus perf probe -v shows same address repeatedly as below: # perf probe -V vfs_read:18 Available variables at vfs_read:18 @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+226> char* buf loff_t* pos ssize_t ret struct file* file With this fix, perf probe -V shows it correctly: # perf probe -V vfs_read:18 Available variables at vfs_read:18 @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+226> char* buf loff_t* pos ssize_t ret struct file* file Fixes: cf6eb489e5c0 ("perf probe: Show accessible local variables") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157241938927.32002.4026859017790562751.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-07perf probe: Return a better scope DIE if there is no best scopeMasami Hiramatsu
Make find_best_scope() returns innermost DIE at given address if there is no best matched scope DIE. Since Gcc sometimes generates intuitively strange line info which is out of inlined function address range, we need this fixup. Without this, sometimes perf probe failed to probe on a line inside an inlined function: # perf probe -D ksys_open:3 Failed to find scope of probe point. Error: Failed to add events. With this fix, 'perf probe' can probe it: # perf probe -D ksys_open:3 p:probe/ksys_open _text+25707308 p:probe/ksys_open_1 _text+25710596 p:probe/ksys_open_2 _text+25711114 p:probe/ksys_open_3 _text+25711343 p:probe/ksys_open_4 _text+25714058 p:probe/ksys_open_5 _text+2819653 p:probe/ksys_open_6 _text+2819701 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Link: http://lore.kernel.org/lkml/157291300887.19771.14936015360963292236.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06perf probe: Fix to list probe event with correct line numberMasami Hiramatsu
Since debuginfo__find_probe_point() uses dwarf_entrypc() for finding the entry address of the function on which a probe is, it will fail when the function DIE has only ranges attribute. To fix this issue, use die_entrypc() instead of dwarf_entrypc(). Without this fix, perf probe -l shows incorrect offset: # perf probe -l probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579263632@work/linux/linux/kernel/cpu.c) probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask+18446744071579263752@work/linux/linux/kernel/cpu.c) With this: # perf probe -l probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@work/linux/linux/kernel/cpu.c) probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:21@work/linux/linux/kernel/cpu.c) Committer testing: Before: [root@quaco ~]# perf probe -l probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579765152@kernel/cpu.c) [root@quaco ~]# After: [root@quaco ~]# perf probe -l probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c) [root@quaco ~]# Fixes: 1d46ea2a6a40 ("perf probe: Fix listing incorrect line number with inline function") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157199321227.8075.14655572419136993015.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06perf probe: Fix to probe an inline function which has no entry pcMasami Hiramatsu
Fix perf probe to probe an inlne function which has no entry pc or low pc but only has ranges attribute. This seems very rare case, but I could find a few examples, as same as probe_point_search_cb(), use die_entrypc() to get the entry address in probe_point_inline_cb() too. Without this patch: # perf probe -D __amd_put_nb_event_constraints Failed to get entry address of __amd_put_nb_event_constraints. Probe point '__amd_put_nb_event_constraints' not found. Error: Failed to add events. With this patch: # perf probe -D __amd_put_nb_event_constraints p:probe/__amd_put_nb_event_constraints amd_put_event_constraints+43 Committer testing: Before: [root@quaco ~]# perf probe -D __amd_put_nb_event_constraints Failed to get entry address of __amd_put_nb_event_constraints. Probe point '__amd_put_nb_event_constraints' not found. Error: Failed to add events. [root@quaco ~]# After: [root@quaco ~]# perf probe -D __amd_put_nb_event_constraints p:probe/__amd_put_nb_event_constraints _text+33789 [root@quaco ~]# Fixes: 4ea42b181434 ("perf: Add perf probe subcommand, a kprobe-event setup helper") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157199320336.8075.16189530425277588587.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06perf probe: Fix to probe a function which has no entry pcMasami Hiramatsu
Fix 'perf probe' to probe a function which has no entry pc or low pc but only has ranges attribute. probe_point_search_cb() uses dwarf_entrypc() to get the probe address, but that doesn't work for the function DIE which has only ranges attribute. Use die_entrypc() instead. Without this fix: # perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0 Probe point 'clear_tasks_mm_cpumask' not found. Error: Failed to add events. With this: # perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0 p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0 Committer testing: Before: [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 Probe point 'clear_tasks_mm_cpumask' not found. Error: Failed to add events. [root@quaco ~]# After: [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 Added new event: probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask) You can now use it in all perf tools, such as: perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1 [root@quaco ~]# Using it with 'perf trace': [root@quaco ~]# perf trace -e probe:clear_tasks_mm_cpumask Doesn't seem to be used in x86_64: $ find . -name "*.c" | xargs grep clear_tasks_mm_cpumask ./kernel/cpu.c: * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU ./kernel/cpu.c:void clear_tasks_mm_cpumask(int cpu) ./arch/xtensa/kernel/smp.c: clear_tasks_mm_cpumask(cpu); ./arch/csky/kernel/smp.c: clear_tasks_mm_cpumask(cpu); ./arch/sh/kernel/smp.c: clear_tasks_mm_cpumask(cpu); ./arch/arm/kernel/smp.c: clear_tasks_mm_cpumask(cpu); ./arch/powerpc/mm/nohash/mmu_context.c: clear_tasks_mm_cpumask(cpu); $ find . -name "*.h" | xargs grep clear_tasks_mm_cpumask ./include/linux/cpu.h:void clear_tasks_mm_cpumask(int cpu); $ find . -name "*.S" | xargs grep clear_tasks_mm_cpumask $ Fixes: e1ecbbc3fa83 ("perf probe: Fix to handle optimized not-inlined functions") Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157199319438.8075.4695576954550638618.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06perf probe: Fix wrong address verificationMasami Hiramatsu
Since there are some DIE which has only ranges instead of the combination of entrypc/highpc, address verification must use dwarf_haspc() instead of dwarf_entrypc/dwarf_highpc. Also, the ranges only DIE will have a partial code in different section (e.g. unlikely code will be in text.unlikely as "FUNC.cold" symbol). In that case, we can not use dwarf_entrypc() or die_entrypc(), because the offset from original DIE can be a minus value. Instead, this simply gets the symbol and offset from symtab. Without this patch; # perf probe -D clear_tasks_mm_cpumask:1 Failed to get entry address of clear_tasks_mm_cpumask Error: Failed to add events. And with this patch: # perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0 p:probe/clear_tasks_mm_cpumask_1 clear_tasks_mm_cpumask+5 p:probe/clear_tasks_mm_cpumask_2 clear_tasks_mm_cpumask+8 p:probe/clear_tasks_mm_cpumask_3 clear_tasks_mm_cpumask+16 p:probe/clear_tasks_mm_cpumask_4 clear_tasks_mm_cpumask+82 Committer testing: I managed to reproduce the above: [root@quaco ~]# perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask _text+919968 p:probe/clear_tasks_mm_cpumask_1 _text+919973 p:probe/clear_tasks_mm_cpumask_2 _text+919976 [root@quaco ~]# But then when trying to actually put the probe in place, it fails if I use :0 as the offset: [root@quaco ~]# perf probe -L clear_tasks_mm_cpumask | head -5 <clear_tasks_mm_cpumask@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/kernel/cpu.c:0> 0 void clear_tasks_mm_cpumask(int cpu) 1 { 2 struct task_struct *p; [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 Probe point 'clear_tasks_mm_cpumask' not found. Error: Failed to add events. [root@quaco The next patch is needed to fix this case. Fixes: 576b523721b7 ("perf probe: Fix probing symbols with optimization suffix") Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157199318513.8075.10463906803299647907.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-20perf probe: Skip same probe address for a given lineMasami Hiramatsu
Fix to skip making a same probe address on given line. Since a DWARF line info contains several entries for one line with different column, perf probe will make a different probe on same address if user specifies a probe point by "function:line" or "file:line". e.g. $ perf probe -D kernel_read:8 p:probe/kernel_read_L8 kernel_read+39 p:probe/kernel_read_L8_1 kernel_read+39 This skips such duplicated probe addresses. Committer testing: # uname -a Linux quaco 5.3.0+ #2 SMP Thu Sep 19 16:13:22 -03 2019 x86_64 x86_64 x86_64 GNU/Linux # Before: # perf probe -D kernel_read:8 p:probe/kernel_read _text+3115191 p:probe/kernel_read_1 _text+3115191 # After: # perf probe -D kernel_read:8 p:probe/kernel_read _text+3115191 # Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lore.kernel.org/lkml/156886447061.10772.4261569305869149178.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-08-31perf debug: Remove needless include directives from debug.hArnaldo Carvalho de Melo
All we need there is a forward declaration for 'union perf_event', so remove it from there and add missing header directives in places using things from this indirect include. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-07-18Merge tag 'trace-v5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The main changes in this release include: - Add user space specific memory reading for kprobes - Allow kprobes to be executed earlier in boot The rest are mostly just various clean ups and small fixes" * tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Make trace_get_fields() global tracing: Let filter_assign_type() detect FILTER_PTR_STRING tracing: Pass type into tracing_generic_entry_update() ftrace/selftest: Test if set_event/ftrace_pid exists before writing ftrace/selftests: Return the skip code when tracing directory not configured in kernel tracing/kprobe: Check registered state using kprobe tracing/probe: Add trace_event_call accesses APIs tracing/probe: Add probe event name and group name accesses APIs tracing/probe: Add trace flag access APIs for trace_probe tracing/probe: Add trace_event_file access APIs for trace_probe tracing/probe: Add trace_event_call register API for trace_probe tracing/probe: Add trace_probe init and free functions tracing/uprobe: Set print format when parsing command tracing/kprobe: Set print format right after parsed command kprobes: Fix to init kprobes in subsys_initcall tracepoint: Use struct_size() in kmalloc() ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS ftrace: Enable trampoline when rec count returns back to one tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline tracing: Make a separate config for trace event self tests ...
2019-07-09tools lib: Adopt zalloc()/zfree() from tools/perfArnaldo Carvalho de Melo
Eroding a bit more the tools/perf/util/util.h hodpodge header. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-natazosyn9rwjka25tvcnyi0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-25perf-probe: Add user memory access attribute supportMasami Hiramatsu
Add user memory access attribute for kprobe event arguments. If a given 'local variable' is in user-space, User can specify memory access method by '@user' suffix. This is not only for string but also for data structure. If we access a field of data structure in user memory from kernel on some arch, it will fail. e.g. perf probe -a "sched_setscheduler param->sched_priority" This will fail to access the "param->sched_priority" because the param is __user pointer. Instead, we can now specify @user suffix for such argument. perf probe -a "sched_setscheduler param->sched_priority@user" Note that kernel memory access with "@user" must always fail on any arch. Link: http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2 Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-19perf probe: Use right type to access array elementsMasami Hiramatsu
Current 'perf probe' converts the type of array-elements incorrectly. It always converts the types as a pointer of array. This passes the "array" type DIE to the type converter so that it can get correct "element of array" type DIE from it. E.g. ==== $ cat hello.c #include <stdio.h> void foo(int a[]) { printf("%d\n", a[1]); } void main() { int a[3] = {4, 5, 6}; printf("%d\n", a[0]); foo(a); } $ gcc -g hello.c -o hello $ perf probe -x ./hello -D "foo a[1]" ==== Without this fix, above outputs ==== p:probe_hello/foo /tmp/hello:0x4d3 a=+4(-8(%bp)):u64 ==== The "u64" means "int *", but a[1] is "int". With this, ==== p:probe_hello/foo /tmp/hello:0x4d3 a=+4(-8(%bp)):s32 ==== So, "int" correctly converted to "s32" Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: linux-kselftest@vger.kernel.org Cc: linux-trace-users@vger.kernel.org Fixes: b2a3c12b7442 ("perf probe: Support tracing an entry of array") Link: http://lkml.kernel.org/r/152129114502.31874.2474068470011496356.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-19perf str{filter,list}: Disentangle headersArnaldo Carvalho de Melo
There are places where we just need a forward declaration, and others were we need to include strlist.h and/or strfilter.h, reducing the impact of changes in headers on the build time, do it. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-19perf tools: Move extra string util functions to util/string2.hArnaldo Carvalho de Melo
Moving them from util.h, where they don't belong. Since libc already have string.h, name it slightly differently, as string2.h. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-eh3vz5sqxsrdd8lodoro4jrw@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-19perf tools: Including missing inttypes.h headerArnaldo Carvalho de Melo
Needed to use the PRI[xu](32,64) formatting macros. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-wkbho8kaw24q67dd11q0j39f@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-27scripts/spelling.txt: add "an union" pattern and fix typo instancesMasahiro Yamada
Fix typos and add the following to the scripts/spelling.txt: an union||a union Link: http://lkml.kernel.org/r/1481573103-11329-5-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-16perf probe: Fix to probe on gcc generated functions in modulesMasami Hiramatsu
Fix to probe on gcc generated functions on modules. Since probing on a module is based on its symbol name, it should be adjusted on actual symbols. E.g. without this fix, perf probe shows probe definition on non-exist symbol as below. $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range* in_range.isra.12 $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range p:probe/in_range nf_nat:in_range+0 With this fix, perf probe correctly shows a probe on gcc-generated symbol. $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range p:probe/in_range nf_nat:in_range.isra.12+0 This also fixes same problem on online module as below. $ perf probe -m i915 -D assert_plane p:probe/assert_plane i915:assert_plane.constprop.134+0 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-16perf probe: Fix to show correct locations for events on modulesMasami Hiramatsu
Fix to show correct locations for events on modules by relocating given address instead of retrying after failure. This happens when the module text size is big enough, bigger than sh_addr, because the original code retries with given address + sh_addr if it failed to find CU DIE at the given address. Any address smaller than sh_addr always fails and it retries with the correct address, but addresses bigger than sh_addr will get a CU DIE which is on the given address (not adjusted by sh_addr). In my environment(x86-64), the sh_addr of ".text" section is 0x10030. Since i915 is a huge kernel module, we can see this issue as below. $ grep "[Tt] .*\[i915\]" /proc/kallsyms | sort | head -n1 ffffffffc0270000 t i915_switcheroo_can_switch [i915] ffffffffc0270000 + 0x10030 = ffffffffc0280030, so we'll check symbols cross this boundary. $ grep "[Tt] .*\[i915\]" /proc/kallsyms | grep -B1 ^ffffffffc028\ | head -n 2 ffffffffc027ff80 t haswell_init_clock_gating [i915] ffffffffc0280110 t valleyview_init_clock_gating [i915] So setup probes on both function and see what happen. $ sudo ./perf probe -m i915 -a haswell_init_clock_gating \ -a valleyview_init_clock_gating Added new events: probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915) probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915) You can now use it in all perf tools, such as: perf record -e probe:valleyview_init_clock_gating -aR sleep 1 $ sudo ./perf probe -l probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915) probe:valleyview_init_clock_gating (on i915_vga_set_decode:4@gpu/drm/i915/i915_drv.c in i915) As you can see, haswell_init_clock_gating is correctly shown, but valleyview_init_clock_gating is not. With this patch, both events are shown correctly. $ sudo ./perf probe -l probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915) probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915) Committer notes: In my case: # perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating Added new events: probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915) probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915) You can now use it in all perf tools, such as: perf record -e probe:valleyview_init_clock_gating -aR sleep 1 # perf probe -l probe:haswell_init_clock_gating (on i915_getparam+432@gpu/drm/i915/i915_drv.c in i915) probe:valleyview_init_clock_gating (on __i915_printk+240@gpu/drm/i915/i915_drv.c in i915) # # readelf -SW /lib/modules/4.9.0+/build/vmlinux | egrep -w '.text|Name' [Nr] Name Type Address Off Size ES Flg Lk Inf Al [ 1] .text PROGBITS ffffffff81000000 200000 822fd3 00 AX 0 0 4096 # So both are b0rked, now with the fix: # perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating Added new events: probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915) probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915) You can now use it in all perf tools, such as: perf record -e probe:valleyview_init_clock_gating -aR sleep 1 # perf probe -l probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915) probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915) # Both looks correct. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/148411436777.9978.1440275861947194930.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-29perf probe: Skip if the function address is 0Masami Hiramatsu
Skip probes if the entry address of the target function is 0. This can happen when we're handling C++ debuginfo files. E.g. without this fix, below case still fail. ---- $ ./perf probe -x /usr/lib64/libstdc++.so.6 -vD is_open probe-definition(0): is_open symbol:is_open file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null) symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null) symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null) Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug Try to find probe point from debuginfo. Matched function: is_open [295df] found inline addr: 0x8ca80 Probe point found: is_open+0 found inline addr: 0x8ca70 Probe point found: is_open+0 found inline addr: 0x8ca60 Probe point found: is_open+0 Matched function: is_open [6527f] Matched function: is_open [9fe8a] Probe point found: is_open+0 Matched function: is_open [19710b] found inline addr: 0xecca9 Probe point found: stdio_filebuf+57 found inline addr: 0x0 Probe point found: swap+0 Matched function: is_open [19fc9d] Probe point found: is_open+0 Found 7 probe_trace_events. p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80 p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70 p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60 p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0 p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9 Failed to synthesize probe trace event. Error: Failed to add events. Reason: Invalid argument (Code: -22) ---- This is because some instances have entry_pc == 0 (see 19710b and 19fc9d). With this fix, those are skipped. ---- $ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80 p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70 p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60 p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0 p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9 ---- Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/147464490707.29804.14277897643725143867.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-29perf probe: Ignore the error of finding inline instanceMasami Hiramatsu
Ignore the error when the perf probe failed to find inline function instances. This can happen when we search a method in C++ debuginfo. If there is completely no instance in target, perf probe can return an error. E.g. without this fix: ---- $ perf probe -x /usr/lib64/libstdc++.so.6 -vD showmanyc probe-definition(0): showmanyc symbol:showmanyc file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null) symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null) symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null) Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug Try to find probe point from debuginfo. Matched function: showmanyc An error occurred in debuginfo analysis (-2). Trying to use symbols. Failed to find symbol showmanyc in /usr/lib64/libstdc++.so.6.0.22 Error: Failed to add events. Reason: No such file or directory (Code: -2) ---- This is because one of showmanyc is defined as inline but no instance found. With this fix, it is succeeded to show as below. ---- $ perf probe -x /usr/lib64/libstdc++.so.6 -D showmanyc p:probe_libstdc++/showmanyc /usr/lib64/libstdc++.so.6.0.22:0xb0e50 p:probe_libstdc++/showmanyc_1 /usr/lib64/libstdc++.so.6.0.22:0xc7c40 p:probe_libstdc++/showmanyc_2 /usr/lib64/libstdc++.so.6.0.22:0xecfa0 p:probe_libstdc++/showmanyc_3 /usr/lib64/libstdc++.so.6.0.22:0x115fc0 p:probe_libstdc++/showmanyc_4 /usr/lib64/libstdc++.so.6.0.22:0x121a90 ---- Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/147464489775.29804.3190419491209875936.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01perf probe: Move dwarf specific functions to dwarf-aux.cRavi Bangoria
Move generic dwarf related functions from util/probe-finder.c to util/dwarf-aux.c. Functions name and their prototype are also changed accordingly. No functionality changes. Suggested-and-Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1472546377-25612-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01perf uprobe: Skip prologue if program compiled without optimizationRavi Bangoria
The function prologue prepares stack and registers before executing function logic. When target program is compiled without optimization, function parameter information is only valid after the prologue. When we probe entrypc of the function, and try to record a function parameter, it contains a garbage value. For example: $ vim test.c #include <stdio.h> void foo(int i) { printf("i: %d\n", i); } int main() { foo(42); return 0; } $ gcc -g test.c -o test $ objdump -dl test | less foo(): /home/ravi/test.c:4 400536: 55 push %rbp 400537: 48 89 e5 mov %rsp,%rbp 40053a: 48 83 ec 10 sub -bashx10,%rsp 40053e: 89 7d fc mov %edi,-0x4(%rbp) /home/ravi/test.c:5 400541: 8b 45 fc mov -0x4(%rbp),%eax ... ... main(): /home/ravi/test.c:9 400558: 55 push %rbp 400559: 48 89 e5 mov %rsp,%rbp /home/ravi/test.c:10 40055c: bf 2a 00 00 00 mov -bashx2a,%edi 400561: e8 d0 ff ff ff callq 400536 <foo> $ perf probe -x ./test 'foo i' $ cat /sys/kernel/debug/tracing/uprobe_events p:probe_test/foo /home/ravi/test:0x0000000000000536 i=-12(%sp):s32 $ perf record -e probe_test:foo ./test $ perf script test 5778 [001] 4918.562027: probe_test:foo: (400536) i=0 Here variable 'i' is passed via stack which is pushed on stack at 0x40053e. But we are probing at 0x400536. To resolve this issues, we need to probe on next instruction after prologue. gdb and systemtap also does same thing. I've implemented this patch based on approach systemtap has used. After applying patch: $ perf probe -x ./test 'foo i' $ cat /sys/kernel/debug/tracing/uprobe_events p:probe_test/foo /home/ravi/test:0x0000000000000541 i=-4(%bp):s32 $ perf record -e probe_test:foo ./test $ perf script test 6300 [001] 5877.879327: probe_test:foo: (400541) i=42 No need to skip prologue for optimized case since debug info is correct for each instructions for -O2 -g. For more details please visit: https://bugzilla.redhat.com/show_bug.cgi?id=612253#c6 Changes in v2: - Skipping prologue only when any ARG is either C variable, $params or $vars. - Probe on line(:1) may not be always possible. Recommend only address to force probe on function entry. Committer notes: Testing it with 'perf trace': # perf probe -x ./test foo i Added new event: probe_test:foo (on foo in /home/acme/c/test with i) You can now use it in all perf tools, such as: perf record -e probe_test:foo -aR sleep 1 # cat /sys/kernel/debug/tracing/uprobe_events p:probe_test/foo /home/acme/c/test:0x0000000000000526 i=-12(%sp):s32 # trace --no-sys --event probe_*:* ./test i: 42 0.000 probe_test:foo:(400526) i=0) # After the patch: # perf probe -d *:* Removed event: probe_test:foo # perf probe -x ./test foo i Target program is compiled without optimization. Skipping prologue. Probe on address 0x400526 to force probing at the function entry. Added new event: probe_test:foo (on foo in /home/acme/c/test with i) You can now use it in all perf tools, such as: perf record -e probe_test:foo -aR sleep 1 # cat /sys/kernel/debug/tracing/uprobe_events p:probe_test/foo /home/acme/c/test:0x0000000000000531 i=-4(%bp):s32 # trace --no-sys --event probe_*:* ./test i: 42 0.000 probe_test:foo:(400531) i=42) # Reported-by: Michael Petlan <mpetlan@redhat.com> Report-Link: https://www.mail-archive.com/linux-perf-users@vger.kernel.org/msg02348.html Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1299021 Link: http://lkml.kernel.org/r/1470214725-5023-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com [ Rename 'die' to 'cu_die' to avoid shadowing a die() definition on at least centos 5, Debian 7 and ubuntu:12.04.5] [ Use PRIx64 instead of lx to format a Dwarf_Addr, aka long long unsigned int, fixing the build on 32-bit systems ] [ dwarf_getsrclines() expects a size_t * argument ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-09-01perf probe: Support probing on offline cross-arch binaryMasami Hiramatsu
Support probing on offline cross-architecture binary by adding getting the target machine arch from ELF and choose correct register string for the machine. Here is an example: ----- $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params' p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16 ----- Here, we can get probe/do_sys_open from above and append it to to the target machine's tracing/kprobe_events file in the tracefs mountput, usually /sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox [ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-23perf probe: Use hexadecimal type by default if possibleMasami Hiramatsu
Use hexadecimal type by default if it is available on current running kernel. This keeps the default behavior of perf probe after changing the output format of 'u8/16/32/64' to unsigned decimal number. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Naohiro Aota <naohiro.aota@hgst.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/147151074685.12957.16415861010796255514.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-23perf probe: Support hexadecimal castingMasami Hiramatsu
Support hexadecimal unsigned integer casting by 'x'. This allows user to explicitly specify the output format of the probe arguments as hexadecimal. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Naohiro Aota <naohiro.aota@hgst.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/147151072679.12957.4458656416765710753.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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