kernel/tools/perf/util/probe-finder.c, branch linux-4.17.y

perf probe: Use right type to access array elements

2018-03-19T16:51:53Z

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 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 Tested-by: Arnaldo Carvalho de Melo Cc: Namhyung Kim Cc: Ravi Bangoria Cc: Shuah Khan Cc: Steven Rostedt Cc: Tom Zanussi 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

perf str{filter,list}: Disentangle headers

2017-04-19T16:01:52Z

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 Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Move extra string util functions to util/string2.h

2017-04-19T16:01:51Z

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 Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-eh3vz5sqxsrdd8lodoro4jrw@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Including missing inttypes.h header

2017-04-19T16:01:46Z

Needed to use the PRI[xu](32,64) formatting macros. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-wkbho8kaw24q67dd11q0j39f@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

scripts/spelling.txt: add "an union" pattern and fix typo instances

2017-02-28T02:43:46Z

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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

perf probe: Fix to probe on gcc generated functions in modules

2017-01-16T18:43:04Z

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 Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix to show correct locations for events on modules

2017-01-16T18:14:06Z

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 Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/148411436777.9978.1440275861947194930.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Skip if the function address is 0

2016-09-29T14:17:07Z

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 Tested-by: Arnaldo Carvalho de Melo Tested-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/147464490707.29804.14277897643725143867.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Ignore the error of finding inline instance

2016-09-29T14:17:07Z

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 Tested-by: Arnaldo Carvalho de Melo Tested-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/147464489775.29804.3190419491209875936.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Move dwarf specific functions to dwarf-aux.c

2016-09-01T15:42:26Z

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 Signed-off-by: Ravi Bangoria Cc: Alexander Shishkin Cc: Hemant Kumar Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Wang Nan 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