kernel.git/tools/perf/arch/powerpc/util, branch linux-4.12.y

perf symbols: Allow user probes on versioned symbols

2017-05-02T21:23:11Z

Symbol versioning, as in glibc, results in symbols being defined as: @[@] (Note that "@@" identifies a default symbol, if the symbol name is repeated.) perf is currently unable to deal with this, and is unable to create user probes at such symbols: -- $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create 0000000000008d30 t __pthread_create_2_1 0000000000008d30 T pthread_create@@GLIBC_2.17 $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create probe-definition(0): pthread_create symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so Try to find probe point from debuginfo. Probe point 'pthread_create' not found. Error: Failed to add events. Reason: No such file or directory (Code: -2) -- One is not able to specify the fully versioned symbol, either, due to syntactic conflicts with other uses of "@" by perf: -- $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create@@GLIBC_2.17 probe-definition(0): pthread_create@@GLIBC_2.17 Semantic error :SRC@SRC is not allowed. 0 arguments Error: Command Parse Error. Reason: Invalid argument (Code: -22) -- This patch ignores versioning for default symbols, thus allowing probes to be created for these symbols: -- $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create Added new event: probe_libpthread:pthread_create (on pthread_create in /lib/powerpc64le-linux-gnu/libpthread-2.19.so) You can now use it in all perf tools, such as: perf record -e probe_libpthread:pthread_create -aR sleep 1 $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ] $ /usr/bin/sudo ./perf script test 2915 [000] 19124.260729: probe_libpthread:pthread_create: (3fff99248d38) test 2916 [000] 19124.260962: probe_libpthread:pthread_create: (3fff99248d38) $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create Removed event: probe_libpthread:pthread_create -- Committer note: Change the variable storing the result of strlen() to 'int', to fix the build on debian:experimental-x-mipsel, fedora:24-x-ARC-uClibc, ubuntu:16.04-x-arm, etc: util/symbol.c: In function 'symbol__match_symbol_name': util/symbol.c:422:11: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] if (len < versioning - name) ^ Signed-off-by: Paul A. Clarke Tested-by: Arnaldo Carvalho de Melo Acked-by: Masami Hiramatsu Cc: David Ahern Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Include errno.h where needed

2017-04-19T16:01:51Z

Removing it from util.h, part of an effort to disentangle the includes hell, that makes changes to util.h or something included by it to cause a complete rebuild of the tools. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-ztrjy52q1rqcchuy3rubfgt2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Replace STR() calls with __stringify()

2017-04-19T16:01:47Z

Both do the same thing, the later is the one we get from linux/stringify.h, i.e. we now use the same function name/practice as the kernel sources. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-w2sxa5o4bfx7fjrd5mu4zmke@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf sdt powerpc: Add argument support

2017-04-04T13:36:59Z

SDT marker argument is in N@OP format. Here OP is arch dependent component. Add powerpc logic to parse OP and convert it to uprobe compatible format. Signed-off-by: Ravi Bangoria Acked-by: Masami Hiramatsu Cc: Alexander Shishkin Cc: Alexis Berlemont Cc: Hemant Kumar Cc: Michael Ellerman Cc: Naveen N. Rao Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170328094754.3156-4-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf powerpc: Choose local entry point with kretprobes

2017-03-14T18:17:39Z

perf now uses an offset from _text/_stext for kretprobes if the kernel supports it, rather than the actual function name. As such, let's choose the LEP for powerpc ABIv2 so as to ensure the probe gets hit. Do it only if the kernel supports specifying offsets with kretprobes. Signed-off-by: Naveen N. Rao Acked-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Michael Ellerman Cc: Steven Rostedt Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/7445b5334673ef5404ac1d12609bad4d73d2b567.1488961018.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf uretprobe ppc64le: Fix probe location

2016-10-05T11:14:22Z

Perf uretprobe probes on GEP(Global Entry Point) which fails to record all function calls via LEP(Local Entry Point). Fix that by probing on LEP. Objdump: 00000000100005f0 : 100005f0: 02 10 40 3c lis r2,4098 100005f4: 00 7f 42 38 addi r2,r2,32512 100005f8: a6 02 08 7c mflr r0 100005fc: 10 00 01 f8 std r0,16(r1) 10000600: f8 ff e1 fb std r31,-8(r1) Before applying patch: $ cat /sys/kernel/debug/tracing/uprobe_events r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f0 After applying patch: $ cat /sys/kernel/debug/tracing/uprobe_events r:probe_uprobe_test/doit /home/ravi/uprobe_test:0x00000000000005f8 This is not the case with kretprobes because the kernel itself finds LEP and probes on it. Signed-off-by: Ravi Bangoria Cc: Alexander Shishkin Cc: Balbir Singh Cc: Masami Hiramatsu Cc: Naveen N. Rao Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1475576865-6562-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf powerpc: Support CPU ID matching for Powerpc

2016-10-03T22:58:01Z

Implement code that returns the generic CPU ID string for Powerpc. This will be used to identify the specific table of PMU events to parse/compare user specified events against. Signed-off-by: Sukadev Bhattiprolu Acked-by: Ingo Molnar Acked-by: Jiri Olsa Cc: Madhavan Srinivasan Cc: Peter Zijlstra Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1473978296-20712-5-git-send-email-sukadev@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Remove symbol_filter_t machinery

2016-09-05T14:14:50Z

We're not using it anymore, few users were, but we really could do without it, simplify lots of functions by removing it. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf ppc64le: Fix build failure when libelf is not present

2016-08-12T17:39:48Z

arch__post_process_probe_trace_events() calls get_target_map() to prepare symbol table. get_target_map() is defined inside util/probe-event.c. probe-event.c will only get included in perf binary if CONFIG_LIBELF is set. Hence arch__post_process_probe_trace_events() needs to be defined inside #ifdef HAVE_LIBELF_SUPPORT to solve compilation error. Reported-and-Tested-by: Anton Blanchard Tested-by: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Alexander Shishkin Cc: Balbir Singh Cc: Naveen N. Rao Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Wang Nan Cc: Namhyung Kim Link: http://lkml.kernel.org/r/57ABFF88.8030905@linux.vnet.ibm.com [ Thunderbird MUA mangled it, fix that ] Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc64le: Fix probe location when using DWARF

2016-08-09T15:14:29Z

Powerpc has Global Entry Point and Local Entry Point for functions. LEP catches call from both the GEP and the LEP. Symbol table of ELF contains GEP and Offset from which we can calculate LEP, but debuginfo does not have LEP info. Currently, perf prioritize symbol table over dwarf to probe on LEP for ppc64le. But when user tries to probe with function parameter, we fall back to using dwarf(i.e. GEP) and when function called via LEP, probe will never hit. For example: $ objdump -d vmlinux ... do_sys_open(): c0000000002eb4a0: e8 00 4c 3c addis r2,r12,232 c0000000002eb4a4: 60 00 42 38 addi r2,r2,96 c0000000002eb4a8: a6 02 08 7c mflr r0 c0000000002eb4ac: d0 ff 41 fb std r26,-48(r1) $ sudo ./perf probe do_sys_open $ sudo cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_sys_open _text+3060904 $ sudo ./perf probe 'do_sys_open filename:string' $ sudo cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_sys_open _text+3060896 filename_string=+0(%gpr4):string For second case, perf probed on GEP. So when function will be called via LEP, probe won't hit. $ sudo ./perf record -a -e probe:do_sys_open ls [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.195 MB perf.data ] To resolve this issue, let's not prioritize symbol table, let perf decide what it wants to use. Perf is already converting GEP to LEP when it uses symbol table. When perf uses debuginfo, let it find LEP offset form symbol table. This way we fall back to probe on LEP for all cases. After patch: $ sudo ./perf probe 'do_sys_open filename:string' $ sudo cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_sys_open _text+3060904 filename_string=+0(%gpr4):string $ sudo ./perf record -a -e probe:do_sys_open ls [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.197 MB perf.data (11 samples) ] Signed-off-by: Ravi Bangoria Acked-by: Masami Hiramatsu Cc: Alexander Shishkin Cc: Ananth N Mavinakayanahalli Cc: Balbir Singh Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1470723805-5081-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo