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* perf symbols: Consolidate symbol fixup issueLeo Yan2020-03-231-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After copying Arm64's perf archive with object files and perf.data file to x86 laptop, the x86's perf kernel symbol resolution fails. It outputs 'unknown' for all symbols parsing. This issue is root caused by the function elf__needs_adjust_symbols(), x86 perf tool uses one weak version, Arm64 (and powerpc) has rewritten their own version. elf__needs_adjust_symbols() decides if need to parse symbols with the relative offset address; but x86 building uses the weak function which misses to check for the elf type 'ET_DYN', so that it cannot parse symbols in Arm DSOs due to the wrong result from elf__needs_adjust_symbols(). The DSO parsing should not depend on any specific architecture perf building; e.g. x86 perf tool can parse Arm and Arm64 DSOs, vice versa. And confirmed by Naveen N. Rao that powerpc64 kernels are not being built as ET_DYN anymore and change to ET_EXEC. This patch removes the arch specific functions for Arm64 and powerpc and changes elf__needs_adjust_symbols() as a common function. In the common elf__needs_adjust_symbols(), it checks an extra condition 'ET_DYN' for elf header type. With this fixing, the Arm64 DSO can be parsed properly with x86's perf tool. Before: # perf script main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c46670 [unknown] ([kernel.kallsyms]) => ffff800010c4eaec [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eaec [unknown] ([kernel.kallsyms]) => ffff800010c4eb00 [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eb08 [unknown] ([kernel.kallsyms]) => ffff800010c4e780 [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4e7a0 [unknown] ([kernel.kallsyms]) => ffff800010c4eeac [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eebc [unknown] ([kernel.kallsyms]) => ffff800010c4ed80 [unknown] ([kernel.kallsyms]) After: # perf script main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c coresight_timeout+0x54 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c46670 coresight_timeout+0x68 ([kernel.kallsyms]) => ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms]) => ffff800010c4eb00 etm4_enable_hw+0x3e0 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eb08 etm4_enable_hw+0x3e8 ([kernel.kallsyms]) => ffff800010c4e780 etm4_enable_hw+0x60 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4e7a0 etm4_enable_hw+0x80 ([kernel.kallsyms]) => ffff800010c4eeac etm4_enable+0x2d4 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eebc etm4_enable+0x2e4 ([kernel.kallsyms]) => ffff800010c4ed80 etm4_enable+0x1a8 ([kernel.kallsyms]) v3: Changed to check for ET_DYN across all architectures. v2: Fixed Arm64 and powerpc native building. Reported-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Allison Randal <allison@lohutok.net> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: John Garry <john.garry@huawei.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.vnet.ibm.com> Link: http://lore.kernel.org/lkml/20200306015759.10084-1-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Remove debug.h from places where it is not neededArnaldo Carvalho de Melo2019-09-201-1/+0
| | | | | | | | | | | | | | | | | Pruning a bit more the includes dependency tree. Building this thing on lots of containers takes time, we better reduce the time per build, each container is doing 6 builds when clang and clang-devel are available, and the plan is to do a 'make -C tools/perf build-test' that have many more. Also helps when doing normal development, as touching some random file will have a much reduced chance of triggering lots of rebuilds. 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-r889ur2cxe16m91m2a4pl15p@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf symbols: Move symsrc prototypes to a separate headerArnaldo Carvalho de Melo2019-09-011-0/+1
| | | | | | | | | | | | | | So that we can remove dso.h from symbol.h and reduce the header dependency tree. Fixup cases where struct dso guts are needed but were obtained via symbol.h, indirectly. 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-ip683cegt306ncu3gsz7ii21@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-191-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 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 version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* perf probe powerpc: Ignore SyS symbols irrespective of endiannessSandipan Das2018-08-301-1/+3
| | | | | | | | | | | | | | | This makes sure that the SyS symbols are ignored for any powerpc system, not just the big endian ones. Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Fixes: fb6d59423115 ("perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc") Link: http://lkml.kernel.org/r/20180828090848.1914-1-sandipan@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe powerpc: Fix trace event post-processingSandipan Das2018-08-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some cases, a symbol may have multiple aliases. Attempting to add an entry probe for such symbols results in a probe being added at an incorrect location while it fails altogether for return probes. This is only applicable for binaries with debug information. During the arch-dependent post-processing, the offset from the start of the symbol at which the probe is to be attached is determined and added to the start address of the symbol to get the probe's location. In case there are multiple aliases, this offset gets added multiple times for each alias of the symbol and we end up with an incorrect probe location. This can be verified on a powerpc64le system as shown below. $ nm /lib/modules/$(uname -r)/build/vmlinux | grep "sys_open$" ... c000000000414290 T __se_sys_open c000000000414290 T sys_open $ objdump -d /lib/modules/$(uname -r)/build/vmlinux | grep -A 10 "<__se_sys_open>:" c000000000414290 <__se_sys_open>: c000000000414290: 19 01 4c 3c addis r2,r12,281 c000000000414294: 70 c4 42 38 addi r2,r2,-15248 c000000000414298: a6 02 08 7c mflr r0 c00000000041429c: e8 ff a1 fb std r29,-24(r1) c0000000004142a0: f0 ff c1 fb std r30,-16(r1) c0000000004142a4: f8 ff e1 fb std r31,-8(r1) c0000000004142a8: 10 00 01 f8 std r0,16(r1) c0000000004142ac: c1 ff 21 f8 stdu r1,-64(r1) c0000000004142b0: 78 23 9f 7c mr r31,r4 c0000000004142b4: 78 1b 7e 7c mr r30,r3 For both the entry probe and the return probe, the probe location should be _text+4276888 (0xc000000000414298). Since another alias exists for 'sys_open', the post-processing code will end up adding the offset (8 for powerpc64le) twice and perf will attempt to add the probe at _text+4276896 (0xc0000000004142a0) instead. Before: # perf probe -v -a sys_open probe-definition(0): sys_open symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux Try to find probe point from debuginfo. Symbol sys_open address found : c000000000414290 Matched function: __se_sys_open [2ad03a0] Probe point found: __se_sys_open+0 Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing/kprobe_events write=1 Writing event: p:probe/sys_open _text+4276896 Added new event: probe:sys_open (on sys_open) ... # perf probe -v -a sys_open%return $retval probe-definition(0): sys_open%return symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux Try to find probe point from debuginfo. Symbol sys_open address found : c000000000414290 Matched function: __se_sys_open [2ad03a0] Probe point found: __se_sys_open+0 Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing/README write=0 Opening /sys/kernel/debug/tracing/kprobe_events write=1 Parsing probe_events: p:probe/sys_open _text+4276896 Group:probe Event:sys_open probe:p Writing event: r:probe/sys_open__return _text+4276896 Failed to write event: Invalid argument Error: Failed to add events. Reason: Invalid argument (Code: -22) After: # perf probe -v -a sys_open probe-definition(0): sys_open symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux Try to find probe point from debuginfo. Symbol sys_open address found : c000000000414290 Matched function: __se_sys_open [2ad03a0] Probe point found: __se_sys_open+0 Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing/kprobe_events write=1 Writing event: p:probe/sys_open _text+4276888 Added new event: probe:sys_open (on sys_open) ... # perf probe -v -a sys_open%return $retval probe-definition(0): sys_open%return symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux Try to find probe point from debuginfo. Symbol sys_open address found : c000000000414290 Matched function: __se_sys_open [2ad03a0] Probe point found: __se_sys_open+0 Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing/README write=0 Opening /sys/kernel/debug/tracing/kprobe_events write=1 Parsing probe_events: p:probe/sys_open _text+4276888 Group:probe Event:sys_open probe:p Writing event: r:probe/sys_open__return _text+4276888 Added new event: probe:sys_open__return (on sys_open%return) ... Reported-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Fixes: 99e608b5954c ("perf probe ppc64le: Fix probe location when using DWARF") Link: http://lkml.kernel.org/r/20180809161929.35058-1-sandipan@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe: Find versioned symbols from mapMasami Hiramatsu2017-12-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d80406453ad4 ("perf symbols: Allow user probes on versioned symbols") allows user to find default versioned symbols (with "@@") in map. However, it did not enable normal versioned symbol (with "@") for perf-probe. E.g. ===== # ./perf probe -x /lib64/libc-2.25.so malloc_get_state Failed to find symbol malloc_get_state in /usr/lib64/libc-2.25.so Error: Failed to add events. ===== This solves above issue by improving perf-probe symbol search function, as below. ===== # ./perf probe -x /lib64/libc-2.25.so malloc_get_state Added new event: probe_libc:malloc_get_state (on malloc_get_state in /usr/lib64/libc-2.25.so) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc_get_state -aR sleep 1 # ./perf probe -l probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so) ===== Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Clarke <pc@us.ibm.com> Cc: bhargavb <bhargavaramudu@gmail.com> Cc: linux-rt-users@vger.kernel.org Link: http://lkml.kernel.org/r/151275049269.24652.1639103455496216255.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe: Allow placing uprobes in alternate namespaces.Krister Johansen2017-07-191-1/+1
| | | | | | | | | | | | | | | | | | | Teaches perf how to place a uprobe on a file that's in a different mount namespace. The user must add the probe using the --target-ns argument to perf probe. Once it has been placed, it may be recorded against without further namespace-specific commands. Signed-off-by: Krister Johansen <kjlx@templeofstupid.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> [ PPC build fixed by Ravi: ] Link: http://lkml.kernel.org/r/1500287542-6219-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com> [ Fix !HAVE_DWARF_SUPPORT build ] Link: http://lkml.kernel.org/r/1499305693-1599-4-git-send-email-kjlx@templeofstupid.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf symbols: Allow user probes on versioned symbolsPaul Clarke2017-05-021-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Symbol versioning, as in glibc, results in symbols being defined as: <real symbol>@[@]<version> (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 <pc@us.ibm.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf powerpc: Choose local entry point with kretprobesNaveen N. Rao2017-03-141-4/+10
| | | | | | | | | | | | | | | | 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 <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Steven Rostedt <rostedt@goodmis.org> 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 <acme@redhat.com>
* perf uretprobe ppc64le: Fix probe locationRavi Bangoria2016-10-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <doit>: 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 <ravi.bangoria@linux.vnet.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> 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 <acme@redhat.com>
* perf symbols: Remove symbol_filter_t machineryArnaldo Carvalho de Melo2016-09-051-1/+1
| | | | | | | | | | | | | | 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 <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf ppc64le: Fix build failure when libelf is not presentRavi Bangoria2016-08-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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 <anton@samba.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Namhyung Kim <namhyung@kernel.org> 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 <acme@redhat.com>
* perf probe ppc64le: Fix probe location when using DWARFRavi Bangoria2016-08-091-4/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <ravi.bangoria@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> 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/1470723805-5081-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf symbols: Fix kallsyms perf test on ppc64leNaveen N. Rao2016-05-061-8/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | ppc64le functions have a Global Entry Point (GEP) and a Local Entry Point (LEP). While placing a probe, we always prefer the LEP since it catches function calls through both the GEP and the LEP. In order to do this, we fixup the function entry points during elf symbol table lookup to point to the LEPs. This works, but breaks 'perf test kallsyms' since the symbols loaded from the symbol table (pointing to the LEP) do not match the symbols in kallsyms. To fix this, we do not adjust all the symbols during symbol table load. Instead, we note down st_other in a newly introduced arch-specific member of perf symbol structure, and later use this to adjust the probe trace point. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Mark Wielaard <mjw@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/6be7c2b17e370100c2f79dd444509df7929bdd3e.1460451721.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf powerpc: Fix kprobe and kretprobe handling with kallsyms on ppc64leNaveen N. Rao2016-05-061-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | So far, we used to treat probe point offsets as being offset from the LEP. However, userspace applications (objdump/readelf) always show disassembly and offsets from the function GEP. This is confusing to the user as we will end up probing at an address different from what the user expects when looking at the function disassembly with readelf/objdump. Fix this by changing how we modify probe address with perf. If only the function name is provided, we assume the user needs the LEP. Otherwise, if an offset is specified, we assume that the user knows the exact address to probe based on function disassembly, and so we just place the probe from the GEP offset. Finally, kretprobe was also broken with kallsyms as we were trying to specify an offset. This patch also fixes that issue. Reported-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Mark Wielaard <mjw@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/75df860aad8216bf4b9bcd10c6351ecc0e3dee54.1460451721.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc64le: Fixup function entry if using kallsyms lookupNaveen N. Rao2015-05-041-0/+15
| | | | | | | | | | | | | | | | | On powerpc ABIv2, if no debug-info is found and we use kallsyms, we need to fixup the function entry to point to the local entry point. Use offset of 8 since current toolchains always generate 2 instructions (8 bytes). Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/92253021e77a104b23b615c8c23bf9501dfe60bf.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc64le: Prefer symbol table lookup over DWARFNaveen N. Rao2015-05-041-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use symbol table lookups by default if DWARF is not necessary, since powerpc ABIv2 encodes local entry points in the symbol table and the function entry address in DWARF may not be appropriate for kprobes, as described here: https://sourceware.org/bugzilla/show_bug.cgi?id=17638 "The DWARF address ranges deliberately include the *whole* function, both global and local entry points." ... "If you want to set probes on a local entry point, you should look up the symbol in the main symbol table (not DWARF), and check the st_other bits; they will indicate whether the function has a local entry point, and what its offset from the global entry point is. Note that GDB does the same when setting a breakpoint on a function entry." Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/88a10e22f4aaba2aef812824ca4b10d7beeea012.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc64le: Fix ppc64 ABIv2 symbol decodingAnanth N Mavinakayanahalli2015-05-041-0/+7
| | | | | | | | | | | | | | | | ppc64 ELF ABIv2 has a Global Entry Point (GEP) and a Local Entry Point (LEP). For purposes of probing, we need the LEP - the offset to which is encoded in st_other. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/ab9cc5e2b9de4cbaaf50f6ef2346a6a81100bad1.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc: Enable matching against dot symbols automaticallyNaveen N. Rao2015-05-041-0/+13
| | | | | | | | | | | | | | | | | | | | Allow perf probe to work on ppc ABIv1 without the need to specify the leading dot '.' for functions. 'perf probe do_fork' works with this patch. We do this by changing how symbol name comparison works on ppc ABIv1 - we simply ignore and skip over the initial dot, if one exists, during symbol name comparison. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/652a8f3bfa919bd02a1836a128370eaed59b4a34.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc: Use the right prefix when ignoring SyS symbols on ppcNaveen N. Rao2015-05-041-0/+20
| | | | | | | | | | | | | | | | Use the proper prefix when ignoring SyS symbols on ppc ABIv1. While at it, generalize symbol selection so architectures can implement their own logic. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/adf1f98b121ecaf292777fe5cc69fe1038feabce.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe ppc: Fix symbol fixup issues due to ELF typeNaveen N. Rao2015-05-041-0/+19
If using the symbol table, symbol addresses are not being fixed up properly, resulting in probes being placed at wrong addresses: # perf probe do_fork Added new event: probe:do_fork (on do_fork) You can now use it in all perf tools, such as: perf record -e probe:do_fork -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_fork _text+635952 # printf "%x" 635952 9b430 # grep do_fork /boot/System.map c0000000000ab430 T .do_fork Fix by checking for ELF type ET_DYN used by ppc64 kernels. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>