kernel.git/tools/perf/util/symbol.c, branch linux-4.5.y

perf symbols: Fix reading of build-id from vDSO

2016-01-15T19:31:58Z

We need to use the long name (the filename) when reading the build-id from a DSO. Using the short name doesn't work for (at least) vDSOs. Signed-off-by: Ben Hutchings Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20160113172301.GT28542@decadent.org.uk Signed-off-by: Arnaldo Carvalho de Melo

perf report: Change default to use event group view

2016-01-08T15:41:37Z

The event group view feature is to see related events together. To use the group view, events should be recorded as a group with a dedicated syntax of surrounding events by braces (-e '{ evt1, evt2, ... }'). Also 'perf report' also requires the --group option to enable it. However it's almost always beneficial to use the group view to see the group events as it's more expressive. And I think it's more natural to see events together if they are recorded as a group. Thus this patch changes the default value to enable it. If users don't want to see like it and keep the original behavior, they can set the report.group config variable to false and/or use --no-group option in the 'perf report' command line. Requested-by: Ingo Molnar Signed-off-by: Namhyung Kim Cc: David Ahern Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Taeung Song Link: http://lkml.kernel.org/r/1448807057-3506-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add the path to vmlinux.debug

2015-11-26T19:50:35Z

Currently when debuginfo is separated to vmlinux.debug, it's contents get ignored. Let's change that and add it to the vmlinux_path list. Signed-off-by: Ekaterina Tumanova Acked-by: Alexander Yarygin Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Christian Borntraeger Cc: David Ahern Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1448469166-61363-3-git-send-email-tumanova@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Refactor vmlinux_path__init() to ease path additions

2015-11-26T19:49:29Z

Refactor vmlinux_path__init() to ease subsequent additions of new vmlinux locations. Signed-off-by: Ekaterina Tumanova Acked-by: Alexander Yarygin Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Christian Borntraeger Cc: David Ahern Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1448469166-61363-2-git-send-email-tumanova@linux.vnet.ibm.com [ Rename vmlinux_path__update() to vmlinux_path__add() ] Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Allow forcing reading of non-root owned files by root

2015-11-12T21:58:18Z

When the root user tries to read a file owned by some other user we get: # ls -la perf.data -rw-------. 1 acme acme 20032 Nov 12 15:50 perf.data # perf report File perf.data not owned by current user or root (use -f to override) # perf report -f | grep -v ^# | head -2 30.96% ls [kernel.vmlinux] [k] do_set_pte 28.24% ls libc-2.20.so [.] intel_check_word # That wasn't happening when the symbol code tried to read a JIT map, where the same check was done but no forcing was possible, fix it. Reported-by: Brendan Gregg Tested-by: Brendan Gregg Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/2380 Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Rebuild rbtree when adjusting symbols for kcore

2015-11-12T21:58:17Z

Normally symbols are read from the DSO and adjusted, if need be, so that the symbol start matches the file offset in the DSO file (we want the file offset because that is what we know from MMAP events). That is done by dso__load_sym() which inserts the symbols *after* adjusting them. In the case of kcore, the symbols have been read from kallsyms and the symbol start is the memory address. The symbols have to be adjusted to match the kcore file offsets. dso__split_kallsyms_for_kcore() does that, but now the adjustment is being done *after* the symbols have been inserted. It appears dso__split_kallsyms_for_kcore() was assuming that changing the symbol start would not change the order in the rbtree - which is, of course, not guaranteed. Signed-off-by: Adrian Hunter Tested-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/563CB241.2090701@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore

2015-10-28T14:19:30Z

Currently we split symbols based on the map comparison, but symbols are stored within dso objects and maps could point into same dso objects (kernel maps). Hence we could end up changing rbtree we are currently iterating and mess it up. It's easily reproduced on s390x by running: $ perf record -a -- sleep 3 $ perf buildid-list -i perf.data --with-hits The fix is to compare dso objects instead. Reported-by: Michael Petlan Signed-off-by: Jiri Olsa Acked-by: Adrian Hunter Cc: Andi Kleen Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151026135130.GA26003@krava.brq.redhat.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: we can now read separate debug-info files based on a build ID

2015-10-28T13:04:27Z

Recent GDB (at least on a vanilla Debian box) looks for debug information in /usr/lib/debug/.build-id/nn/nnnnnnn where nn/nnnnnn is the build-id of the stripped ELF binary. This is documented here: https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html This was not working in perf because we didn't read the build id until AFTER we searched for the separate debug information file. This patch reads the build ID and THEN does the search. Signed-off-by: Dima Kogan Link: http://lkml.kernel.org/r/87si6pfwz4.fsf@secretsauce.net Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Try the .debug/ DSO cache as a last resort

2015-10-12T16:52:27Z

Not as the first attempt at finding a vmlinux for the running kernel, this way we get a more informative filename to present in tools, it will check that the build-id is the same as the one previously loaded in the DSO in dso->build_id, reading from /sys/kernel/notes, for instance. E.g. in the annotation TUI, going from 'perf top', for the scsi_sg_alloc kernel function, in the first line: Before: scsi_sg_alloc /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1 After: scsi_sg_alloc /lib/modules/4.3.0-rc1+/build/vmlinux And: # ls -la /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1 lrwxrwxrwx. 1 root root 81 Sep 22 16:11 /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1 -> ../../home/git/build/v4.3.0-rc1+/vmlinux/282777c262e6b3c0451375163c9a81c893218ab1 # file ~/.debug/home/git/build/v4.3.0-rc1+/vmlinux/282777c262e6b3c0451375163c9a81c893218ab1 /root/.debug/home/git/build/v4.3.0-rc1+/vmlinux/282777c262e6b3c0451375163c9a81c893218ab1: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, BuildID[sha1]=282777c262e6b3c0451375163c9a81c893218ab1, not stripped # The same as: # file /lib/modules/4.3.0-rc1+/build/vmlinux /lib/modules/4.3.0-rc1+/build/vmlinux: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, BuildID[sha1]=282777c262e6b3c0451375163c9a81c893218ab1, not stripped Furthermore: # sha256sum /lib/modules/4.3.0-rc1+/build/vmlinux e7a789bbdc61029ec09140c228e1dd651271f38ef0b8416c0b7d5ff727b98be2 /lib/modules/4.3.0-rc1+/build/vmlinux # sha256sum ~/.debug/home/git/build/v4.3.0-rc1+/vmlinux/282777c262e6b3c0451375163c9a81c893218ab1 e7a789bbdc61029ec09140c228e1dd651271f38ef0b8416c0b7d5ff727b98be2 /root/.debug/home/git/build/v4.3.0-rc1+/vmlinux/282777c262e6b3c0451375163c9a81c893218ab1 [root@zoo new]# Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-9y42ikzq3jisiddoi6f07n8z@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools lib symbol: Rename kallsyms2elf_type to kallsyms2elf_binding

2015-09-30T21:34:30Z

It is about binding, not type, we have just a letter in kallsyms that should map both for the ELF type (STT_FUNC, etc) and to the ELF symbol binding (STB_WEAK, STB_GLOBAL, etc), so rename it now before introducing kallsyms2_elf_type() Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-uu5vj343ms1q2wm55690on6v@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo