linux/tools
Masami Hiramatsu 26bbf45fc8 perf probe: Avoid setting probes on the same address for the same event
There is a case that several same-name symbols points to the same
address.  In that case, 'perf probe' returns an error.

E.g.

  # perf probe -x /lib64/libc-2.30.so -v -a "memcpy arg1=%di"
  probe-definition(0): memcpy arg1=%di
  symbol:memcpy file:(null) line:0 offset:0 return:0 lazy:(null)
  parsing arg: arg1=%di into name:arg1 %di
  1 arguments
  symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_arena_max file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_arena_test file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_tunable_tcache_max_bytes file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_tunable_tcache_count file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_tunable_tcache_unsorted_limit file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_trim_threshold file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_top_pad file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_mmap_threshold file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_mmap_max file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_perturb file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_mxfast file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_heap_new file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_arena_reuse_free_list file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_arena_reuse file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_arena_reuse_wait file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_arena_new file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_arena_retry file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_sbrk_less file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_heap_free file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_heap_less file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_tcache_double_free file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_heap_more file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_sbrk_more file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_malloc_retry file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_memalign_retry file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt_free_dyn_thresholds file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_realloc_retry file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_calloc_retry file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:memory_mallopt file:(null) line:0 offset:0 return:0 lazy:(null)
  Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.30.so.debug
  Try to find probe point from debuginfo.
  Opening /sys/kernel/debug/tracing//README write=0
  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.
  An error occurred in debuginfo analysis (-2).
  Trying to use symbols.
  Opening /sys/kernel/debug/tracing//uprobe_events write=1
  Writing event: p:probe_libc/memcpy /usr/lib64/libc-2.30.so:0x914c0 arg1=%di
  Writing event: p:probe_libc/memcpy /usr/lib64/libc-2.30.so:0x914c0 arg1=%di
  Failed to write event: File exists
    Error: Failed to add events. Reason: File exists (Code: -17)

You can see that perf tried to write completely the same probe
definition twice, which caused an error.

To fix this issue, check the symbol list and drop duplicated symbols
(which has the same symbol name and address) from it.

With 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

Committer notes:

Fix this build error on 32-bit arches by using PRIx64 for symbol->start,
that is an u64:

  In file included from util/probe-event.c:27:
  util/probe-event.c: In function 'find_probe_trace_events_from_map':
  util/probe-event.c:2978:14: error: format '%lx' expects argument of type 'long unsigned int', but argument 5 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=]
       pr_debug("Found duplicated symbol %s @ %lx\n",
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/debug.h:17:21: note: in definition of macro 'pr_fmt'
   #define pr_fmt(fmt) fmt
                       ^~~
  util/probe-event.c:2978:5: note: in expansion of macro 'pr_debug'
       pr_debug("Found duplicated symbol %s @ %lx\n",
       ^~~~~~~~

Reported-by: Andi Kleen <andi@firstfloor.org>
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>
Link: http://lore.kernel.org/lkml/159438666401.62703.15196394835032087840.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-17 09:07:34 -03:00
..
accounting SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
arch tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy' 2020-07-03 08:11:16 -03:00
bootconfig tools/bootconfig: Add testcase for show-command and quotes test 2020-06-16 21:21:03 -04:00
bpf tools, bpftool: Add ringbuf map type to map command docs 2020-06-17 17:52:30 +02:00
build perf build: Remove libaudit from the default feature checks 2020-05-29 16:51:13 -03:00
cgroup Merge branch 'block-5.7' into for-5.8/block 2020-05-09 16:13:58 -06:00
debugging
edid
firewire
firmware
gpio tools: gpio: add bias flags to lsgpio 2020-05-05 18:27:09 +02:00
hv
iio .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
include perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL 2020-07-10 08:30:25 -03:00
io_uring
kvm/kvm_stat tools/kvm_stat: add sample systemd unit file 2020-04-21 09:13:12 -04:00
laptop change email address for Pali Rohár 2020-04-10 15:36:22 -07:00
leds .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
lib perf tools: Add support for PERF_RECORD_TEXT_POKE 2020-07-10 08:20:01 -03:00
memory-model .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
nfsd
objtool Peter Zijlstra says: 2020-06-28 10:16:15 -07:00
pci tools: PCI: Add 'e' to clear IRQ 2020-04-02 17:57:10 +01:00
pcmcia .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
perf perf probe: Avoid setting probes on the same address for the same event 2020-07-17 09:07:34 -03:00
power Merge branch 'acpica' 2020-06-10 17:27:28 +02:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
spi spi: tools: Make default_tx/rx and input_tx static 2020-06-11 16:27:24 +01:00
testing A series of fixes for x86: 2020-07-05 12:23:49 -07:00
thermal/tmon - Convert tsens configuration DT binding to yaml (Rajeshwari) 2020-04-07 20:00:16 -07:00
time
usb .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
virtio tools/virtio: Use tools/include/list.h instead of stubs 2020-06-22 12:34:22 -04:00
vm tools/vm/page_owner_sort.c: filter out unneeded line 2020-06-03 20:09:49 -07:00
wmi
Makefile