linux/tools
Masami Hiramatsu 11fd3eb874 perf probe: Fix wrong variable warning when the probe point is not found
Fix a wrong "variable not found" warning when the probe point is not
found in the debuginfo.

Since the debuginfo__find_probes() can return 0 even if it does not find
given probe point in the debuginfo, fill_empty_trace_arg() can be called
with tf.ntevs == 0 and it can emit a wrong warning.  To fix this, reject
ntevs == 0 in fill_empty_trace_arg().

E.g. without 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

With this;

  # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di"
  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

Fixes: cb40273085 ("perf probe: Trace a magic number if variable is not found")
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Andi Kleen <ak@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/159438667364.62703.2200642186798763202.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-07-17 09:09:37 -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 tools/edid: Move EDID data sets from Documentation/ 2020-02-19 04:10:32 -07:00
firewire
firmware
gpio tools: gpio: add bias flags to lsgpio 2020-05-05 18:27:09 +02:00
hv Tools: hv: Reopen the devices if read() or write() returns errors 2020-01-26 22:10:10 -05:00
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: Fix wrong variable warning when the probe point is not found 2020-07-17 09:09:37 -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