linux/tools
David Tolnay cae15db749 perf symbols: Add Rust demangling
Rust demangling is another step after bfd demangling. Add a diagnosis to
identify mangled Rust symbols based on the hash that the Rust mangler appends
as the last path component, as well as other characteristics.  Add a demangler
to reconstruct the original symbol.

Committer notes:

How I tested it:

Enabled COPR on Fedora 24 and then installed the 'rust-binary' package,
with it:

  $ cat src/main.rs
  fn main() {
      println!("Hello, world!");
  }
  $ cat Cargo.toml
  [package]

  name = "hello_world"
  version = "0.0.1"
  authors = [ "Arnaldo Carvalho de Melo <acme@kernel.org>" ]

  $ perf record cargo bench
   Compiling hello_world v0.0.1 (file:///home/acme/projects/hello_world)
     Running target/release/hello_world-d4b9dab4b2a47d75

  running 0 tests

  test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.096 MB perf.data (1457 samples) ]
  $

Before this patch:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .............................................................................................................
  #
       1.78%  rustc    [.] rbml::reader::maybe_get_doc::hb9d387df6024b15b
       1.50%  rustc    [.] _$LT$reader..DocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::hd9af9e60d79a35c8
       1.20%  rustc    [.] rbml::reader::doc_at::hc88107fba445af31
       0.46%  rustc    [.] _$LT$reader..TaggedDocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::h0cb40e696e4bb489
       0.35%  rustc    [.] rbml::reader::Decoder::_next_int::h66eef7825a398bc3
       0.29%  rustc    [.] rbml::reader::Decoder::_next_sub::h8e5266005580b836
       0.15%  rustc    [.] rbml::reader::get_doc::h094521c645459139
       0.14%  rustc    [.] _$LT$reader..Decoder$LT$$u27$doc$GT$$u20$as$u20$serialize..Decoder$GT$::read_u32::h0acea2fff9669327
       0.07%  rustc    [.] rbml::reader::Decoder::next_doc::h6714d469c9dfaf91
       0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
       0.06%  rustc    [.] _fini
  $

After:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .................................................................
  #
     1.78%  rustc    [.] rbml::reader::maybe_get_doc
     1.50%  rustc    [.] <reader::DocsIterator<'a> as std::iter::Iterator>::next
     1.20%  rustc    [.] rbml::reader::doc_at
     0.46%  rustc    [.] <reader::TaggedDocsIterator<'a> as std::iter::Iterator>::next
     0.35%  rustc    [.] rbml::reader::Decoder::_next_int
     0.29%  rustc    [.] rbml::reader::Decoder::_next_sub
     0.15%  rustc    [.] rbml::reader::get_doc
     0.14%  rustc    [.] <reader::Decoder<'doc> as serialize::Decoder>::read_u32
     0.07%  rustc    [.] rbml::reader::Decoder::next_doc
     0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
     0.06%  rustc    [.] _fini
  $

Signed-off-by: David Tolnay <dtolnay@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5780B7FA.3030602@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 16:12:38 -03:00
..
arch tools: Copy the bitsperlong.h files from the kernel 2016-07-12 15:20:39 -03:00
build perf tools: Add feature detection for gelf_getnote() 2016-07-12 15:20:41 -03:00
cgroup
firewire
gpio tools/gpio: Add missing initialization of device_name 2016-03-31 11:51:30 +02:00
hv tools: hv: lsvmbus: add pci pass-through UUID 2016-05-01 09:23:14 -07:00
iio iio: tools: generic_buffer: auto-enable channels 2016-04-19 19:58:13 +01:00
include tools: Copy the bitsperlong.h files from the kernel 2016-07-12 15:20:39 -03:00
kvm/kvm_stat tools: kvm_stat: Add comments 2016-05-25 16:12:06 +02:00
laptop/freefall Move freefall program from Documentation/ to tools/ 2015-06-08 16:42:07 -06:00
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib tools lib bpf: Copy bpf.h and bpf_common.h from the kernel 2016-07-12 15:20:32 -03:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool tools lib subcmd: Use str_error_r() 2016-07-12 15:20:30 -03:00
perf perf symbols: Add Rust demangling 2016-07-12 16:12:38 -03:00
power Merge branch 'for-4.7/acpi6.1' into libnvdimm-for-next 2016-05-18 10:07:19 -07:00
scripts tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
spi spi: spidev_test: Fix typo in error message 2015-12-08 17:58:56 +00:00
testing selftests/vm/compaction_test: fix write to restore nr_hugepages 2016-06-24 17:23:52 -07:00
thermal/tmon tools/thermal: tmon: use pkg-config also for CFLAGS 2015-10-10 11:32:31 +08:00
time
usb usbip: adding names db to port operation 2016-05-03 14:32:07 -07:00
virtio tools/virtio: add noring tool 2016-06-06 13:00:11 +03:00
vm tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences" 2016-06-24 17:23:52 -07:00
Makefile - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00