Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.kernel > #88293

Bug#1108037: linux-perf: perf report --demangle only works on some(?) symbols

Cross-posted to 2 groups.

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

Control: tag -1 moreinfo

On Thu, 19 Jun 2025 16:09:24 +0200 =?utf-8?B?0L3QsNCx?= <nabijaczleweli@nabijaczleweli.xyz> wrote:
> Package: linux-perf
> Version: 6.1.140-1
> Version: 6.12.30-1
> Version: 6.12.32-1
> Severity: normal
> 
> Dear Maintainer,
> 
> I'm attaching a tarball that, when extracted in the home directory,
> should demonstrate the issue.
> 
> Running perf report -g --demangle shows
>   Samples: 278K of event 'cycles:u', Event count (approx.): 183133005676
>     Children      Self  Command  Shared Object         Symbol
>   +   98.44%     0.00%  bench    bench                 [.] main
>   +   89.76%     0.00%  bench    bench                 [.] _ZN5Botan11Cipher_Mode6updateITkNS_8concepts21resizable_byte_bufferESt6vectorIhNS_16secure_allocatorIhEEEEEvRT_m
[...]

None of bfd_demangle() from libbfd, cplus_demangle() from libiberty,
abi::__cxx_demangle() from libstdc++ are able to demangle this symbol. 
(We currently configure perf to use abi::__cxx_demangle.)

The llvm-cxxfilt command demangles it to "void
Botan::Cipher_Mode::update<std::vector<unsigned char,
Botan::secure_allocator<unsigned char>>>(std::vector<unsigned char,
Botan::secure_allocator<unsigned char>>&, unsigned long)" but it seems
to be ignoring part of the symbol, specifically 
"Botan::concepts::resizable_byte_buffer".

If I delete the "Tk" from the mangled symbol then they all agree it
should be demangled to "void
Botan::Cipher_Mode::update<std::vector<unsigned char,
Botan::secure_allocator<unsigned char>>>(std::vector<unsigned char,
Botan::secure_allocator<unsigned char>>&, unsigned long)".

What does the actual declaration of this function look like, and what
toolchain are you using to compile it?

Ben.

-- 
Ben Hutchings
73.46% of all statistics are made up.

Back to linux.debian.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Bug#1108037: linux-perf: perf report --demangle only works on some(?) symbols наб <nabijaczleweli@nabijaczleweli.xyz> - 2025-06-19 16:20 +0200
  Bug#1108037: linux-perf: perf report --demangle only works on some(?) symbols Ben Hutchings <ben@decadent.org.uk> - 2025-07-09 18:20 +0200
    Bug#1108037: linux-perf: perf report --demangle only works on some(?) symbols наб <nabijaczleweli@nabijaczleweli.xyz> - 2025-07-09 19:20 +0200
      Bug#1108037: linux-perf: perf report --demangle only works on some(?) symbols Ben Hutchings <ben@decadent.org.uk> - 2025-07-11 00:30 +0200
  Processed: Re: linux-perf: perf report --demangle only works on  some(?) symbols "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-07-09 18:20 +0200
  Processed: Re: linux-perf: perf report --demangle only works on  some(?) symbols "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-07-09 19:20 +0200
  Bug#1108037: 惊人的5大长寿定律，看懂了能让你一辈子不生病 Wilfred Ha <ytong8632@gmail.com> - 2025-09-18 05:40 +0200

csiph-web