[Bug 2142105] [NEW] Address Sanitizer extremely slow on ARM

[rustyx]

Public bug reported:

ASAN is extremely slow on ARM64 (aarch64) in Ubuntu 24.04.

Tried with GCC 13, GCC 14, clang 17 and clang 20 - same issue.

Here's a minimal repro:
https://github.com/rustyx/json-test-asan

On Ubuntu 24.04 with GCC 14:

$ make
$ ./json-test-asan 
Parsing took 4626 ms
$ ./json-test-no-asan 
Parsing took 8 ms

On Debian 13 with GCC 14 there is no such slowdown:
$ make
$ ./json-test-asan 
Parsing took 26 ms
$ ./json-test-no-asan 
Parsing took 8 ms

Note - this happens on ARM only. There is no slowdown on amd64 or x86.

perf shows most CPU time is spent in:
71.90%  [.] __asan_stack_malloc_0
27.28%  [.] __asan_stack_malloc_1

Running with ASAN_OPTIONS=detect_stack_use_after_return=0 "fixes" the
issue, but obviously disables an important check so is not a solution.

** Affects: gcc-14 (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/2142105

Title:
  Address Sanitizer extremely slow on ARM

Status in gcc-14 package in Ubuntu:
  New

Bug description:
  ASAN is extremely slow on ARM64 (aarch64) in Ubuntu 24.04.

  Tried with GCC 13, GCC 14, clang 17 and clang 20 - same issue.

  Here's a minimal repro:
  https://github.com/rustyx/json-test-asan

  On Ubuntu 24.04 with GCC 14:

  $ make
  $ ./json-test-asan 
  Parsing took 4626 ms
  $ ./json-test-no-asan 
  Parsing took 8 ms

  On Debian 13 with GCC 14 there is no such slowdown:
  $ make
  $ ./json-test-asan 
  Parsing took 26 ms
  $ ./json-test-no-asan 
  Parsing took 8 ms

  Note - this happens on ARM only. There is no slowdown on amd64 or x86.

  perf shows most CPU time is spent in:
  71.90%  [.] __asan_stack_malloc_0
  27.28%  [.] __asan_stack_malloc_1

  Running with ASAN_OPTIONS=detect_stack_use_after_return=0 "fixes" the
  issue, but obviously disables an important check so is not a solution.

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