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[Vladimir Petko <2121834@xxxxxxxxxxxxxxxxxx>]

Here is the reproducer for the issue.


** Attachment added: "guard_bug.c"
   https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/2121834/+attachment/5904576/+files/guard_bug.c

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https://bugs.launchpad.net/bugs/2121834

Title:
  glibc 2.42-0ubuntu1 fails to start the thread on kernel < 6.13

Status in glibc package in Ubuntu:
  New

Bug description:
  The issue was detected when building openjdk-17[1].

  The bug occurs due to the introduction of a new guard mechanism[2] ALLOCATE_GUARD_MADV_GUARD. 
  This is a default value for the stack protection guard  (0) and it is unchanged when the thread is created with 0 size guard area[3]. The stack block is added to the list of the stacks in use[4].
  The first thread runs its course and exits.

  When the subsequent thread is created with non-zero guard area, the existing stack can be reused[5].
  It has ALLOCATE_GUARD_MADV_GUARD stack protection flag set, but the kernel does not support it. adjust_stack_prot function will try to adjust the guard area[6], but the call will fail with EINVAL. 

  This breaks OpenJDK and other multithreaded applications running glibc
  2.42-0ubuntu1 on kernels < 6.13.


  [1] https://launchpad.net/ubuntu/+source/openjdk-17/17.0.17~5ea-1/+build/31115316
  [2] https://github.com/bminor/glibc/commit/a6fbe36b7f31292981422692236465ab56670ea9
  [3] https://github.com/bminor/glibc/blob/0c6cb5285bc90b35dfdb476f47fe9bad721abf8b/nptl/allocatestack.c#L191
  [4] https://github.com/bminor/glibc/blob/0c6cb5285bc90b35dfdb476f47fe9bad721abf8b/nptl/allocatestack.c#L558
  [5] https://github.com/bminor/glibc/blob/0c6cb5285bc90b35dfdb476f47fe9bad721abf8b/nptl/allocatestack.c#L483
  [6] https://github.com/bminor/glibc/blob/0c6cb5285bc90b35dfdb476f47fe9bad721abf8b/nptl/allocatestack.c#L256

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