[llvm-bugs] [Bug 42918] New: libc++ passes invalid values to pthread_equal
via llvm-bugs
llvm-bugs at lists.llvm.org
Wed Aug 7 07:49:33 PDT 2019
https://bugs.llvm.org/show_bug.cgi?id=42918
Bug ID: 42918
Summary: libc++ passes invalid values to pthread_equal
Product: libc++
Version: unspecified
Hardware: All
OS: FreeBSD
Status: NEW
Severity: normal
Priority: P
Component: All Bugs
Assignee: unassignedclangbugs at nondot.org
Reporter: mclow.lists at gmail.com
CC: llvm-bugs at lists.llvm.org, mclow.lists at gmail.com
[ received from Ed Maste at FreeBSD ]
We just had a FreeBSD bug submitted for a failure arising from
libc++'s use of pthread_equal.
FreeBSD's pthread_equal stub implementation (used in non-threaded
programs) returns true unconditionally, since a non-threaded program
cannot have two different threads. However, std::thread::id defines a
special value that should not equal any real thread, and this is may
be passed to pthread_equal. See FreeBSD PR 239550 for more details,
and PR 239038 for the user-facing issue that prompted this.
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=239550
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=239038
Now the most expedient fix is probably for us to make pthread_equal
somewhat less of a stub, but for correctness it seems
__libcpp_thread_id_equal would need to check for libc++'s special
value before calling pthread_equal.
--
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20190807/d137c6fa/attachment.html>
More information about the llvm-bugs
mailing list