path: root/src/fenv/sh
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authorRich Felker <>2020-10-24 13:34:29 -0400
committerRich Felker <>2020-10-24 15:59:40 -0400
commit0b87551bdfb74ac411caa335d8ad0b89a7f139c6 (patch)
tree7e8aea0b9b9f7b18f33001184ba2e9cb4d1384f8 /src/fenv/sh
parent99d5098a885feae3ae8c32b407350d8ca85dd178 (diff)
lift sigaction abort locking to fix posix_spawn child deadlock
commit 25ea9f712c30c32957de493d4711ee39d0bbb024 introduced a deadlock to the posix_spawn child whereby, if abort was called in the parent and ended up taking the abort lock to terminate the process, the __libc_sigaction calls in the child would wait forever to obtain a lock that would not be released. this could be fixed by having abort set the abort lock as the exit futex address, but it's cleaner to just remove the SIGABRT special handling from the internal __libc_sigaction and lift it to the public sigaction function. nothing but the posix_spawn child calls __libc_sigaction on SIGABRT, and since commit b7bc966522d73e1dc420b5ee6fc7a2e78099a08c the abort lock is held at the time of __clone, which precludes the child inheriting a kernel-level signal disposition inconsistent with the disposition on the abstract machine. this means it's fine to inspect and modify the disposition in the child without a lock.
Diffstat (limited to 'src/fenv/sh')
0 files changed, 0 insertions, 0 deletions