This patch increases the timeouts for some tests that I've seen timing
out on slow systems in my 2.26 release testing. (In the case of
tst-tsearch.c, increasing the timeout means removing a setting of 10
that was put there before the default timeout was increased to 20
seconds, so putting the default into effect.)
* iconvdata/tst-loading.c (TIMEOUT): Define to 30.
* misc/tst-tsearch.c (TIMEOUT): Remove.
* nptl/tst-create-detached.c (TIMEOUT): Define to 100.
* nptl/tst-robust-fork.c (TIMEOUT): Likewise.
* nptl/tst-rwlock19.c (TIMEOUT): Likewise.
* string/tst-cmp.c (TIMEOUT): Define to 600.
The commit documents the ownership rules around 'struct pthread' and
when a thread can read or write to the descriptor. With those ownership
rules in place it becomes obvious that pd->stopped_start should not be
touched in several of the paths during thread startup, particularly so
for detached threads. In the case of detached threads, between the time
the thread is created by the OS kernel and the creating thread checks
pd->stopped_start, the detached thread might have already exited and the
memory for pd unmapped. As a regression test we add a simple test which
exercises this exact case by quickly creating detached threads with
large enough stacks to ensure the thread stack cache is bypassed and the
stacks are unmapped. Before the fix the testcase segfaults, after the
fix it works correctly and completes without issue.
For a detailed discussion see:
https://www.sourceware.org/ml/libc-alpha/2017-01/msg00505.html
Joseph Myers
Carlos O'Donell