commit 0d796fb327dc6e14e7888eb4a0531fdde4ce93b2
Author: Stefan Liebler <stli@linux.vnet.ibm.com>
Date: Tue Mar 21 09:29:09 2017 +0100
Fix failing test malloc/tst-interpose-nothread with GCC 7.
The test malloc/tst-interpose-nothread fails on s390x if built
with GCC 7 and glibc commit "Remove the str(n)dup inlines
from string/bits/string2.h. Although inlining"
(ae65d4f3c3995279ca458c460ebf8bab1885fa03) with output:
error: free: 0x3fffdffa010: invalid allocation index: 0 (not less than 0)
The destructor check_for_allocations in malloc/tst-interpose-aux.c is
called twice. One time after the test-child-process has finished successfully
and once after the test-parent-process finishes.
During the latter invocation, allocation_index = 0. GCC 7 is now inlining the
free function and calls unconditionally fail in get_header as
header->allocation_index (type == size_t) is always >= allocation_index (= 0).
Before the mentioned commit above, strdup was replaced by strlen, malloc and
memcpy. The malloc call was also inlined and allocation_index was set to one.
This patch moves the already existing compiler barrier before the invocation
of free.
ChangeLog:
* malloc/tst-interpose-aux.c (check_for_allocations):
Move compiler barrier before free.
@@ -113,11 +113,11 @@ check_for_allocations (void)
{
/* Make sure that malloc is called at least once from libc. */
void *volatile ptr = strdup ("ptr");
- free (ptr);
/* Compiler barrier. The strdup function calls malloc, which
updates allocation_index, but strdup is marked __THROW, so
the compiler could optimize away the reload. */
__asm__ volatile ("" ::: "memory");
+ free (ptr);
/* If the allocation count is still zero, it means we did not
interpose malloc successfully. */
if (allocation_index == 0)
Hi, The test malloc/tst-interpose-nothread fails on s390x if built with GCC 7 and recent glibc commit "Remove the str(n)dup inlines from string/bits/string2.h. Although inlining" (ae65d4f3c3995279ca458c460ebf8bab1885fa03) with output: error: free: 0x3fffdffa010: invalid allocation index: 0 (not less than 0) The destructor check_for_allocations in malloc/tst-interpose-aux.c is called twice. One time after the test-child-process has finished successfully and once after the test-parent-process finishes. During the latter invocation, allocation_index == 0. GCC 7 is now inlining the free function and calls unconditionally fail in get_header as header->allocation_index (type == size_t) is always >= allocation_index (== 0). Before the mentioned commit above, strdup was replaced by strlen, malloc and memcpy. The malloc call was also inlined and allocation_index was set to one. This patch moves the already existing compiler barrier before the invocation of free. Okay to commit? ChangeLog: * malloc/tst-interpose-aux.c (check_for_allocations): Move compiler barrier before free.