glibc/support/support.h
Stefan Liebler bc79db3fd4 Fix alignment of TLS variables for tls variant TLS_TCB_AT_TP [BZ #23403]
The alignment of TLS variables is wrong if accessed from within a thread
for architectures with tls variant TLS_TCB_AT_TP.
For the main thread the static tls data is properly aligned.
For other threads the alignment depends on the alignment of the thread
pointer as the static tls data is located relative to this pointer.

This patch adds this alignment for TLS_TCB_AT_TP variants in the same way
as it is already done for TLS_DTV_AT_TP. The thread pointer is also already
properly aligned if the user provides its own stack for the new thread.

This patch extends the testcase nptl/tst-tls1.c in order to check the
alignment of the tls variables and it adds a pthread_create invocation
with a user provided stack.
The test itself is migrated from test-skeleton.c to test-driver.c
and the missing support functions xpthread_attr_setstack and xposix_memalign
are added.

ChangeLog:

	[BZ #23403]
	* nptl/allocatestack.c (allocate_stack): Align pointer pd for
	TLS_TCB_AT_TP tls variant.
	* nptl/tst-tls1.c: Migrate to support/test-driver.c.
	Add alignment checks.
	* support/Makefile (libsupport-routines): Add xposix_memalign and
	xpthread_setstack.
	* support/support.h: Add xposix_memalign.
	* support/xthread.h: Add xpthread_attr_setstack.
	* support/xposix_memalign.c: New File.
	* support/xpthread_attr_setstack.c: Likewise.
2019-02-06 09:06:34 +01:00

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C

/* Common extra functions.
Copyright (C) 2016-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* This header file should only contain definitions compatible with
C90. (Using __attribute__ is fine because <features.h> provides a
fallback.) */
#ifndef SUPPORT_H
#define SUPPORT_H
#include <stddef.h>
#include <sys/cdefs.h>
/* For mode_t. */
#include <sys/stat.h>
/* For ssize_t and off64_t. */
#include <sys/types.h>
__BEGIN_DECLS
/* Write a message to standard output. Can be used in signal
handlers. */
void write_message (const char *message) __attribute__ ((nonnull (1)));
/* Avoid all the buffer overflow messages on stderr. */
void ignore_stderr (void);
/* Set fortification error handler. Used when tests want to verify that bad
code is caught by the library. */
void set_fortify_handler (void (*handler) (int sig));
/* Report an out-of-memory error for the allocation of SIZE bytes in
FUNCTION, terminating the process. */
void oom_error (const char *function, size_t size)
__attribute__ ((nonnull (1)));
/* Return a pointer to a memory region of SIZE bytes. The memory is
initialized to zero and will be shared with subprocesses (across
fork). The returned pointer must be freed using
support_shared_free; it is not compatible with the malloc
functions. */
void *support_shared_allocate (size_t size);
/* Deallocate a pointer returned by support_shared_allocate. */
void support_shared_free (void *);
/* Write CONTENTS to the file PATH. Create or truncate the file as
needed. The file mode is 0666 masked by the umask. Terminate the
process on error. */
void support_write_file_string (const char *path, const char *contents);
/* Quote the contents of the byte array starting at BLOB, of LENGTH
bytes, in such a way that the result string can be included in a C
literal (in single/double quotes, without putting the quotes into
the result). */
char *support_quote_blob (const void *blob, size_t length);
/* Quote the contents of the string, in such a way that the result
string can be included in a C literal (in single/double quotes,
without putting the quotes into the result). */
char *support_quote_string (const char *);
/* Returns non-zero if the file descriptor is a regular file on a file
system which supports holes (that is, seeking and writing does not
allocate storage for the range of zeros). FD must refer to a
regular file open for writing, and initially empty. */
int support_descriptor_supports_holes (int fd);
/* Error-checking wrapper functions which terminate the process on
error. */
void *xmalloc (size_t) __attribute__ ((malloc));
void *xcalloc (size_t n, size_t s) __attribute__ ((malloc));
void *xrealloc (void *p, size_t n);
void *xposix_memalign (size_t alignment, size_t n);
char *xasprintf (const char *format, ...)
__attribute__ ((format (printf, 1, 2), malloc));
char *xstrdup (const char *);
char *xstrndup (const char *, size_t);
/* These point to the TOP of the source/build tree, not your (or
support's) subdirectory. */
extern const char support_srcdir_root[];
extern const char support_objdir_root[];
/* Corresponds to the path to the runtime linker used by the testsuite,
e.g. OBJDIR_PATH/elf/ld-linux-x86-64.so.2 */
extern const char support_objdir_elf_ldso[];
/* Corresponds to the --prefix= passed to configure. */
extern const char support_install_prefix[];
/* Corresponds to the install's lib/ or lib64/ directory. */
extern const char support_libdir_prefix[];
extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
size_t, unsigned int);
__END_DECLS
#endif /* SUPPORT_H */