Single thread optimization is valid if at thread creation time the
optimization can be disabled. This is in principle true for all
stream objects that user code can access (and thus needs locking),
using the same internal list as fflush(0) uses. However in glibc
open_memstream is not on that list (BZ 21735) so the optimization
has to be disabled.
* libio/memstream.c (__open_memstream): Set _IO_FLAGS2_NEED_LOCK.
* libio/wmemstream.c (open_wmemstream): Likewise.
* nptl/tst-memstream.c: New.
There is bug report that ld.so in GLIBC 2.24 built by Binutils 2.29 will crash
on arm-linux-gnueabihf. This is confirmed, and the details is at:
https://sourceware.org/bugzilla/show_bug.cgi?id=21725.
As analyzed in the PR, the old code was with the assumption that assembler
won't set bit0 of thumb function address if it comes from PC-relative
instructions and the calculation can be finished during assembling. This
assumption however does not hold after PR gas/21458.
* sysdeps/arm/dl-machine.h (elf_machine_load_address): Also strip bit 0
of pcrel_address under Thumb mode.
Compile tst-ssp-1.c with -fstack-protector-all in case the the stack
protector heuristics do not instrument a thirty-byte array.
* debug/Makefile (CFLAGS-tst-ssp-1.c): Set to
-fstack-protector-all.
On powerpc64le, the compilation of the files related to float128 support
requires the option -mfloat128 to be passed to gcc. However, not all
possible object suffixes were covered in the Makefile. This patch uses
$(all-object-suffixes) in all remaining rules.
Tested for powerpc64le.
* sysdeps/powerpc/powerpc64le/Makefile: Use $(all-object-suffixes)
to iterate over all possible object suffixes. Add a comment
explaining the use of sysdep-CFLAGS instead of CFLAGS.
__stack_chk_fail is called on corrupted stack. Stack backtrace is very
unreliable against corrupted stack. __libc_message is changed to accept
enum __libc_message_action and call BEFORE_ABORT only if action includes
do_backtrace. __fortify_fail_abort is added to avoid backtrace from
__stack_chk_fail.
[BZ #12189]
* debug/Makefile (CFLAGS-tst-ssp-1.c): New.
(tests): Add tst-ssp-1 if -fstack-protector works.
* debug/fortify_fail.c: Include <stdbool.h>.
(_fortify_fail_abort): New function.
(__fortify_fail): Call _fortify_fail_abort.
(__fortify_fail_abort): Add a hidden definition.
* debug/stack_chk_fail.c: Include <stdbool.h>.
(__stack_chk_fail): Call __fortify_fail_abort, instead of
__fortify_fail.
* debug/tst-ssp-1.c: New file.
* include/stdio.h (__libc_message_action): New enum.
(__libc_message): Replace int with enum __libc_message_action.
(__fortify_fail_abort): New hidden prototype.
* malloc/malloc.c (malloc_printerr): Update __libc_message calls.
* sysdeps/posix/libc_fatal.c (__libc_message): Replace int
with enum __libc_message_action. Call BEFORE_ABORT only if
action includes do_backtrace.
(__libc_fatal): Update __libc_message call.
Linux 4.12 (b745fafaf70c0a98a2e1e7ac8cb14542889ceb0e) adds a new
p{read,write}v2 flag RWF_NOWAIT. This patch adds it for linux
uio-ext.h header.
Checked on x86_64-linux-gnu (on a 4.10 kernel).
[BZ #21738]
* manual/llio.texi (RWF_NOWAIT): New item.
* misc/tst-preadvwritev2-common.c (do_test_with_invalid_flags):
Add RWF_NOWAIT check.
* sysdeps/unix/sysv/linux/bits/uio-ext.h (RWF_NOWAIT): New flag.
The request PTRACE_SINGLEBLOCK was introduced in Linux 3.15. Thus the ptrace call
will fail on older kernels.
Thus the test is now testing PTRACE_SINGLEBLOCK with data argument pointing to a
buffer on stack which is assumed to fail. If the request would be interpreted as
PTRACE_GETREGS, then the ptrace call will not fail and the regs are written to buf.
If we run with a kernel with support for PTRACE_SINGLEBLOCK a ptrace call with
data=NULL, returns zero with no error. If we run with a kernel without support for
PTRACE_SINGLEBLOCK a ptrace call with data=NULL reports an error.
In the latter case, the test is just continuing with PTRACE_CONT.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c:
Support running on kernels without PTRACE_SINGLEBLOCK.
Since _dl_resolve_conflicts is only used in elf/rtld.c, don't include
it in libc.a.
[BZ #21742]
* elf/Makefile (dl-routines): Move dl-conflict to ...
(rtld-routines): Here.
Since there are no multiarch versions of memmove_chk and memset_chk,
test multiarch versions of memmove_chk and memset_chk only in libc.so.
[BZ #21741]
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Test memmove_chk and memset_chk only
in libc.so.
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.
This patch fixes some build issues when including types/sigevent_t.h
along with bits/pthreadtypes.h.
Checked on x86_64-linux-gnu and on a build on supported major ABIs.
[BZ #21715]
* sysdeps/nptl/bits/pthreadtypes.h (__have_pthread_attr_t): Fix typo
on definition.
This change forces realignment of the stack pointer in __tls_get_addr, so
that binaries compiled by GCCs older than GCC 4.9:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
continue to work even if vector instructions are used in glibc which
require the ABI stack realignment.
__tls_get_addr_slow is added to handle the slow paths in the default
implementation of__tls_get_addr in elf/dl-tls.c. The new __tls_get_addr
calls __tls_get_addr_slow after realigning the stack. Internal calls
within ld.so go directly to the default implementation of __tls_get_addr
because they do not need stack realignment.
[BZ #21609]
* sysdeps/x86_64/Makefile (sysdep-dl-routines): Add tls_get_addr.
(gen-as-const-headers): Add rtld-offsets.sym.
* sysdeps/x86_64/dl-tls.c: New file.
* sysdeps/x86_64/rtld-offsets.sym: Likwise.
* sysdeps/x86_64/tls_get_addr.S: Likewise.
* sysdeps/x86_64/dl-tls.h: Add multiple inclusion guards.
* sysdeps/x86_64/tlsdesc.sym (TI_MODULE_OFFSET): New.
(TI_OFFSET_OFFSET): Likwise.
This patch fix the return value for error conditions for default
posix_spawn (where the errno is expected). It also avoid clobber
errno on fork call.
Checked on x86_64 (with Linux implementation removed).
[BZ# 21697]
* sysdeps/posix/spawni.c (__spawni_child): Fix return value.
(__spawnix): Do not clober errno.
Locking overhead can be significant in some stdio operations
that are common in single threaded applications.
This patch adds the _IO_FLAGS2_NEED_LOCK flag to indicate if
an _IO_FILE object needs to be locked and some of the stdio
functions just jump to their _unlocked variant when not. The
flag is set on all _IO_FILE objects when the first thread is
created. A new GLIBC_PRIVATE libc symbol, _IO_enable_locks,
was added to do this from libpthread.
The optimization can be applied to more stdio functions,
currently it is only applied to single flag check or single
non-wide-char standard operations. The flag should probably
be never set for files with _IO_USER_LOCK, but that's just a
further optimization, not a correctness requirement.
The optimization is valid in a single thread because stdio
operations are non-as-safe (so lock state is not observable
from a signal handler) and stdio locks are recursive (so lock
state is not observable via deadlock). The optimization is not
valid if a thread may be created while an stdio lock is taken
and thus it should be disabled if any user code may run during
an stdio operation (interposed malloc, printf hooks, etc).
This makes the optimization more complicated for some stdio
operations (e.g. printf), but those are bigger and thus less
important to optimize so this patch does not try to do that.
* libio/libio.h (_IO_FLAGS2_NEED_LOCK, _IO_need_lock): Define.
* libio/libioP.h (_IO_enable_locks): Declare.
* libio/Versions (_IO_enable_locks): New symbol.
* libio/genops.c (_IO_enable_locks): Define.
(_IO_old_init): Initialize flags2.
* libio/feof.c.c (_IO_feof): Avoid locking when not needed.
* libio/ferror.c (_IO_ferror): Likewise.
* libio/fputc.c (fputc): Likewise.
* libio/putc.c (_IO_putc): Likewise.
* libio/getc.c (_IO_getc): Likewise.
* libio/getchar.c (getchar): Likewise.
* libio/ioungetc.c (_IO_ungetc): Likewise.
* nptl/pthread_create.c (__pthread_create_2_1): Enable stdio locks.
* libio/iofopncook.c (_IO_fopencookie): Enable locking for the file.
* sysdeps/pthread/flockfile.c (__flockfile): Likewise.
A dot-less host name without an /etc/resolv.conf file caused an
assertion failure in update_from_conf because the function would not
deal correctly with the empty search list case.
Thanks to Andreas Schwab for debugging assistence.
This patch updates build-many-glibcs.py to use the current release
branch of binutils and current releases of GMP and the Linux kernel.
* scripts/build-many-glibcs.py (Context.checkout): Default
binutils version to 2.29 branch, GMP version to 6.1.2 and Linux
kernel version to 4.12.
This commit enhances the stub resolver to reload the configuration
in the per-thread _res object if the /etc/resolv.conf file has
changed. The resolver checks whether the application has modified
_res and will not overwrite the _res object in that case.
The struct resolv_context mechanism is used to check the
configuration file only once per name lookup.
This commit adds the remaining unchanging members (which are loaded
from /etc/resolv.conf) to struct resolv_conf.
The extended name server list is currently not used by the stub
resolver. The switch depends on a cleanup: The _u._ext.nssocks
array stores just a single socket, and needs to be replaced with
a single socket value.
(The compatibility gethostname implementation does not use the
extended addres sort list, either. Updating the compat code is
not worthwhile.)
This change uses the extended resolver state in struct resolv_conf to
store the search list. If applications have not patched the _res
object directly, this extended search list will be used by the stub
resolver during name resolution.
This change provides additional resolver configuration state which
is not exposed through the _res ABI. It reuses the existing
initstamp field in the supposedly-private part of _res. Some effort
is undertaken to avoid memory safety issues introduced by applications
which directly patch the _res object.
With this commit, only the initstamp field is moved into struct
resolv_conf. Additional members will be added later, eventually
migrating the entire resolver configuration.
struct resolv_context objects provide a temporary resolver context
which does not change during a name lookup operation. Only when the
outmost context is created, the stub resolver configuration is
verified to be current (at present, only against previous res_init
calls). Subsequent attempts to obtain the context will reuse the
result of the initial verification operation.
struct resolv_context can also be extended in the future to store
data which needs to be deallocated during thread cancellation.
