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author | Florian Weimer <fweimer@redhat.com> | 2020-10-07 16:39:50 +0200 |
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committer | Florian Weimer <fweimer@redhat.com> | 2020-10-07 16:41:30 +0200 |
commit | b31d4355ae817aa3caf9414f842cc07465bca028 (patch) | |
tree | 92b53e557c324461904d3bcb0f1131cc15ae7aa9 /elf/dl-write.c | |
parent | 56f8d442942ee51824b4683be83f776a811a3f2a (diff) | |
download | glibc-b31d4355ae817aa3caf9414f842cc07465bca028.zip glibc-b31d4355ae817aa3caf9414f842cc07465bca028.tar.gz glibc-b31d4355ae817aa3caf9414f842cc07465bca028.tar.bz2 |
elf: Implement _dl_write
The generic version is parallel to _dl_writev. It cannot use
_dl_writev directly because the errno value needs to be obtained
under a lock.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'elf/dl-write.c')
-rw-r--r-- | elf/dl-write.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/elf/dl-write.c b/elf/dl-write.c new file mode 100644 index 0000000..7350aff --- /dev/null +++ b/elf/dl-write.c @@ -0,0 +1,56 @@ +/* Implementation of the _dl_write function. Generic version. + Copyright (C) 2020 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 + <https://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <ldsodefs.h> +#include <libc-lock.h> +#include <sys/uio.h> + +ssize_t +_dl_write (int fd, const void *buffer, size_t length) +{ + struct iovec iov = { .iov_base = (void *) buffer, .iov_len = length }; + ssize_t ret; + +#if RTLD_PRIVATE_ERRNO + /* We have to take this lock just to be sure we don't clobber the private + errno when it's being used by another thread that cares about it. + Yet we must be sure not to try calling the lock functions before + the thread library is fully initialized. */ + if (__glibc_unlikely (_dl_starting_up)) + { + ret = __writev (fd, &iov, 1); + if (ret < 0) + ret = -errno; + } + else + { + __rtld_lock_lock_recursive (GL(dl_load_lock)); + __writev (fd, &iov, 1); + if (ret < 0) + ret = -errno; + __rtld_lock_unlock_recursive (GL(dl_load_lock)); + } +#else + ret = __writev (fd, &iov, 1); + if (ret < 0) + ret = -errno; +#endif + + return ret; +} |