* [2.30 COMMITTED] Add nocancel version of pread64()
@ 2020-01-01 0:00 Florian Weimer
0 siblings, 0 replies; only message in thread
From: Florian Weimer @ 2020-01-01 0:00 UTC (permalink / raw)
To: libc-stable
From: Leandro Pereira <leandro.pereira@microsoft.com>
This is in preparation for changes in the dynamic linker so that
pread() is used instead of lseek()+read().
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit fed33b0fb03d1942a6713286176d42869c0f1580)
diff --git a/sysdeps/generic/not-cancel.h b/sysdeps/generic/not-cancel.h
index f3d862651e..724c3e5e71 100644
--- a/sysdeps/generic/not-cancel.h
+++ b/sysdeps/generic/not-cancel.h
@@ -41,6 +41,8 @@
(void) __close (fd)
#define __read_nocancel(fd, buf, n) \
__read (fd, buf, n)
+#define __pread64_nocancel(fd, buf, count, offset) \
+ __pread64 (fd, buf, count, offset)
#define __write_nocancel(fd, buf, n) \
__write (fd, buf, n)
#define __writev_nocancel_nostatus(fd, iov, n) \
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 1ab6bcbfc8..a7980a60f6 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -212,8 +212,8 @@ sysdep_routines += xstatconv internal_statvfs internal_statvfs64 \
close_nocancel fcntl_nocancel nanosleep_nocancel \
open_nocancel open64_nocancel \
openat_nocancel openat64_nocancel \
- pause_nocancel read_nocancel waitpid_nocancel \
- write_nocancel statx_cp
+ pause_nocancel read_nocancel pread64_nocancel \
+ waitpid_nocancel write_nocancel statx_cp
sysdep_headers += bits/fcntl-linux.h
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 1ca102a9e2..d385085c61 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -182,6 +182,7 @@ libc {
__syscall_rt_sigqueueinfo;
__open_nocancel;
__read_nocancel;
+ __pread64_nocancel;
__close_nocancel;
__sigtimedwait;
# functions used by nscd
diff --git a/sysdeps/unix/sysv/linux/not-cancel.h b/sysdeps/unix/sysv/linux/not-cancel.h
index 16cc31cba5..bf7d80125a 100644
--- a/sysdeps/unix/sysv/linux/not-cancel.h
+++ b/sysdeps/unix/sysv/linux/not-cancel.h
@@ -43,6 +43,9 @@ __typeof (openat64) __openat64_nocancel;
/* Non cancellable read syscall. */
__typeof (__read) __read_nocancel;
+/* Non cancellable pread syscall (LFS version). */
+__typeof (__pread64) __pread64_nocancel;
+
/* Uncancelable write. */
__typeof (__write) __write_nocancel;
@@ -84,6 +87,7 @@ hidden_proto (__open64_nocancel)
hidden_proto (__openat_nocancel)
hidden_proto (__openat64_nocancel)
hidden_proto (__read_nocancel)
+hidden_proto (__pread64_nocancel)
hidden_proto (__write_nocancel)
hidden_proto (__close_nocancel)
hidden_proto (__waitpid_nocancel)
diff --git a/sysdeps/unix/sysv/linux/pread64_nocancel.c b/sysdeps/unix/sysv/linux/pread64_nocancel.c
new file mode 100644
index 0000000000..dab61260e5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pread64_nocancel.c
@@ -0,0 +1,32 @@
+/* Linux pread64() syscall implementation -- non-cancellable.
+ Copyright (C) 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/>. */
+
+#include <unistd.h>
+#include <sysdep-cancel.h>
+#include <not-cancel.h>
+
+#ifndef __NR_pread64
+# define __NR_pread64 __NR_pread
+#endif
+
+ssize_t
+__pread64_nocancel (int fd, void *buf, size_t count, off64_t offset)
+{
+ return INLINE_SYSCALL_CALL (pread64, fd, buf, count, SYSCALL_LL64_PRW (offset));
+}
+hidden_def (__pread64_nocancel)
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2020-01-01 0:00 [2.30 COMMITTED] Add nocancel version of pread64() Florian Weimer
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