+2019-06-07 Florian Weimer <fweimer@redhat.com>
+
+ Linux: Add getdents64 system call.
+ * include/dirnent.h (getdents): Add comment and change buffer
+ argument type to void *.
+ (getdents64): Likewise. Add hidden prototype.
+ * sysdeps/unix/sysv/linux/bits/Versions (GLIBC_2.30): Export
+ getdents64.
+ * sysdeps/unix/sysv/linux/Makefile [$(subdir) == dirent] (tests):
+ Add tst-getdents64.
+ * sysdeps/unix/sysv/linux/bits/unistd_ext.h (getdents64): Declare.
+ * sysdeps/unix/sysv/linux/getdents.c (__getdents): Change buffer
+ argument type to void *.
+ * sysdeps/unix/sysv/linux/getdents64.c (__getdents64): Likewise.
+ Add hidden definition and getdents64 alias.
+ * sysdeps/unix/sysv/linux/mips/mips64/getdents64.c (__getdents64):
+ Likewise.
+ * sysdeps/unix/sysv/linux/tst-getdents64.c: New file.
+ * manual/filesys.texi (Accessing Directories): Add Low-level
+ Directory Access node reference.
+ (Opening a Directory): Cross-reference it.
+ (Low-level Directory Access): New node.
+ * sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.30): Add
+ getdents64.
+ * sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/csky/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+ (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.30): Likewise.
+ * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.30):
+ Likewise.
+ * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.30):
+ Likewise.
+
2019-06-06 Paul A. Clarke <pc@us.ibm.com>
* sysdeps/powerpc/fpu_control.h (_FPU_MASK_RC): New.
twalk function, but it passes an additional caller-supplied argument
to the callback function.
-* On Linux, the gettid and tgkill functions have been added.
+* On Linux, the getdents64, gettid, and tgkill functions have been added.
* Minguo (Republic of China) calendar support has been added as an
alternative calendar for the following locales: zh_TW, cmn_TW, hak_TW,
size_t __nbytes,
__off_t *__restrict __basep)
__THROW __nonnull ((2, 4));
-extern __ssize_t __getdents (int __fd, char *__buf, size_t __nbytes)
- attribute_hidden;
-extern __ssize_t __getdents64 (int __fd, char *__buf, size_t __nbytes)
+
+/* These functions are only implemented on Linux. The public
+ interface for getdents64 is declared in <unistd.h>. */
+extern __ssize_t __getdents (int __fd, void *__buf, size_t __nbytes)
attribute_hidden;
+extern __ssize_t __getdents64 (int __fd, void *__buf, size_t __nbytes);
+libc_hidden_proto (__getdents64)
+
extern int __alphasort64 (const struct dirent64 **a, const struct dirent64 **b)
__attribute_pure__;
extern int __versionsort64 (const struct dirent64 **a,
* Scanning Directory Content:: Get entries for user selected subset of
contents in given directory.
* Simple Directory Lister Mark II:: Revised version of the program.
+* Low-level Directory Access:: AS-Safe functions for directory access.
@end menu
@node Directory Entries
you. Instead, you refer to these objects using the pointers returned by
the following functions.
+Directory streams are a high-level interface. On Linux, alternative
+interfaces for accessing directories using file descriptors are
+available. @xref{Low-level Directory Access}.
+
@deftypefun {DIR *} opendir (const char *@var{dirname})
@standards{POSIX.1, dirent.h}
@safety{@prelim{}@mtsafe{}@asunsafe{@ascuheap{}}@acunsafe{@acsmem{} @acsfd{}}}
Note the simple selector function in this example. Since we want to see
all directory entries we always return @code{1}.
+@node Low-level Directory Access
+@subsection Low-level Directory Access
+
+The stream-based directory functions are not AS-Safe and cannot be
+used after @code{vfork}. @xref{POSIX Safety Concepts}. The functions
+below provide an alternative that can be used in these contexts.
+
+Directory data is obtained from a file descriptor, as created by the
+@code{open} function, with or without the @code{O_DIRECTORY} flag.
+@xref{Opening and Closing Files}.
+
+@deftypefun ssize_t getdents64 (int @var{fd}, void *@var{buffer}, size_t @var{length})
+@standards{Linux, unistd.h}
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+The @code{getdents64} function reads at most @var{length} bytes of
+directory entry data from the file descriptor @var{fd} and stores it
+into the byte array starting at @var{buffer}.
+
+On success, the function returns the number of bytes written to the
+buffer. This number is zero if @var{fd} is already at the end of the
+directory stream. On error, the function returns @code{-1} and sets
+@code{errno} to the appropriate error code.
+
+The data is stored as a sequence of @code{struct dirent64} records,
+which can be traversed using the @code{d_reclen} member. The buffer
+should be large enough to hold the largest possible directory entry.
+Note that some file systems support file names longer than
+@code{NAME_MAX} bytes (e.g., because they support up to 255 Unicode
+characters), so a buffer size of at least 1024 is recommended.
+
+This function is specific to Linux.
+@end deftypefun
+
@node Working with Directory Trees
@section Working with Directory Trees
ifeq ($(subdir),dirent)
sysdep_routines += getdirentries getdirentries64
+tests += tst-getdents64
tests-internal += tst-readdir64-compat
endif
getcpu;
}
GLIBC_2.30 {
- gettid; tgkill;
+ getdents64; gettid; tgkill;
}
GLIBC_PRIVATE {
# functions used in other libraries
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
#ifdef __USE_GNU
+/* Read from the directory descriptor FD into LENGTH bytes at BUFFER.
+ Return the number of bytes read on success (0 for end of
+ directory), and -1 for failure. */
+extern ssize_t getdents64 (int __fd, void *__buffer, size_t __length)
+ __THROW __nonnull ((2));
+
/* Return the kernel thread ID (TID) of the current thread. The
returned value is not subject to caching. Most Linux system calls
accept a TID in place of a PID. Using the TID to change properties
GLIBC_2.29 xencrypt F
GLIBC_2.29 xprt_register F
GLIBC_2.29 xprt_unregister F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
/* Pack the dirent64 struct down into 32-bit offset/inode fields, and
ensure that no overflow occurs. */
ssize_t
-__getdents (int fd, char *buf, size_t nbytes)
+__getdents (int fd, void *buf0, size_t nbytes)
{
+ char *buf = buf0;
+
union
{
/* For !_DIRENT_MATCHES_DIRENT64 kernel 'linux_dirent64' has the same
#include <dirent.h>
#include <errno.h>
-/* The kernel struct linux_dirent64 matches the 'struct getdents64' type. */
+/* The kernel struct linux_dirent64 matches the 'struct dirent64' type. */
ssize_t
-__getdents64 (int fd, char *buf, size_t nbytes)
+__getdents64 (int fd, void *buf, size_t nbytes)
{
return INLINE_SYSCALL_CALL (getdents64, fd, buf, nbytes);
}
+libc_hidden_def (__getdents64)
+weak_alias (__getdents64, getdents64)
#if _DIRENT_MATCHES_DIRENT64
strong_alias (__getdents64, __getdents)
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 vm86 F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
#include <scratch_buffer.h>
ssize_t
-__getdents64 (int fd, char *buf, size_t nbytes)
+__getdents64 (int fd, void *buf0, size_t nbytes)
{
+ char *buf = buf0;
+
#ifdef __NR_getdents64
ssize_t ret = INLINE_SYSCALL_CALL (getdents64, fd, buf, nbytes);
if (ret != -1)
scratch_buffer_free (&tmpbuf);
return (char *) dp - buf;
}
+libc_hidden_def (__getdents64)
+weak_alias (__getdents64, getdents64)
+
#if _DIRENT_MATCHES_DIRENT64
strong_alias (__getdents64, __getdents)
#endif
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.30 __nldbl_vwarnx F
GLIBC_2.30 __nldbl_warn F
GLIBC_2.30 __nldbl_warnx F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
--- /dev/null
+/* Test for reading directories with getdents64.
+ 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 <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+#include <unistd.h>
+
+static int
+do_test (void)
+{
+ /* The test compares the iteration order with readdir64. */
+ DIR *reference = opendir (".");
+ TEST_VERIFY_EXIT (reference != NULL);
+
+ int fd = xopen (".", O_RDONLY | O_DIRECTORY, 0);
+ TEST_VERIFY (fd >= 0);
+
+ /* Perform two passes, with a rewind operating between passes. */
+ for (int pass = 0; pass < 2; ++pass)
+ {
+ /* Check that we need to fill the buffer multiple times. */
+ int read_count = 0;
+
+ while (true)
+ {
+ /* Simple way to make sure that the memcpy below does not read
+ non-existing data. */
+ struct
+ {
+ char buffer[1024];
+ struct dirent64 pad;
+ } data;
+
+ ssize_t ret = getdents64 (fd, &data.buffer, sizeof (data.buffer));
+ if (ret < 0)
+ FAIL_EXIT1 ("getdents64: %m");
+ if (ret == 0)
+ break;
+ ++read_count;
+
+ char *current = data.buffer;
+ char *end = data.buffer + ret;
+ while (current != end)
+ {
+ struct dirent64 entry;
+ memcpy (&entry, current, sizeof (entry));
+ /* Truncate overlong strings. */
+ entry.d_name[sizeof (entry.d_name) - 1] = '\0';
+ TEST_VERIFY (strlen (entry.d_name) < sizeof (entry.d_name) - 1);
+
+ errno = 0;
+ struct dirent64 *refentry = readdir64 (reference);
+ if (refentry == NULL && errno == 0)
+ FAIL_EXIT1 ("readdir64 failed too early, at: %s",
+ entry.d_name);
+ else if (refentry == NULL)
+ FAIL_EXIT1 ("readdir64: %m");
+
+ TEST_COMPARE_STRING (entry.d_name, refentry->d_name);
+ TEST_COMPARE (entry.d_ino, refentry->d_ino);
+ TEST_COMPARE (entry.d_off, refentry->d_off);
+ TEST_COMPARE (entry.d_type, refentry->d_type);
+
+ /* Offset zero is reserved for the first entry. */
+ TEST_VERIFY (entry.d_off != 0);
+
+ TEST_VERIFY_EXIT (entry.d_reclen <= end - current);
+ current += entry.d_reclen;
+ }
+ }
+
+ /* We expect to have reached the end of the stream. */
+ errno = 0;
+ TEST_VERIFY (readdir64 (reference) == NULL);
+ TEST_COMPARE (errno, 0);
+
+ /* direntries_read has been called more than once. */
+ TEST_VERIFY (read_count > 0);
+
+ /* Rewind both directory streams. */
+ xlseek (fd, 0, SEEK_SET);
+ rewinddir (reference);
+ }
+
+ xclose (fd);
+ closedir (reference);
+ return 0;
+}
+
+#include <support/test-driver.c>
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 getdents64 F
GLIBC_2.30 gettid F
GLIBC_2.30 tgkill F
GLIBC_2.30 twalk_r F
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