diff options
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/Makefile | 1 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/getdents64.c | 89 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/tst-readdir64-compat.c | 111 |
4 files changed, 187 insertions, 25 deletions
@@ -1,3 +1,14 @@ +2018-08-10 Florian Weimer <fweimer@redhat.com> + + [BZ #23497] + * sysdeps/unix/sysv/linux/getdents64.c (handle_overflow): New + function. + (__old_getdents64): Use getdents64. Convert entries without + moving them. + * sysdeps/unix/sysv/linux/tst-readdir64-compat.c: New file. + * sysdeps/unix/sysv/linux/Makefile (tests-internal): Add + tst-readdir64-compat. + 2018-08-10 Ilya Leoshkevich <iii@linux.ibm.com> * sysdeps/s390/s390-32/s390-mcount.S (_mcount): diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index f71cc39c7e..773aaea0e9 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -161,6 +161,7 @@ inhibit-glue = yes ifeq ($(subdir),dirent) sysdep_routines += getdirentries getdirentries64 +tests-internal += tst-readdir64-compat endif ifeq ($(subdir),nis) diff --git a/sysdeps/unix/sysv/linux/getdents64.c b/sysdeps/unix/sysv/linux/getdents64.c index 3bde0cf4f0..bc140b5a7f 100644 --- a/sysdeps/unix/sysv/linux/getdents64.c +++ b/sysdeps/unix/sysv/linux/getdents64.c @@ -33,41 +33,80 @@ strong_alias (__getdents64, __getdents) # include <shlib-compat.h> # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2) -# include <olddirent.h> +# include <olddirent.h> +# include <unistd.h> -/* kernel definition of as of 3.2. */ -struct compat_linux_dirent +static ssize_t +handle_overflow (int fd, __off64_t offset, ssize_t count) { - /* Both d_ino and d_off are compat_ulong_t which are defined in all - architectures as 'u32'. */ - uint32_t d_ino; - uint32_t d_off; - unsigned short d_reclen; - char d_name[1]; -}; + /* If this is the first entry in the buffer, we can report the + error. */ + if (count == 0) + { + __set_errno (EOVERFLOW); + return -1; + } + + /* Otherwise, seek to the overflowing entry, so that the next call + will report the error, and return the data read so far.. */ + if (__lseek64 (fd, offset, SEEK_SET) != 0) + return -1; + return count; +} ssize_t __old_getdents64 (int fd, char *buf, size_t nbytes) { - ssize_t retval = INLINE_SYSCALL_CALL (getdents, fd, buf, nbytes); + /* We do not move the individual directory entries. This is only + possible if the target type (struct __old_dirent64) is smaller + than the source type. */ + _Static_assert (offsetof (struct __old_dirent64, d_name) + <= offsetof (struct dirent64, d_name), + "__old_dirent64 is larger than dirent64"); + _Static_assert (__alignof__ (struct __old_dirent64) + <= __alignof__ (struct dirent64), + "alignment of __old_dirent64 is larger than dirent64"); - /* The kernel added the d_type value after the name. Change this now. */ - if (retval != -1) + ssize_t retval = INLINE_SYSCALL_CALL (getdents64, fd, buf, nbytes); + if (retval > 0) { - union - { - struct compat_linux_dirent k; - struct dirent u; - } *kbuf = (void *) buf; - - while ((char *) kbuf < buf + retval) + char *p = buf; + char *end = buf + retval; + while (p < end) { - char d_type = *((char *) kbuf + kbuf->k.d_reclen - 1); - memmove (kbuf->u.d_name, kbuf->k.d_name, - strlen (kbuf->k.d_name) + 1); - kbuf->u.d_type = d_type; + struct dirent64 *source = (struct dirent64 *) p; + + /* Copy out the fixed-size data. */ + __ino_t ino = source->d_ino; + __off64_t offset = source->d_off; + unsigned int reclen = source->d_reclen; + unsigned char type = source->d_type; + + /* Check for ino_t overflow. */ + if (__glibc_unlikely (ino != source->d_ino)) + return handle_overflow (fd, offset, p - buf); + + /* Convert to the target layout. Use a separate struct and + memcpy to side-step aliasing issues. */ + struct __old_dirent64 result; + result.d_ino = ino; + result.d_off = offset; + result.d_reclen = reclen; + result.d_type = type; + + /* Write the fixed-sized part of the result to the + buffer. */ + size_t result_name_offset = offsetof (struct __old_dirent64, d_name); + memcpy (p, &result, result_name_offset); + + /* Adjust the position of the name if necessary. Copy + everything until the end of the record, including the + terminating NUL byte. */ + if (result_name_offset != offsetof (struct dirent64, d_name)) + memmove (p + result_name_offset, source->d_name, + reclen - offsetof (struct dirent64, d_name)); - kbuf = (void *) ((char *) kbuf + kbuf->k.d_reclen); + p += reclen; } } return retval; diff --git a/sysdeps/unix/sysv/linux/tst-readdir64-compat.c b/sysdeps/unix/sysv/linux/tst-readdir64-compat.c new file mode 100644 index 0000000000..43c4a8477c --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-readdir64-compat.c @@ -0,0 +1,111 @@ +/* Test readdir64 compatibility symbol. + Copyright (C) 2018 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 <dlfcn.h> +#include <errno.h> +#include <shlib-compat.h> +#include <stdbool.h> +#include <stdio.h> +#include <string.h> +#include <support/check.h> + +/* Copied from <olddirent.h>. */ +struct __old_dirent64 + { + __ino_t d_ino; + __off64_t d_off; + unsigned short int d_reclen; + unsigned char d_type; + char d_name[256]; + }; + +typedef struct __old_dirent64 *(*compat_readdir64_type) (DIR *); + +#if TEST_COMPAT (libc, GLIBC_2_1, GLIBC_2_2) +struct __old_dirent64 *compat_readdir64 (DIR *); +compat_symbol_reference (libc, compat_readdir64, readdir64, GLIBC_2_1); +#endif + +static int +do_test (void) +{ +#if TEST_COMPAT (libc, GLIBC_2_1, GLIBC_2_2) + + /* Directory stream using the non-compat readdir64 symbol. The test + checks against this. */ + DIR *dir_reference = opendir ("."); + TEST_VERIFY_EXIT (dir_reference != NULL); + DIR *dir_test = opendir ("."); + TEST_VERIFY_EXIT (dir_test != NULL); + + /* This loop assumes that the enumeration order is consistent for + two different handles. Nothing should write to the current + directory (in the source tree) while this test runs, so there + should not be any difference due to races. */ + size_t count = 0; + while (true) + { + errno = 0; + struct dirent64 *entry_reference = readdir64 (dir_reference); + if (entry_reference == NULL && errno != 0) + FAIL_EXIT1 ("readdir64 entry %zu: %m\n", count); + struct __old_dirent64 *entry_test = compat_readdir64 (dir_test); + if (entry_reference == NULL) + { + if (errno == EOVERFLOW) + { + TEST_VERIFY (entry_reference->d_ino + != (__ino_t) entry_reference->d_ino); + printf ("info: inode number overflow at entry %zu\n", count); + break; + } + if (errno != 0) + FAIL_EXIT1 ("compat readdir64 entry %zu: %m\n", count); + } + + /* Check that both streams end at the same time. */ + if (entry_reference == NULL) + { + TEST_VERIFY (entry_test == NULL); + break; + } + else + TEST_VERIFY_EXIT (entry_test != NULL); + + /* Check that the entries are the same. */ + TEST_COMPARE_BLOB (entry_reference->d_name, + strlen (entry_reference->d_name), + entry_test->d_name, strlen (entry_test->d_name)); + TEST_COMPARE (entry_reference->d_ino, entry_test->d_ino); + TEST_COMPARE (entry_reference->d_off, entry_test->d_off); + TEST_COMPARE (entry_reference->d_type, entry_test->d_type); + TEST_COMPARE (entry_reference->d_reclen, entry_test->d_reclen); + + ++count; + } + printf ("info: %zu directory entries found\n", count); + TEST_VERIFY (count >= 3); /* ".", "..", and some source files. */ + + TEST_COMPARE (closedir (dir_test), 0); + TEST_COMPARE (closedir (dir_reference), 0); +#endif + return 0; +} + +#include <support/test-driver.c> |