From 831372e7c1bb907f9f2c3d78909b15717b8ac095 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 28 Jan 1997 03:59:29 +0000 Subject: update from main archive 970127 1997-01-28 04:23 Ulrich Drepper * version.h (VERSION): Bump to 2.0.1. * posix/getopt.c: Handle another problem introduced by the nonoption_flags array. We must be able to work with reordered argv arrays. Reported by Andreas Schwab. 1997-01-28 02:38 Ulrich Drepper * sysdeps/unix/sysv/linux/i386/clone.S: Correct handling of new 1997-01-27 17:34 Thorsten Kukuk * nis/rpcsvc/yp_prot.h: Correct definitions and types in file so that it works with yp.h. 1997-01-27 13:28 Ulrich Drepper * malloc/malloc.h (__malloc_initialized) [_LIBC]: Define as __libc_malloc_initialized so that this variable is not shared with other users of GNU malloc. Suggested by Martin von Loewis . * mcheck.h: Correct typo. Use malloc/ instead of new-malloc/. * sysdeps/i386/Makefile (CFLAGS-dl-load.c, CFLAGS-dl-reloc.c): New variables to prevent warnings. * sysdeps/i386/dl-machine.h (fixup): Add prototype and declare using attribute regparm. (ELF_MACHINE_RUNTIME_TRAMPOLINE): Rewrite so that no register is changed by the resolver code. 1997-01-14 14:20 Andreas Schwab * malloc/malloc.c (weak_variable): Define. (__malloc_initialize_hook, __free_hook, __malloc_hook, __realloc_hook, __memalign_hook): Make them weak definitions. 1997-01-26 11:35 Andreas Schwab * sysdeps/unix/sysv/linux/getdents.c: Don't write beyond buffer limits, correctly take structure padding into account, use correct offset when resetting the stream, change heuristic to assume an average name length of 14 characters. 1997-01-25 18:06 Andreas Schwab * sysdeps/unix/sysv/linux/alpha/termbits.h: Protect against multiple inclusion. See ChangeLog.6 for earlier changes. --- sysdeps/unix/sysv/linux/getdents.c | 45 ++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 19 deletions(-) (limited to 'sysdeps/unix/sysv/linux/getdents.c') diff --git a/sysdeps/unix/sysv/linux/getdents.c b/sysdeps/unix/sysv/linux/getdents.c index 40b31617ef..b4b12d48eb 100644 --- a/sysdeps/unix/sysv/linux/getdents.c +++ b/sysdeps/unix/sysv/linux/getdents.c @@ -49,11 +49,11 @@ struct kernel_dirent /* The problem here is that we cannot simply read the next NBYTES bytes. We need to take the additional field into account. We use - some heuristic. Assume the directory contains names with at least - 3 characters we can compute a maximum number of entries which fit - in the buffer. Taking this number allows us to specify a correct - number of bytes to read. If we should be wrong, we can reset the - file descriptor. */ + some heuristic. Assuming the directory contains names with 14 + characters on average we can compute an estimate number of entries + which fit in the buffer. Taking this number allows us to specify a + correct number of bytes to read. If we should be wrong, we can reset + the file descriptor. */ ssize_t __getdirentries (fd, buf, nbytes, basep) int fd; @@ -62,12 +62,16 @@ __getdirentries (fd, buf, nbytes, basep) off_t *basep; { off_t base = __lseek (fd, (off_t) 0, SEEK_CUR); + off_t last_offset = base; size_t red_nbytes; struct kernel_dirent *skdp, *kdp; struct dirent *dp; int retval; + const size_t size_diff = (offsetof (struct dirent, d_name) + - offsetof (struct kernel_dirent, d_name)); - red_nbytes = nbytes - (nbytes / (offsetof (struct dirent, d_name) + 3)); + red_nbytes = nbytes - ((nbytes / (offsetof (struct dirent, d_name) + 14)) + * size_diff); dp = (struct dirent *) buf; skdp = kdp = __alloca (red_nbytes); @@ -76,26 +80,29 @@ __getdirentries (fd, buf, nbytes, basep) while ((char *) kdp < (char *) skdp + retval) { - const size_t size_diff = MAX (offsetof (struct dirent, d_name) - - offsetof (struct kernel_dirent, d_name), - __alignof__ (struct dirent)); + const size_t alignment = __alignof__ (struct dirent); + /* Since kdp->d_reclen is already aligned for the kernel structure + this may compute a value that is bigger than necessary. */ + size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1) + & ~(alignment - 1)); + if ((char *) dp + new_reclen > buf + nbytes) + { + /* Our heuristic failed. We read too many entries. Reset + the stream. */ + __lseek (fd, last_offset, SEEK_SET); + break; + } + + last_offset = kdp->d_off; dp->d_ino = kdp->d_ino; dp->d_off = kdp->d_off; - dp->d_reclen = kdp->d_reclen + size_diff; + dp->d_reclen = new_reclen; dp->d_type = DT_UNKNOWN; memcpy (dp->d_name, kdp->d_name, kdp->d_reclen - offsetof (struct kernel_dirent, d_name)); - dp = (struct dirent *) (((char *) dp) + dp->d_reclen); + dp = (struct dirent *) ((char *) dp + new_reclen); kdp = (struct kernel_dirent *) (((char *) kdp) + kdp->d_reclen); - - if ((char *) dp >= buf + nbytes) - { - /* Our heuristic failed. We read too many entries. Reset - the stream. */ - off_t used = ((char *) kdp - (char *) buf) - (nbytes - red_nbytes); - base = __lseek (fd, retval - used, SEEK_CUR); - } } if (basep) -- cgit v1.2.3