FreeChainXenon/binutils-gdb
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Use make_tempname file descriptor in smart_rename

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This patch makes use of the temp file descriptor in smart_rename
rather than reopening the file.  I don't believe there is a security
issue in reopening the file, but this way is one less directory
operation.  The patch also attempts to preserve S_ISUID and S_ISGID.

	PR 27456
	* bucomm.h (smart_rename): Update prototype.
	* rename.c (smart_rename): Add fromfd and preserve_dates params.
	Pass fromfd and target_stat to simple_copy.  Call set_times
	when preserve_dates.
	(simple_copy): Accept fromfd rather than from filename.  Add
	target_stat param.  Rewind fromfd rather than opening.  Open
	"to" file without O_CREAT.  Try to preserve S_ISUID and S_ISGID.
	* ar.c (write_archive): Rename ofd to tmpfd.  Dup tmpfd before
	closing output temp file, and pass tmpfd to smart_rename.
	* arsup.c (temp_fd): Rename from real_fd.
	(ar_save): Dup temp_fd and pass to smart_rename.
	* objcopy.c (strip_main, copy_main): Likewise, and pass
	preserve_dates.
This commit is contained in:
Alan Modra 2021-02-23 12:10:58 +10:30
parent cca8873dd5
commit c42c71a152
6 changed files with 83 additions and 35 deletions
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35
binutils/rename.c
View file

@ -31,24 +31,21 @@
/* The number of bytes to copy at once. */
#define COPY_BUF 8192
/* Copy file FROM to file TO, performing no translations.
/* Copy file FROMFD to file TO, performing no translations.
Return 0 if ok, -1 if error. */
static int
simple_copy (const char *from, const char *to)
simple_copy (int fromfd, const char *to, struct stat *target_stat)
{
int fromfd, tofd, nread;
int tofd, nread;
int saved;
char buf[COPY_BUF];
fromfd = open (from, O_RDONLY | O_BINARY);
if (fromfd < 0)
if (fromfd < 0
|| lseek (fromfd, 0, SEEK_SET) != 0)
return -1;
#ifdef O_CREAT
tofd = open (to, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0777);
#else
tofd = creat (to, 0777);
#endif
tofd = open (to, O_WRONLY | O_TRUNC | O_BINARY);
if (tofd < 0)
{
saved = errno;
@ -56,6 +53,7 @@ simple_copy (const char *from, const char *to)
errno = saved;
return -1;
}
while ((nread = read (fromfd, buf, sizeof buf)) > 0)
{
if (write (tofd, buf, nread) != nread)
@ -67,7 +65,16 @@ simple_copy (const char *from, const char *to)
return -1;
}
}
saved = errno;
#if !defined (_WIN32) || defined (__CYGWIN32__)
/* Writing to a setuid/setgid file may clear S_ISUID and S_ISGID.
Try to restore them, ignoring failure. */
if (target_stat != NULL)
fchmod (tofd, target_stat->st_mode);
#endif
close (fromfd);
close (tofd);
if (nread < 0)
@ -118,17 +125,17 @@ set_times (const char *destination, const struct stat *statbuf)
various systems. So now we just copy. */
int
smart_rename (const char *from, const char *to,
struct stat *target_stat)
smart_rename (const char *from, const char *to, int fromfd,
struct stat *target_stat, bfd_boolean preserve_dates)
{
int ret;
ret = simple_copy (from, to);
ret = simple_copy (fromfd, to, target_stat);
if (ret != 0)
non_fatal (_("unable to copy file '%s'; reason: %s"),
to, strerror (errno));
if (target_stat != NULL)
if (preserve_dates)
set_times (to, target_stat);
unlink (from);