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-rw-r--r--locale/loadarchive.c78
1 files changed, 42 insertions, 36 deletions
diff --git a/locale/loadarchive.c b/locale/loadarchive.c
index 59ac916e29..845b9b0774 100644
--- a/locale/loadarchive.c
+++ b/locale/loadarchive.c
@@ -41,6 +41,10 @@
/* Name of the locale archive file. */
static const char archfname[] = LOCALEDIR "/locale-archive";
+/* Size of initial mapping window, optimal if large enough to
+ cover the header plus the initial locale. */
+#define ARCHIVE_MAPPING_WINDOW (2 * 1024 * 1024)
+
/* Record of contiguous pages already mapped from the locale archive. */
struct archmapped
@@ -174,6 +178,9 @@ _nl_load_locale_from_archive (int category, const char **namep)
/* Make sure the archive is loaded. */
if (archmapped == NULL)
{
+ void *result;
+ size_t headsize, mapsize;
+
/* We do this early as a sign that we have tried to open the archive.
If headmap.ptr remains null, that's an indication that we tried
and failed, so we won't try again. */
@@ -193,49 +200,48 @@ _nl_load_locale_from_archive (int category, const char **namep)
return NULL;
}
- if (sizeof (void *) > 4)
- {
- /* We will just map the whole file, what the hell. */
- void *result = __mmap64 (NULL, archive_stat.st_size,
- PROT_READ, MAP_SHARED, fd, 0);
- if (result == MAP_FAILED)
- goto close_and_out;
- /* Check whether the file is large enough for the sizes given in the
- header. */
- if (calculate_head_size ((const struct locarhead *) result)
- > archive_stat.st_size)
- {
- (void) __munmap (result, archive_stat.st_size);
- goto close_and_out;
- }
- __close (fd);
- fd = -1;
- headmap.ptr = result;
- /* headmap.from already initialized to zero. */
- headmap.len = archive_stat.st_size;
- }
- else
- {
- struct locarhead head;
- off_t head_size;
- void *result;
+ /* Map an initial window probably large enough to cover the header
+ and the first locale's data. With a large address space, we can
+ just map the whole file and be sure everything is covered. */
- if (TEMP_FAILURE_RETRY (__read (fd, &head, sizeof (head)))
- != sizeof (head))
- goto close_and_out;
- head_size = calculate_head_size (&head);
- if (head_size > archive_stat.st_size)
+ mapsize = (sizeof (void *) > 4 ? archive_stat.st_size
+ : MAX (archive_stat.st_size, ARCHIVE_MAPPING_WINDOW));
+
+ result = __mmap64 (NULL, mapsize, PROT_READ, MAP_SHARED, fd, 0);
+ if (result == MAP_FAILED)
+ goto close_and_out;
+
+ /* Check whether the file is large enough for the sizes given in
+ the header. Theoretically an archive could be so large that
+ just the header fails to fit in our initial mapping window. */
+ headsize = calculate_head_size ((const struct locarhead *) result);
+ if (headsize > mapsize)
+ {
+ (void) __munmap (result, mapsize);
+ if (sizeof (void *) > 4 || headsize > archive_stat.st_size)
+ /* The file is not big enough for the header. Bogus. */
goto close_and_out;
- result = __mmap64 (NULL, head_size, PROT_READ, MAP_SHARED, fd, 0);
+
+ /* Freakishly long header. */
+ /* XXX could use mremap when available */
+ mapsize = (headsize + ps - 1) & ~(ps - 1);
+ result = __mmap64 (NULL, mapsize, PROT_READ, MAP_SHARED, fd, 0);
if (result == MAP_FAILED)
goto close_and_out;
+ }
- /* Record that we have mapped the initial pages of the file. */
- headmap.ptr = result;
- headmap.len = MIN ((head_size + ps - 1) & ~(ps - 1),
- archive_stat.st_size);
+ if (sizeof (void *) > 4 || mapsize >= archive_stat.st_size)
+ {
+ /* We've mapped the whole file already, so we can be
+ sure we won't need this file descriptor later. */
+ __close (fd);
+ fd = -1;
}
+
+ headmap.ptr = result;
+ /* headmap.from already initialized to zero. */
+ headmap.len = mapsize;
}
/* If there is no archive or it cannot be loaded for some reason fail. */