diff options
Diffstat (limited to 'locale/loadarchive.c')
| -rw-r--r-- | locale/loadarchive.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/locale/loadarchive.c b/locale/loadarchive.c index e32e8c7648..d25334a7fd 100644 --- a/locale/loadarchive.c +++ b/locale/loadarchive.c @@ -45,6 +45,19 @@ static const char archfname[] = LOCALEDIR "/locale-archive"; cover the header plus the initial locale. */ #define ARCHIVE_MAPPING_WINDOW (2 * 1024 * 1024) +#ifndef MAP_COPY +/* This is not quite as good as MAP_COPY since unexamined pages + can change out from under us and give us inconsistent data. + But we rely on the user not to diddle the system's live archive. + Even though we only ever use PROT_READ, using MAP_SHARED would + not give the system sufficient freedom to e.g. let the on disk + file go away because it doesn't know we won't call mprotect later. */ +# define MAP_COPY MAP_PRIVATE +#endif +#ifndef MAP_FILE + /* Some systems do not have this flag; it is superfluous. */ +# define MAP_FILE 0 +#endif /* Record of contiguous pages already mapped from the locale archive. */ struct archmapped @@ -208,7 +221,7 @@ _nl_load_locale_from_archive (int category, const char **namep) mapsize = (sizeof (void *) > 4 ? archive_stat.st_size : MIN (archive_stat.st_size, ARCHIVE_MAPPING_WINDOW)); - result = __mmap64 (NULL, mapsize, PROT_READ, MAP_SHARED, fd, 0); + result = __mmap64 (NULL, mapsize, PROT_READ, MAP_FILE|MAP_COPY, fd, 0); if (result == MAP_FAILED) goto close_and_out; @@ -226,7 +239,8 @@ _nl_load_locale_from_archive (int category, const char **namep) /* 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); + result = __mmap64 (NULL, mapsize, PROT_READ, MAP_FILE|MAP_COPY, + fd, 0); if (result == MAP_FAILED) goto close_and_out; } @@ -357,20 +371,21 @@ _nl_load_locale_from_archive (int category, const char **namep) upper = cnt; do { + to = ranges[upper].from + ranges[upper].len; + if (to > archive_stat.st_size) + /* The archive locrectab contains bogus offsets. */ + return NULL; + to = (to + ps - 1) & ~(ps - 1); + /* If a range is already mmaped in, stop. */ if (mapped != NULL && ranges[upper].from >= mapped->from) break; - to = ((ranges[upper].from + ranges[upper].len + ps - 1) - & ~(ps - 1)); + ++upper; } /* Loop while still in contiguous pages. */ while (upper < nranges && ranges[upper].from < to + ps); - if (to > archive_stat.st_size) - /* The archive locrectab contains bogus offsets. */ - return NULL; - /* Open the file if it hasn't happened yet. */ if (fd == -1) { @@ -391,7 +406,8 @@ _nl_load_locale_from_archive (int category, const char **namep) } /* Map the range from the archive. */ - addr = __mmap64 (NULL, to - from, PROT_READ, MAP_SHARED, fd, from); + addr = __mmap64 (NULL, to - from, PROT_READ, MAP_FILE|MAP_COPY, + fd, from); if (addr == MAP_FAILED) return NULL; |