From: Tobias Stoeckmann Date: Sun, 25 Feb 2018 19:27:18 +0000 (+0100) Subject: fincore: Handle large files correctly on 32 bit X-Git-Tag: v2.32-rc2~11 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ea62c152766ff22038630c9afdeb1df5dcc044cb;p=thirdparty%2Futil-linux.git fincore: Handle large files correctly on 32 bit If a file is larger than 4 GB on a 32 bit system with large file support (default), it can happen that not all pages are properly processed. This happens due to an int truncation (off_t vs size_t). You can reproduce this on 32 bit with these commands: $ dd if=/dev/zero of=4gb-file seek=4294967295 count=1 bs=1 $ fincore 4gb-file fincore: failed to do mmap: 4gb-file: Invalid argument If a file is larger than 4 GB, the first few pages of a file won't be properly processed. "len" will be smaller than window_size, but the for-loop iterates "window_size" bytes, skipping some pages. Signed-off-by: Tobias Stoeckmann --- diff --git a/misc-utils/fincore.c b/misc-utils/fincore.c index 4641408f89..ab11594cc7 100644 --- a/misc-utils/fincore.c +++ b/misc-utils/fincore.c @@ -199,11 +199,11 @@ static int fincore_fd (struct fincore_control *ctl, int warned_once = 0; for (file_offset = 0; file_offset < file_size; file_offset += window_size) { - size_t len; + off_t len; void *window = NULL; len = file_size - file_offset; - if (len >= window_size) + if (len >= (off_t) window_size) len = window_size; window = mmap(window, len, PROT_NONE, MAP_PRIVATE, fd, file_offset);