# [PATCH] xsize_t: check whether we lose bits 1 messages from 2010-07-28 to 2010-07-28. Participants: Thomas Rast. Thread: https://gitlist.dev/t/24560 ## Thomas Rast, 2010-07-28 16:36 Subject: [PATCH] xsize_t: check whether we lose bits Message-ID: URL: https://gitlist.dev/e/a619b6d672b4d01ce4107566267ba9b67904652b.1280334553.git.trast%40student.ethz.ch ``` Attempting to mmap (via git-add or similar) a file larger than 4GB on 32-bit Linux systems results in a repository that has only the file modulo 4GB stored, because of truncation of the off_t file size to a size_t for mmap. When xsize_t was introduced to handle this truncation in dc49cd7 (Cast 64 bit off_t to 32 bit size_t, 2007-03-06), Shawn even pointed out that it should detect when such a cutoff happens. Make it so. Signed-off-by: Thomas Rast --- Of course this does not fix the underlying issue that we want to mmap the file, so you still cannot add them. Also, I must be missing something, this patch is way too simple. git-compat-util.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/git-compat-util.h b/git-compat-util.h index 02a73ee..fe845ae 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -388,6 +388,8 @@ extern int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1); static inline size_t xsize_t(off_t len) { + if (len > (size_t) len) + die("Cannot handle files this big"); return (size_t)len; } -- 1.7.2.349.gd5452 ```