Re: [PATCH] compat: let git_mmap use malloc(3) directly
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Aug 23, 2021, 20:27 UTC
- Message-ID
- <nycvar.QRO.7.76.6.2108232227140.55@tvgsbejvaqbjf.bet>
- In-Reply-To
- <9c2fe5de-be23-3e66-6edf-3c2edfb804f3@web.de>
Hi René,
On Sat, 21 Aug 2021, René Scharfe wrote:
Show 5 quoted lines
> xmalloc() dies on error, allows zero-sized allocations and enforces > GIT_ALLOC_LIMIT for testing. Our mmap replacement doesn't need any of > that. Let's cut out the wrapper, reject zero-sized requests as required > by POSIX and use malloc(3) directly. Allocation errors were needlessly > handled by git_mmap() before; this code becomes reachable now.
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Thanks! Dscho
Show 27 quoted lines
>
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
> compat/mmap.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/compat/mmap.c b/compat/mmap.c
> index 14d31010df..8d6c02d4bc 100644
> --- a/compat/mmap.c
> +++ b/compat/mmap.c
> @@ -7,7 +7,12 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
> if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ)
> die("Invalid usage of mmap when built with NO_MMAP");
>
> - start = xmalloc(length);
> + if (length == 0) {
> + errno = EINVAL;
> + return MAP_FAILED;
> + }
> +
> + start = malloc(length);
> if (start == NULL) {
> errno = ENOMEM;
> return MAP_FAILED;
> --
> 2.33.0
>