From: René Scharfe <l.s.r@web.de>
Date: Sat, 21 Aug 2021 12:52:40 +0000 (+0200)
Subject: compat: let git_mmap use malloc(3) directly
X-Git-Tag: v2.33.1~29^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=95b4ff3931064ff222e87eecf6af504ba55069d7;p=thirdparty%2Fgit.git

compat: let git_mmap use malloc(3) directly

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.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

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;