From: Pavel Roskin <proski@gnu.org>
To: git <git@vger.kernel.org>
Subject: [PATCH] Use MAP_FAILED instead of double cast
Date: Sun, 03 Jul 2005 23:05:31 -0400 [thread overview]
Message-ID: <1120446331.1265.30.camel@dv> (raw)
Hello!
I have found some really ugly code to used to check the result of
mmap():
if (-1 == (int)(long)map)
return;
Double cast almost always indicates that something fishy is going on.
Indeed, mmap() could (in theory) return 0xffffffff on a 64-bit platform,
and that would be misinterpreted as a failure.
There is a preprocessor symbol MAP_FAILED that should be used instead.
It's used already in some places, so let's use it consistently.
Signed-off-by: Pavel Roskin <proski@gnu.org>
diff --git a/diffcore-order.c b/diffcore-order.c
--- a/diffcore-order.c
+++ b/diffcore-order.c
@@ -28,7 +28,7 @@ static void prepare_order(const char *or
}
map = mmap(NULL, st.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
- if (-1 == (int)(long)map)
+ if (map == MAP_FAILED)
return;
endp = map + st.st_size;
for (pass = 0; pass < 2; pass++) {
diff --git a/local-pull.c b/local-pull.c
--- a/local-pull.c
+++ b/local-pull.c
@@ -54,7 +54,7 @@ int fetch(unsigned char *sha1)
}
map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, ifd, 0);
close(ifd);
- if (-1 == (int)(long)map) {
+ if (map == MAP_FAILED) {
fprintf(stderr, "cannot mmap %s\n", filename);
return -1;
}
diff --git a/read-cache.c b/read-cache.c
--- a/read-cache.c
+++ b/read-cache.c
@@ -376,7 +376,7 @@ int read_cache(void)
map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
}
close(fd);
- if (-1 == (int)(long)map)
+ if (map == MAP_FAILED)
return error("mmap failed");
hdr = map;
diff --git a/sha1_file.c b/sha1_file.c
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -507,7 +507,7 @@ static void *map_sha1_file_internal(cons
}
map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if (-1 == (int)(long)map)
+ if (map == MAP_FAILED)
return NULL;
*size = st.st_size;
return map;
@@ -1293,7 +1293,7 @@ int index_fd(unsigned char *sha1, int fd
if (size)
buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
- if ((int)(long)buf == -1)
+ if (buf == MAP_FAILED)
return -1;
ret = write_sha1_file(buf, size, "blob", sha1);
--
Regards,
Pavel Roskin
reply other threads:[~2005-07-04 3:06 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1120446331.1265.30.camel@dv \
--to=proski@gnu.org \
--cc=git@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).