Re: Results of static analysis with clang static analyser

[Szabolcs Nagy <nsz@port70.net>]

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* Khem Raj <raj.khem@gmail.com> [2015-09-22 22:58:55 -0700]:
> I have run scan-build on musl-git and here are results
> 
> http://busybox.net/~kraj/scan-build-2015-09-22-224330-15962-1/

not a bug, but i'd fix this one:

http://busybox.net/~kraj/scan-build-2015-09-22-224330-15962-1/report-15c463.html#EndPath


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From da5379205664d62b56acd8f40c405f2b91703afd Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <nsz@port70.net>
Date: Wed, 23 Sep 2015 20:22:33 +0000
Subject: [PATCH] cosmetic fix: avoid reading uninitialized memory in
 __map_file

The value of *size is not relevant in case of failure, but it's
better not to copy garbage from the stack into it.
(The compiler cannot see through the syscall, so optimization
was not affected by the unspecified value).
---
 src/time/__map_file.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/time/__map_file.c b/src/time/__map_file.c
index d06a581..b91eb8e 100644
--- a/src/time/__map_file.c
+++ b/src/time/__map_file.c
@@ -11,9 +11,10 @@ const char unsigned *__map_file(const char *pathname, size_t *size)
 	const unsigned char *map = MAP_FAILED;
 	int fd = __sys_open(pathname, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 	if (fd < 0) return 0;
-	if (!__syscall(SYS_fstat, fd, &st))
+	if (!__syscall(SYS_fstat, fd, &st)) {
 		map = __mmap(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+		*size = st.st_size;
+	}
 	__syscall(SYS_close, fd);
-	*size = st.st_size;
 	return map == MAP_FAILED ? 0 : map;
 }
-- 
2.4.1