[dpdk-dev] [PATCH] eal: fix compilation when optimization level is O1

[dpdk-dev] [PATCH] eal: fix compilation when optimization level is O1

[Olivier Matz]

When compiled with EXTRA_CFLAGS="-O1", the compiler is not
able to detect that size is always initialized when used, and
issues a wrong warning:

  eal_memory.c: In function ‘rte_eal_hugepage_attach’:
  eal_memory.c:1684:3: error: ‘size’ may be used uninitialized in this
                       function [-Werror=maybe-uninitialized]
     munmap(hp, size);
     ^

Workaround this issue by initializing size to 0.
Seen on gcc (Debian 5.4.1-1) 5.4.1 20160803.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_eal/linuxapp/eal/eal_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 992a1b1..4697fef 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -1545,7 +1545,7 @@ rte_eal_hugepage_attach(void)
 	struct hugepage_file *hp = NULL;
 	unsigned num_hp = 0;
 	unsigned i, s = 0; /* s used to track the segment number */
-	off_t size;
+	off_t size = 0;
 	int fd, fd_zero = -1, fd_hugepage = -1;
 
 	if (aslr_enabled() > 0) {
-- 
2.8.1

Re: [dpdk-dev] [PATCH] eal: fix compilation when optimization level is O1

[Thomas Monjalon]

2016-09-19 14:26, Olivier Matz:
> When compiled with EXTRA_CFLAGS="-O1", the compiler is not
> able to detect that size is always initialized when used, and
> issues a wrong warning:
> 
>   eal_memory.c: In function ‘rte_eal_hugepage_attach’:
>   eal_memory.c:1684:3: error: ‘size’ may be used uninitialized in this
>                        function [-Werror=maybe-uninitialized]
>      munmap(hp, size);
>      ^
> 
> Workaround this issue by initializing size to 0.
> Seen on gcc (Debian 5.4.1-1) 5.4.1 20160803.
> 
> Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

Applied, thanks