[dpdk-dev] [PATCH v4 1/1] eal: fix resource leak of mapped memory

[Marcin Kerlin <marcinx.kerlin@intel.com>]

Patch fixes resource leak in rte_eal_hugepage_attach() where mapped files
were not freed back to the OS in case of failure. Patch uses the behavior
of Linux munmap: "It is not an error if the indicated range does not
contain any mapped pages".

v4:
1)removed keyword const from pointer and dependent on that casting (void *) 
v3:
1)removed redundant casting
2)removed update error message
v2:
1)unmapping also previous addresses

Coverity issue: 13295, 13296, 13303
Fixes: af75078fece3 ("first public release")

Signed-off-by: Marcin Kerlin <marcinx.kerlin@intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_memory.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 79d1d2d..c935765 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -1399,7 +1399,7 @@ int
 rte_eal_hugepage_attach(void)
 {
 	const struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
-	const struct hugepage_file *hp = NULL;
+	struct hugepage_file *hp = NULL;
 	unsigned num_hp = 0;
 	unsigned i, s = 0; /* s used to track the segment number */
 	off_t size;
@@ -1481,7 +1481,7 @@ rte_eal_hugepage_attach(void)
 
 	size = getFileSize(fd_hugepage);
 	hp = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd_hugepage, 0);
-	if (hp == NULL) {
+	if (hp == MAP_FAILED) {
 		RTE_LOG(ERR, EAL, "Could not mmap %s\n", eal_hugepage_info_path());
 		goto error;
 	}
@@ -1545,12 +1545,19 @@ rte_eal_hugepage_attach(void)
 		s++;
 	}
 	/* unmap the hugepage config file, since we are done using it */
-	munmap((void *)(uintptr_t)hp, size);
+	munmap(hp, size);
 	close(fd_zero);
 	close(fd_hugepage);
 	return 0;
 
 error:
+	s = 0;
+	while (s < RTE_MAX_MEMSEG && mcfg->memseg[s].len > 0) {
+		munmap(mcfg->memseg[s].addr, mcfg->memseg[s].len);
+		s++;
+	}
+	if (hp != NULL && hp != MAP_FAILED)
+		munmap(hp, size);
 	if (fd_zero >= 0)
 		close(fd_zero);
 	if (fd_hugepage >= 0)
-- 
1.9.1