lsmmc: replace strncpy with memmove on overlapping memory copy

Message ID 20180405170141.31075-1-raj.khem@gmail.com
State New
Headers show
Series
  • lsmmc: replace strncpy with memmove on overlapping memory copy
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Commit Message

Khem Raj April 5, 2018, 5:01 p.m.
here source and destination addresses are overlapping so using memmove is
going to be more efficient.

Additionally, the bounded size for copy is overflowing for first copy

In function 'strncpy',
    inlined from 'read_file' at lsmmc.c:356:3:
/mnt/a/oe/build/tmp/work/cortexa7t2hf-neon-vfpv4-bec-linux-gnueabi/mmc-utils/0.1-r0/recipe-sysroot/usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' accessing 4096 bytes at offsets 0 and 1 overlaps 4095 bytes at offset 1 [-Werror=restrict]
   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Khem Raj <raj.khem@gmail.com>

---
 lsmmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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Patch

diff --git a/lsmmc.c b/lsmmc.c
index c4faa00..bcb854d 100644
--- a/lsmmc.c
+++ b/lsmmc.c
@@ -353,7 +353,7 @@  char *read_file(char *name)
 		line[strlen(line) - 1] = '\0';
 
 	while (isspace(line[0]))
-		strncpy(&line[0], &line[1], sizeof(line));
+		memmove(&line[0], &line[1], sizeof(line)-1);
 
 	return strdup(line);
 }