| Message ID | 20180329081914.43509-1-raj.khem@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | lsmmc: replace strncpy with memmove on overlapping memory copy | expand |
On 29 March 2018 at 10:19, Khem Raj <raj.khem@gmail.com> wrote: > 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(-) This git is maintained by Chris Ball. Please re-post adding him in the to-field. Kind regards Uffe > > 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); > } > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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); }
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(-) -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html