| Message ID | 20181104104356.18120-1-egtvedt@samfundet.no (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: use memmove to avoid strncpy on overlapping strings | expand |
Hi Hans-Christian, Le dim. 4 nov. 2018 à 12:29, Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> a écrit : > > Using GCC 8.2.0 I see the following error. > > /usr/bin/gcc-8 -Wall -Werror -Wuninitialized -Wundef -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -g -O2 -Wp,-MMD,./.lsmmc.o.d,-MT,lsmmc.o -c lsmmc.c -o lsmmc.o > In file included from /usr/include/string.h:494, > from lsmmc.c:46: > In function ‘strncpy’, > inlined from ‘read_file’ at lsmmc.c:356:3: > /usr/include/x86_64-linux-gnu/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)); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > Makefile:36: recipe for target 'lsmmc.o' failed > make: *** [lsmmc.o] Error 1 > > Hence replace the strncpy with memmove, since using strncpy on > overlapping strings is not allowed. > > Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> > --- > lsmmc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lsmmc.c b/lsmmc.c > index c4faa00..7637198 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); Post the same patch a week ago : https://patchwork.kernel.org/patch/10654531/ Could you add your review ? Thanks, Clement > > > return strdup(line); > } > -- > 2.17.1 > >
Around Mon 05 Nov 2018 08:15:50 +0100 or thereabout, Clément Péron wrote: Hello Clément, > Le dim. 4 nov. 2018 à 12:29, Hans-Christian Noren Egtvedt > <egtvedt@samfundet.no> a écrit : >> >> Using GCC 8.2.0 I see the following error. >> >> /usr/bin/gcc-8 -Wall -Werror -Wuninitialized -Wundef -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -g -O2 -Wp,-MMD,./.lsmmc.o.d,-MT,lsmmc.o -c lsmmc.c -o lsmmc.o >> In file included from /usr/include/string.h:494, >> from lsmmc.c:46: >> In function ‘strncpy’, >> inlined from ‘read_file’ at lsmmc.c:356:3: >> /usr/include/x86_64-linux-gnu/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)); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> cc1: all warnings being treated as errors >> Makefile:36: recipe for target 'lsmmc.o' failed >> make: *** [lsmmc.o] Error 1 >> >> Hence replace the strncpy with memmove, since using strncpy on >> overlapping strings is not allowed. >> >> Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> >> --- >> lsmmc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/lsmmc.c b/lsmmc.c >> index c4faa00..7637198 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); > > > Post the same patch a week ago : https://patchwork.kernel.org/patch/10654531/ > > Could you add your review ? That looks good by me, however I could not immediate figure out how to ack a patch in patchwork. I even tried creating an account. <snipp>
Hi Hans-Christian On Mon, 5 Nov 2018 at 16:29, Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> wrote: > > Around Mon 05 Nov 2018 08:15:50 +0100 or thereabout, Clément Péron wrote: > > Hello Clément, > > > Le dim. 4 nov. 2018 à 12:29, Hans-Christian Noren Egtvedt > > <egtvedt@samfundet.no> a écrit : > >> > >> Using GCC 8.2.0 I see the following error. > >> > >> /usr/bin/gcc-8 -Wall -Werror -Wuninitialized -Wundef -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -g -O2 -Wp,-MMD,./.lsmmc.o.d,-MT,lsmmc.o -c lsmmc.c -o lsmmc.o > >> In file included from /usr/include/string.h:494, > >> from lsmmc.c:46: > >> In function ‘strncpy’, > >> inlined from ‘read_file’ at lsmmc.c:356:3: > >> /usr/include/x86_64-linux-gnu/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)); > >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> cc1: all warnings being treated as errors > >> Makefile:36: recipe for target 'lsmmc.o' failed > >> make: *** [lsmmc.o] Error 1 > >> > >> Hence replace the strncpy with memmove, since using strncpy on > >> overlapping strings is not allowed. > >> > >> Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> > >> --- > >> lsmmc.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/lsmmc.c b/lsmmc.c > >> index c4faa00..7637198 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); > > > > > > Post the same patch a week ago : https://patchwork.kernel.org/patch/10654531/ > > > > Could you add your review ? > > That looks good by me, however I could not immediate figure out how to ack a > patch in patchwork. I even tried creating an account. I thought you were a subscriber of the linux-mmc ML. Patchwork is more a patch viewer/manager, you should subscribe to the linux-mmc ML to be able to reply and add your tags. I will add you in the next refresh, Regards, Clement > > <snipp> > > -- > mvh > Hans-Christian Noren Egtvedt
Around Mon 05 Nov 2018 17:12:21 +0100 or thereabout, Clément Péron wrote: Hello Clément, > On Mon, 5 Nov 2018 at 16:29, Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> wrote: >> Around Mon 05 Nov 2018 08:15:50 +0100 or thereabout, Clément Péron wrote: >> > Le dim. 4 nov. 2018 à 12:29, Hans-Christian Noren Egtvedt >> > <egtvedt@samfundet.no> a écrit : <snipp patch> >> > Post the same patch a week ago : https://patchwork.kernel.org/patch/10654531/ >> > >> > Could you add your review ? >> >> That looks good by me, however I could not immediate figure out how to ack a >> patch in patchwork. I even tried creating an account. > > I thought you were a subscriber of the linux-mmc ML. No, sorry, I did not plan to subscribe to the linux-mmc mailing list. The mmc-util works well for me, with exception to this minor change required for GCC 8 compilation. > Patchwork is more a patch viewer/manager, you should subscribe to the > linux-mmc ML to be able to reply and add your tags. If you bounce the original patch email to me, I can reply to it. > I will add you in the next refresh, > Thanks.
diff --git a/lsmmc.c b/lsmmc.c index c4faa00..7637198 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); }
Using GCC 8.2.0 I see the following error. /usr/bin/gcc-8 -Wall -Werror -Wuninitialized -Wundef -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -g -O2 -Wp,-MMD,./.lsmmc.o.d,-MT,lsmmc.o -c lsmmc.c -o lsmmc.o In file included from /usr/include/string.h:494, from lsmmc.c:46: In function ‘strncpy’, inlined from ‘read_file’ at lsmmc.c:356:3: /usr/include/x86_64-linux-gnu/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)); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Makefile:36: recipe for target 'lsmmc.o' failed make: *** [lsmmc.o] Error 1 Hence replace the strncpy with memmove, since using strncpy on overlapping strings is not allowed. Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> --- lsmmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)