* Clang warnings in net/phonet
@ 2019-01-08 2:54 Nathan Chancellor
2019-01-26 8:10 ` Nathan Chancellor
2019-02-19 21:50 ` Arnd Bergmann
0 siblings, 2 replies; 3+ messages in thread
From: Nathan Chancellor @ 2019-01-08 2:54 UTC (permalink / raw)
To: Remi Denis-Courmont, David S. Miller
Cc: netdev, linux-kernel, Nick Desaulniers
Hi all,
When building the kernel with Clang, this warning comes up in net/phonet.
net/phonet/pep.c:224:16: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
ph->data[0] = oph->data[1]; /* CTRL id */
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:281:10: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
switch (hdr->data[1]) {
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:285:12: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
switch (hdr->data[4]) {
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:295:8: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
if (hdr->data[4] == PEP_IND_READY)
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:304:21: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
atomic_add(wake = hdr->data[4], &pn->tx_credits);
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:509:9: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
n_sb = hdr->data[4];
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:817:14: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
peer_type = hdr->other_pep_type << 8;
^ ~~~~~~~~~~~~~~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
net/phonet/pep.c:820:9: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
n_sb = hdr->data[4];
^ ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
u8 data[1];
^
8 warnings generated.
I have taken a look at the effected code but I can't really figure out
the proper fix for this warning (my knowledge of C just isn't there
yet). Nick had suggested changing 'u8 data[1]' to 'u8 *data' in
'struct pnpipehdr', which seems logical but I can't say for sure. Any
advice would be appreciated :)
Thanks,
Nathan
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Clang warnings in net/phonet
2019-01-08 2:54 Clang warnings in net/phonet Nathan Chancellor
@ 2019-01-26 8:10 ` Nathan Chancellor
2019-02-19 21:50 ` Arnd Bergmann
1 sibling, 0 replies; 3+ messages in thread
From: Nathan Chancellor @ 2019-01-26 8:10 UTC (permalink / raw)
To: Rémi Denis-Courmont, Remi Denis-Courmont
Cc: David S. Miller, netdev, linux-kernel, Nick Desaulniers
On Mon, Jan 07, 2019 at 07:54:20PM -0700, Nathan Chancellor wrote:
> Hi all,
>
> When building the kernel with Clang, this warning comes up in net/phonet.
>
> net/phonet/pep.c:224:16: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
> ph->data[0] = oph->data[1]; /* CTRL id */
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:281:10: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
> switch (hdr->data[1]) {
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:285:12: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
> switch (hdr->data[4]) {
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:295:8: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
> if (hdr->data[4] == PEP_IND_READY)
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:304:21: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
> atomic_add(wake = hdr->data[4], &pn->tx_credits);
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:509:9: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
> n_sb = hdr->data[4];
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:817:14: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
> peer_type = hdr->other_pep_type << 8;
> ^ ~~~~~~~~~~~~~~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> net/phonet/pep.c:820:9: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
> n_sb = hdr->data[4];
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
> 8 warnings generated.
>
> I have taken a look at the effected code but I can't really figure out
> the proper fix for this warning (my knowledge of C just isn't there
> yet). Nick had suggested changing 'u8 data[1]' to 'u8 *data' in
> 'struct pnpipehdr', which seems logical but I can't say for sure. Any
> advice would be appreciated :)
>
> Thanks,
> Nathan
Gentle ping?
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Clang warnings in net/phonet
2019-01-08 2:54 Clang warnings in net/phonet Nathan Chancellor
2019-01-26 8:10 ` Nathan Chancellor
@ 2019-02-19 21:50 ` Arnd Bergmann
1 sibling, 0 replies; 3+ messages in thread
From: Arnd Bergmann @ 2019-02-19 21:50 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Remi Denis-Courmont, David S. Miller, Networking,
Linux Kernel Mailing List, Nick Desaulniers
On Tue, Jan 8, 2019 at 3:55 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> Hi all,
>
> When building the kernel with Clang, this warning comes up in net/phonet.
>
> net/phonet/pep.c:224:16: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
> ph->data[0] = oph->data[1]; /* CTRL id */
> ^ ~
> include/net/phonet/pep.h:66:3: note: array 'data' declared here
> u8 data[1];
> ^
>
> I have taken a look at the effected code but I can't really figure out
> the proper fix for this warning (my knowledge of C just isn't there
> yet). Nick had suggested changing 'u8 data[1]' to 'u8 *data' in
> 'struct pnpipehdr', which seems logical but I can't say for sure. Any
> advice would be appreciated :)
>
A pointer wouldn't work here, as this is a network header with a
fixed layout. Using a flexible array at the end of the structure works,
but unfortunately all indices change that way. Sending an experimental
patch.
Arnd
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-01-08 2:54 Clang warnings in net/phonet Nathan Chancellor
2019-01-26 8:10 ` Nathan Chancellor
2019-02-19 21:50 ` Arnd Bergmann
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