net/vmw_vsock/vmci_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
From: Arnd Bergmann <arnd@arndb.de>
The gcc-16.0.1 snapshot produces a false-positive warning that turns
into a build failure with CONFIG_WERROR:
In file included from arch/x86/include/asm/string.h:6,
from net/vmw_vsock/vmci_transport.c:10:
In function 'vmci_transport_packet_init',
inlined from '__vmci_transport_send_control_pkt.constprop' at net/vmw_vsock/vmci_transport.c:198:2:
arch/x86/include/asm/string_32.h:150:25: error: argument 2 null where non-null expected because argument 3 is nonzero [-Werror=nonnull]
150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy'
164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
| ^~~~~~
arch/x86/include/asm/string_32.h:150:25: note: in a call to built-in function '__builtin_memcpy'
net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy'
164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
| ^~~~~~
This seems relatively harmless, and it so far the only instance of this
warning I have found. The __vmci_transport_send_control_pkt function
is called either with wait=NULL or with one of the type values that
pass 'wait' into memcpy() here, but not from the same caller.
Replacing the memcpy with a struct assignment is otherwise the same
but avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
net/vmw_vsock/vmci_transport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 00f6bbdb035a..a64522be1bad 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -161,7 +161,7 @@ vmci_transport_packet_init(struct vmci_transport_packet *pkt,
case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
- memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
+ pkt->u.wait = *wait;
break;
case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2:
--
2.39.5On Tue, Feb 3, 2026 at 4:34 PM Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > The gcc-16.0.1 snapshot produces a false-positive warning that turns > into a build failure with CONFIG_WERROR: > > In file included from arch/x86/include/asm/string.h:6, > from net/vmw_vsock/vmci_transport.c:10: > In function 'vmci_transport_packet_init', > inlined from '__vmci_transport_send_control_pkt.constprop' at net/vmw_vsock/vmci_transport.c:198:2: > arch/x86/include/asm/string_32.h:150:25: error: argument 2 null where non-null expected because argument 3 is nonzero [-Werror=nonnull] > 150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n) > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ > arch/x86/include/asm/string_32.h:150:25: note: in a call to built-in function '__builtin_memcpy' > net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ > > This seems relatively harmless, and it so far the only instance of this > warning I have found. The __vmci_transport_send_control_pkt function > is called either with wait=NULL or with one of the type values that > pass 'wait' into memcpy() here, but not from the same caller. > > Replacing the memcpy with a struct assignment is otherwise the same > but avoids the warning. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > net/vmw_vsock/vmci_transport.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c > index 00f6bbdb035a..a64522be1bad 100644 > --- a/net/vmw_vsock/vmci_transport.c > +++ b/net/vmw_vsock/vmci_transport.c > @@ -161,7 +161,7 @@ vmci_transport_packet_init(struct vmci_transport_packet *pkt, > > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ: > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE: > - memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > + pkt->u.wait = *wait; > break; > > case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2: > -- > 2.39.5 > Reviewed-by: Bryan Tan <bryan-bt.tan@broadcom.com>
On Tue, Feb 03, 2026 at 05:34:00PM +0100, Arnd Bergmann wrote: >From: Arnd Bergmann <arnd@arndb.de> > >The gcc-16.0.1 snapshot produces a false-positive warning that turns >into a build failure with CONFIG_WERROR: > >In file included from arch/x86/include/asm/string.h:6, > from net/vmw_vsock/vmci_transport.c:10: >In function 'vmci_transport_packet_init', > inlined from '__vmci_transport_send_control_pkt.constprop' at net/vmw_vsock/vmci_transport.c:198:2: >arch/x86/include/asm/string_32.h:150:25: error: argument 2 null where non-null expected because argument 3 is nonzero [-Werror=nonnull] > 150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n) > | ^~~~~~~~~~~~~~~~~~~~~~~~~ >net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ >arch/x86/include/asm/string_32.h:150:25: note: in a call to built-in function '__builtin_memcpy' >net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ > >This seems relatively harmless, and it so far the only instance of this >warning I have found. The __vmci_transport_send_control_pkt function >is called either with wait=NULL or with one of the type values that >pass 'wait' into memcpy() here, but not from the same caller. > >Replacing the memcpy with a struct assignment is otherwise the same >but avoids the warning. > >Signed-off-by: Arnd Bergmann <arnd@arndb.de> >--- > net/vmw_vsock/vmci_transport.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Not sure if it's net or net-next material, maybe net to avoid the warning/error on v6.19 too ? Anyway LGTM and thanks for the fix! Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > >diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c >index 00f6bbdb035a..a64522be1bad 100644 >--- a/net/vmw_vsock/vmci_transport.c >+++ b/net/vmw_vsock/vmci_transport.c >@@ -161,7 +161,7 @@ vmci_transport_packet_init(struct vmci_transport_packet *pkt, > > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ: > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE: >- memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); >+ pkt->u.wait = *wait; > break; > > case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2: >-- >2.39.5 >
On Wed, 4 Feb 2026 12:29:44 +0100 Stefano Garzarella wrote: > Not sure if it's net or net-next material, maybe net to avoid the > warning/error on v6.19 too ? I think net-next. I assume people who build with werror like pain, and we need to be inclusive.
On Tue, Feb 03, 2026 at 05:34:00PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > The gcc-16.0.1 snapshot produces a false-positive warning that turns > into a build failure with CONFIG_WERROR: > > In file included from arch/x86/include/asm/string.h:6, > from net/vmw_vsock/vmci_transport.c:10: > In function 'vmci_transport_packet_init', > inlined from '__vmci_transport_send_control_pkt.constprop' at net/vmw_vsock/vmci_transport.c:198:2: > arch/x86/include/asm/string_32.h:150:25: error: argument 2 null where non-null expected because argument 3 is nonzero [-Werror=nonnull] > 150 | #define memcpy(t, f, n) __builtin_memcpy(t, f, n) > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ > arch/x86/include/asm/string_32.h:150:25: note: in a call to built-in function '__builtin_memcpy' > net/vmw_vsock/vmci_transport.c:164:17: note: in expansion of macro 'memcpy' > 164 | memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > | ^~~~~~ > > This seems relatively harmless, and it so far the only instance of this > warning I have found. The __vmci_transport_send_control_pkt function > is called either with wait=NULL or with one of the type values that > pass 'wait' into memcpy() here, but not from the same caller. > > Replacing the memcpy with a struct assignment is otherwise the same > but avoids the warning. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > net/vmw_vsock/vmci_transport.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c > index 00f6bbdb035a..a64522be1bad 100644 > --- a/net/vmw_vsock/vmci_transport.c > +++ b/net/vmw_vsock/vmci_transport.c > @@ -161,7 +161,7 @@ vmci_transport_packet_init(struct vmci_transport_packet *pkt, > > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ: > case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE: > - memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait)); > + pkt->u.wait = *wait; > break; > > case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2: > -- > 2.39.5 > Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
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