* [PATCH] kcov: refactor common handle ID into kcov_common_handle_id
@ 2026-04-30 14:15 Jann Horn
2026-04-30 16:49 ` Greg KH
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Jann Horn @ 2026-04-30 14:15 UTC (permalink / raw)
To: Dmitry Vyukov, Andrey Konovalov, kasan-dev, Andrew Morton
Cc: Alexander Potapenko, Valentina Manea, Shuah Khan, Shuah Khan,
Hongren Zheng, linux-usb, Michael S. Tsirkin, Jason Wang,
Eugenio Pérez, kvm, virtualization, netdev, linux-kernel,
Jann Horn
Store common handle IDs in "struct kcov_common_handle_id", which consumes
no space in non-KCOV builds.
This cleanup removes #ifdef boilerplate code from subsystems that
integrate with KCOV (in particular in usbip_common.h and skbuff.h, see the
diffstat).
This should also make it easier to add KCOV remote coverage to more
subsystems in the future.
Signed-off-by: Jann Horn <jannh@google.com>
---
drivers/usb/usbip/usbip_common.h | 29 +----------------------------
drivers/usb/usbip/vhci_rx.c | 4 ++--
drivers/usb/usbip/vhci_sysfs.c | 2 +-
drivers/vhost/vhost.h | 2 +-
include/linux/kcov.h | 12 ++++++------
include/linux/skbuff.h | 14 +++-----------
include/linux/types.h | 6 ++++++
kernel/kcov.c | 6 +++---
8 files changed, 23 insertions(+), 52 deletions(-)
diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h
index 282efca64a01..be4c5e65a7f8 100644
--- a/drivers/usb/usbip/usbip_common.h
+++ b/drivers/usb/usbip/usbip_common.h
@@ -282,9 +282,7 @@ struct usbip_device {
void (*unusable)(struct usbip_device *);
} eh_ops;
-#ifdef CONFIG_KCOV
- u64 kcov_handle;
-#endif
+ struct kcov_common_handle_id kcov_handle;
};
#define kthread_get_run(threadfn, data, namefmt, ...) \
@@ -339,29 +337,4 @@ static inline int interface_to_devnum(struct usb_interface *interface)
return udev->devnum;
}
-#ifdef CONFIG_KCOV
-
-static inline void usbip_kcov_handle_init(struct usbip_device *ud)
-{
- ud->kcov_handle = kcov_common_handle();
-}
-
-static inline void usbip_kcov_remote_start(struct usbip_device *ud)
-{
- kcov_remote_start_common(ud->kcov_handle);
-}
-
-static inline void usbip_kcov_remote_stop(void)
-{
- kcov_remote_stop();
-}
-
-#else /* CONFIG_KCOV */
-
-static inline void usbip_kcov_handle_init(struct usbip_device *ud) { }
-static inline void usbip_kcov_remote_start(struct usbip_device *ud) { }
-static inline void usbip_kcov_remote_stop(void) { }
-
-#endif /* CONFIG_KCOV */
-
#endif /* __USBIP_COMMON_H */
diff --git a/drivers/usb/usbip/vhci_rx.c b/drivers/usb/usbip/vhci_rx.c
index a75f4a898a41..a678e7c89837 100644
--- a/drivers/usb/usbip/vhci_rx.c
+++ b/drivers/usb/usbip/vhci_rx.c
@@ -261,9 +261,9 @@ int vhci_rx_loop(void *data)
if (usbip_event_happened(ud))
break;
- usbip_kcov_remote_start(ud);
+ kcov_remote_start_common(ud->kcov_handle);
vhci_rx_pdu(ud);
- usbip_kcov_remote_stop();
+ kcov_remote_stop();
}
return 0;
diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c
index 5bc8c47788d4..b98d14c43d13 100644
--- a/drivers/usb/usbip/vhci_sysfs.c
+++ b/drivers/usb/usbip/vhci_sysfs.c
@@ -425,7 +425,7 @@ static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
vdev->ud.tcp_rx = tcp_rx;
vdev->ud.tcp_tx = tcp_tx;
vdev->ud.status = VDEV_ST_NOTASSIGNED;
- usbip_kcov_handle_init(&vdev->ud);
+ vdev->ud.kcov_handle = kcov_common_handle();
spin_unlock(&vdev->ud.lock);
spin_unlock_irqrestore(&vhci->lock, flags);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 4fe99765c5c7..0192ade6e749 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -44,7 +44,7 @@ struct vhost_worker {
/* Used to serialize device wide flushing with worker swapping. */
struct mutex mutex;
struct llist_head work_list;
- u64 kcov_handle;
+ struct kcov_common_handle_id kcov_handle;
u32 id;
int attachment_cnt;
bool killed;
diff --git a/include/linux/kcov.h b/include/linux/kcov.h
index 0143358874b0..cdb72b3859d8 100644
--- a/include/linux/kcov.h
+++ b/include/linux/kcov.h
@@ -43,11 +43,11 @@ do { \
/* See Documentation/dev-tools/kcov.rst for usage details. */
void kcov_remote_start(u64 handle);
void kcov_remote_stop(void);
-u64 kcov_common_handle(void);
+struct kcov_common_handle_id kcov_common_handle(void);
-static inline void kcov_remote_start_common(u64 id)
+static inline void kcov_remote_start_common(struct kcov_common_handle_id id)
{
- kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
+ kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id.val));
}
static inline void kcov_remote_start_usb(u64 id)
@@ -99,11 +99,11 @@ static inline void kcov_prepare_switch(struct task_struct *t) {}
static inline void kcov_finish_switch(struct task_struct *t) {}
static inline void kcov_remote_start(u64 handle) {}
static inline void kcov_remote_stop(void) {}
-static inline u64 kcov_common_handle(void)
+static inline struct kcov_common_handle_id kcov_common_handle(void)
{
- return 0;
+ return (struct kcov_common_handle_id){};
}
-static inline void kcov_remote_start_common(u64 id) {}
+static inline void kcov_remote_start_common(struct kcov_common_handle_id id) {}
static inline void kcov_remote_start_usb(u64 id) {}
static inline void kcov_remote_start_usb_softirq(u64 id) {}
static inline void kcov_remote_stop_softirq(void) {}
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 2bcf78a4de7b..a3fe418f7ced 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1082,9 +1082,7 @@ struct sk_buff {
__u16 network_header;
__u16 mac_header;
-#ifdef CONFIG_KCOV
- u64 kcov_handle;
-#endif
+ struct kcov_common_handle_id kcov_handle;
); /* end headers group */
@@ -5437,20 +5435,14 @@ static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
}
static inline void skb_set_kcov_handle(struct sk_buff *skb,
- const u64 kcov_handle)
+ struct kcov_common_handle_id kcov_handle)
{
-#ifdef CONFIG_KCOV
skb->kcov_handle = kcov_handle;
-#endif
}
-static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
+static inline struct kcov_common_handle_id skb_get_kcov_handle(struct sk_buff *skb)
{
-#ifdef CONFIG_KCOV
return skb->kcov_handle;
-#else
- return 0;
-#endif
}
static inline void skb_mark_for_recycle(struct sk_buff *skb)
diff --git a/include/linux/types.h b/include/linux/types.h
index 608050dbca6a..93166b0b0617 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -224,6 +224,12 @@ struct ustat {
char f_fpack[6];
};
+struct kcov_common_handle_id {
+#ifdef CONFIG_KCOV
+ u64 val;
+#endif
+};
+
/**
* struct callback_head - callback structure for use with RCU and task_work
* @next: next update requests in a list
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 0b369e88c7c9..a43e33a28adb 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1083,11 +1083,11 @@ void kcov_remote_stop(void)
EXPORT_SYMBOL(kcov_remote_stop);
/* See the comment before kcov_remote_start() for usage details. */
-u64 kcov_common_handle(void)
+struct kcov_common_handle_id kcov_common_handle(void)
{
if (!in_task())
- return 0;
- return current->kcov_handle;
+ return (struct kcov_common_handle_id){ .val = 0 };
+ return (struct kcov_common_handle_id){ .val = current->kcov_handle };
}
EXPORT_SYMBOL(kcov_common_handle);
---
base-commit: 57b8e2d666a31fa201432d58f5fe3469a0dd83ba
change-id: 20260430-kcov-refactor-common-handle-25178495b2eb
--
Jann Horn <jannh@google.com>
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] kcov: refactor common handle ID into kcov_common_handle_id
2026-04-30 14:15 [PATCH] kcov: refactor common handle ID into kcov_common_handle_id Jann Horn
@ 2026-04-30 16:49 ` Greg KH
2026-05-01 7:39 ` Dmitry Vyukov
2026-05-01 23:52 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Greg KH @ 2026-04-30 16:49 UTC (permalink / raw)
To: Jann Horn
Cc: Dmitry Vyukov, Andrey Konovalov, kasan-dev, Andrew Morton,
Alexander Potapenko, Valentina Manea, Shuah Khan, Shuah Khan,
Hongren Zheng, linux-usb, Michael S. Tsirkin, Jason Wang,
Eugenio Pérez, kvm, virtualization, netdev, linux-kernel
On Thu, Apr 30, 2026 at 04:15:33PM +0200, Jann Horn wrote:
> Store common handle IDs in "struct kcov_common_handle_id", which consumes
> no space in non-KCOV builds.
> This cleanup removes #ifdef boilerplate code from subsystems that
> integrate with KCOV (in particular in usbip_common.h and skbuff.h, see the
> diffstat).
> This should also make it easier to add KCOV remote coverage to more
> subsystems in the future.
>
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
> drivers/usb/usbip/usbip_common.h | 29 +----------------------------
> drivers/usb/usbip/vhci_rx.c | 4 ++--
> drivers/usb/usbip/vhci_sysfs.c | 2 +-
> drivers/vhost/vhost.h | 2 +-
> include/linux/kcov.h | 12 ++++++------
> include/linux/skbuff.h | 14 +++-----------
> include/linux/types.h | 6 ++++++
> kernel/kcov.c | 6 +++---
> 8 files changed, 23 insertions(+), 52 deletions(-)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] kcov: refactor common handle ID into kcov_common_handle_id
2026-04-30 14:15 [PATCH] kcov: refactor common handle ID into kcov_common_handle_id Jann Horn
2026-04-30 16:49 ` Greg KH
@ 2026-05-01 7:39 ` Dmitry Vyukov
2026-05-01 23:52 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Dmitry Vyukov @ 2026-05-01 7:39 UTC (permalink / raw)
To: Jann Horn
Cc: Andrey Konovalov, kasan-dev, Andrew Morton, Alexander Potapenko,
Valentina Manea, Shuah Khan, Shuah Khan, Hongren Zheng, linux-usb,
Michael S. Tsirkin, Jason Wang, Eugenio Pérez, kvm,
virtualization, netdev, linux-kernel
On Thu, 30 Apr 2026 at 16:15, Jann Horn <jannh@google.com> wrote:
>
> Store common handle IDs in "struct kcov_common_handle_id", which consumes
> no space in non-KCOV builds.
> This cleanup removes #ifdef boilerplate code from subsystems that
> integrate with KCOV (in particular in usbip_common.h and skbuff.h, see the
> diffstat).
> This should also make it easier to add KCOV remote coverage to more
> subsystems in the future.
>
> Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Thanks!
> ---
> drivers/usb/usbip/usbip_common.h | 29 +----------------------------
> drivers/usb/usbip/vhci_rx.c | 4 ++--
> drivers/usb/usbip/vhci_sysfs.c | 2 +-
> drivers/vhost/vhost.h | 2 +-
> include/linux/kcov.h | 12 ++++++------
> include/linux/skbuff.h | 14 +++-----------
> include/linux/types.h | 6 ++++++
> kernel/kcov.c | 6 +++---
> 8 files changed, 23 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h
> index 282efca64a01..be4c5e65a7f8 100644
> --- a/drivers/usb/usbip/usbip_common.h
> +++ b/drivers/usb/usbip/usbip_common.h
> @@ -282,9 +282,7 @@ struct usbip_device {
> void (*unusable)(struct usbip_device *);
> } eh_ops;
>
> -#ifdef CONFIG_KCOV
> - u64 kcov_handle;
> -#endif
> + struct kcov_common_handle_id kcov_handle;
> };
>
> #define kthread_get_run(threadfn, data, namefmt, ...) \
> @@ -339,29 +337,4 @@ static inline int interface_to_devnum(struct usb_interface *interface)
> return udev->devnum;
> }
>
> -#ifdef CONFIG_KCOV
> -
> -static inline void usbip_kcov_handle_init(struct usbip_device *ud)
> -{
> - ud->kcov_handle = kcov_common_handle();
> -}
> -
> -static inline void usbip_kcov_remote_start(struct usbip_device *ud)
> -{
> - kcov_remote_start_common(ud->kcov_handle);
> -}
> -
> -static inline void usbip_kcov_remote_stop(void)
> -{
> - kcov_remote_stop();
> -}
> -
> -#else /* CONFIG_KCOV */
> -
> -static inline void usbip_kcov_handle_init(struct usbip_device *ud) { }
> -static inline void usbip_kcov_remote_start(struct usbip_device *ud) { }
> -static inline void usbip_kcov_remote_stop(void) { }
> -
> -#endif /* CONFIG_KCOV */
> -
> #endif /* __USBIP_COMMON_H */
> diff --git a/drivers/usb/usbip/vhci_rx.c b/drivers/usb/usbip/vhci_rx.c
> index a75f4a898a41..a678e7c89837 100644
> --- a/drivers/usb/usbip/vhci_rx.c
> +++ b/drivers/usb/usbip/vhci_rx.c
> @@ -261,9 +261,9 @@ int vhci_rx_loop(void *data)
> if (usbip_event_happened(ud))
> break;
>
> - usbip_kcov_remote_start(ud);
> + kcov_remote_start_common(ud->kcov_handle);
> vhci_rx_pdu(ud);
> - usbip_kcov_remote_stop();
> + kcov_remote_stop();
> }
>
> return 0;
> diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c
> index 5bc8c47788d4..b98d14c43d13 100644
> --- a/drivers/usb/usbip/vhci_sysfs.c
> +++ b/drivers/usb/usbip/vhci_sysfs.c
> @@ -425,7 +425,7 @@ static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
> vdev->ud.tcp_rx = tcp_rx;
> vdev->ud.tcp_tx = tcp_tx;
> vdev->ud.status = VDEV_ST_NOTASSIGNED;
> - usbip_kcov_handle_init(&vdev->ud);
> + vdev->ud.kcov_handle = kcov_common_handle();
>
> spin_unlock(&vdev->ud.lock);
> spin_unlock_irqrestore(&vhci->lock, flags);
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 4fe99765c5c7..0192ade6e749 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -44,7 +44,7 @@ struct vhost_worker {
> /* Used to serialize device wide flushing with worker swapping. */
> struct mutex mutex;
> struct llist_head work_list;
> - u64 kcov_handle;
> + struct kcov_common_handle_id kcov_handle;
> u32 id;
> int attachment_cnt;
> bool killed;
> diff --git a/include/linux/kcov.h b/include/linux/kcov.h
> index 0143358874b0..cdb72b3859d8 100644
> --- a/include/linux/kcov.h
> +++ b/include/linux/kcov.h
> @@ -43,11 +43,11 @@ do { \
> /* See Documentation/dev-tools/kcov.rst for usage details. */
> void kcov_remote_start(u64 handle);
> void kcov_remote_stop(void);
> -u64 kcov_common_handle(void);
> +struct kcov_common_handle_id kcov_common_handle(void);
>
> -static inline void kcov_remote_start_common(u64 id)
> +static inline void kcov_remote_start_common(struct kcov_common_handle_id id)
> {
> - kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
> + kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id.val));
> }
>
> static inline void kcov_remote_start_usb(u64 id)
> @@ -99,11 +99,11 @@ static inline void kcov_prepare_switch(struct task_struct *t) {}
> static inline void kcov_finish_switch(struct task_struct *t) {}
> static inline void kcov_remote_start(u64 handle) {}
> static inline void kcov_remote_stop(void) {}
> -static inline u64 kcov_common_handle(void)
> +static inline struct kcov_common_handle_id kcov_common_handle(void)
> {
> - return 0;
> + return (struct kcov_common_handle_id){};
> }
> -static inline void kcov_remote_start_common(u64 id) {}
> +static inline void kcov_remote_start_common(struct kcov_common_handle_id id) {}
> static inline void kcov_remote_start_usb(u64 id) {}
> static inline void kcov_remote_start_usb_softirq(u64 id) {}
> static inline void kcov_remote_stop_softirq(void) {}
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 2bcf78a4de7b..a3fe418f7ced 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -1082,9 +1082,7 @@ struct sk_buff {
> __u16 network_header;
> __u16 mac_header;
>
> -#ifdef CONFIG_KCOV
> - u64 kcov_handle;
> -#endif
> + struct kcov_common_handle_id kcov_handle;
>
> ); /* end headers group */
>
> @@ -5437,20 +5435,14 @@ static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
> }
>
> static inline void skb_set_kcov_handle(struct sk_buff *skb,
> - const u64 kcov_handle)
> + struct kcov_common_handle_id kcov_handle)
> {
> -#ifdef CONFIG_KCOV
> skb->kcov_handle = kcov_handle;
> -#endif
> }
>
> -static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
> +static inline struct kcov_common_handle_id skb_get_kcov_handle(struct sk_buff *skb)
> {
> -#ifdef CONFIG_KCOV
> return skb->kcov_handle;
> -#else
> - return 0;
> -#endif
> }
>
> static inline void skb_mark_for_recycle(struct sk_buff *skb)
> diff --git a/include/linux/types.h b/include/linux/types.h
> index 608050dbca6a..93166b0b0617 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -224,6 +224,12 @@ struct ustat {
> char f_fpack[6];
> };
>
> +struct kcov_common_handle_id {
> +#ifdef CONFIG_KCOV
> + u64 val;
> +#endif
> +};
> +
> /**
> * struct callback_head - callback structure for use with RCU and task_work
> * @next: next update requests in a list
> diff --git a/kernel/kcov.c b/kernel/kcov.c
> index 0b369e88c7c9..a43e33a28adb 100644
> --- a/kernel/kcov.c
> +++ b/kernel/kcov.c
> @@ -1083,11 +1083,11 @@ void kcov_remote_stop(void)
> EXPORT_SYMBOL(kcov_remote_stop);
>
> /* See the comment before kcov_remote_start() for usage details. */
> -u64 kcov_common_handle(void)
> +struct kcov_common_handle_id kcov_common_handle(void)
> {
> if (!in_task())
> - return 0;
> - return current->kcov_handle;
> + return (struct kcov_common_handle_id){ .val = 0 };
> + return (struct kcov_common_handle_id){ .val = current->kcov_handle };
> }
> EXPORT_SYMBOL(kcov_common_handle);
>
>
> ---
> base-commit: 57b8e2d666a31fa201432d58f5fe3469a0dd83ba
> change-id: 20260430-kcov-refactor-common-handle-25178495b2eb
>
> --
> Jann Horn <jannh@google.com>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] kcov: refactor common handle ID into kcov_common_handle_id
2026-04-30 14:15 [PATCH] kcov: refactor common handle ID into kcov_common_handle_id Jann Horn
2026-04-30 16:49 ` Greg KH
2026-05-01 7:39 ` Dmitry Vyukov
@ 2026-05-01 23:52 ` Jakub Kicinski
2 siblings, 0 replies; 4+ messages in thread
From: Jakub Kicinski @ 2026-05-01 23:52 UTC (permalink / raw)
To: Jann Horn
Cc: Dmitry Vyukov, Andrey Konovalov, kasan-dev, Andrew Morton,
Alexander Potapenko, Valentina Manea, Shuah Khan, Shuah Khan,
Hongren Zheng, linux-usb, Michael S. Tsirkin, Jason Wang,
Eugenio Pérez, kvm, virtualization, netdev, linux-kernel
On Thu, 30 Apr 2026 16:15:33 +0200 Jann Horn wrote:
> Store common handle IDs in "struct kcov_common_handle_id", which consumes
> no space in non-KCOV builds.
> This cleanup removes #ifdef boilerplate code from subsystems that
> integrate with KCOV (in particular in usbip_common.h and skbuff.h, see the
> diffstat).
> This should also make it easier to add KCOV remote coverage to more
> subsystems in the future.
>
> Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-05-01 23:52 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-30 14:15 [PATCH] kcov: refactor common handle ID into kcov_common_handle_id Jann Horn
2026-04-30 16:49 ` Greg KH
2026-05-01 7:39 ` Dmitry Vyukov
2026-05-01 23:52 ` Jakub Kicinski
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox