#ifndef __ASM_GENERIC_UACCESS_UNALIGNED_H
#define __ASM_GENERIC_UACCESS_UNALIGNED_H
/*
* This macro should be used instead of __get_user() when accessing
* values at locations that are not known to be aligned.
*/
#define __get_user_unaligned(x, ptr) \
({ \
__typeof__ (*(ptr)) __x; \
__copy_from_user(&__x, (ptr), sizeof(*(ptr))) ? -EFAULT : 0; \
(x) = __x; \
})
/*
* This macro should be used instead of __put_user() when accessing
* values at locations that are not known to be aligned.
*/
#define __put_user_unaligned(x, ptr) \
({ \
__typeof__ (*(ptr)) __x = (x); \
__copy_to_user((ptr), &__x, sizeof(*(ptr))) ? -EFAULT : 0; \
})
#endif /* __ASM_GENERIC_UACCESS_UNALIGNED_H */
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Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz < pending_sz"
when making the signal decision.
As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.
This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).
Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>