From: Arnd Bergmann Date: Thu, 26 Jun 2014 12:58:29 +0000 (+0200) Subject: 3w-xxxx: fix mis-aligned struct accesses X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=4bfaa5c4b99ddec00907e854d70453bd2aef39a0;p=deliverable%2Flinux.git 3w-xxxx: fix mis-aligned struct accesses Building an allmodconfig ARM kernel, I get multiple such warnings because of a spinlock contained in packed structure in the 3w-xxxx driver: ../drivers/scsi/3w-xxxx.c: In function 'tw_chrdev_ioctl': ../drivers/scsi/3w-xxxx.c:1001:68: warning: mis-aligned access used for structure member [-fstrict-volatile-bitfields] timeout = wait_event_timeout(tw_dev->ioctl_wqueue, tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE, timeout); ^ ../drivers/scsi/3w-xxxx.c:1001:68: note: when a volatile object spans multiple type-sized locations, the compiler must choose between using a single mis-aligned access to preserve the volatility, or using multiple aligned accesses to avoid runtime faults; this code may fail at runtime if the hardware does not allow this access The same bug apparently was present in 3w-sas and 3w-9xxx, but has been fixed in the past. This patch uses the same fix by moving the pragma in front of the TW_Device_Extension definition, so it only covers hardware structures. Signed-off-by: Arnd Bergmann Acked-by: Adam Radford Cc: Adam Radford Signed-off-by: Christoph Hellwig --- diff --git a/drivers/scsi/3w-xxxx.h b/drivers/scsi/3w-xxxx.h index 49dcf03c631a..29b0b84ed69e 100644 --- a/drivers/scsi/3w-xxxx.h +++ b/drivers/scsi/3w-xxxx.h @@ -392,6 +392,8 @@ typedef struct TAG_TW_Passthru unsigned char padding[12]; } TW_Passthru; +#pragma pack() + typedef struct TAG_TW_Device_Extension { u32 base_addr; unsigned long *alignment_virtual_address[TW_Q_LENGTH]; @@ -430,6 +432,4 @@ typedef struct TAG_TW_Device_Extension { wait_queue_head_t ioctl_wqueue; } TW_Device_Extension; -#pragma pack() - #endif /* _3W_XXXX_H */