From a3632fa3ecefe50d88fc70af90610f79b99e0715 Mon Sep 17 00:00:00 2001 From: Jack Hammer Date: Tue, 25 Oct 2005 14:13:03 -0400 Subject: [PATCH] [SCSI] ips: Fix up for correct scatter/gather processing Added kmap_atomic/kunmap_atomic. Added protection of KM_IRQ0 slot with local_irq_save(), local_irq_restore(), and comments. Signed-off-by: James Bottomley --- drivers/scsi/ips.c | 49 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c index eeae7ccb0dd2..0a252e7aca6e 100644 --- a/drivers/scsi/ips.c +++ b/drivers/scsi/ips.c @@ -219,15 +219,12 @@ module_param(ips, charp, 0); #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,5,0) #include #include "sd.h" -#define IPS_SG_ADDRESS(sg) ((sg)->address) #define IPS_LOCK_SAVE(lock,flags) spin_lock_irqsave(&io_request_lock,flags) #define IPS_UNLOCK_RESTORE(lock,flags) spin_unlock_irqrestore(&io_request_lock,flags) #ifndef __devexit_p #define __devexit_p(x) x #endif #else -#define IPS_SG_ADDRESS(sg) (page_address((sg)->page) ? \ - page_address((sg)->page)+(sg)->offset : NULL) #define IPS_LOCK_SAVE(lock,flags) do{spin_lock(lock);(void)flags;}while(0) #define IPS_UNLOCK_RESTORE(lock,flags) do{spin_unlock(lock);(void)flags;}while(0) #endif @@ -1605,6 +1602,8 @@ ips_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, static int ips_is_passthru(Scsi_Cmnd * SC) { + unsigned long flags; + METHOD_TRACE("ips_is_passthru", 1); if (!SC) @@ -1622,10 +1621,20 @@ ips_is_passthru(Scsi_Cmnd * SC) return 1; else if (SC->use_sg) { struct scatterlist *sg = SC->request_buffer; - char *buffer = IPS_SG_ADDRESS(sg); + char *buffer; + + /* kmap_atomic() ensures addressability of the user buffer.*/ + /* local_irq_save() protects the KM_IRQ0 address slot. */ + local_irq_save(flags); + buffer = kmap_atomic(sg->page, KM_IRQ0) + sg->offset; if (buffer && buffer[0] == 'C' && buffer[1] == 'O' && - buffer[2] == 'P' && buffer[3] == 'P') + buffer[2] == 'P' && buffer[3] == 'P') { + kunmap_atomic(buffer - sg->offset, KM_IRQ0); + local_irq_restore(flags); return 1; + } + kunmap_atomic(buffer - sg->offset, KM_IRQ0); + local_irq_restore(flags); } } return 0; @@ -3656,14 +3665,21 @@ ips_scmd_buf_write(Scsi_Cmnd * scmd, void *data, unsigned int i; unsigned int min_cnt, xfer_cnt; char *cdata = (char *) data; + unsigned char *buffer; + unsigned long flags; struct scatterlist *sg = scmd->request_buffer; for (i = 0, xfer_cnt = 0; (i < scmd->use_sg) && (xfer_cnt < count); i++) { - if (!IPS_SG_ADDRESS(&sg[i])) - return; min_cnt = min(count - xfer_cnt, sg[i].length); - memcpy(IPS_SG_ADDRESS(&sg[i]), &cdata[xfer_cnt], - min_cnt); + + /* kmap_atomic() ensures addressability of the data buffer.*/ + /* local_irq_save() protects the KM_IRQ0 address slot. */ + local_irq_save(flags); + buffer = kmap_atomic(sg[i].page, KM_IRQ0) + sg[i].offset; + memcpy(buffer, &cdata[xfer_cnt], min_cnt); + kunmap_atomic(buffer - sg[i].offset, KM_IRQ0); + local_irq_restore(flags); + xfer_cnt += min_cnt; } @@ -3688,14 +3704,21 @@ ips_scmd_buf_read(Scsi_Cmnd * scmd, void *data, unsigned int i; unsigned int min_cnt, xfer_cnt; char *cdata = (char *) data; + unsigned char *buffer; + unsigned long flags; struct scatterlist *sg = scmd->request_buffer; for (i = 0, xfer_cnt = 0; (i < scmd->use_sg) && (xfer_cnt < count); i++) { - if (!IPS_SG_ADDRESS(&sg[i])) - return; min_cnt = min(count - xfer_cnt, sg[i].length); - memcpy(&cdata[xfer_cnt], IPS_SG_ADDRESS(&sg[i]), - min_cnt); + + /* kmap_atomic() ensures addressability of the data buffer.*/ + /* local_irq_save() protects the KM_IRQ0 address slot. */ + local_irq_save(flags); + buffer = kmap_atomic(sg[i].page, KM_IRQ0) + sg[i].offset; + memcpy(&cdata[xfer_cnt], buffer, min_cnt); + kunmap_atomic(buffer - sg[i].offset, KM_IRQ0); + local_irq_restore(flags); + xfer_cnt += min_cnt; } -- 2.34.1