[patch 01/22] 3ware: kmap_atomic() fix

Greg KH
2006-04-21T04:45:03Z

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From: Andrew Morton <akpm@osdl.org>

We must disable local IRQs while holding KM_IRQ0 or KM_IRQ1. Otherwise, an
IRQ handler could use those kmap slots while this code is using them,
resulting in memory corruption.

Thanks to Nick Orlov <bugfixer@list.ru> for reporting.

Cc: <linuxraid@amcc.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/scsi/3w-xxxx.c | 3 +++
1 file changed, 3 insertions(+)

--- linux-2.6.16.9.orig/drivers/scsi/3w-xxxx.c
+++ linux-2.6.16.9/drivers/scsi/3w-xxxx.c
@@ -1508,10 +1508,12 @@ static void tw_transfer_internal(TW_Devi
struct scsi_cmnd *cmd = tw_dev->srb[request_id];
void *buf;
unsigned int transfer_len;
+ unsigned long flags = 0;

if (cmd->use_sg) {
struct scatterlist *sg =
(struct scatterlist *)cmd->request_buffer;
+ local_irq_save(flags);
buf = kmap_atomic(sg->page, KM_IRQ0) + sg->offset;
transfer_len = min(sg->length, len);
} else {
@@ -1526,6 +1528,7 @@ static void tw_transfer_internal(TW_Devi

sg = (struct scatterlist *)cmd->request_buffer;
kunmap_atomic(buf - sg->offset, KM_IRQ0);
+ local_irq_restore(flags);
}
}

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