diff options
| author | Stuart Hayes <Stuart_Hayes@dell.com> | 2005-05-26 13:38:45 (GMT) |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl> | 2005-05-26 13:38:45 (GMT) |
| commit | 41bb4c43b34bcde7eb62cf19acdcf9f2eb13801d (patch) | |
| tree | cfaeeca6836443ee680e38273cb4f7ae94c023b2 | |
| parent | 8604affde9d4f52f04342d6a37c77d95fa167e7a (diff) | |
| download | linux-41bb4c43b34bcde7eb62cf19acdcf9f2eb13801d.tar.xz | |
[PATCH] ide-scsi: kmap scatter/gather before doing PIO
From: Stuart Hayes <Stuart_Hayes@dell.com>
The system can panic with a null pointer dereference using ide-scsi if
PIO is being done on scatter gather pages that are in high memory,
because page_address() returns 0. We are actually seeing this using a
tape drive. This patch will kmap_atomic() the pages before performing
PIO.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
| -rw-r--r-- | drivers/scsi/ide-scsi.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c index d80c4c9..83f062e 100644 --- a/drivers/scsi/ide-scsi.c +++ b/drivers/scsi/ide-scsi.c @@ -179,8 +179,18 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne return; } count = min(pc->sg->length - pc->b_count, bcount); - buf = page_address(pc->sg->page) + pc->sg->offset; - drive->hwif->atapi_input_bytes(drive, buf + pc->b_count, count); + if (PageHighMem(pc->sg->page)) { + unsigned long flags; + + local_irq_save(flags); + buf = kmap_atomic(pc->sg->page, KM_IRQ0) + pc->sg->offset; + drive->hwif->atapi_input_bytes(drive, buf + pc->b_count, count); + kunmap_atomic(buf - pc->sg->offset, KM_IRQ0); + local_irq_restore(flags); + } else { + buf = page_address(pc->sg->page) + pc->sg->offset; + drive->hwif->atapi_input_bytes(drive, buf + pc->b_count, count); + } bcount -= count; pc->b_count += count; if (pc->b_count == pc->sg->length) { pc->sg++; @@ -201,8 +211,18 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign return; } count = min(pc->sg->length - pc->b_count, bcount); - buf = page_address(pc->sg->page) + pc->sg->offset; - drive->hwif->atapi_output_bytes(drive, buf + pc->b_count, count); + if (PageHighMem(pc->sg->page)) { + unsigned long flags; + + local_irq_save(flags); + buf = kmap_atomic(pc->sg->page, KM_IRQ0) + pc->sg->offset; + drive->hwif->atapi_output_bytes(drive, buf + pc->b_count, count); + kunmap_atomic(buf - pc->sg->offset, KM_IRQ0); + local_irq_restore(flags); + } else { + buf = page_address(pc->sg->page) + pc->sg->offset; + drive->hwif->atapi_output_bytes(drive, buf + pc->b_count, count); + } bcount -= count; pc->b_count += count; if (pc->b_count == pc->sg->length) { pc->sg++; |