diff options
| author | Biju Das <biju.das.jz@bp.renesas.com> | 2022-03-16 20:53:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:22:47 +0300 |
| commit | 8745973cdfc6a833d6d405d63760c9b92d78ff9e (patch) | |
| tree | 8ff5a5165a3c160664b2f2c9bd9008bac4ef08eb /drivers/spi | |
| parent | 20f46b12162cd19ad0c9e85ea6d817028e364853 (diff) | |
| download | linux-8745973cdfc6a833d6d405d63760c9b92d78ff9e.tar.xz | |
spi: Fix erroneous sgs value with min_t()
[ Upstream commit ebc4cb43ea5ada3db46c80156fca58a54b9bbca8 ]
While computing sgs in spi_map_buf(), the data type
used in min_t() for max_seg_size is 'unsigned int' where
as that of ctlr->max_dma_len is 'size_t'.
min_t(unsigned int,x,y) gives wrong results if one of x/y is
'size_t'
Consider the below examples on a 64-bit machine (ie size_t is
64-bits, and unsigned int is 32-bit).
case 1) min_t(unsigned int, 5, 0x100000001);
case 2) min_t(size_t, 5, 0x100000001);
Case 1 returns '1', where as case 2 returns '5'. As you can see
the result from case 1 is wrong.
This patch fixes the above issue by using the data type of the
parameters that are used in min_t with maximum data length.
Fixes: commit 1a4e53d2fc4f68aa ("spi: Fix invalid sgs value")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220316175317.465-1-biju.das.jz@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index c7c8d13b2f83..cb7eb1e2e0e9 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -942,10 +942,10 @@ int spi_map_buf(struct spi_controller *ctlr, struct device *dev, int i, ret; if (vmalloced_buf || kmap_buf) { - desc_len = min_t(unsigned int, max_seg_size, PAGE_SIZE); + desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE); sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); } else if (virt_addr_valid(buf)) { - desc_len = min_t(unsigned int, max_seg_size, ctlr->max_dma_len); + desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len); sgs = DIV_ROUND_UP(len, desc_len); } else { return -EINVAL; |