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| author | Biju Das <biju.das.jz@bp.renesas.com> | 2022-03-16 18:53:17 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2022-03-17 18:59:54 +0100 |
| commit | ebc4cb43ea5ada3db46c80156fca58a54b9bbca8 (patch) | |
| tree | 00c14d428947b0f07d3bb22234f15ce4b319dd88 /drivers/spi/spi.c | |
| parent | spi: Get sgs size fix into branch (diff) | |
| download | linux-ebc4cb43ea5ada3db46c80156fca58a54b9bbca8.tar.xz linux-ebc4cb43ea5ada3db46c80156fca58a54b9bbca8.zip | |
spi: Fix erroneous sgs value with min_t()
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>
Diffstat (limited to '')
| -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 6937cf2d59e0..c4dd1200fe99 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1000,10 +1000,10 @@ 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; |