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| author | Erick Archer <erick.archer@gmx.com> | 2024-01-28 12:27:22 +0100 |
|---|---|---|
| committer | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2024-02-03 10:26:45 +0530 |
| commit | ae1d892d518af5c092f2b1f8e6921996c6a95cb3 (patch) | |
| tree | da831657fe7dc546906924753fe7681ec841fbf6 /drivers/bus/mhi | |
| parent | 8ddf54a32111f6dbe06cd318af443c6545a6c037 (diff) | |
| download | lwn-ae1d892d518af5c092f2b1f8e6921996c6a95cb3.tar.gz lwn-ae1d892d518af5c092f2b1f8e6921996c6a95cb3.zip | |
bus: mhi: ep: Use kcalloc() instead of kzalloc()
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1].
Here the multiplication is obviously safe because the "event_rings"
member never can have a value greater than 255 (8 bits). This member
is set twice using always FIELD_GET:
mhi_cntrl->event_rings = FIELD_GET(MHICFG_NER_MASK, regval);
mhi_cntrl->event_rings = FIELD_GET(MHICFG_NER_MASK, regval);
And the MHICFG_NER_MASK macro defines the 8 bits mask that guarantees
a maximum value of 255.
However, using kcalloc() is more appropriate [1] and improves
readability. This patch has no effect on runtime behavior.
Link: https://github.com/KSPP/linux/issues/162 [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20240128112722.4334-1-erick.archer@gmx.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/bus/mhi')
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index 65fc1d738bec..8d7a4102bdb7 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -1149,8 +1149,9 @@ int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl) mhi_ep_mmio_mask_interrupts(mhi_cntrl); mhi_ep_mmio_init(mhi_cntrl); - mhi_cntrl->mhi_event = kzalloc(mhi_cntrl->event_rings * (sizeof(*mhi_cntrl->mhi_event)), - GFP_KERNEL); + mhi_cntrl->mhi_event = kcalloc(mhi_cntrl->event_rings, + sizeof(*mhi_cntrl->mhi_event), + GFP_KERNEL); if (!mhi_cntrl->mhi_event) return -ENOMEM; |