| Message ID | 20240120120527.3866-1-erick.archer@gmx.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Documentation: power: Use kcalloc() instead of kzalloc() | expand |
diff --git a/Documentation/power/opp.rst b/Documentation/power/opp.rst index a7c03c470980..1b7f1d854f14 100644 --- a/Documentation/power/opp.rst +++ b/Documentation/power/opp.rst @@ -305,7 +305,7 @@ dev_pm_opp_get_opp_count { /* Do things */ num_available = dev_pm_opp_get_opp_count(dev); - speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL); + speeds = kcalloc(num_available, sizeof(u32), GFP_KERNEL); /* populate the table in increasing order */ freq = 0; while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(dev, &freq))) {
As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, in the example code use the purpose specific kcalloc() function instead of the argument size * count in the kzalloc() function. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1] Link: https://github.com/KSPP/linux/issues/162 Signed-off-by: Erick Archer <erick.archer@gmx.com> --- Documentation/power/opp.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1