| Message ID | 20240120120527.3866-1-erick.archer@gmx.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Documentation: power: Use kcalloc() instead of kzalloc() | expand |
On Sat, Jan 20, 2024 at 01:05:27PM +0100, Erick Archer wrote: > 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> Hi, Drop this patch as a new version has been sent to change at the same time the translations. Thanks, Erick > --- > Documentation/power/opp.rst | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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))) { > -- > 2.25.1 >
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