| Message ID | 20211215232446.2069794-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | bus: mhi: core: Use correctly sized arguments for bit field | expand |
On Wed, Dec 15, 2021 at 03:24:46PM -0800, Kees Cook wrote: > The find.h APIs are designed to be used only on unsigned long arguments. > This can technically result in a over-read, but it is harmless in this > case. Regardless, fix it to avoid the warning seen under -Warray-bounds, > which we'd like to enable globally: > > In file included from ./include/linux/bitmap.h:9, > from ./include/linux/cpumask.h:12, > from ./arch/x86/include/asm/cpumask.h:5, > from ./arch/x86/include/asm/msr.h:11, > from ./arch/x86/include/asm/processor.h:22, > from ./arch/x86/include/asm/cpufeature.h:5, > from ./arch/x86/include/asm/thread_info.h:53, > from ./include/linux/thread_info.h:60, > from ./arch/x86/include/asm/preempt.h:7, > from ./include/linux/preempt.h:78, > from ./include/linux/spinlock.h:55, > from ./include/linux/wait.h:9, > from ./include/linux/wait_bit.h:8, > from ./include/linux/fs.h:6, > from ./include/linux/debugfs.h:15, > from drivers/bus/mhi/core/init.c:7: > drivers/bus/mhi/core/init.c: In function 'to_mhi_pm_state_str': > ./include/linux/find.h:187:37: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'enum mhi_pm_state[1]' [-Warray-bounds] > 187 | unsigned long val = *addr & GENMASK(size - 1, 0); > | ^~~~~ > drivers/bus/mhi/core/init.c:80:51: note: while referencing 'state' > 80 | const char *to_mhi_pm_state_str(enum mhi_pm_state state) > | ~~~~~~~~~~~~~~~~~~^~~~~ > > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org> A small nit pick below but I'll fix it up while applying. Thanks, Mani > --- > drivers/bus/mhi/core/init.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index f1ec34417592..b91f75fff962 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -79,7 +79,8 @@ static const char * const mhi_pm_state_str[] = { > > const char *to_mhi_pm_state_str(enum mhi_pm_state state) > { > - int index = find_last_bit((unsigned long *)&state, 32); > + unsigned long bits = state; Variable "bits" could be changed to "pm_state". > + int index = find_last_bit(&bits, 32); > > if (index >= ARRAY_SIZE(mhi_pm_state_str)) > return "Invalid State"; > -- > 2.30.2 >
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c index f1ec34417592..b91f75fff962 100644 --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -79,7 +79,8 @@ static const char * const mhi_pm_state_str[] = { const char *to_mhi_pm_state_str(enum mhi_pm_state state) { - int index = find_last_bit((unsigned long *)&state, 32); + unsigned long bits = state; + int index = find_last_bit(&bits, 32); if (index >= ARRAY_SIZE(mhi_pm_state_str)) return "Invalid State";
The find.h APIs are designed to be used only on unsigned long arguments. This can technically result in a over-read, but it is harmless in this case. Regardless, fix it to avoid the warning seen under -Warray-bounds, which we'd like to enable globally: In file included from ./include/linux/bitmap.h:9, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/cpumask.h:5, from ./arch/x86/include/asm/msr.h:11, from ./arch/x86/include/asm/processor.h:22, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:7, from ./include/linux/preempt.h:78, from ./include/linux/spinlock.h:55, from ./include/linux/wait.h:9, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from ./include/linux/debugfs.h:15, from drivers/bus/mhi/core/init.c:7: drivers/bus/mhi/core/init.c: In function 'to_mhi_pm_state_str': ./include/linux/find.h:187:37: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'enum mhi_pm_state[1]' [-Warray-bounds] 187 | unsigned long val = *addr & GENMASK(size - 1, 0); | ^~~~~ drivers/bus/mhi/core/init.c:80:51: note: while referencing 'state' 80 | const char *to_mhi_pm_state_str(enum mhi_pm_state state) | ~~~~~~~~~~~~~~~~~~^~~~~ Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/bus/mhi/core/init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)