bus: mhi: core: Use correctly sized arguments for bit field

Bugzilla: http://bugzilla.redhat.com/2043454

commit 5a717e93239fc373a314e03e45c43b62ebea1b26
Author: Kees Cook <keescook@chromium.org>
Date:   Thu Dec 16 13:42:26 2021 +0530

    bus: mhi: core: Use correctly sized arguments for bit field
    
    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)
          |                                 ~~~~~~~~~~~~~~~~~~^~~~~
    
    Link: https://lore.kernel.org/r/20211215232446.2069794-1-keescook@chromium.org
    [mani: changed the variable name "bits" to "pm_state"]
    Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
    Signed-off-by: Kees Cook <keescook@chromium.org>
    Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
    Link: https://lore.kernel.org/r/20211216081227.237749-10-manivannan.sadhasivam@linaro.org
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>

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 pm_state = state;
+	int index = find_last_bit(&pm_state, 32);
 
 	if (index >= ARRAY_SIZE(mhi_pm_state_str))
 		return "Invalid State";