> On Aug 5, 2019, at 5:52 AM, Will Deacon <[email protected]> wrote:
>
> On Fri, Aug 02, 2019 at 11:32:24AM -0400, Qian Cai wrote:
>> The commit 155433cb365e ("arm64: cache: Remove support for ASID-tagged
>> VIVT I-caches") introduced some compiation warnings from GCC,
>>
>> arch/arm64/kernel/cpuinfo.c:38:26: warning: initialized field
>> overwritten [-Woverride-init]
>> [ICACHE_POLICY_VIPT] = "VIPT",
>> ^~~~~~
>> arch/arm64/kernel/cpuinfo.c:38:26: note: (near initialization for
>> 'icache_policy_str[2]')
>> arch/arm64/kernel/cpuinfo.c:39:26: warning: initialized field
>> overwritten [-Woverride-init]
>> [ICACHE_POLICY_PIPT] = "PIPT",
>> ^~~~~~
>> arch/arm64/kernel/cpuinfo.c:39:26: note: (near initialization for
>> 'icache_policy_str[3]')
>> arch/arm64/kernel/cpuinfo.c:40:27: warning: initialized field
>> overwritten [-Woverride-init]
>> [ICACHE_POLICY_VPIPT] = "VPIPT",
>> ^~~~~~~
>> arch/arm64/kernel/cpuinfo.c:40:27: note: (near initialization for
>> 'icache_policy_str[0]')
>>
>> because it initializes icache_policy_str[0 ... 3] twice.
>>
>> Fixes: 155433cb365e ("arm64: cache: Remove support for ASID-tagged VIVT
>> I-caches")
>> Signed-off-by: Qian Cai <[email protected]>
>> ---
>> arch/arm64/kernel/cpuinfo.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
>> index 876055e37352..193b38da8d96 100644
>> --- a/arch/arm64/kernel/cpuinfo.c
>> +++ b/arch/arm64/kernel/cpuinfo.c
>> @@ -34,10 +34,10 @@
>> static struct cpuinfo_arm64 boot_cpu_data;
>>
>> static char *icache_policy_str[] = {
>> - [0 ... ICACHE_POLICY_PIPT] = "RESERVED/UNKNOWN",
>> + [ICACHE_POLICY_VPIPT] = "VPIPT",
>> + [ICACHE_POLICY_VPIPT + 1] = "RESERVED/UNKNOWN",
>> [ICACHE_POLICY_VIPT] = "VIPT",
>> [ICACHE_POLICY_PIPT] = "PIPT",
>> - [ICACHE_POLICY_VPIPT] = "VPIPT",
>
> I really don't like this patch. Using "[0 ... MAXIDX] = <default>" is a
> useful idiom and I think the code is more error-prone the way you have
> restructured it.
>
> Why are you passing -Woverride-init to the compiler anyway? There's only
> one Makefile that references that option, and it's specific to a pinctrl
> driver.
Those extra warnings can be enabled by “make W=1”. “-Woverride-init “ seems to
be useful
to catch potential developer mistakes with unintented double-initializations.
It is normal to
start to fix the most of false-positives first before globally enabling the
flag by default just like
“-Wimplicit-fallthrough” mentioned in,
https://lwn.net/Articles/794944/
