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SubjectRe: [PATCH v2] PCI: rpaphp: Avoid a sometimes-uninitialized warning
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Nathan Chancellor <natechancellor@gmail.com> writes:
> On Mon, Jun 03, 2019 at 03:11:58PM -0700, Nathan Chancellor wrote:
>> When building with -Wsometimes-uninitialized, clang warns:
>>
>> drivers/pci/hotplug/rpaphp_core.c:243:14: warning: variable 'fndit' is
>> used uninitialized whenever 'for' loop exits because its condition is
>> false [-Wsometimes-uninitialized]
>> for (j = 0; j < entries; j++) {
>> ^~~~~~~~~~~
>> drivers/pci/hotplug/rpaphp_core.c:256:6: note: uninitialized use occurs
>> here
>> if (fndit)
>> ^~~~~
>> drivers/pci/hotplug/rpaphp_core.c:243:14: note: remove the condition if
>> it is always true
>> for (j = 0; j < entries; j++) {
>> ^~~~~~~~~~~
>> drivers/pci/hotplug/rpaphp_core.c:233:14: note: initialize the variable
>> 'fndit' to silence this warning
>> int j, fndit;
>> ^
>> = 0
>>
>> fndit is only used to gate a sprintf call, which can be moved into the
>> loop to simplify the code and eliminate the local variable, which will
>> fix this warning.
>>
>> Link: https://github.com/ClangBuiltLinux/linux/issues/504
>> Fixes: 2fcf3ae508c2 ("hotplug/drc-info: Add code to search ibm,drc-info property")
>> Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
>> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
>> ---
>>
>> v1 -> v2:
>>
>> * Eliminate fndit altogether by shuffling the sprintf call into the for
>> loop and changing the if conditional, as suggested by Nick.
>>
>> drivers/pci/hotplug/rpaphp_core.c | 18 +++++++-----------
>> 1 file changed, 7 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
>> index bcd5d357ca23..c3899ee1db99 100644
>> --- a/drivers/pci/hotplug/rpaphp_core.c
>> +++ b/drivers/pci/hotplug/rpaphp_core.c
>> @@ -230,7 +230,7 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
>> struct of_drc_info drc;
>> const __be32 *value;
>> char cell_drc_name[MAX_DRC_NAME_LEN];
>> - int j, fndit;
>> + int j;
>>
>> info = of_find_property(dn->parent, "ibm,drc-info", NULL);
>> if (info == NULL)
>> @@ -245,17 +245,13 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
>>
>> /* Should now know end of current entry */
>>
>> - if (my_index > drc.last_drc_index)
>> - continue;
>> -
>> - fndit = 1;
>> - break;
>> + /* Found it */
>> + if (my_index <= drc.last_drc_index) {
>> + sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
>> + my_index);
>> + break;
>> + }
>> }
>> - /* Found it */
>> -
>> - if (fndit)
>> - sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
>> - my_index);
>>
>> if (((drc_name == NULL) ||
>> (drc_name && !strcmp(drc_name, cell_drc_name))) &&
>> --
>> 2.22.0.rc3
>>
>
> Hi all,
>
> Could someone please pick this up?

I'll take it.

I was expecting Bjorn to take it as a PCI patch, but I realise now that
I merged that code in the first place so may as well take this too.

I'll put it in my next branch once that opens next week.

cheers

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