Re: [PATCH v2] PCI: rpaphp: Avoid a sometimes-uninitialized warning

From: Joel Savitz
Date: Thu Jun 27 2019 - 22:59:14 EST


>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@xxxxxxxxxx>
>> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
>> ---
>>
>> 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(-)

>> Gentle ping, can someone pick this up?

Looks a good simplification of somewhat convoluted control flow.

Acked-by: Joel Savitz <jsavitz@xxxxxxxxxx>