| Message ID | 20200615040047.3535543-1-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ACPI: Eliminate usage of uninitialized_var() macro | expand |
On Monday, June 15, 2020 6:00:47 AM CEST Jason Yan wrote: > This is an effort to eliminate the uninitialized_var() macro[1]. > > The use of this macro is the wrong solution because it forces off ANY > analysis by the compiler for a given variable. It even masks "unused > variable" warnings. > > Quoted from Linus[2]: > > "It's a horrible thing to use, in that it adds extra cruft to the > source code, and then shuts up a compiler warning (even the _reliable_ > warnings from gcc)." > > The gcc option "-Wmaybe-uninitialized" has been disabled and this change > will not produce any warnnings even with "make W=1". > > [1] https://github.com/KSPP/linux/issues/81 > [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ > > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Jason Yan <yanaijie@huawei.com> > --- > drivers/acpi/acpi_pad.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c > index e7dc0133f817..6cc4c92d9ff9 100644 > --- a/drivers/acpi/acpi_pad.c > +++ b/drivers/acpi/acpi_pad.c > @@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index) > cpumask_var_t tmp; > int cpu; > unsigned long min_weight = -1; > - unsigned long uninitialized_var(preferred_cpu); > + unsigned long preferred_cpu; > > if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) > return; > Applied as 5.9 material, thanks!
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index e7dc0133f817..6cc4c92d9ff9 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index) cpumask_var_t tmp; int cpu; unsigned long min_weight = -1; - unsigned long uninitialized_var(preferred_cpu); + unsigned long preferred_cpu; if (!alloc_cpumask_var(&tmp, GFP_KERNEL)) return;
This is an effort to eliminate the uninitialized_var() macro[1]. The use of this macro is the wrong solution because it forces off ANY analysis by the compiler for a given variable. It even masks "unused variable" warnings. Quoted from Linus[2]: "It's a horrible thing to use, in that it adds extra cruft to the source code, and then shuts up a compiler warning (even the _reliable_ warnings from gcc)." The gcc option "-Wmaybe-uninitialized" has been disabled and this change will not produce any warnnings even with "make W=1". [1] https://github.com/KSPP/linux/issues/81 [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Jason Yan <yanaijie@huawei.com> --- drivers/acpi/acpi_pad.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)