* [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
@ 2020-04-08 20:53 Nathan Chancellor
2020-04-08 21:12 ` Sedat Dilek
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Nathan Chancellor @ 2020-04-08 20:53 UTC (permalink / raw)
To: Steven Rostedt, Ingo Molnar
Cc: Karol Herbst, Pekka Paalanen, x86, linux-kernel, nouveau,
clang-built-linux, Nathan Chancellor, Sedat Dilek
When building with Clang + -Wtautological-compare and
CONFIG_CPUMASK_OFFSTACK unset:
arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL &&
^~~~~~~~~~~ ~~~~
arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
^~~~~~~~~~~ ~~~~
2 warnings generated.
Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
cpumask_available to fix warnings of this nature. Use that here so that
clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
Link: https://github.com/ClangBuiltLinux/linux/issues/982
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
arch/x86/mm/mmio-mod.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index 109325d77b3e..43fd19b3f118 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL &&
+ if (!cpumask_available(downed_cpus) &&
!alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
pr_notice("Failed to allocate mask\n");
goto out;
@@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
+ if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
return;
pr_notice("Re-enabling CPUs...\n");
for_each_cpu(cpu, downed_cpus) {
base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
--
2.26.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-04-08 20:53 [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables Nathan Chancellor
@ 2020-04-08 21:12 ` Sedat Dilek
2020-04-08 21:36 ` Sedat Dilek
2020-04-15 13:51 ` Steven Rostedt
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Sedat Dilek @ 2020-04-08 21:12 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Steven Rostedt, Ingo Molnar, Karol Herbst, Pekka Paalanen, x86,
linux-kernel, nouveau, Clang-Built-Linux ML
On Wed, Apr 8, 2020 at 10:53 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> When building with Clang + -Wtautological-compare and
> CONFIG_CPUMASK_OFFSTACK unset:
>
Hi Nathan,
thanks for the quick patch.
I can confirm I have no CONFIG_CPUMASK_OFFSTACK set.
Regards,
- Sedat -
> arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL &&
> ^~~~~~~~~~~ ~~~~
> arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> ^~~~~~~~~~~ ~~~~
> 2 warnings generated.
>
> Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> cpumask_available to fix warnings of this nature. Use that here so that
> clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/982
> Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> arch/x86/mm/mmio-mod.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
> index 109325d77b3e..43fd19b3f118 100644
> --- a/arch/x86/mm/mmio-mod.c
> +++ b/arch/x86/mm/mmio-mod.c
> @@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
> int cpu;
> int err;
>
> - if (downed_cpus == NULL &&
> + if (!cpumask_available(downed_cpus) &&
> !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
> pr_notice("Failed to allocate mask\n");
> goto out;
> @@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
> int cpu;
> int err;
>
> - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
> return;
> pr_notice("Re-enabling CPUs...\n");
> for_each_cpu(cpu, downed_cpus) {
>
> base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
> --
> 2.26.0
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-04-08 21:12 ` Sedat Dilek
@ 2020-04-08 21:36 ` Sedat Dilek
2020-04-15 13:58 ` Sedat Dilek
0 siblings, 1 reply; 10+ messages in thread
From: Sedat Dilek @ 2020-04-08 21:36 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Steven Rostedt, Ingo Molnar, Karol Herbst, Pekka Paalanen, x86,
linux-kernel, nouveau, Clang-Built-Linux ML
On Wed, Apr 8, 2020 at 11:12 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Wed, Apr 8, 2020 at 10:53 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > When building with Clang + -Wtautological-compare and
> > CONFIG_CPUMASK_OFFSTACK unset:
> >
>
> Hi Nathan,
>
> thanks for the quick patch.
>
> I can confirm I have no CONFIG_CPUMASK_OFFSTACK set.
>
Feel free to add appropriate credits:
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Regards,
- Sedat -
>
> > arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > if (downed_cpus == NULL &&
> > ^~~~~~~~~~~ ~~~~
> > arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > ^~~~~~~~~~~ ~~~~
> > 2 warnings generated.
> >
> > Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> > cpumask_available to fix warnings of this nature. Use that here so that
> > clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/982
> > Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > ---
> > arch/x86/mm/mmio-mod.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
> > index 109325d77b3e..43fd19b3f118 100644
> > --- a/arch/x86/mm/mmio-mod.c
> > +++ b/arch/x86/mm/mmio-mod.c
> > @@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
> > int cpu;
> > int err;
> >
> > - if (downed_cpus == NULL &&
> > + if (!cpumask_available(downed_cpus) &&
> > !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
> > pr_notice("Failed to allocate mask\n");
> > goto out;
> > @@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
> > int cpu;
> > int err;
> >
> > - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
> > return;
> > pr_notice("Re-enabling CPUs...\n");
> > for_each_cpu(cpu, downed_cpus) {
> >
> > base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
> > --
> > 2.26.0
> >
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-04-08 20:53 [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables Nathan Chancellor
2020-04-08 21:12 ` Sedat Dilek
@ 2020-04-15 13:51 ` Steven Rostedt
2020-05-18 9:31 ` Nathan Chancellor
2020-05-19 17:52 ` [tip: x86/urgent] x86/mmiotrace: Use cpumask_available() " tip-bot2 for Nathan Chancellor
3 siblings, 0 replies; 10+ messages in thread
From: Steven Rostedt @ 2020-04-15 13:51 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Ingo Molnar, Karol Herbst, Pekka Paalanen, x86, linux-kernel,
nouveau, clang-built-linux, Sedat Dilek
On Wed, 8 Apr 2020 13:53:23 -0700
Nathan Chancellor <natechancellor@gmail.com> wrote:
> When building with Clang + -Wtautological-compare and
> CONFIG_CPUMASK_OFFSTACK unset:
>
> arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL &&
> ^~~~~~~~~~~ ~~~~
> arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> ^~~~~~~~~~~ ~~~~
> 2 warnings generated.
>
> Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> cpumask_available to fix warnings of this nature. Use that here so that
> clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/982
> Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-04-08 21:36 ` Sedat Dilek
@ 2020-04-15 13:58 ` Sedat Dilek
0 siblings, 0 replies; 10+ messages in thread
From: Sedat Dilek @ 2020-04-15 13:58 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Steven Rostedt, Ingo Molnar, Karol Herbst, Pekka Paalanen, x86,
linux-kernel, nouveau, Clang-Built-Linux ML
On Wed, Apr 8, 2020 at 11:36 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
[ ... ]
> Feel free to add appropriate credits:
>
> Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
>
Re-tested with Linux v5.7-rc1 which shows this warning - with GCC v9.3
and LLVM/Clang v10.0.0 (and snapshot/pre-release of v10.0.1) on
Debian/testing AMD64.
- Sedat -
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-04-08 20:53 [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables Nathan Chancellor
2020-04-08 21:12 ` Sedat Dilek
2020-04-15 13:51 ` Steven Rostedt
@ 2020-05-18 9:31 ` Nathan Chancellor
2020-05-18 18:52 ` Nick Desaulniers
2020-05-19 17:52 ` [tip: x86/urgent] x86/mmiotrace: Use cpumask_available() " tip-bot2 for Nathan Chancellor
3 siblings, 1 reply; 10+ messages in thread
From: Nathan Chancellor @ 2020-05-18 9:31 UTC (permalink / raw)
To: Steven Rostedt, Ingo Molnar
Cc: Karol Herbst, Pekka Paalanen, x86, linux-kernel, nouveau,
clang-built-linux, Sedat Dilek
On Wed, Apr 08, 2020 at 01:53:23PM -0700, Nathan Chancellor wrote:
> When building with Clang + -Wtautological-compare and
> CONFIG_CPUMASK_OFFSTACK unset:
>
> arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL &&
> ^~~~~~~~~~~ ~~~~
> arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> equal to a null pointer is always false [-Wtautological-pointer-compare]
> if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> ^~~~~~~~~~~ ~~~~
> 2 warnings generated.
>
> Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> cpumask_available to fix warnings of this nature. Use that here so that
> clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/982
> Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> arch/x86/mm/mmio-mod.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
> index 109325d77b3e..43fd19b3f118 100644
> --- a/arch/x86/mm/mmio-mod.c
> +++ b/arch/x86/mm/mmio-mod.c
> @@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
> int cpu;
> int err;
>
> - if (downed_cpus == NULL &&
> + if (!cpumask_available(downed_cpus) &&
> !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
> pr_notice("Failed to allocate mask\n");
> goto out;
> @@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
> int cpu;
> int err;
>
> - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
> return;
> pr_notice("Re-enabling CPUs...\n");
> for_each_cpu(cpu, downed_cpus) {
>
> base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
> --
> 2.26.0
>
Gentle ping for acceptance, I am not sure who should take this.
Cheers,
Nathan
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-05-18 9:31 ` Nathan Chancellor
@ 2020-05-18 18:52 ` Nick Desaulniers
2020-05-18 22:35 ` Steven Rostedt
0 siblings, 1 reply; 10+ messages in thread
From: Nick Desaulniers @ 2020-05-18 18:52 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Steven Rostedt, Ingo Molnar, Karol Herbst, Pekka Paalanen,
maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT),
LKML, nouveau, clang-built-linux, Sedat Dilek
On Mon, May 18, 2020 at 2:31 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Wed, Apr 08, 2020 at 01:53:23PM -0700, Nathan Chancellor wrote:
> > When building with Clang + -Wtautological-compare and
> > CONFIG_CPUMASK_OFFSTACK unset:
> >
> > arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > if (downed_cpus == NULL &&
> > ^~~~~~~~~~~ ~~~~
> > arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > ^~~~~~~~~~~ ~~~~
> > 2 warnings generated.
> >
> > Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> > cpumask_available to fix warnings of this nature. Use that here so that
> > clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/982
> > Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Thanks for the patch, sorry I'm falling behind on code review!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> > arch/x86/mm/mmio-mod.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
> > index 109325d77b3e..43fd19b3f118 100644
> > --- a/arch/x86/mm/mmio-mod.c
> > +++ b/arch/x86/mm/mmio-mod.c
> > @@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
> > int cpu;
> > int err;
> >
> > - if (downed_cpus == NULL &&
> > + if (!cpumask_available(downed_cpus) &&
> > !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
> > pr_notice("Failed to allocate mask\n");
> > goto out;
> > @@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
> > int cpu;
> > int err;
> >
> > - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
> > return;
> > pr_notice("Re-enabling CPUs...\n");
> > for_each_cpu(cpu, downed_cpus) {
> >
> > base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
> > --
> > 2.26.0
> >
>
> Gentle ping for acceptance, I am not sure who should take this.
Looks like Steven or Ingo are the listed maintainers for MMIOTRACE?
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-05-18 18:52 ` Nick Desaulniers
@ 2020-05-18 22:35 ` Steven Rostedt
2020-05-19 0:29 ` Linus Torvalds
0 siblings, 1 reply; 10+ messages in thread
From: Steven Rostedt @ 2020-05-18 22:35 UTC (permalink / raw)
To: Nick Desaulniers, Linus Torvalds
Cc: Nathan Chancellor, Ingo Molnar, Karol Herbst, Pekka Paalanen,
maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT),
LKML, nouveau, clang-built-linux, Sedat Dilek
On Mon, 18 May 2020 11:52:47 -0700
Nick Desaulniers <ndesaulniers@google.com> wrote:
> On Mon, May 18, 2020 at 2:31 AM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Wed, Apr 08, 2020 at 01:53:23PM -0700, Nathan Chancellor wrote:
> > > When building with Clang + -Wtautological-compare and
> > > CONFIG_CPUMASK_OFFSTACK unset:
> > >
> > > arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
> > > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > > if (downed_cpus == NULL &&
> > > ^~~~~~~~~~~ ~~~~
> > > arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
> > > equal to a null pointer is always false [-Wtautological-pointer-compare]
> > > if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > > ^~~~~~~~~~~ ~~~~
> > > 2 warnings generated.
> > >
> > > Commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") added
> > > cpumask_available to fix warnings of this nature. Use that here so that
> > > clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's value.
> > >
> > > Link: https://github.com/ClangBuiltLinux/linux/issues/982
> > > Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
>
> Thanks for the patch, sorry I'm falling behind on code review!
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Linus sent me a issue about this failure privately as well, and had two
solutions for it (one being identical to this one, and I shared that with
him, and another one he thought would be better, but had some issues).
Linus,
Are you OK with this patch?
-- Steve
>
> > > ---
> > > arch/x86/mm/mmio-mod.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
> > > index 109325d77b3e..43fd19b3f118 100644
> > > --- a/arch/x86/mm/mmio-mod.c
> > > +++ b/arch/x86/mm/mmio-mod.c
> > > @@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
> > > int cpu;
> > > int err;
> > >
> > > - if (downed_cpus == NULL &&
> > > + if (!cpumask_available(downed_cpus) &&
> > > !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
> > > pr_notice("Failed to allocate mask\n");
> > > goto out;
> > > @@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
> > > int cpu;
> > > int err;
> > >
> > > - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
> > > + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
> > > return;
> > > pr_notice("Re-enabling CPUs...\n");
> > > for_each_cpu(cpu, downed_cpus) {
> > >
> > > base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25
> > > --
> > > 2.26.0
> > >
> >
> > Gentle ping for acceptance, I am not sure who should take this.
>
> Looks like Steven or Ingo are the listed maintainers for MMIOTRACE?
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables
2020-05-18 22:35 ` Steven Rostedt
@ 2020-05-19 0:29 ` Linus Torvalds
0 siblings, 0 replies; 10+ messages in thread
From: Linus Torvalds @ 2020-05-19 0:29 UTC (permalink / raw)
To: Steven Rostedt
Cc: Nick Desaulniers, Nathan Chancellor, Ingo Molnar, Karol Herbst,
Pekka Paalanen, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT),
LKML, nouveau, clang-built-linux, Sedat Dilek
On Mon, May 18, 2020 at 3:35 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> Linus,
>
> Are you OK with this patch?
Yup, I don't care deeply either way, as long as we can get rid of the warning.
Linus
^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: x86/urgent] x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables
2020-04-08 20:53 [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables Nathan Chancellor
` (2 preceding siblings ...)
2020-05-18 9:31 ` Nathan Chancellor
@ 2020-05-19 17:52 ` tip-bot2 for Nathan Chancellor
3 siblings, 0 replies; 10+ messages in thread
From: tip-bot2 for Nathan Chancellor @ 2020-05-19 17:52 UTC (permalink / raw)
To: linux-tip-commits
Cc: Sedat Dilek, Nathan Chancellor, Borislav Petkov,
Nick Desaulniers, Steven Rostedt (VMware),
x86, LKML
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: d7110a26e5905ec2fe3fc88bc6a538901accb72b
Gitweb: https://git.kernel.org/tip/d7110a26e5905ec2fe3fc88bc6a538901accb72b
Author: Nathan Chancellor <natechancellor@gmail.com>
AuthorDate: Wed, 08 Apr 2020 13:53:23 -07:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Tue, 19 May 2020 19:30:28 +02:00
x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables
When building with Clang + -Wtautological-compare and
CONFIG_CPUMASK_OFFSTACK unset:
arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL &&
^~~~~~~~~~~ ~~~~
arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
^~~~~~~~~~~ ~~~~
2 warnings generated.
Commit
f7e30f01a9e2 ("cpumask: Add helper cpumask_available()")
added cpumask_available() to fix warnings of this nature. Use that here
so that clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's
value.
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/982
Link: https://lkml.kernel.org/r/20200408205323.44490-1-natechancellor@gmail.com
---
arch/x86/mm/mmio-mod.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index 109325d..43fd19b 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL &&
+ if (!cpumask_available(downed_cpus) &&
!alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
pr_notice("Failed to allocate mask\n");
goto out;
@@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
+ if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
return;
pr_notice("Re-enabling CPUs...\n");
for_each_cpu(cpu, downed_cpus) {
^ permalink raw reply related [flat|nested] 10+ messages in thread
end of thread, other threads:[~2020-05-19 17:52 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-08 20:53 [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables Nathan Chancellor
2020-04-08 21:12 ` Sedat Dilek
2020-04-08 21:36 ` Sedat Dilek
2020-04-15 13:58 ` Sedat Dilek
2020-04-15 13:51 ` Steven Rostedt
2020-05-18 9:31 ` Nathan Chancellor
2020-05-18 18:52 ` Nick Desaulniers
2020-05-18 22:35 ` Steven Rostedt
2020-05-19 0:29 ` Linus Torvalds
2020-05-19 17:52 ` [tip: x86/urgent] x86/mmiotrace: Use cpumask_available() " tip-bot2 for Nathan Chancellor
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