RE: [PATCH] selftests/bpf: use !E instead of comparing with NULL
> -Original Message-
> From: Alexei Starovoitov
>
> On Tue, Apr 13, 2021 at 9:32 AM wrote:
> >
> > > -Original Message-
> > > From: Alexei Starovoitov
> > >
> > > On Tue, Apr 13, 2021 at 9:19 AM wrote:
> > > >
> > > > > -Original Message-
> > > > > From: Alexei Starovoitov
> > > > >
> > > > > On Tue, Apr 13, 2021 at 9:10 AM wrote:
> > > > > >
> > > > > >
> > > > > >
> > > > > > > -Original Message-
> > > > > > > From: Alexei Starovoitov
> > > > > > >
> > > > > > > On Tue, Apr 13, 2021 at 2:52 AM Yang Li
> > > > > > > wrote:
> > > > > > > >
> > > > > > > > Fix the following coccicheck warnings:
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11:
> > > > > > > > WARNING
> > > > > > > > comparing pointer to 0, suggest !E
> > > > > > > >
> > > > > > > > Reported-by: Abaci Robot
> > > > > > > > Signed-off-by: Yang Li
> > > > > > > > ---
> > > > > > > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > > > > > > +++---
> > > > > > > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > > index 4896fdf8..a33066c 100644
> > > > > > > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > > @@ -189,7 +189,7 @@ static INLINE void
> > > > > > > > populate_ancestors(struct task_struct* task,
> > > > > > > > #endif
> > > > > > > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > > > > > > num_ancestors++) {
> > > > > > > > parent = BPF_CORE_READ(parent, real_parent);
> > > > > > > > - if (parent == NULL)
> > > > > > > > + if (!parent)
> > > > > > >
> > > > > > > Sorry, but I'd like the progs to stay as close as possible to the
> > > > > > > way
> > > > > > > they were written.
> > > > > > Why?
> > > > > >
> > > > > > > They might not adhere to kernel coding style in some cases.
> > > > > > > The code could be grossly inefficient and even buggy.
> > > > > > There would have to be a really good reason to accept
> > > > > > grossly inefficient and even buggy code into the kernel.
> > > > > >
> > > > > > Can you please explain what that reason is?
> > > > >
> > > > > It's not the kernel. It's a test of bpf program.
> > > > That doesn't answer the question of why you don't want any changes.
> > > >
> > > > Why would we not use kernel coding style guidelines and quality
> > > > thresholds for
> > > > testing code? This *is* going into the kernel source tree, where it
> > > > will be
> > > > maintained and used by other developers.
> > >
> > > because the way the C code is written makes llvm generate a particular
> > > code pattern that may not be seen otherwise.
> > > Like removing 'if' because it's useless to humans, but not to the compiler
> > > will change generated code which may or may not trigger the behavior
> > > the prog intends to cover.
> > > In particular this profiler.inc.h test is compiled three different ways to
> > > maximize code generation differences.
> > > It may not be checking error paths in some cases which can be considered
> > > a bug, but that's the intended behavior of the C code as it was written.
> > > So it has nothing to do with "quality of kernel code".
> > > and it should not be used by developers. It's neither sample nor example.
> >
> > Ok - in this case it looks like a program, but it is essentially test data
> > (for testing
> > the compiler). Thanks for the explanation.
>
> yes. That's a good way of saying it.
> Of course not all tests are like this.
> Majority of bpf progs in selftests/bpf/progs/ are carefully written,
> short and designed
> as a unit test. While few are "test data" for llvm.
Thanks. It mi
Re: [PATCH] selftests/bpf: use !E instead of comparing with NULL
On Tue, Apr 13, 2021 at 9:32 AM wrote:
>
> > -Original Message-
> > From: Alexei Starovoitov
> >
> > On Tue, Apr 13, 2021 at 9:19 AM wrote:
> > >
> > > > -Original Message-
> > > > From: Alexei Starovoitov
> > > >
> > > > On Tue, Apr 13, 2021 at 9:10 AM wrote:
> > > > >
> > > > >
> > > > >
> > > > > > -Original Message-
> > > > > > From: Alexei Starovoitov
> > > > > >
> > > > > > On Tue, Apr 13, 2021 at 2:52 AM Yang Li
> > > > > > wrote:
> > > > > > >
> > > > > > > Fix the following coccicheck warnings:
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11:
> > > > > > > WARNING
> > > > > > > comparing pointer to 0, suggest !E
> > > > > > >
> > > > > > > Reported-by: Abaci Robot
> > > > > > > Signed-off-by: Yang Li
> > > > > > > ---
> > > > > > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > > > > > +++---
> > > > > > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > > > > > >
> > > > > > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > index 4896fdf8..a33066c 100644
> > > > > > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > > > > > > task_struct* task,
> > > > > > > #endif
> > > > > > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > > > > > num_ancestors++) {
> > > > > > > parent = BPF_CORE_READ(parent, real_parent);
> > > > > > > - if (parent == NULL)
> > > > > > > + if (!parent)
> > > > > >
> > > > > > Sorry, but I'd like the progs to stay as close as possible to the
> > > > > > way
> > > > > > they were written.
> > > > > Why?
> > > > >
> > > > > > They might not adhere to kernel coding style in some cases.
> > > > > > The code could be grossly inefficient and even buggy.
> > > > > There would have to be a really good reason to accept
> > > > > grossly inefficient and even buggy code into the kernel.
> > > > >
> > > > > Can you please explain what that reason is?
> > > >
> > > > It's not the kernel. It's a test of bpf program.
> > > That doesn't answer the question of why you don't want any changes.
> > >
> > > Why would we not use kernel coding style guidelines and quality
> > > thresholds for
> > > testing code? This *is* going into the kernel source tree, where it will
> > > be
> > > maintained and used by other developers.
> >
> > because the way the C code is written makes llvm generate a particular
> > code pattern that may not be seen otherwise.
> > Like removing 'if' because it's useless to humans, but not to the compiler
> > will change generated code which may or may not trigger the behavior
> > the prog intends to cover.
> > In particular this profiler.inc.h test is compiled three different ways to
> > maximize code generation differences.
> > It may not be checking error paths in some cases which can be considered
> > a bug, but that's the intended behavior of the C code as it was written.
> > So it has nothing to do with "quality of kernel code".
> > and it should not be used by developers. It's neither sample nor example.
>
> Ok - in this case it looks like a program, but it is essentially test data
> (for testing
> the compiler). Thanks for the explanation.
yes. That's a good way of saying it.
Of course not all tests are like this.
Majority of bpf progs in selftests/bpf/progs/ are carefully written,
short and designed
as a unit test. While few are "test data" for llvm.
RE: [PATCH] selftests/bpf: use !E instead of comparing with NULL
> -Original Message-
> From: Alexei Starovoitov
>
> On Tue, Apr 13, 2021 at 9:19 AM wrote:
> >
> > > -Original Message-
> > > From: Alexei Starovoitov
> > >
> > > On Tue, Apr 13, 2021 at 9:10 AM wrote:
> > > >
> > > >
> > > >
> > > > > -Original Message-
> > > > > From: Alexei Starovoitov
> > > > >
> > > > > On Tue, Apr 13, 2021 at 2:52 AM Yang Li
> > > > > wrote:
> > > > > >
> > > > > > Fix the following coccicheck warnings:
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18:
> > > > > > WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18:
> > > > > > WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18:
> > > > > > WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> > > > > > comparing pointer to 0, suggest !E
> > > > > >
> > > > > > Reported-by: Abaci Robot
> > > > > > Signed-off-by: Yang Li
> > > > > > ---
> > > > > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > > > > +++---
> > > > > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > > > > >
> > > > > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > index 4896fdf8..a33066c 100644
> > > > > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > > > > > task_struct* task,
> > > > > > #endif
> > > > > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > > > > num_ancestors++) {
> > > > > > parent = BPF_CORE_READ(parent, real_parent);
> > > > > > - if (parent == NULL)
> > > > > > + if (!parent)
> > > > >
> > > > > Sorry, but I'd like the progs to stay as close as possible to the way
> > > > > they were written.
> > > > Why?
> > > >
> > > > > They might not adhere to kernel coding style in some cases.
> > > > > The code could be grossly inefficient and even buggy.
> > > > There would have to be a really good reason to accept
> > > > grossly inefficient and even buggy code into the kernel.
> > > >
> > > > Can you please explain what that reason is?
> > >
> > > It's not the kernel. It's a test of bpf program.
> > That doesn't answer the question of why you don't want any changes.
> >
> > Why would we not use kernel coding style guidelines and quality thresholds
> > for
> > testing code? This *is* going into the kernel source tree, where it will be
> > maintained and used by other developers.
>
> because the way the C code is written makes llvm generate a particular
> code pattern that may not be seen otherwise.
> Like removing 'if' because it's useless to humans, but not to the compiler
> will change generated code which may or may not trigger the behavior
> the prog intends to cover.
> In particular this profiler.inc.h test is compiled three different ways to
> maximize code generation differences.
> It may not be checking error paths in some cases which can be considered
> a bug, but that's the intended behavior of the C code as it was written.
> So it has nothing to do with "quality of kernel code".
> and it should not be used by developers. It's neither sample nor example.
Ok - in this case it looks like a program, but it is essentially test data (for
testing
the compiler). Thanks for the explanation.
-- Tim
Re: [PATCH] selftests/bpf: use !E instead of comparing with NULL
On Tue, Apr 13, 2021 at 9:19 AM wrote:
>
> > -Original Message-
> > From: Alexei Starovoitov
> >
> > On Tue, Apr 13, 2021 at 9:10 AM wrote:
> > >
> > >
> > >
> > > > -Original Message-
> > > > From: Alexei Starovoitov
> > > >
> > > > On Tue, Apr 13, 2021 at 2:52 AM Yang Li
> > > > wrote:
> > > > >
> > > > > Fix the following coccicheck warnings:
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> > > > > comparing pointer to 0, suggest !E
> > > > >
> > > > > Reported-by: Abaci Robot
> > > > > Signed-off-by: Yang Li
> > > > > ---
> > > > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > > > +++---
> > > > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > > > >
> > > > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > index 4896fdf8..a33066c 100644
> > > > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > > > > task_struct* task,
> > > > > #endif
> > > > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > > > num_ancestors++) {
> > > > > parent = BPF_CORE_READ(parent, real_parent);
> > > > > - if (parent == NULL)
> > > > > + if (!parent)
> > > >
> > > > Sorry, but I'd like the progs to stay as close as possible to the way
> > > > they were written.
> > > Why?
> > >
> > > > They might not adhere to kernel coding style in some cases.
> > > > The code could be grossly inefficient and even buggy.
> > > There would have to be a really good reason to accept
> > > grossly inefficient and even buggy code into the kernel.
> > >
> > > Can you please explain what that reason is?
> >
> > It's not the kernel. It's a test of bpf program.
> That doesn't answer the question of why you don't want any changes.
>
> Why would we not use kernel coding style guidelines and quality thresholds for
> testing code? This *is* going into the kernel source tree, where it will be
> maintained and used by other developers.
because the way the C code is written makes llvm generate a particular
code pattern that may not be seen otherwise.
Like removing 'if' because it's useless to humans, but not to the compiler
will change generated code which may or may not trigger the behavior
the prog intends to cover.
In particular this profiler.inc.h test is compiled three different ways to
maximize code generation differences.
It may not be checking error paths in some cases which can be considered
a bug, but that's the intended behavior of the C code as it was written.
So it has nothing to do with "quality of kernel code".
and it should not be used by developers. It's neither sample nor example.
RE: [PATCH] selftests/bpf: use !E instead of comparing with NULL
> -Original Message-
> From: Alexei Starovoitov
>
> On Tue, Apr 13, 2021 at 2:52 AM Yang Li wrote:
> >
> > Fix the following coccicheck warnings:
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> > comparing pointer to 0, suggest !E
> > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> > comparing pointer to 0, suggest !E
> >
> > Reported-by: Abaci Robot
> > Signed-off-by: Yang Li
> > ---
> > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > +++---
> > 1 file changed, 11 insertions(+), 11 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > index 4896fdf8..a33066c 100644
> > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > task_struct* task,
> > #endif
> > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > num_ancestors++) {
> > parent = BPF_CORE_READ(parent, real_parent);
> > - if (parent == NULL)
> > + if (!parent)
>
> Sorry, but I'd like the progs to stay as close as possible to the way
> they were written.
Why?
> They might not adhere to kernel coding style in some cases.
> The code could be grossly inefficient and even buggy.
There would have to be a really good reason to accept
grossly inefficient and even buggy code into the kernel.
Can you please explain what that reason is?
> Please don't run spell checks, coccicheck, checkpatch.pl on them.
-- Tim
RE: [PATCH] selftests/bpf: use !E instead of comparing with NULL
> -Original Message-
> From: Alexei Starovoitov
>
> On Tue, Apr 13, 2021 at 9:10 AM wrote:
> >
> >
> >
> > > -Original Message-
> > > From: Alexei Starovoitov
> > >
> > > On Tue, Apr 13, 2021 at 2:52 AM Yang Li
> > > wrote:
> > > >
> > > > Fix the following coccicheck warnings:
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> > > > comparing pointer to 0, suggest !E
> > > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> > > > comparing pointer to 0, suggest !E
> > > >
> > > > Reported-by: Abaci Robot
> > > > Signed-off-by: Yang Li
> > > > ---
> > > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > > +++---
> > > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > > >
> > > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > index 4896fdf8..a33066c 100644
> > > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > > > task_struct* task,
> > > > #endif
> > > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > > num_ancestors++) {
> > > > parent = BPF_CORE_READ(parent, real_parent);
> > > > - if (parent == NULL)
> > > > + if (!parent)
> > >
> > > Sorry, but I'd like the progs to stay as close as possible to the way
> > > they were written.
> > Why?
> >
> > > They might not adhere to kernel coding style in some cases.
> > > The code could be grossly inefficient and even buggy.
> > There would have to be a really good reason to accept
> > grossly inefficient and even buggy code into the kernel.
> >
> > Can you please explain what that reason is?
>
> It's not the kernel. It's a test of bpf program.
That doesn't answer the question of why you don't want any changes.
Why would we not use kernel coding style guidelines and quality thresholds for
testing code? This *is* going into the kernel source tree, where it will be
maintained and used by other developers.
-- Tim
Re: [PATCH] selftests/bpf: use !E instead of comparing with NULL
On Tue, Apr 13, 2021 at 9:10 AM wrote:
>
>
>
> > -Original Message-
> > From: Alexei Starovoitov
> >
> > On Tue, Apr 13, 2021 at 2:52 AM Yang Li wrote:
> > >
> > > Fix the following coccicheck warnings:
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> > > comparing pointer to 0, suggest !E
> > > ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> > > comparing pointer to 0, suggest !E
> > >
> > > Reported-by: Abaci Robot
> > > Signed-off-by: Yang Li
> > > ---
> > > tools/testing/selftests/bpf/progs/profiler.inc.h | 22
> > > +++---
> > > 1 file changed, 11 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > index 4896fdf8..a33066c 100644
> > > --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> > > @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct
> > > task_struct* task,
> > > #endif
> > > for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> > > num_ancestors++) {
> > > parent = BPF_CORE_READ(parent, real_parent);
> > > - if (parent == NULL)
> > > + if (!parent)
> >
> > Sorry, but I'd like the progs to stay as close as possible to the way
> > they were written.
> Why?
>
> > They might not adhere to kernel coding style in some cases.
> > The code could be grossly inefficient and even buggy.
> There would have to be a really good reason to accept
> grossly inefficient and even buggy code into the kernel.
>
> Can you please explain what that reason is?
It's not the kernel. It's a test of bpf program.
Re: [PATCH] selftests/bpf: use !E instead of comparing with NULL
On Tue, Apr 13, 2021 at 2:52 AM Yang Li wrote:
>
> Fix the following coccicheck warnings:
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:189:7-11: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:361:7-11: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:386:14-18: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:402:14-18: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:433:7-11: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:534:14-18: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:625:7-11: WARNING
> comparing pointer to 0, suggest !E
> ./tools/testing/selftests/bpf/progs/profiler.inc.h:767:7-11: WARNING
> comparing pointer to 0, suggest !E
>
> Reported-by: Abaci Robot
> Signed-off-by: Yang Li
> ---
> tools/testing/selftests/bpf/progs/profiler.inc.h | 22 +++---
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> b/tools/testing/selftests/bpf/progs/profiler.inc.h
> index 4896fdf8..a33066c 100644
> --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> @@ -189,7 +189,7 @@ static INLINE void populate_ancestors(struct task_struct*
> task,
> #endif
> for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS;
> num_ancestors++) {
> parent = BPF_CORE_READ(parent, real_parent);
> - if (parent == NULL)
> + if (!parent)
Sorry, but I'd like the progs to stay as close as possible to the way
they were written.
They might not adhere to kernel coding style in some cases.
The code could be grossly inefficient and even buggy.
Please don't run spell checks, coccicheck, checkpatch.pl on them.
