| Message ID | 20241205154247.43444-6-ubizjak@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Enable strict percpu address space checks | expand |
Hi Uros, On Thu, Dec 05, 2024 at 04:40:55PM +0100, Uros Bizjak wrote: > The patch introduces per_cpu_qual define and repurposes __percpu > tag as a named address space qualifier using the new define. > > Arches can now conditionally define __per_cpu_qual as their > named address space qualifier for percpu variables. > > Signed-off-by: Uros Bizjak <ubizjak@gmail.com> > Acked-by: Nadav Amit <nadav.amit@gmail.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Dennis Zhou <dennis@kernel.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: Christoph Lameter <cl@linux.com> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Brian Gerst <brgerst@gmail.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Peter Zijlstra <peterz@infradead.org> > --- > include/asm-generic/percpu.h | 15 +++++++++++++++ > include/linux/compiler_types.h | 2 +- > 2 files changed, 16 insertions(+), 1 deletion(-) > > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h > index 50597b975a49..3b93b168faa1 100644 > --- a/include/asm-generic/percpu.h > +++ b/include/asm-generic/percpu.h > @@ -6,6 +6,21 @@ > #include <linux/threads.h> > #include <linux/percpu-defs.h> > > +/* > + * per_cpu_qual is the qualifier for the percpu named address space. > + * > + * Most arches use generic named address space for percpu variables but > + * some arches define percpu variables in different named address space > + * (on the x86 arch, percpu variable may be declared as being relative > + * to the %fs or %gs segments using __seg_fs or __seg_gs named address > + * space qualifier). > + */ > +#ifdef __per_cpu_qual I read through the series and I think my only nit would be here. Can we name this __percpu_qual? My thoughts are that it keeps it consistent with the old address space identifier and largely most of the core percpu stuff is defined with percpu as the naming scheme. > +# define per_cpu_qual __per_cpu_qual > +#else > +# define per_cpu_qual > +#endif > + > #ifdef CONFIG_SMP > > /* > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h > index 981cc3d7e3aa..877fe0c43c5d 100644 > --- a/include/linux/compiler_types.h > +++ b/include/linux/compiler_types.h > @@ -57,7 +57,7 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { } > # define __user BTF_TYPE_TAG(user) > # endif > # define __iomem > -# define __percpu BTF_TYPE_TAG(percpu) > +# define __percpu per_cpu_qual BTF_TYPE_TAG(percpu) > # define __rcu BTF_TYPE_TAG(rcu) > > # define __chk_user_ptr(x) (void)0 > -- > 2.42.0 > Thanks, Dennis
On Thu, 5 Dec 2024, Dennis Zhou wrote: > I read through the series and I think my only nit would be here. Can we > name this __percpu_qual? My thoughts are that it keeps it consistent > with the old address space identifier and largely most of the core > percpu stuff is defined with percpu as the naming scheme. Yes lets keep it consistent.
On Fri, Dec 6, 2024 at 8:35 AM Dennis Zhou <dennis@kernel.org> wrote: > > Hi Uros, > > On Thu, Dec 05, 2024 at 04:40:55PM +0100, Uros Bizjak wrote: > > The patch introduces per_cpu_qual define and repurposes __percpu > > tag as a named address space qualifier using the new define. > > > > Arches can now conditionally define __per_cpu_qual as their > > named address space qualifier for percpu variables. > > > > Signed-off-by: Uros Bizjak <ubizjak@gmail.com> > > Acked-by: Nadav Amit <nadav.amit@gmail.com> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Cc: Dennis Zhou <dennis@kernel.org> > > Cc: Tejun Heo <tj@kernel.org> > > Cc: Christoph Lameter <cl@linux.com> > > Cc: Linus Torvalds <torvalds@linux-foundation.org> > > Cc: Andy Lutomirski <luto@kernel.org> > > Cc: Ingo Molnar <mingo@kernel.org> > > Cc: Brian Gerst <brgerst@gmail.com> > > Cc: "H. Peter Anvin" <hpa@zytor.com> > > Cc: Peter Zijlstra <peterz@infradead.org> > > --- > > include/asm-generic/percpu.h | 15 +++++++++++++++ > > include/linux/compiler_types.h | 2 +- > > 2 files changed, 16 insertions(+), 1 deletion(-) > > > > diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h > > index 50597b975a49..3b93b168faa1 100644 > > --- a/include/asm-generic/percpu.h > > +++ b/include/asm-generic/percpu.h > > @@ -6,6 +6,21 @@ > > #include <linux/threads.h> > > #include <linux/percpu-defs.h> > > > > +/* > > + * per_cpu_qual is the qualifier for the percpu named address space. > > + * > > + * Most arches use generic named address space for percpu variables but > > + * some arches define percpu variables in different named address space > > + * (on the x86 arch, percpu variable may be declared as being relative > > + * to the %fs or %gs segments using __seg_fs or __seg_gs named address > > + * space qualifier). > > + */ > > +#ifdef __per_cpu_qual > > I read through the series and I think my only nit would be here. Can we > name this __percpu_qual? My thoughts are that it keeps it consistent > with the old address space identifier and largely most of the core > percpu stuff is defined with percpu as the naming scheme. I based the approach on the definition of per_cpu_offset() a few lines bellow in include/asm-generic/percpu.h: --q-- #ifndef __per_cpu_offset extern unsigned long __per_cpu_offset[NR_CPUS]; #define per_cpu_offset(x) (__per_cpu_offset[x]) #endif --/q-- Sure, we can call this __percpu_qual. So, the definition in arch/x86/include/asm/percpu.h would read as: # define __percpu_qual __percpu_seg_override > > +# define per_cpu_qual __per_cpu_qual > > +#else > > +# define per_cpu_qual > > +#endif The above part could be recoded as: #ifndef __percpu_qual # define __percpu_qual #endif while the line below would become: # define __percpu __percpu_qual BTF_TYPE_TAG(percpu) > > + > > #ifdef CONFIG_SMP > > > > /* > > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h > > index 981cc3d7e3aa..877fe0c43c5d 100644 > > --- a/include/linux/compiler_types.h > > +++ b/include/linux/compiler_types.h > > @@ -57,7 +57,7 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { } > > # define __user BTF_TYPE_TAG(user) > > # endif > > # define __iomem > > -# define __percpu BTF_TYPE_TAG(percpu) > > +# define __percpu per_cpu_qual BTF_TYPE_TAG(percpu) > > # define __rcu BTF_TYPE_TAG(rcu) > > > > # define __chk_user_ptr(x) (void)0 Let me test these changes a bit, I'll send a v3 in a couple of days. Thanks, Uros.
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index 50597b975a49..3b93b168faa1 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -6,6 +6,21 @@ #include <linux/threads.h> #include <linux/percpu-defs.h> +/* + * per_cpu_qual is the qualifier for the percpu named address space. + * + * Most arches use generic named address space for percpu variables but + * some arches define percpu variables in different named address space + * (on the x86 arch, percpu variable may be declared as being relative + * to the %fs or %gs segments using __seg_fs or __seg_gs named address + * space qualifier). + */ +#ifdef __per_cpu_qual +# define per_cpu_qual __per_cpu_qual +#else +# define per_cpu_qual +#endif + #ifdef CONFIG_SMP /* diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 981cc3d7e3aa..877fe0c43c5d 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -57,7 +57,7 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { } # define __user BTF_TYPE_TAG(user) # endif # define __iomem -# define __percpu BTF_TYPE_TAG(percpu) +# define __percpu per_cpu_qual BTF_TYPE_TAG(percpu) # define __rcu BTF_TYPE_TAG(rcu) # define __chk_user_ptr(x) (void)0