| Message ID | 20240311-arm32-cfi-v3-7-224a0f0a45c2@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | CFI for ARM32 using LLVM | expand |
On Mon, 11 Mar 2024 at 10:15, Linus Walleij <linus.walleij@linaro.org> wrote: > > Clearing and copying pages in highmem uses either the cpu_user > vtable or the __glue() assembler stubs to call into per-CPU > versions of these functions. > > This is all really confusing for KCFI so wrap these into static > inlines and prefix each inline function with __nocfi. > > __cpu_clear_user_highpage() and __cpu_copy_user_highpage() are > exported in arch/arm/mm/proc-syms.c which causes a problem with > using static inlines, but it turns out that these exports are > completely unused, so we can just delete them. > > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > arch/arm/include/asm/page.h | 36 +++++++++++++++++++++++++++++------- > arch/arm/mm/proc-syms.c | 7 +------ > 2 files changed, 30 insertions(+), 13 deletions(-) > Are you sure this patch is needed? > diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h > index 119aa85d1feb..8bf297228627 100644 > --- a/arch/arm/include/asm/page.h > +++ b/arch/arm/include/asm/page.h > @@ -138,17 +138,39 @@ void xscale_mc_clear_user_highpage(struct page *page, unsigned long vaddr); > #ifdef MULTI_USER > extern struct cpu_user_fns cpu_user; > > -#define __cpu_clear_user_highpage cpu_user.cpu_clear_user_highpage > -#define __cpu_copy_user_highpage cpu_user.cpu_copy_user_highpage > +static inline void __nocfi __cpu_clear_user_highpage(struct page *page, > + unsigned long vaddr) > +{ > + cpu_user.cpu_clear_user_highpage(page, vaddr); > +} > + > +static inline void __nocfi __cpu_copy_user_highpage(struct page *to, > + struct page *from, unsigned long vaddr, > + struct vm_area_struct *vma) > +{ > + cpu_user.cpu_copy_user_highpage(to, from, vaddr, vma); > +} > > #else > > -#define __cpu_clear_user_highpage __glue(_USER,_clear_user_highpage) > -#define __cpu_copy_user_highpage __glue(_USER,_copy_user_highpage) > +/* These turn into function declarations for each per-CPU glue function */ > +void __glue(_USER,_clear_user_highpage)(struct page *page, unsigned long vaddr); > +void __glue(_USER,_copy_user_highpage)(struct page *to, struct page *from, > + unsigned long vaddr, struct vm_area_struct *vma); > + > +static inline void __nocfi __cpu_clear_user_highpage(struct page *page, > + unsigned long vaddr) > +{ > + __glue(_USER,_clear_user_highpage)(page, vaddr); > +} > + > +static inline void __nocfi __cpu_copy_user_highpage(struct page *to, > + struct page *from, unsigned long vaddr, > + struct vm_area_struct *vma) > +{ > + __glue(_USER,_copy_user_highpage)(to, from, vaddr, vma); > +} > > -extern void __cpu_clear_user_highpage(struct page *page, unsigned long vaddr); > -extern void __cpu_copy_user_highpage(struct page *to, struct page *from, > - unsigned long vaddr, struct vm_area_struct *vma); > #endif > > #define clear_user_highpage(page,vaddr) \ > diff --git a/arch/arm/mm/proc-syms.c b/arch/arm/mm/proc-syms.c > index e21249548e9f..c93fec38d9f4 100644 > --- a/arch/arm/mm/proc-syms.c > +++ b/arch/arm/mm/proc-syms.c > @@ -31,14 +31,9 @@ EXPORT_SYMBOL(__cpuc_flush_dcache_area); > EXPORT_SYMBOL(cpu_cache); > #endif > > -#ifdef CONFIG_MMU > -#ifndef MULTI_USER > -EXPORT_SYMBOL(__cpu_clear_user_highpage); > -EXPORT_SYMBOL(__cpu_copy_user_highpage); > -#else > +#if defined(CONFIG_MMU) && defined(MULTI_USER) > EXPORT_SYMBOL(cpu_user); > #endif > -#endif > > /* > * No module should need to touch the TLB (and currently > > -- > 2.34.1 >
On Mon, Mar 11, 2024 at 1:15 PM Ard Biesheuvel <ardb@kernel.org> wrote: > On Mon, 11 Mar 2024 at 10:15, Linus Walleij <linus.walleij@linaro.org> wrote: > > > > Clearing and copying pages in highmem uses either the cpu_user > > vtable or the __glue() assembler stubs to call into per-CPU > > versions of these functions. > > > > This is all really confusing for KCFI so wrap these into static > > inlines and prefix each inline function with __nocfi. > > > > __cpu_clear_user_highpage() and __cpu_copy_user_highpage() are > > exported in arch/arm/mm/proc-syms.c which causes a problem with > > using static inlines, but it turns out that these exports are > > completely unused, so we can just delete them. > > > > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > > --- > > arch/arm/include/asm/page.h | 36 +++++++++++++++++++++++++++++------- > > arch/arm/mm/proc-syms.c | 7 +------ > > 2 files changed, 30 insertions(+), 13 deletions(-) > > > > Are you sure this patch is needed? It's not needed, it was a development artifact from fixing the highmem access before fixing cache and TLB flush. The highmem code did a bunch of that. Posting v4! Yours, Linus Walleij
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h index 119aa85d1feb..8bf297228627 100644 --- a/arch/arm/include/asm/page.h +++ b/arch/arm/include/asm/page.h @@ -138,17 +138,39 @@ void xscale_mc_clear_user_highpage(struct page *page, unsigned long vaddr); #ifdef MULTI_USER extern struct cpu_user_fns cpu_user; -#define __cpu_clear_user_highpage cpu_user.cpu_clear_user_highpage -#define __cpu_copy_user_highpage cpu_user.cpu_copy_user_highpage +static inline void __nocfi __cpu_clear_user_highpage(struct page *page, + unsigned long vaddr) +{ + cpu_user.cpu_clear_user_highpage(page, vaddr); +} + +static inline void __nocfi __cpu_copy_user_highpage(struct page *to, + struct page *from, unsigned long vaddr, + struct vm_area_struct *vma) +{ + cpu_user.cpu_copy_user_highpage(to, from, vaddr, vma); +} #else -#define __cpu_clear_user_highpage __glue(_USER,_clear_user_highpage) -#define __cpu_copy_user_highpage __glue(_USER,_copy_user_highpage) +/* These turn into function declarations for each per-CPU glue function */ +void __glue(_USER,_clear_user_highpage)(struct page *page, unsigned long vaddr); +void __glue(_USER,_copy_user_highpage)(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma); + +static inline void __nocfi __cpu_clear_user_highpage(struct page *page, + unsigned long vaddr) +{ + __glue(_USER,_clear_user_highpage)(page, vaddr); +} + +static inline void __nocfi __cpu_copy_user_highpage(struct page *to, + struct page *from, unsigned long vaddr, + struct vm_area_struct *vma) +{ + __glue(_USER,_copy_user_highpage)(to, from, vaddr, vma); +} -extern void __cpu_clear_user_highpage(struct page *page, unsigned long vaddr); -extern void __cpu_copy_user_highpage(struct page *to, struct page *from, - unsigned long vaddr, struct vm_area_struct *vma); #endif #define clear_user_highpage(page,vaddr) \ diff --git a/arch/arm/mm/proc-syms.c b/arch/arm/mm/proc-syms.c index e21249548e9f..c93fec38d9f4 100644 --- a/arch/arm/mm/proc-syms.c +++ b/arch/arm/mm/proc-syms.c @@ -31,14 +31,9 @@ EXPORT_SYMBOL(__cpuc_flush_dcache_area); EXPORT_SYMBOL(cpu_cache); #endif -#ifdef CONFIG_MMU -#ifndef MULTI_USER -EXPORT_SYMBOL(__cpu_clear_user_highpage); -EXPORT_SYMBOL(__cpu_copy_user_highpage); -#else +#if defined(CONFIG_MMU) && defined(MULTI_USER) EXPORT_SYMBOL(cpu_user); #endif -#endif /* * No module should need to touch the TLB (and currently
Clearing and copying pages in highmem uses either the cpu_user vtable or the __glue() assembler stubs to call into per-CPU versions of these functions. This is all really confusing for KCFI so wrap these into static inlines and prefix each inline function with __nocfi. __cpu_clear_user_highpage() and __cpu_copy_user_highpage() are exported in arch/arm/mm/proc-syms.c which causes a problem with using static inlines, but it turns out that these exports are completely unused, so we can just delete them. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- arch/arm/include/asm/page.h | 36 +++++++++++++++++++++++++++++------- arch/arm/mm/proc-syms.c | 7 +------ 2 files changed, 30 insertions(+), 13 deletions(-)