| Message ID | 20170930025319.987-6-sergey.senozhatsky@gmail.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream, archived |
| Headers | show |
On Sat 2017-09-30 11:53:17, Sergey Senozhatsky wrote: > We are moving towards separate kernel and module function descriptor > dereference callbacks. This patch enables it for parisc64. > > For pointers that belong to the kernel > - Added __start_opd and __end_opd pointers, to track the kernel > .opd section address range; > > - Added dereference_kernel_function_descriptor(). Now we > will dereference only function pointers that are within > [__start_opd, __end_opd]; > > For pointers that belong to a module > - Added dereference_module_function_descriptor() to handle module > function descriptor dereference. Now we will dereference only > pointers that are within [module->opd.start, module->opd.end]. > diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c > index f1a76935a314..28f89b3dcc11 100644 > --- a/arch/parisc/kernel/module.c > +++ b/arch/parisc/kernel/module.c > @@ -954,3 +955,19 @@ void module_arch_cleanup(struct module *mod) > { > deregister_unwind_table(mod); > } > + > +#ifdef CONFIG_64BIT > +unsigned long dereference_module_function_descriptor(struct module *mod, > + unsigned long addr) > +{ > + unsigned long start_opd = (Elf64_Addr)mod->core_layout.base + > + mod->arch.fdesc_offset; > + unsigned long end_opd = start_opd + > + mod->arch.fdesc_count * sizeof(Elf64_Fdesc); I know that this is used in rather slow paths. But it still might make sense to have these section borders pre-computed and stored in struct mod_arch_specific. I mean to do similar thing that we do on powerpc. Well, we could do this in a followup patch if parisc people wanted it. > + if (addr < start_opd || addr >= end_opd) > + return addr; > + > + return dereference_function_descriptor(addr); > +} > +#endif Otherwise the patch looks fine to me. Reviewed-by: Petr Mladek <pmladek@suse.com> Best Regards, Petr -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On (10/04/17 12:40), Petr Mladek wrote: > > +unsigned long dereference_module_function_descriptor(struct module *mod, > > + unsigned long addr) > > +{ > > + unsigned long start_opd = (Elf64_Addr)mod->core_layout.base + > > + mod->arch.fdesc_offset; > > + unsigned long end_opd = start_opd + > > + mod->arch.fdesc_count * sizeof(Elf64_Fdesc); > > I know that this is used in rather slow paths. But it still might > make sense to have these section borders pre-computed and > stored in struct mod_arch_specific. I mean to do similar > thing that we do on powerpc. > > Well, we could do this in a followup patch if parisc people > wanted it. > > > > + if (addr < start_opd || addr >= end_opd) > > + return addr; > > + > > + return dereference_function_descriptor(addr); > > +} > > +#endif > > Otherwise the patch looks fine to me. > > Reviewed-by: Petr Mladek <pmladek@suse.com> let's do it later, if need be. -ss -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/parisc/boot/compressed/vmlinux.lds.S b/arch/parisc/boot/compressed/vmlinux.lds.S index a4ce3314e78e..4ebd4e65524c 100644 --- a/arch/parisc/boot/compressed/vmlinux.lds.S +++ b/arch/parisc/boot/compressed/vmlinux.lds.S @@ -29,7 +29,9 @@ SECTIONS . = ALIGN(16); /* Linkage tables */ .opd : { + __start_opd = .; *(.opd) + __end_opd = .; } PROVIDE (__gp = .); .plt : { *(.plt) diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h index 59fbe0067112..845ddc9a3421 100644 --- a/arch/parisc/include/asm/sections.h +++ b/arch/parisc/include/asm/sections.h @@ -7,6 +7,8 @@ #ifdef CONFIG_64BIT #undef dereference_function_descriptor unsigned long dereference_function_descriptor(unsigned long); +#undef dereference_kernel_function_descriptor +unsigned long dereference_kernel_function_descriptor(unsigned long); #endif #endif diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c index f1a76935a314..28f89b3dcc11 100644 --- a/arch/parisc/kernel/module.c +++ b/arch/parisc/kernel/module.c @@ -66,6 +66,7 @@ #include <asm/pgtable.h> #include <asm/unwind.h> +#include <asm/sections.h> #if 0 #define DEBUGP printk @@ -954,3 +955,19 @@ void module_arch_cleanup(struct module *mod) { deregister_unwind_table(mod); } + +#ifdef CONFIG_64BIT +unsigned long dereference_module_function_descriptor(struct module *mod, + unsigned long addr) +{ + unsigned long start_opd = (Elf64_Addr)mod->core_layout.base + + mod->arch.fdesc_offset; + unsigned long end_opd = start_opd + + mod->arch.fdesc_count * sizeof(Elf64_Fdesc); + + if (addr < start_opd || addr >= end_opd) + return addr; + + return dereference_function_descriptor(addr); +} +#endif diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index d350aa913acc..423bbfe90e2b 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -276,6 +276,15 @@ unsigned long dereference_function_descriptor(unsigned long ptr) ptr = (unsigned long)p; return ptr; } + +unsigned long dereference_kernel_function_descriptor(unsigned long addr) +{ + if (addr < (unsigned long)__start_opd || + addr >= (unsigned long)__end_opd) + return addr; + + return dereference_function_descriptor(addr); +} #endif static inline unsigned long brk_rnd(void) diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index ffe2cbf52d1a..ab030895dd1e 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -99,7 +99,9 @@ SECTIONS . = ALIGN(16); /* Linkage tables */ .opd : { + __start_opd = .; *(.opd) + __end_opd = .; } PROVIDE (__gp = .); .plt : { *(.plt)