We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for powerpc64. 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]. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> --- arch/powerpc/include/asm/module.h | 3 +++ arch/powerpc/include/asm/sections.h | 11 +++++++++++ arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 2 ++ 4 files changed, 32 insertions(+) diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index 6c0132c7212f..7e28442827f1 100644 --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -45,6 +45,9 @@ struct mod_arch_specific { unsigned long tramp; #endif + /* For module function descriptor dereference */ + unsigned long start_opd; + unsigned long end_opd; #else /* powerpc64 */ /* Indices of PLT sections within module. */ unsigned int core_plt_section; diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index 67379b8945e8..6b4ee0d1645f 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -75,6 +75,17 @@ static inline unsigned long dereference_function_descriptor(unsigned long ptr) ptr = (unsigned long)p; return ptr; } + +#undef dereference_kernel_function_descriptor +static inline 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 /* PPC64_ELF_ABI_v1 */ #endif diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 0b0f89685b67..94caec045a90 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -344,6 +344,11 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) dedotify_versions((void *)hdr + sechdrs[i].sh_offset, sechdrs[i].sh_size); + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) { + me->arch.start_opd = sechdrs[i].sh_addr; + me->arch.end_opd = sechdrs[i].sh_addr + + sechdrs[i].sh_size; + } /* We don't handle .init for the moment: rename to _init */ while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) @@ -712,6 +717,17 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, return 0; } +#ifdef PPC64_ELF_ABI_v1 +unsigned long dereference_module_function_descriptor(struct module *mod, + unsigned long addr) +{ + if (addr < mod->arch.start_opd || addr >= mod->arch.end_opd) + return addr; + + return dereference_function_descriptor(addr); +} +#endif /* PPC64_ELF_ABI_v1 */ + #ifdef CONFIG_DYNAMIC_FTRACE #ifdef CC_USING_MPROFILE_KERNEL diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 882628fa6987..70e10251e083 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -277,7 +277,9 @@ SECTIONS } .opd : AT(ADDR(.opd) - LOAD_OFFSET) { + __start_opd = .; *(.opd) + __end_opd = .; } . = ALIGN(256); -- 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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