[PATCHv3 3/7] ia64: Add .opd based function descriptor dereference
From: Sergey Senozhatsky <hidden>
Date: 2017-09-30 02:54:19
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for IA64. 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 <redacted> Tested-by: Helge Deller <deller@gmx.de> # parisc64 Tested-by: Santosh Sivaraj <redacted> # powerpc64 Acked-by: Michael Ellerman <mpe@ellerman.id.au> # powerpc64 Tested-by: Tony Luck <tony.luck@intel.com> # ia64 --- arch/ia64/include/asm/sections.h | 10 +++++++++- arch/ia64/kernel/module.c | 13 +++++++++++++ arch/ia64/kernel/vmlinux.lds.S | 2 ++ 3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index de6bfa1ef8fb..3ba7ce9d8bc8 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h@@ -37,6 +37,14 @@ static inline unsigned long dereference_function_descriptor(unsigned long ptr) 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 /* _ASM_IA64_SECTIONS_H */ -
diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index d1d945c6bd05..0741ae6fa957 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c@@ -35,6 +35,7 @@ #include <asm/patch.h> #include <asm/unaligned.h> +#include <asm/sections.h> #define ARCH_MODULE_DEBUG 0
@@ -917,3 +918,15 @@ module_arch_cleanup (struct module *mod) if (mod->arch.core_unw_table) unw_remove_unwind_table(mod->arch.core_unw_table); } + +unsigned long +dereference_module_function_descriptor(struct module *mod, unsigned long addr) +{ + Elf64_Shdr *opd = mod->arch.opd; + + if (addr < opd->sh_addr || + addr >= (opd->sh_addr + opd->sh_size)) + return addr; + + return dereference_function_descriptor(addr); +}
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 798026dde52e..f872ba5ff82a 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S@@ -107,7 +107,9 @@ SECTIONS { RODATA .opd : AT(ADDR(.opd) - LOAD_OFFSET) { + __start_opd = .; *(.opd) + __end_opd = .; } /*
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2.14.2