Commit b40a142b authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Thomas Gleixner
Browse files

x86: Add support for 64-bit place relative relocations 



Add support for R_X86_64_PC64 relocations, which operate on 64-bit
quantities holding a relative symbol reference. Also remove the
definition of R_X86_64_NUM: given that it is currently unused, it
is unclear what the new value should be.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jessica Yu <jeyu@kernel.org>
Link: https://lkml.kernel.org/r/20180919065144.25010-5-ard.biesheuvel@linaro.org
parent c296146c

arch/x86/include/asm/elf.h

+1 −2
Original line number Diff line number Diff line
@@ -62,8 +62,7 @@ typedef struct user_fxsr_struct elf_fpxregset_t; 
#define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */

#define R_X86_64_8		14	/* Direct 8 bit sign extended  */

#define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */



#define R_X86_64_NUM		16

#define R_X86_64_PC64		24	/* Place relative 64-bit signed */



/*

 * These are used to set parameters in the core dumps.

arch/x86/kernel/module.c

+6 −0
Original line number Diff line number Diff line
@@ -201,6 +201,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, 
				goto overflow;

#endif

			break;

		case R_X86_64_PC64:

			if (*(u64 *)loc != 0)

				goto invalid_relocation;

			val -= (u64)loc;

			*(u64 *)loc = val;

			break;

		default:

			pr_err("%s: Unknown rela relocation: %llu\n",

			       me->name, ELF64_R_TYPE(rel[i].r_info));

arch/x86/tools/relocs.c

+10 −0
Original line number Diff line number Diff line
@@ -196,6 +196,7 @@ static const char *rel_type(unsigned type) 
#if ELF_BITS == 64

		REL_TYPE(R_X86_64_NONE),

		REL_TYPE(R_X86_64_64),

		REL_TYPE(R_X86_64_PC64),

		REL_TYPE(R_X86_64_PC32),

		REL_TYPE(R_X86_64_GOT32),

		REL_TYPE(R_X86_64_PLT32),
@@ -782,6 +783,15 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, 
			add_reloc(&relocs32neg, offset);

		break;



	case R_X86_64_PC64:

		/*

		 * Only used by jump labels

		 */

		if (is_percpu_sym(sym, symname))

			die("Invalid R_X86_64_PC64 relocation against per-CPU symbol %s\n",

			    symname);

		break;



	case R_X86_64_32:

	case R_X86_64_32S:

	case R_X86_64_64:

arch/x86/um/asm/elf.h

+1 −2
Original line number Diff line number Diff line
@@ -116,8 +116,7 @@ do { \ 
#define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */

#define R_X86_64_8		14	/* Direct 8 bit sign extended  */

#define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */



#define R_X86_64_NUM		16

#define R_X86_64_PC64		24	/* Place relative 64-bit signed */



/*

 * This is used to ensure we don't load something for the wrong architecture.

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