From 214fad550772929d97fb90a6a2637ebf5a796c11 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 31 Mar 2017 08:55:33 +0100 Subject: [PATCH] arm64: relocation testing module This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig.debug | 4 ++ arch/arm64/kernel/Makefile | 2 + arch/arm64/kernel/reloc_test_core.c | 81 ++++++++++++++++++++++++++++++++++++ arch/arm64/kernel/reloc_test_syms.S | 83 +++++++++++++++++++++++++++++++++++++ 4 files changed, 170 insertions(+) create mode 100644 arch/arm64/kernel/reloc_test_core.c create mode 100644 arch/arm64/kernel/reloc_test_syms.S diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug index fca2f02..cc6bd55 100644 --- a/arch/arm64/Kconfig.debug +++ b/arch/arm64/Kconfig.debug @@ -92,6 +92,10 @@ config DEBUG_EFI the kernel that are only useful when using a debug build of the UEFI firmware +config ARM64_RELOC_TEST + depends on m + tristate "Relocation testing module" + source "drivers/hwtracing/coresight/Kconfig" endmenu diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 1606c6b..aaaf06b 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -50,6 +50,8 @@ arm64-obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o arm64-obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o arm64-obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o \ cpu-reset.o +arm64-obj-$(CONFIG_ARM64_RELOC_TEST) += arm64-reloc-test.o +arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o obj-y += $(arm64-obj-y) vdso/ probes/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/reloc_test_core.c b/arch/arm64/kernel/reloc_test_core.c new file mode 100644 index 0000000..c124752 --- /dev/null +++ b/arch/arm64/kernel/reloc_test_core.c @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2017 Linaro, Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include + +int sym64_rel; + +#define SYM64_ABS_VAL 0xffff880000cccccc +#define SYM32_ABS_VAL 0xf800cccc +#define SYM16_ABS_VAL 0xf8cc + +#define __SET_ABS(name, val) asm(".globl " #name "; .set "#name ", " #val) +#define SET_ABS(name, val) __SET_ABS(name, val) + +SET_ABS(sym64_abs, SYM64_ABS_VAL); +SET_ABS(sym32_abs, SYM32_ABS_VAL); +SET_ABS(sym16_abs, SYM16_ABS_VAL); + +asmlinkage u64 absolute_data64(void); +asmlinkage u64 absolute_data32(void); +asmlinkage u64 absolute_data16(void); +asmlinkage u64 signed_movw(void); +asmlinkage u64 unsigned_movw(void); +asmlinkage u64 relative_adrp(void); +asmlinkage u64 relative_adr(void); +asmlinkage u64 relative_data64(void); +asmlinkage u64 relative_data32(void); +asmlinkage u64 relative_data16(void); + +static struct { + char name[32]; + u64 (*f)(void); + u64 expect; +} const funcs[] = { + { "R_AARCH64_ABS64", absolute_data64, UL(SYM64_ABS_VAL) }, + { "R_AARCH64_ABS32", absolute_data32, UL(SYM32_ABS_VAL) }, + { "R_AARCH64_ABS16", absolute_data16, UL(SYM16_ABS_VAL) }, + { "R_AARCH64_MOVW_SABS_Gn", signed_movw, UL(SYM64_ABS_VAL) }, + { "R_AARCH64_MOVW_UABS_Gn", unsigned_movw, UL(SYM64_ABS_VAL) }, +#ifndef CONFIG_ARM64_ERRATUM_843419 + { "R_AARCH64_ADR_PREL_PG_HI21", relative_adrp, (u64)&sym64_rel }, +#endif + { "R_AARCH64_ADR_PREL_LO21", relative_adr, (u64)&sym64_rel }, + { "R_AARCH64_PREL64", relative_data64, (u64)&sym64_rel }, + { "R_AARCH64_PREL32", relative_data32, (u64)&sym64_rel }, + { "R_AARCH64_PREL16", relative_data16, (u64)&sym64_rel }, +}; + +static int reloc_test_init(void) +{ + int i; + + pr_info("Relocation test:\n"); + pr_info("-------------------------------------------------------\n"); + + for (i = 0; i < ARRAY_SIZE(funcs); i++) { + u64 ret = funcs[i].f(); + + pr_info("%-31s 0x%016llx %s\n", funcs[i].name, ret, + ret == funcs[i].expect ? "pass" : "fail"); + if (ret != funcs[i].expect) + pr_err("Relocation failed, expected 0x%016llx, not 0x%016llx\n", + funcs[i].expect, ret); + } + return 0; +} + +static void reloc_test_exit(void) +{ +} + +module_init(reloc_test_init); +module_exit(reloc_test_exit); + +MODULE_LICENSE("GPL v2"); diff --git a/arch/arm64/kernel/reloc_test_syms.S b/arch/arm64/kernel/reloc_test_syms.S new file mode 100644 index 0000000..e1edcef --- /dev/null +++ b/arch/arm64/kernel/reloc_test_syms.S @@ -0,0 +1,83 @@ +/* + * Copyright (C) 2017 Linaro, Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include + +ENTRY(absolute_data64) + ldr x0, 0f + ret +0: .quad sym64_abs +ENDPROC(absolute_data64) + +ENTRY(absolute_data32) + ldr w0, 0f + ret +0: .long sym32_abs +ENDPROC(absolute_data32) + +ENTRY(absolute_data16) + adr x0, 0f + ldrh w0, [x0] + ret +0: .short sym16_abs, 0 +ENDPROC(absolute_data16) + +ENTRY(signed_movw) + movz x0, #:abs_g2_s:sym64_abs + movk x0, #:abs_g1_nc:sym64_abs + movk x0, #:abs_g0_nc:sym64_abs + ret +ENDPROC(signed_movw) + +ENTRY(unsigned_movw) + movz x0, #:abs_g3:sym64_abs + movk x0, #:abs_g2_nc:sym64_abs + movk x0, #:abs_g1_nc:sym64_abs + movk x0, #:abs_g0_nc:sym64_abs + ret +ENDPROC(unsigned_movw) + +#ifndef CONFIG_ARM64_ERRATUM_843419 + +ENTRY(relative_adrp) + adrp x0, sym64_rel + add x0, x0, #:lo12:sym64_rel + ret +ENDPROC(relative_adrp) + +#endif + +ENTRY(relative_adr) + adr x0, sym64_rel + ret +ENDPROC(relative_adr) + +ENTRY(relative_data64) + adr x1, 0f + ldr x0, [x1] + add x0, x0, x1 + ret +0: .quad sym64_rel - . +ENDPROC(relative_data64) + +ENTRY(relative_data32) + adr x1, 0f + ldr w0, [x1] + add x0, x0, x1 + ret +0: .long sym64_rel - . +ENDPROC(relative_data32) + +ENTRY(relative_data16) + adr x1, 0f + ldrsh w0, [x1] + add x0, x0, x1 + ret +0: .short sym64_rel - ., 0 +ENDPROC(relative_data16) -- 2.7.4