From: "Steven J. Hill" <[email protected]> This patch fixes MIPS64r6 kernel modules by adding new ELF relocations. Toolchains that compile 64-bit R6 binaries emit two new ELF relocations R_MIPS_PC21_S2 and R_MIPS_PC26_S2. The pre-existing R_MIPS_PC16 ELF relocation is also emitted.
Signed-off-by: Steven J. Hill <[email protected]> Signed-off-by: James Hogan <[email protected]> Signed-off-by: Paul Burton <[email protected]> --- arch/mips/include/asm/elf.h | 5 +++ arch/mips/kernel/module-rela.c | 69 +++++++++++++++++++++++++++++++++++++++++- 2 files changed, 73 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h index cefb7a5..7cec234 100644 --- a/arch/mips/include/asm/elf.h +++ b/arch/mips/include/asm/elf.h @@ -111,6 +111,11 @@ #define R_MIPS_CALLHI16 30 #define R_MIPS_CALLLO16 31 /* + * Introduced for MIPSr6. + */ +#define R_MIPS_PC21_S2 60 +#define R_MIPS_PC26_S2 61 +/* * This range is reserved for vendor specific relocations. */ #define R_MIPS_LOVENDOR 100 diff --git a/arch/mips/kernel/module-rela.c b/arch/mips/kernel/module-rela.c index f1ff64b..2dbe1b0 100644 --- a/arch/mips/kernel/module-rela.c +++ b/arch/mips/kernel/module-rela.c @@ -16,6 +16,7 @@ * Copyright (C) 2001 Rusty Russell. * Copyright (C) 2003, 2004 Ralf Baechle ([email protected]) * Copyright (C) 2005 Thiemo Seufer + * Copyright (C) 2015 Imagination Technologies Ltd. */ #include <linux/elf.h> @@ -65,6 +66,27 @@ static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) return 0; } +static int apply_r_mips_pc16_rela(struct module *me, u32 *location, Elf_Addr v) +{ + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC16 RELA relocation\n", + me->name); + return -ENOEXEC; + } + + offset = ((long)v - (long)location) >> 2; + if (offset != (int16_t)offset) { + pr_err("module %s: relocation overflow\n", me->name); + return -ENOEXEC; + } + + *location = (*location & ~0xffff) | (offset & 0xffff); + + return 0; +} + static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) { *(Elf_Addr *)location = v; @@ -90,6 +112,48 @@ static int apply_r_mips_highest_rela(struct module *me, u32 *location, return 0; } +static int apply_r_mips_pc21_rela(struct module *me, u32 *location, Elf_Addr v) +{ + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC21 RELA relocation\n", + me->name); + return -ENOEXEC; + } + + offset = ((long)v - (long)location) >> 2; + if ((offset >> 20) > 0 || (offset >> 20) < -1) { + pr_err("module %s: relocation overflow\n", me->name); + return -ENOEXEC; + } + + *location = (*location & ~0x001fffff) | (offset & 0x001fffff); + + return 0; +} + +static int apply_r_mips_pc26_rela(struct module *me, u32 *location, Elf_Addr v) +{ + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC26 RELA relocation\n", + me->name); + return -ENOEXEC; + } + + offset = ((long)v - (long)location) >> 2; + if ((offset >> 25) > 0 || (offset >> 25) < -1) { + pr_err("module %s: relocation overflow\n", me->name); + return -ENOEXEC; + } + + *location = (*location & ~0x03ffffff) | (offset & 0x03ffffff); + + return 0; +} + static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, Elf_Addr v) = { [R_MIPS_NONE] = apply_r_mips_none, @@ -97,9 +161,12 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, [R_MIPS_26] = apply_r_mips_26_rela, [R_MIPS_HI16] = apply_r_mips_hi16_rela, [R_MIPS_LO16] = apply_r_mips_lo16_rela, + [R_MIPS_PC16] = apply_r_mips_pc16_rela, [R_MIPS_64] = apply_r_mips_64_rela, [R_MIPS_HIGHER] = apply_r_mips_higher_rela, - [R_MIPS_HIGHEST] = apply_r_mips_highest_rela + [R_MIPS_HIGHEST] = apply_r_mips_highest_rela, + [R_MIPS_PC21_S2] = apply_r_mips_pc21_rela, + [R_MIPS_PC26_S2] = apply_r_mips_pc26_rela, }; int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, -- 2.7.0
