MIPS32r6 code makes use of rel-stye relocations & may contain the new relocations R_MIPS_PC21_S2 or R_MIPS_PC26_S2 which were introduced with MIPSr6. Implement support for those relocations such that we can load MIPS32r6 kernel modules.
Signed-off-by: Paul Burton <[email protected]> --- arch/mips/kernel/module.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c index f2de9b8..d62fd56 100644 --- a/arch/mips/kernel/module.c +++ b/arch/mips/kernel/module.c @@ -194,6 +194,56 @@ static int apply_r_mips_pc16_rel(struct module *me, u32 *location, Elf_Addr v) return 0; } +static int apply_r_mips_pc21_rel(struct module *me, u32 *location, Elf_Addr v) +{ + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC21 REL relocation\n", + me->name); + return -ENOEXEC; + } + + /* retrieve & sign extend implicit addend */ + offset = *location & 0x1fffff; + offset |= (offset & BIT(20)) ? (~0l & ~0x1fffffl) : 0; + + 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_rel(struct module *me, u32 *location, Elf_Addr v) +{ + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC26 REL relocation\n", + me->name); + return -ENOEXEC; + } + + /* retrieve & sign extend implicit addend */ + offset = *location & 0x3ffffff; + offset |= (offset & BIT(25)) ? (~0l & ~0x3ffffffl) : 0; + + 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_rel[]) (struct module *me, u32 *location, Elf_Addr v) = { [R_MIPS_NONE] = apply_r_mips_none, @@ -202,6 +252,8 @@ static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, [R_MIPS_HI16] = apply_r_mips_hi16_rel, [R_MIPS_LO16] = apply_r_mips_lo16_rel, [R_MIPS_PC16] = apply_r_mips_pc16_rel, + [R_MIPS_PC21_S2] = apply_r_mips_pc21_rel, + [R_MIPS_PC26_S2] = apply_r_mips_pc26_rel, }; int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, -- 2.7.0
