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| author | Paul Burton <paul.burton@imgtec.com> | 2016-02-04 13:05:04 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-05-13 14:01:54 +0200 |
| commit | ad8319ea4647c897c837643a611714a83d8f6a0f (patch) | |
| tree | ee82cdd2110100d47ceb7e9a899b4082485e29d7 /arch/mips/kernel/module-rela.c | |
| parent | 55d791f37c905b9ca68b96cdab89678654a5d16e (diff) | |
| download | talos-obmc-linux-ad8319ea4647c897c837643a611714a83d8f6a0f.tar.gz talos-obmc-linux-ad8319ea4647c897c837643a611714a83d8f6a0f.zip | |
MIPS: Support R_MIPS_PC{21,26} rela-style relocs
MIPS64 code uses rela-style relocs, and MIPS64r6 modules may include the
new R_MIPS_PC21 & R_MIPS_PC26 relocations. We thus need to support these
relocations in order to load MIPS64r6 kernel modules. They are similar
to the existing R_MIPS_PC16 relocation but applying to a wider field.
Implement support for them by genericising the existing R_MIPS_PC16
implementation such that it can be used for different field widths, and
calling it for all 3 reloc types.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Steven J. Hill <sjhill@realitydiluted.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12434/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/module-rela.c')
| -rw-r--r-- | arch/mips/kernel/module-rela.c | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/arch/mips/kernel/module-rela.c b/arch/mips/kernel/module-rela.c index 0570676b10e2..b3611426b128 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 (ralf@linux-mips.org) * Copyright (C) 2005 Thiemo Seufer + * Copyright (C) 2015 Imagination Technologies Ltd. */ #include <linux/elf.h> @@ -65,6 +66,48 @@ static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) return 0; } +static int apply_r_mips_pc_rela(struct module *me, u32 *location, Elf_Addr v, + unsigned bits) +{ + unsigned long mask = GENMASK(bits - 1, 0); + unsigned long se_bits; + long offset; + + if (v % 4) { + pr_err("module %s: dangerous R_MIPS_PC%u RELA relocation\n", + me->name, bits); + return -ENOEXEC; + } + + offset = ((long)v - (long)location) >> 2; + + /* check the sign bit onwards are identical - ie. we didn't overflow */ + se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0; + if ((offset & ~mask) != (se_bits & ~mask)) { + pr_err("module %s: relocation overflow\n", me->name); + return -ENOEXEC; + } + + *location = (*location & ~mask) | (offset & mask); + + return 0; +} + +static int apply_r_mips_pc16_rela(struct module *me, u32 *location, Elf_Addr v) +{ + return apply_r_mips_pc_rela(me, location, v, 16); +} + +static int apply_r_mips_pc21_rela(struct module *me, u32 *location, Elf_Addr v) +{ + return apply_r_mips_pc_rela(me, location, v, 21); +} + +static int apply_r_mips_pc26_rela(struct module *me, u32 *location, Elf_Addr v) +{ + return apply_r_mips_pc_rela(me, location, v, 26); +} + static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) { *(Elf_Addr *)location = v; @@ -97,9 +140,12 @@ 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, |
