[PATCH v2 08/18] arm64: don't disable ADR_PREL_PG_HI21* with ARM64_ERRATUM_843419
From: Ard Biesheuvel <hidden>
Date: 2017-11-15 22:29:29
Also in:
linux-kbuild, lkml
On 15 November 2017 at 21:34, Sami Tolvanen [off-list ref] wrote:
quoted hunk ↗ jump to hunk
CONFIG_LTO_CLANG depends on GNU gold, which can generate ADR_PREL_PG_HI21* relocations even with --fix-cortex-a53-843419. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- arch/arm64/kernel/module.c | 2 -- 1 file changed, 2 deletions(-)diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index f469e0435903..fec9a578f122 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c@@ -336,14 +336,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 0, 21, AARCH64_INSN_IMM_ADR); break; -#ifndef CONFIG_ARM64_ERRATUM_843419 case R_AARCH64_ADR_PREL_PG_HI21_NC: overflow_check = false; case R_AARCH64_ADR_PREL_PG_HI21: ovf = reloc_insn_imm(RELOC_OP_PAGE, loc, val, 12, 21, AARCH64_INSN_IMM_ADR); break; -#endif case R_AARCH64_ADD_ABS_LO12_NC: case R_AARCH64_LDST8_ABS_LO12_NC: overflow_check = false; --2.15.0.448.gf294e3d99a-goog
I think this change is reasonable in itself, but i do wonder how we can ensure that the adrp instructions that GNU gold does generate are not affected by the erratum, given that modules are partially linked object files, not shared libraries.