From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Mon, 1 Jun 2015 10:47:38 +0100 Subject: [PATCH v2 0/4] arm64: alternative patching rework Message-ID: <1433152062-21907-1-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The current alternative instruction framework is not kind to branches, potentially leading to all kind of hacks in the code that uses alternatives. This series expands it to deal with immediate and conditional branches. This is a rewrite of fef7f2b20103, which got reverted in b9a95e85bbc as it was breaking unsuspecting branches inside an alternate sequence. It now also deals with conditional branches (instead of just asserting a BUG). Another nit is addressed by the last patch, where GAS gets confused by the combinaison of a .inst directive (as used by the msr_s/mrs_s pseudo-instruction), a label, and a .if directive evaluating said label. As this is exactly what the alternative framework uses to detect length mismatch, this patch reverts to using a pair of .org directives in a creative way. To make this a bit easier, alternative-asm.h is folded into alternative.h. This has been tested on v4.1-rc5. Marc Zyngier (4): arm64: insn: Add aarch64_{get,set}_branch_offset arm64: alternative: Allow immediate branch as alternative instruction arm64: alternative: Merge alternative-asm.h into alternative.h arm64: alternative: Work around .inst assembler bugs arch/arm64/include/asm/alternative-asm.h | 29 ------------- arch/arm64/include/asm/alternative.h | 46 +++++++++++++++++++-- arch/arm64/include/asm/insn.h | 3 ++ arch/arm64/kernel/alternative.c | 71 +++++++++++++++++++++++++++++--- arch/arm64/kernel/entry.S | 2 +- arch/arm64/kernel/insn.c | 60 +++++++++++++++++++++++++++ arch/arm64/mm/cache.S | 2 +- 7 files changed, 173 insertions(+), 40 deletions(-) delete mode 100644 arch/arm64/include/asm/alternative-asm.h -- 2.1.4