From: Catalin Marinas <catalin.marinas@arm.com>
Date: Fri, 30 Sep 2022 08:18:22 +0000 (+0100)
Subject: Merge branch 'for-next/alternatives' into for-next/core
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c704cf27a1adc5fa40fb8e40b5617bdca889a419;p=linux.git

Merge branch 'for-next/alternatives' into for-next/core

* for-next/alternatives:
  : Alternatives (code patching) improvements
  arm64: fix the build with binutils 2.27
  arm64: avoid BUILD_BUG_ON() in alternative-macros
  arm64: alternatives: add shared NOP callback
  arm64: alternatives: add alternative_has_feature_*()
  arm64: alternatives: have callbacks take a cap
  arm64: alternatives: make alt_region const
  arm64: alternatives: hoist print out of __apply_alternatives()
  arm64: alternatives: proton-pack: prepare for cap changes
  arm64: alternatives: kvm: prepare for cap changes
  arm64: cpufeature: make cpus_have_cap() noinstr-safe
---

c704cf27a1adc5fa40fb8e40b5617bdca889a419
diff --cc arch/arm64/kernel/alternative.c
index a97775963f356,5a904d4e98eab..64045e3ef03a9
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@@ -195,30 -193,11 +196,35 @@@ static void __nocfi __apply_alternative
  	}
  }
  
 +void apply_alternatives_vdso(void)
 +{
 +	struct alt_region region;
 +	const struct elf64_hdr *hdr;
 +	const struct elf64_shdr *shdr;
 +	const struct elf64_shdr *alt;
- 	DECLARE_BITMAP(all_capabilities, ARM64_NPATCHABLE);
++	DECLARE_BITMAP(all_capabilities, ARM64_NCAPS);
 +
- 	bitmap_fill(all_capabilities, ARM64_NPATCHABLE);
++	bitmap_fill(all_capabilities, ARM64_NCAPS);
 +
 +	hdr = (struct elf64_hdr *)vdso_start;
 +	shdr = (void *)hdr + hdr->e_shoff;
 +	alt = find_section(hdr, shdr, ".altinstructions");
 +	if (!alt)
 +		return;
 +
 +	region = (struct alt_region){
 +		.begin	= (void *)hdr + alt->sh_offset,
 +		.end	= (void *)hdr + alt->sh_offset + alt->sh_size,
 +	};
 +
 +	__apply_alternatives(&region, false, &all_capabilities[0]);
 +}
 +
+ static const struct alt_region kernel_alternatives = {
+ 	.begin	= (struct alt_instr *)__alt_instructions,
+ 	.end	= (struct alt_instr *)__alt_instructions_end,
+ };
+ 
  /*
   * We might be patching the stop_machine state machine, so implement a
   * really simple polling protocol here.
@@@ -252,7 -227,8 +254,9 @@@ static int __apply_alternatives_multi_s
  
  void __init apply_alternatives_all(void)
  {
+ 	pr_info("applying system-wide alternatives\n");
+ 
 +	apply_alternatives_vdso();
  	/* better not try code patching on a live SMP system */
  	stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
  }