Commit c3405d68 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 

Pull arm64 fixes from Will Deacon:
 "Another handful of arm64 fixes here. Most of the complication comes
  from improving our kpti code to avoid lengthy pauses (30+ seconds)
  during boot when we rewrite the page tables. There are also a couple
  of IORT fixes that came in via Lorenzo.

  Summary:

   - Don't error in kexec_file_load if kaslr-seed is missing in
     device-tree

   - Fix incorrect argument type passed to iort_match_node_callback()

   - Fix IORT build failure when CONFIG_IOMMU_API=n

   - Fix kpti performance regression with new rodata default option

   - Typo fix"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kexec_file: return successfully even if kaslr-seed doesn't exist
  ACPI/IORT: Fix rc_dma_get_range()
  arm64: kpti: Avoid rewriting early page tables when KASLR is enabled
  arm64: asm-prototypes: Fix fat-fingered typo in comment
  ACPI/IORT: Fix build when CONFIG_IOMMU_API=n
parents f87092c4 27966721

arch/arm64/include/asm/asm-prototypes.h

+1 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
#ifndef __ASM_PROTOTYPES_H

#define __ASM_PROTOTYPES_H

/*

 * CONFIG_MODEVERIONS requires a C declaration to generate the appropriate CRC

 * CONFIG_MODVERSIONS requires a C declaration to generate the appropriate CRC

 * for each symbol. Since commit:

 *

 *   4efca4ed05cbdfd1 ("kbuild: modversions for EXPORT_SYMBOL() for asm")

arch/arm64/include/asm/mmu.h

+41 −0
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 
#ifndef __ASM_MMU_H

#define __ASM_MMU_H



#include <asm/cputype.h>



#define MMCF_AARCH32	0x1	/* mm context flag for AArch32 executables */

#define USER_ASID_BIT	48

#define USER_ASID_FLAG	(UL(1) << USER_ASID_BIT)
@@ -44,6 +46,45 @@ static inline bool arm64_kernel_unmapped_at_el0(void) 
	       cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);

}



static inline bool arm64_kernel_use_ng_mappings(void)

{

	bool tx1_bug;



	/* What's a kpti? Use global mappings if we don't know. */

	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))

		return false;



	/*

	 * Note: this function is called before the CPU capabilities have

	 * been configured, so our early mappings will be global. If we

	 * later determine that kpti is required, then

	 * kpti_install_ng_mappings() will make them non-global.

	 */

	if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))

		return arm64_kernel_unmapped_at_el0();



	/*

	 * KASLR is enabled so we're going to be enabling kpti on non-broken

	 * CPUs regardless of their susceptibility to Meltdown. Rather

	 * than force everybody to go through the G -> nG dance later on,

	 * just put down non-global mappings from the beginning.

	 */

	if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {

		tx1_bug = false;

#ifndef MODULE

	} else if (!static_branch_likely(&arm64_const_caps_ready)) {

		extern const struct midr_range cavium_erratum_27456_cpus[];



		tx1_bug = is_midr_in_range_list(read_cpuid_id(),

						cavium_erratum_27456_cpus);

#endif

	} else {

		tx1_bug = __cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456);

	}



	return !tx1_bug && kaslr_offset() > 0;

}



typedef void (*bp_hardening_cb_t)(void);



struct bp_hardening_data {

arch/arm64/include/asm/pgtable-prot.h

+2 −2
Original line number Diff line number Diff line
@@ -37,8 +37,8 @@ 
#define _PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)

#define _PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)



#define PTE_MAYBE_NG		(arm64_kernel_unmapped_at_el0() ? PTE_NG : 0)

#define PMD_MAYBE_NG		(arm64_kernel_unmapped_at_el0() ? PMD_SECT_NG : 0)

#define PTE_MAYBE_NG		(arm64_kernel_use_ng_mappings() ? PTE_NG : 0)

#define PMD_MAYBE_NG		(arm64_kernel_use_ng_mappings() ? PMD_SECT_NG : 0)



#define PROT_DEFAULT		(_PROT_DEFAULT | PTE_MAYBE_NG)

#define PROT_SECT_DEFAULT	(_PROT_SECT_DEFAULT | PMD_MAYBE_NG)

arch/arm64/kernel/cpu_errata.c

+1 −1
Original line number Diff line number Diff line
@@ -553,7 +553,7 @@ static const struct midr_range arm64_repeat_tlbi_cpus[] = { 
#endif



#ifdef CONFIG_CAVIUM_ERRATUM_27456

static const struct midr_range cavium_erratum_27456_cpus[] = {

const struct midr_range cavium_erratum_27456_cpus[] = {

	/* Cavium ThunderX, T88 pass 1.x - 2.1 */

	MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 1),

	/* Cavium ThunderX, T81 pass 1.0 */

arch/arm64/kernel/cpufeature.c

+7 −2
Original line number Diff line number Diff line
@@ -983,7 +983,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, 


	/* Useful for KASLR robustness */

	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))

		return true;

		return kaslr_offset() > 0;



	/* Don't force KPTI for CPUs that are not vulnerable */

	if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
@@ -1003,7 +1003,12 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) 
	static bool kpti_applied = false;

	int cpu = smp_processor_id();



	if (kpti_applied)

	/*

	 * We don't need to rewrite the page-tables if either we've done

	 * it already or we have KASLR enabled and therefore have not

	 * created any global mappings at all.

	 */

	if (kpti_applied || kaslr_offset() > 0)

		return;



	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);

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