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

Pull arm64 updates from Will Deacon:
 "There's good stuff across the board, including some nice mm
  improvements for CPUs with the 'noabort' BBML2 feature and a clever
  patch to allow ptdump to play nicely with block mappings in the
  vmalloc area.

  Confidential computing:

   - Add support for accepting secrets from firmware (e.g. ACPI CCEL)
     and mapping them with appropriate attributes.

  CPU features:

   - Advertise atomic floating-point instructions to userspace

   - Extend Spectre workarounds to cover additional Arm CPU variants

   - Extend list of CPUs that support break-before-make level 2 and
     guarantee not to generate TLB conflict aborts for changes of
     mapping granularity (BBML2_NOABORT)

   - Add GCS support to our uprobes implementation.

  Documentation:

   - Remove bogus SME documentation concerning register state when
     entering/exiting streaming mode.

  Entry code:

   - Switch over to the generic IRQ entry code (GENERIC_IRQ_ENTRY)

   - Micro-optimise syscall entry path with a compiler branch hint.

  Memory management:

   - Enable huge mappings in vmalloc space even when kernel page-table
     dumping is enabled

   - Tidy up the types used in our early MMU setup code

   - Rework rodata= for closer parity with the behaviour on x86

   - For CPUs implementing BBML2_NOABORT, utilise block mappings in the
     linear map even when rodata= applies to virtual aliases

   - Don't re-allocate the virtual region between '_text' and '_stext',
     as doing so confused tools parsing /proc/vmcore.

  Miscellaneous:

   - Clean-up Kconfig menuconfig text for architecture features

   - Avoid redundant bitmap_empty() during determination of supported
     SME vector lengths

   - Re-enable warnings when building the 32-bit vDSO object

   - Avoid breaking our eggs at the wrong end.

  Perf and PMUs:

   - Support for v3 of the Hisilicon L3C PMU

   - Support for Hisilicon's MN and NoC PMUs

   - Support for Fujitsu's Uncore PMU

   - Support for SPE's extended event filtering feature

   - Preparatory work to enable data source filtering in SPE

   - Support for multiple lanes in the DWC PCIe PMU

   - Support for i.MX94 in the IMX DDR PMU driver

   - MAINTAINERS update (Thank you, Yicong)

   - Minor driver fixes (PERF_IDX2OFF() overflow, CMN register offsets).

  Selftests:

   - Add basic LSFE check to the existing hwcaps test

   - Support nolibc in GCS tests

   - Extend SVE ptrace test to pass unsupported regsets and invalid
     vector lengths

   - Minor cleanups (typos, cosmetic changes).

  System registers:

   - Fix ID_PFR1_EL1 definition

   - Fix incorrect signedness of some fields in ID_AA64MMFR4_EL1

   - Sync TCR_EL1 definition with the latest Arm ARM (L.b)

   - Be stricter about the input fed into our AWK sysreg generator
     script

   - Typo fixes and removal of redundant definitions.

  ACPI, EFI and PSCI:

   - Decouple Arm's "Software Delegated Exception Interface" (SDEI)
     support from the ACPI GHES code so that it can be used by platforms
     booted with device-tree

   - Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
     runtime calls

   - Fix a node refcount imbalance in the PSCI device-tree code.

  CPU Features:

   - Ensure register sanitisation is applied to fields in ID_AA64MMFR4

   - Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM
     guests can reliably query the underlying CPU types from the VMM

   - Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
     to our context-switching, signal handling and ptrace code"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
  arm64: cpufeature: Remove duplicate asm/mmu.h header
  arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
  perf/dwc_pcie: Fix use of uninitialized variable
  arm/syscalls: mark syscall invocation as likely in invoke_syscall
  Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU
  Documentation: hisi-pmu: Fix of minor format error
  drivers/perf: hisi: Add support for L3C PMU v3
  drivers/perf: hisi: Refactor the event configuration of L3C PMU
  drivers/perf: hisi: Extend the field of tt_core
  drivers/perf: hisi: Extract the event filter check of L3C PMU
  drivers/perf: hisi: Simplify the probe process of each L3C PMU version
  drivers/perf: hisi: Export hisi_uncore_pmu_isr()
  drivers/perf: hisi: Relax the event ID check in the framework
  perf: Fujitsu: Add the Uncore PMU driver
  arm64: map [_text, _stext) virtual address range non-executable+read-only
  arm64/sysreg: Update TCR_EL1 register
  arm64: Enable vmalloc-huge with ptdump
  arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
  arm64: errata: Apply workarounds for Neoverse-V3AE
  arm64: cputype: Add Neoverse-V3AE definitions
  ...

1 files changed, 24 insertions, 12 deletions

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 648038247a8d..936689d8bcac 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -606,10 +606,32 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
 int walk_kernel_page_table_range(unsigned long start, unsigned long end,
 		const struct mm_walk_ops *ops, pgd_t *pgd, void *private)
 {
-	struct mm_struct *mm = &init_mm;
+	/*
+	 * Kernel intermediate page tables are usually not freed, so the mmap
+	 * read lock is sufficient. But there are some exceptions.
+	 * E.g. memory hot-remove. In which case, the mmap lock is insufficient
+	 * to prevent the intermediate kernel pages tables belonging to the
+	 * specified address range from being freed. The caller should take
+	 * other actions to prevent this race.
+	 */
+	mmap_assert_locked(&init_mm);
+
+	return walk_kernel_page_table_range_lockless(start, end, ops, pgd,
+						     private);
+}
+
+/*
+ * Use this function to walk the kernel page tables locklessly. It should be
+ * guaranteed that the caller has exclusive access over the range they are
+ * operating on - that there should be no concurrent access, for example,
+ * changing permissions for vmalloc objects.
+ */
+int walk_kernel_page_table_range_lockless(unsigned long start, unsigned long end,
+		const struct mm_walk_ops *ops, pgd_t *pgd, void *private)
+{
 	struct mm_walk walk = {
 		.ops		= ops,
-		.mm		= mm,
+		.mm		= &init_mm,
 		.pgd		= pgd,
 		.private	= private,
 		.no_vma		= true
@@ -620,16 +642,6 @@ int walk_kernel_page_table_range(unsigned long start, unsigned long end,
 	if (!check_ops_valid(ops))
 		return -EINVAL;
 
-	/*
-	 * Kernel intermediate page tables are usually not freed, so the mmap
-	 * read lock is sufficient. But there are some exceptions.
-	 * E.g. memory hot-remove. In which case, the mmap lock is insufficient
-	 * to prevent the intermediate kernel pages tables belonging to the
-	 * specified address range from being freed. The caller should take
-	 * other actions to prevent this race.
-	 */
-	mmap_assert_locked(mm);
-
 	return walk_pgd_range(start, end, &walk);
 }