Merge tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "A healthy mix of EFI contributions this time:

   - Performance tweaks for efifb earlycon (Andy)

   - Preparatory refactoring and cleanup work in the efivar layer, which
     is needed to accommodate the Snapdragon arm64 laptops that expose
     their EFI variable store via a TEE secure world API (Johan)

   - Enhancements to the EFI memory map handling so that Xen dom0 can
     safely access EFI configuration tables (Demi Marie)

   - Wire up the newly introduced IBT/BTI flag in the EFI memory
     attributes table, so that firmware that is generated with ENDBR/BTI
     landing pads will be mapped with enforcement enabled

   - Clean up how we check and print the EFI revision exposed by the
     firmware

   - Incorporate EFI memory attributes protocol definition and wire it
     up in the EFI zboot code (Evgeniy)

     This ensures that these images can execute under new and stricter
     rules regarding the default memory permissions for EFI page
     allocations (More work is in progress here)

   - CPER header cleanup (Dan Williams)

   - Use a raw spinlock to protect the EFI runtime services stack on
     arm64 to ensure the correct semantics under -rt (Pierre)

   - EFI framebuffer quirk for Lenovo Ideapad (Darrell)"

* tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  firmware/efi sysfb_efi: Add quirk for Lenovo IdeaPad Duet 3
  arm64: efi: Make efi_rt_lock a raw_spinlock
  efi: Add mixed-mode thunk recipe for GetMemoryAttributes
  efi: x86: Wire up IBT annotation in memory attributes table
  efi: arm64: Wire up BTI annotation in memory attributes table
  efi: Discover BTI support in runtime services regions
  efi/cper, cxl: Remove cxl_err.h
  efi: Use standard format for printing the EFI revision
  efi: Drop minimum EFI version check at boot
  efi: zboot: Use EFI protocol to remap code/data with the right attributes
  efi/libstub: Add memory attribute protocol definitions
  efi: efivars: prevent double registration
  efi: verify that variable services are supported
  efivarfs: always register filesystem
  efi: efivars: add efivars printk prefix
  efi: Warn if trying to reserve memory under Xen
  efi: Actually enable the ESRT under Xen
  efi: Apply allowlist to EFI configuration tables when running under Xen
  efi: xen: Implement memory descriptor lookup based on hypercall
  efi: memmap: Disregard bogus entries instead of returning them
  ...

1 files changed, 57 insertions, 17 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 1e0b016fdc2b..abeff7dc0b58 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -187,8 +187,27 @@ static const struct attribute_group efi_subsys_attr_group = {
 static struct efivars generic_efivars;
 static struct efivar_operations generic_ops;
 
+static bool generic_ops_supported(void)
+{
+	unsigned long name_size;
+	efi_status_t status;
+	efi_char16_t name;
+	efi_guid_t guid;
+
+	name_size = sizeof(name);
+
+	status = efi.get_next_variable(&name_size, &name, &guid);
+	if (status == EFI_UNSUPPORTED)
+		return false;
+
+	return true;
+}
+
 static int generic_ops_register(void)
 {
+	if (!generic_ops_supported())
+		return 0;
+
 	generic_ops.get_variable = efi.get_variable;
 	generic_ops.get_next_variable = efi.get_next_variable;
 	generic_ops.query_variable_store = efi_query_variable_store;
@@ -197,11 +216,14 @@ static int generic_ops_register(void)
 		generic_ops.set_variable = efi.set_variable;
 		generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
 	}
-	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
+	return efivars_register(&generic_efivars, &generic_ops);
 }
 
 static void generic_ops_unregister(void)
 {
+	if (!generic_ops.get_variable)
+		return;
+
 	efivars_unregister(&generic_efivars);
 }
 
@@ -481,7 +503,7 @@ void __init efi_find_mirror(void)
  * and if so, populate the supplied memory descriptor with the appropriate
  * data.
  */
-int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
+int __efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 {
 	efi_memory_desc_t *md;
 
@@ -499,6 +521,12 @@ int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 		u64 size;
 		u64 end;
 
+		/* skip bogus entries (including empty ones) */
+		if ((md->phys_addr & (EFI_PAGE_SIZE - 1)) ||
+		    (md->num_pages <= 0) ||
+		    (md->num_pages > (U64_MAX - md->phys_addr) >> EFI_PAGE_SHIFT))
+			continue;
+
 		size = md->num_pages << EFI_PAGE_SHIFT;
 		end = md->phys_addr + size;
 		if (phys_addr >= md->phys_addr && phys_addr < end) {
@@ -509,6 +537,9 @@ int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 	return -ENOENT;
 }
 
+extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
+	__weak __alias(__efi_mem_desc_lookup);
+
 /*
  * Calculate the highest address of an efi memory descriptor.
  */
@@ -535,6 +566,10 @@ void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
  */
 void __init efi_mem_reserve(phys_addr_t addr, u64 size)
 {
+	/* efi_mem_reserve() does not work under Xen */
+	if (WARN_ON_ONCE(efi_enabled(EFI_PARAVIRT)))
+		return;
+
 	if (!memblock_is_region_reserved(addr, size))
 		memblock_reserve(addr, size);
 
@@ -583,13 +618,20 @@ static __init int match_config_table(const efi_guid_t *guid,
 	int i;
 
 	for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
-		if (!efi_guidcmp(*guid, table_types[i].guid)) {
-			*(table_types[i].ptr) = table;
+		if (efi_guidcmp(*guid, table_types[i].guid))
+			continue;
+
+		if (!efi_config_table_is_usable(guid, table)) {
 			if (table_types[i].name[0])
-				pr_cont("%s=0x%lx ",
+				pr_cont("(%s=0x%lx unusable) ",
 					table_types[i].name, table);
 			return 1;
 		}
+
+		*(table_types[i].ptr) = table;
+		if (table_types[i].name[0])
+			pr_cont("%s=0x%lx ", table_types[i].name, table);
+		return 1;
 	}
 
 	return 0;
@@ -720,20 +762,13 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 	return 0;
 }
 
-int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
-				   int min_major_version)
+int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr)
 {
 	if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 		pr_err("System table signature incorrect!\n");
 		return -EINVAL;
 	}
 
-	if ((systab_hdr->revision >> 16) < min_major_version)
-		pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
-		       systab_hdr->revision >> 16,
-		       systab_hdr->revision & 0xffff,
-		       min_major_version);
-
 	return 0;
 }
 
@@ -764,6 +799,7 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
 	char vendor[100] = "unknown";
 	const efi_char16_t *c16;
 	size_t i;
+	u16 rev;
 
 	c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
 	if (c16) {
@@ -774,10 +810,14 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
 		unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
 	}
 
-	pr_info("EFI v%u.%.02u by %s\n",
-		systab_hdr->revision >> 16,
-		systab_hdr->revision & 0xffff,
-		vendor);
+	rev = (u16)systab_hdr->revision;
+	pr_info("EFI v%u.%u", systab_hdr->revision >> 16, rev / 10);
+
+	rev %= 10;
+	if (rev)
+		pr_cont(".%u", rev);
+
+	pr_cont(" by %s\n", vendor);
 
 	if (IS_ENABLED(CONFIG_X86_64) &&
 	    systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&