Commit fc9f248d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'efi-fixes-for-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi 

Pull EFI fix from Ard Biesheuvel:
 "Fix for the x86 EFI workaround keeping boot services code and data
  regions reserved until after SetVirtualAddressMap() completes:
  deferred struct page initialization may result in some of this memory
  being lost permanently"

* tag 'efi-fixes-for-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  x86/efi: defer freeing of boot services memory
parents 014441d1 a4b0bf6a

arch/x86/include/asm/efi.h

+1 −1
Original line number Diff line number Diff line
@@ -138,7 +138,7 @@ extern void __init efi_apply_memmap_quirks(void); 
extern int __init efi_reuse_config(u64 tables, int nr_tables);

extern void efi_delete_dummy_variable(void);

extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);

extern void efi_free_boot_services(void);

extern void efi_unmap_boot_services(void);



void arch_efi_call_virt_setup(void);

void arch_efi_call_virt_teardown(void);

arch/x86/platform/efi/efi.c

+1 −1
Original line number Diff line number Diff line
@@ -836,7 +836,7 @@ static void __init __efi_enter_virtual_mode(void) 
	}



	efi_check_for_embedded_firmwares();

	efi_free_boot_services();

	efi_unmap_boot_services();



	if (!efi_is_mixed())

		efi_native_runtime_setup();

arch/x86/platform/efi/quirks.c

+52 −3
Original line number Diff line number Diff line
@@ -341,7 +341,7 @@ void __init efi_reserve_boot_services(void) 


		/*

		 * Because the following memblock_reserve() is paired

		 * with memblock_free_late() for this region in

		 * with free_reserved_area() for this region in

		 * efi_free_boot_services(), we must be extremely

		 * careful not to reserve, and subsequently free,

		 * critical regions of memory (like the kernel image) or
@@ -404,17 +404,33 @@ static void __init efi_unmap_pages(efi_memory_desc_t *md) 
		pr_err("Failed to unmap VA mapping for 0x%llx\n", va);

}



void __init efi_free_boot_services(void)

struct efi_freeable_range {

	u64 start;

	u64 end;

};



static struct efi_freeable_range *ranges_to_free;



void __init efi_unmap_boot_services(void)

{

	struct efi_memory_map_data data = { 0 };

	efi_memory_desc_t *md;

	int num_entries = 0;

	int idx = 0;

	size_t sz;

	void *new, *new_md;



	/* Keep all regions for /sys/kernel/debug/efi */

	if (efi_enabled(EFI_DBG))

		return;



	sz = sizeof(*ranges_to_free) * efi.memmap.nr_map + 1;

	ranges_to_free = kzalloc(sz, GFP_KERNEL);

	if (!ranges_to_free) {

		pr_err("Failed to allocate storage for freeable EFI regions\n");

		return;

	}



	for_each_efi_memory_desc(md) {

		unsigned long long start = md->phys_addr;

		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
@@ -471,7 +487,15 @@ void __init efi_free_boot_services(void) 
			start = SZ_1M;

		}



		memblock_free_late(start, size);

		/*

		 * With CONFIG_DEFERRED_STRUCT_PAGE_INIT parts of the memory

		 * map are still not initialized and we can't reliably free

		 * memory here.

		 * Queue the ranges to free at a later point.

		 */

		ranges_to_free[idx].start = start;

		ranges_to_free[idx].end = start + size;

		idx++;

	}



	if (!num_entries)
@@ -512,6 +536,31 @@ void __init efi_free_boot_services(void) 
	}

}



static int __init efi_free_boot_services(void)

{

	struct efi_freeable_range *range = ranges_to_free;

	unsigned long freed = 0;



	if (!ranges_to_free)

		return 0;



	while (range->start) {

		void *start = phys_to_virt(range->start);

		void *end = phys_to_virt(range->end);



		free_reserved_area(start, end, -1, NULL);

		freed += (end - start);

		range++;

	}

	kfree(ranges_to_free);



	if (freed)

		pr_info("Freeing EFI boot services memory: %ldK\n", freed / SZ_1K);



	return 0;

}

arch_initcall(efi_free_boot_services);



/*

 * A number of config table entries get remapped to virtual addresses

 * after entering EFI virtual mode. However, the kexec kernel requires

drivers/firmware/efi/mokvar-table.c

+1 −1
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ static struct kobject *mokvar_kobj; 
 * as an alternative to ordinary EFI variables, due to platform-dependent

 * limitations. The memory occupied by this table is marked as reserved.

 *

 * This routine must be called before efi_free_boot_services() in order

 * This routine must be called before efi_unmap_boot_services() in order

 * to guarantee that it can mark the table as reserved.

 *

 * Implicit inputs: