The kernel's EFI stub locates and copies EFI ROM images into memory, which it allocates using the byte-granular EFI allocate_pool function. These memory ranges are then added to setup_data, and later to e820 (in e820__reserve_setup_data()). The e820 ranges are parsed to create nosave regions (in e820__register_nosave_regions()), but when non-page-aligned e820 regions are parsed, a nosave page is added at the beginning and end of each non-page-aligned region, which results in data not getting saved or restored during a hibernate/resume. This can result in random failures after a hibernate/resume.
Round up the allocation size to a whole number of pages, and use EFI allocate_pages to ensure that the EFI ROM copy regions are page-aligned.
On a system with six EFI ROM images, before the patch:
e820: update [mem 0x64866020-0x6486e05f] usable ==> usable
e820: update [mem 0x6147a020-0x61499c5f] usable ==> usable
e820: update [mem 0x60fff020-0x6105785f] usable ==> usable
e820: update [mem 0x60fa6020-0x60ffe85f] usable ==> usable
e820: update [mem 0x60f4d020-0x60fa585f] usable ==> usable
e820: update [mem 0x60ef4020-0x60f4c85f] usable ==> usable
...
PM: Registered nosave memory: [mem 0x00000000-0x00000fff]
PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]
PM: Registered nosave memory: [mem 0x60ef4000-0x60ef4fff]
PM: Registered nosave memory: [mem 0x60f4c000-0x60f4cfff]
PM: Registered nosave memory: [mem 0x60f4d000-0x60f4dfff]
PM: Registered nosave memory: [mem 0x60fa5000-0x60fa5fff]
PM: Registered nosave memory: [mem 0x60fa6000-0x60fa6fff]
PM: Registered nosave memory: [mem 0x60ffe000-0x60ffefff]
PM: Registered nosave memory: [mem 0x60fff000-0x60ffffff]
PM: Registered nosave memory: [mem 0x61057000-0x61057fff]
PM: Registered nosave memory: [mem 0x6147a000-0x6147afff]
PM: Registered nosave memory: [mem 0x61499000-0x61499fff]
PM: Registered nosave memory: [mem 0x64866000-0x64866fff]
PM: Registered nosave memory: [mem 0x6486e000-0x6486efff]
PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff]
After the patch:
e820: update [mem 0x64866000-0x6486efff] usable ==> usable
e820: update [mem 0x6147a000-0x61499fff] usable ==> usable
e820: update [mem 0x60fff000-0x61057fff] usable ==> usable
e820: update [mem 0x60fa6000-0x60ffefff] usable ==> usable
e820: update [mem 0x60f4d000-0x60fa5fff] usable ==> usable
e820: update [mem 0x60ef4000-0x60f4cfff] usable ==> usable
...
PM: Registered nosave memory: [mem 0x00000000-0x00000fff]
PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]
PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff]
Signed-off-by: Stuart Hayes <stuart.w.hayes@xxxxxxxxx>
---
--- linux-4.13-rc2/arch/x86/boot/compressed/eboot.c.orig 2017-08-01 12:12:04.696049106 -0400
+++ linux-4.13-rc2/arch/x86/boot/compressed/eboot.c 2017-08-01 12:11:33.120182236 -0400
@@ -235,7 +235,12 @@ __setup_efi_pci64(efi_pci_io_protocol_64
size = pci->romsize + sizeof(*rom);
- status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
+ /*
+ * Get whole pages because this will be added to e820.
+ */
+ size = PAGE_ALIGN(size);
+ status = efi_call_early(allocate_pages, EFI_ALLOCATE_ANY_PAGES,
+ EFI_LOADER_DATA, (size >> PAGE_SHIFT), &rom);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to alloc mem for rom\n");
return status;
--
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