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.ha...@gmail.com>
---
Changes in V2:
  Update the comments in the code.
  Add same fix to __setup_efi_pci32()

--- 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     2017-08-07 
13:00:15.165374388 -0400
@@ -127,7 +127,13 @@ __setup_efi_pci32(efi_pci_io_protocol_32
 
        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, and
+        * e820__register_nosave_regions() expects page-aligned regions.
+        */
+       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;
@@ -235,7 +241,13 @@ __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, and
+        * e820__register_nosave_regions() expects page-aligned regions.
+        */
+       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;
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to