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authorMatthew Garrett <matthew.garrett@nebula.com>2013-06-01 16:06:20 -0400
committerMatt Fleming <matt.fleming@intel.com>2013-06-10 21:59:37 +0100
commitf8b8404337de4e2466e2e1139ea68b1f8295974f (patch)
tree6dc89e9602b7c25ea9998e47da3d4d31e2ac40c4 /arch/x86/include/asm/efi.h
parenteccaf52fee8305d5207ff110950a82c100e459bc (diff)
downloadvexpress-lsk-f8b8404337de4e2466e2e1139ea68b1f8295974f.tar.gz
Modify UEFI anti-bricking code
This patch reworks the UEFI anti-bricking code, including an effective reversion of cc5a080c and 31ff2f20. It turns out that calling QueryVariableInfo() from boot services results in some firmware implementations jumping to physical addresses even after entering virtual mode, so until we have 1:1 mappings for UEFI runtime space this isn't going to work so well. Reverting these gets us back to the situation where we'd refuse to create variables on some systems because they classify deleted variables as "used" until the firmware triggers a garbage collection run, which they won't do until they reach a lower threshold. This results in it being impossible to install a bootloader, which is unhelpful. Feedback from Samsung indicates that the firmware doesn't need more than 5KB of storage space for its own purposes, so that seems like a reasonable threshold. However, there's still no guarantee that a platform will attempt garbage collection merely because it drops below this threshold. It seems that this is often only triggered if an attempt to write generates a genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to create a variable larger than the remaining space. This should fail, but if it somehow succeeds we can then immediately delete it. I've tested this on the UEFI machines I have available, but I don't have a Samsung and so can't verify that it avoids the bricking problem. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ] Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'arch/x86/include/asm/efi.h')
-rw-r--r--arch/x86/include/asm/efi.h7
1 files changed, 0 insertions, 7 deletions
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 2fb5d5884e2..60c89f30c72 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -102,13 +102,6 @@ extern void efi_call_phys_epilog(void);
extern void efi_unmap_memmap(void);
extern void efi_memory_uc(u64 addr, unsigned long size);
-struct efi_var_bootdata {
- struct setup_data data;
- u64 store_size;
- u64 remaining_size;
- u64 max_var_size;
-};
-
#ifdef CONFIG_EFI
static inline bool efi_is_native(void)