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authorJeffrey Hugo <jhugo@codeaurora.org>2016-08-29 14:38:52 -0600
committerMatt Fleming <matt@codeblueprint.co.uk>2016-09-05 12:32:28 +0100
commitfc07716ba803483be91bc4b2344f9c84985e6f07 (patch)
tree67256f8edc0ddb23dc5f6be586c90ee01877a2a4 /include/linux/efi.h
parentdadb57abc37499f565b23933dbf49b435c3ba8af (diff)
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efi/libstub: Introduce ExitBootServices helper
The spec allows ExitBootServices to fail with EFI_INVALID_PARAMETER if a race condition has occurred where the EFI has updated the memory map after the stub grabbed a reference to the map. The spec defines a retry proceedure with specific requirements to handle this scenario. This scenario was previously observed on x86 - commit d3768d885c6c ("x86, efi: retry ExitBootServices() on failure") but the current fix is not spec compliant and the scenario is now observed on the Qualcomm Technologies QDF2432 via the FDT stub which does not handle the error and thus causes boot failures. The user will notice the boot failure as the kernel is not executed and the system may drop back to a UEFI shell, but will be unresponsive to input and the system will require a power cycle to recover. Add a helper to the stub library that correctly adheres to the spec in the case of EFI_INVALID_PARAMETER from ExitBootServices and can be universally used across all stub implementations. Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Diffstat (limited to 'include/linux/efi.h')
-rw-r--r--include/linux/efi.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 943fee524176..0148a3046b48 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1462,4 +1462,14 @@ extern void efi_call_virt_check_flags(unsigned long flags, const char *call);
arch_efi_call_virt_teardown(); \
})
+typedef efi_status_t (*efi_exit_boot_map_processing)(
+ efi_system_table_t *sys_table_arg,
+ struct efi_boot_memmap *map,
+ void *priv);
+
+efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table,
+ void *handle,
+ struct efi_boot_memmap *map,
+ void *priv,
+ efi_exit_boot_map_processing priv_func);
#endif /* _LINUX_EFI_H */