On 21/01/2019 15:42, Ard Biesheuvel wrote:
> On Mon, 21 Jan 2019 at 16:34, Julien Thierry <julien.thierry@xxxxxxx> wrote:
>>
>> Currently, irqflags are saved before calling runtime services and
>> checked for mismatch on return.
>>
>> Provide a pair of overridable macros to save and restore (if needed) the
>> state that need to be preserved on return from a runtime service.
>> This allows to check for flags that are not necesarly related to
>> irqflags.
>>
>> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
>> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
>> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>> Cc: linux-efi@xxxxxxxxxxxxxxx
>> ---
>> drivers/firmware/efi/runtime-wrappers.c | 17 +++++++++++++++--
>> include/linux/efi.h | 5 +++--
>> 2 files changed, 18 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
>> index 8903b9c..2f4b68b 100644
>> --- a/drivers/firmware/efi/runtime-wrappers.c
>> +++ b/drivers/firmware/efi/runtime-wrappers.c
>> @@ -89,11 +89,24 @@
>> efi_rts_work.status; \
>> })
>>
>> +#ifndef arch_efi_save_flags
>> +#define arch_efi_save_flags(state_flags) local_save_flags(state_flags)
>> +#define arch_efi_restore_flags(state_flags) local_irq_restore(state_flags)
>> +#endif
>> +
>> +inline unsigned long efi_call_virt_save_flags(void)
>
> If you drop the 'inline' here,
>
Sure, I'll drop it in the next version.
> Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>
Thanks,
Julien
>> +{
>> + unsigned long flags;
>> +
>> + arch_efi_save_flags(flags);
>> + return flags;
>> +}
>> +
>> void efi_call_virt_check_flags(unsigned long flags, const char *call)
>> {
>> unsigned long cur_flags, mismatch;
>>
>> - local_save_flags(cur_flags);
>> + cur_flags = efi_call_virt_save_flags();
>>
>> mismatch = flags ^ cur_flags;
>> if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK))
>> @@ -102,7 +115,7 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call)
>> add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE);
>> pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI %s\n",
>> flags, cur_flags, call);
>> - local_irq_restore(flags);
>> + arch_efi_restore_flags(flags);
>> }
>>
>> /*
>> diff --git a/include/linux/efi.h b/include/linux/efi.h
>> index 45ff763..bd80b7e 100644
>> --- a/include/linux/efi.h
>> +++ b/include/linux/efi.h
>> @@ -1607,6 +1607,7 @@ efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg,
>>
>> bool efi_runtime_disabled(void);
>> extern void efi_call_virt_check_flags(unsigned long flags, const char *call);
>> +extern unsigned long efi_call_virt_save_flags(void);
>>
>> enum efi_secureboot_mode {
>> efi_secureboot_mode_unset,
>> @@ -1652,7 +1653,7 @@ enum efi_secureboot_mode {
>> \
>> arch_efi_call_virt_setup(); \
>> \
>> - local_save_flags(__flags); \
>> + __flags = efi_call_virt_save_flags(); \
>> __s = arch_efi_call_virt(p, f, args); \
>> efi_call_virt_check_flags(__flags, __stringify(f)); \
>> \
>> @@ -1667,7 +1668,7 @@ enum efi_secureboot_mode {
>> \
>> arch_efi_call_virt_setup(); \
>> \
>> - local_save_flags(__flags); \
>> + __flags = efi_call_virt_save_flags(); \
>> arch_efi_call_virt(p, f, args); \
>> efi_call_virt_check_flags(__flags, __stringify(f)); \
>> \
>> --
>> 1.9.1
>>
--
Julien Thierry
