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,
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> +{
> + 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
>
