Re: [PATCH 1/1] efi/efi_test: read RuntimeServicesSupported

[Heinrich Schuchardt]

On 11/30/20 9:16 AM, ivanhu wrote:
> Hi Heinrich,
>
> Thanks for the patch.
> It looks good to me, but I noticed that the runtime_supported_mask was
> introduced after 5.7-rc1.
> Maybe we should add the kernel version checking for the old kernels.

This is a kernel patch. Why should we check the kernel version in the
kernel code?

As patches may be back-ported we should not make any assumptions in fwts
based on the kernel version. If the ioctl() call fails with errno =
ENOTTY, we know that the kernel does not implement the ioctl call and we
have to assume that all runtime services are available.

Best regards

Heinrich

> Cheers,
> Ivan
>
> On 11/28/20 3:20 AM, Heinrich Schuchardt wrote:
> > Since the UEFI 2.8A specification the UEFI enabled firmware provides a
> > configuration table EFI_RT_PROPERTIES_TABLE which indicates which runtime
> > services are enabled. The EFI stub reads this table and saves the value of
> > the field RuntimeServicesSupported internally.
> >
> > The Firmware Test Suite requires the value to determine if UEFI runtime
> > services are correctly implemented.
> >
> > With this patch an IOCTL call is provided to read the value of the field
> > RuntimeServicesSupported, e.g.
> >
> >      #define EFI_RUNTIME_GET_SUPPORTED_MASK \
> >              _IOR('p', 0x0C, unsigned int)
> >      unsigned int mask;
> >      fd = open("/dev/efi_test", O_RDWR);
> >      ret = ioctl(fd, EFI_RUNTIME_GET_SUPPORTED_MASK, &mask);
> >
> > Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
> > ---
> >   drivers/firmware/efi/test/efi_test.c | 16 ++++++++++++++++
> >   drivers/firmware/efi/test/efi_test.h |  3 +++
> >   2 files changed, 19 insertions(+)
> >
> > diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c
> > index ddf9eae396fe..47d67bb0a516 100644
> > --- a/drivers/firmware/efi/test/efi_test.c
> > +++ b/drivers/firmware/efi/test/efi_test.c
> > @@ -663,6 +663,19 @@ static long efi_runtime_query_capsulecaps(unsigned long arg)
> >   	return rv;
> >   }
> >
> > +static long efi_runtime_get_supported_mask(unsigned long arg)
> > +{
> > +	unsigned int __user *supported_mask;
> > +	int rv = 0;
> > +
> > +	supported_mask = (unsigned int *)arg;
> > +
> > +	if (put_user(efi.runtime_supported_mask, supported_mask))
> > +		rv = -EFAULT;
> > +
> > +	return rv;
> > +}
> > +
> >   static long efi_test_ioctl(struct file *file, unsigned int cmd,
> >   							unsigned long arg)
> >   {
> > @@ -699,6 +712,9 @@ static long efi_test_ioctl(struct file *file, unsigned int cmd,
> >
> >   	case EFI_RUNTIME_RESET_SYSTEM:
> >   		return efi_runtime_reset_system(arg);
> > +
> > +	case EFI_RUNTIME_GET_SUPPORTED_MASK:
> > +		return efi_runtime_get_supported_mask(arg);
> >   	}
> >
> >   	return -ENOTTY;
> > diff --git a/drivers/firmware/efi/test/efi_test.h b/drivers/firmware/efi/test/efi_test.h
> > index f2446aa1c2e3..117349e57993 100644
> > --- a/drivers/firmware/efi/test/efi_test.h
> > +++ b/drivers/firmware/efi/test/efi_test.h
> > @@ -118,4 +118,7 @@ struct efi_resetsystem {
> >   #define EFI_RUNTIME_RESET_SYSTEM \
> >   	_IOW('p', 0x0B, struct efi_resetsystem)
> >
> > +#define EFI_RUNTIME_GET_SUPPORTED_MASK \
> > +	_IOR('p', 0x0C, unsigned int)
> > +
> >   #endif /* _DRIVERS_FIRMWARE_EFI_TEST_H_ */
> > --
> > 2.29.2