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Commit c87d8ef1 authored by Hedi Berriche's avatar Hedi Berriche Committed by Greg Kroah-Hartman
Browse files

x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls 



commit f331e766c4be33f4338574f3c9f7f77e98ab4571 upstream.

Calls into UV firmware must be protected against concurrency, expose the
efi_runtime_lock to the UV platform, and use it to serialise UV BIOS
calls.

Signed-off-by: default avatarHedi Berriche <hedi.berriche@hpe.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: default avatarRuss Anderson <rja@hpe.com>
Reviewed-by: default avatarDimitri Sivanich <sivanich@hpe.com>
Reviewed-by: default avatarMike Travis <mike.travis@hpe.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-efi <linux-efi@vger.kernel.org>
Cc: platform-driver-x86@vger.kernel.org
Cc: stable@vger.kernel.org # v4.9+
Cc: Steve Wahl <steve.wahl@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190213193413.25560-5-hedi.berriche@hpe.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 092fc755

arch/x86/include/asm/uv/bios.h

+7 −1
Original line number Diff line number Diff line
@@ -48,7 +48,8 @@ enum { 
	BIOS_STATUS_SUCCESS		=  0,

	BIOS_STATUS_UNIMPLEMENTED	= -ENOSYS,

	BIOS_STATUS_EINVAL		= -EINVAL,

	BIOS_STATUS_UNAVAIL		= -EBUSY

	BIOS_STATUS_UNAVAIL		= -EBUSY,

	BIOS_STATUS_ABORT		= -EINTR,

};



/* Address map parameters */
@@ -167,4 +168,9 @@ extern long system_serial_number; 


extern struct kobject *sgi_uv_kobj;	/* /sys/firmware/sgi_uv */



/*

 * EFI runtime lock; cf. firmware/efi/runtime-wrappers.c for details

 */

extern struct semaphore __efi_uv_runtime_lock;



#endif /* _ASM_X86_UV_BIOS_H */

arch/x86/platform/uv/bios_uv.c

+21 −2
Original line number Diff line number Diff line
@@ -29,7 +29,8 @@ 


struct uv_systab *uv_systab;



s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)

static s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,

			u64 a4, u64 a5)

{

	struct uv_systab *tab = uv_systab;

	s64 ret;
@@ -51,6 +52,19 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5) 


	return ret;

}



s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)

{

	s64 ret;



	if (down_interruptible(&__efi_uv_runtime_lock))

		return BIOS_STATUS_ABORT;



	ret = __uv_bios_call(which, a1, a2, a3, a4, a5);

	up(&__efi_uv_runtime_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(uv_bios_call);



s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,
@@ -59,10 +73,15 @@ s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, 
	unsigned long bios_flags;

	s64 ret;



	if (down_interruptible(&__efi_uv_runtime_lock))

		return BIOS_STATUS_ABORT;



	local_irq_save(bios_flags);

	ret = uv_bios_call(which, a1, a2, a3, a4, a5);

	ret = __uv_bios_call(which, a1, a2, a3, a4, a5);

	local_irq_restore(bios_flags);



	up(&__efi_uv_runtime_lock);



	return ret;

}

drivers/firmware/efi/runtime-wrappers.c

+7 −0
Original line number Diff line number Diff line
@@ -49,6 +49,13 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call) 
	local_irq_restore(flags);

}



/*

 * Expose the EFI runtime lock to the UV platform

 */

#ifdef CONFIG_X86_UV

extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);

#endif



/*

 * According to section 7.1 of the UEFI spec, Runtime Services are not fully

 * reentrant, and there are particular combinations of calls that need to be