Commit 6c64447e authored by Daniel Kiper's avatar Daniel Kiper Committed by Ingo Molnar
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x86/xen/efi: Initialize only the EFI struct members used by Xen 



The current approach, which is the wholesale efi struct initialization from
a 'efi_xen' local template is not robust. Usually if new member is defined
then it is properly initialized in drivers/firmware/efi/efi.c, but not in
arch/x86/xen/efi.c.

The effect is that the Xen initialization clears any fields the generic code
might have set and the Xen code does not know about yet.

I saw this happen a few times, so let's initialize only the EFI struct members
used by Xen and maintain no local duplicate, to avoid such issues in the future.

Signed-off-by: default avatarDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: jgross@suse.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: stable@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1498128697-12943-3-git-send-email-daniel.kiper@oracle.com


[ Clarified the changelog. ]
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 457ea3f7

arch/x86/xen/efi.c

+12 −33
Original line number Diff line number Diff line
@@ -54,38 +54,6 @@ static efi_system_table_t efi_systab_xen __initdata = { 
	.tables		= EFI_INVALID_TABLE_ADDR  /* Initialized later. */

};



static const struct efi efi_xen __initconst = {

	.systab                   = NULL, /* Initialized later. */

	.runtime_version	  = 0,    /* Initialized later. */

	.mps                      = EFI_INVALID_TABLE_ADDR,

	.acpi                     = EFI_INVALID_TABLE_ADDR,

	.acpi20                   = EFI_INVALID_TABLE_ADDR,

	.smbios                   = EFI_INVALID_TABLE_ADDR,

	.smbios3                  = EFI_INVALID_TABLE_ADDR,

	.sal_systab               = EFI_INVALID_TABLE_ADDR,

	.boot_info                = EFI_INVALID_TABLE_ADDR,

	.hcdp                     = EFI_INVALID_TABLE_ADDR,

	.uga                      = EFI_INVALID_TABLE_ADDR,

	.uv_systab                = EFI_INVALID_TABLE_ADDR,

	.fw_vendor                = EFI_INVALID_TABLE_ADDR,

	.runtime                  = EFI_INVALID_TABLE_ADDR,

	.config_table             = EFI_INVALID_TABLE_ADDR,

	.get_time                 = xen_efi_get_time,

	.set_time                 = xen_efi_set_time,

	.get_wakeup_time          = xen_efi_get_wakeup_time,

	.set_wakeup_time          = xen_efi_set_wakeup_time,

	.get_variable             = xen_efi_get_variable,

	.get_next_variable        = xen_efi_get_next_variable,

	.set_variable             = xen_efi_set_variable,

	.query_variable_info      = xen_efi_query_variable_info,

	.update_capsule           = xen_efi_update_capsule,

	.query_capsule_caps       = xen_efi_query_capsule_caps,

	.get_next_high_mono_count = xen_efi_get_next_high_mono_count,

	.reset_system             = xen_efi_reset_system,

	.set_virtual_address_map  = NULL, /* Not used under Xen. */

	.flags			  = 0     /* Initialized later. */

};



static efi_system_table_t __init *xen_efi_probe(void)

{

	struct xen_platform_op op = {
@@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void) 


	/* Here we know that Xen runs on EFI platform. */



	efi = efi_xen;

	efi.get_time                 = xen_efi_get_time;

	efi.set_time                 = xen_efi_set_time;

	efi.get_wakeup_time          = xen_efi_get_wakeup_time;

	efi.set_wakeup_time          = xen_efi_set_wakeup_time;

	efi.get_variable             = xen_efi_get_variable;

	efi.get_next_variable        = xen_efi_get_next_variable;

	efi.set_variable             = xen_efi_set_variable;

	efi.query_variable_info      = xen_efi_query_variable_info;

	efi.update_capsule           = xen_efi_update_capsule;

	efi.query_capsule_caps       = xen_efi_query_capsule_caps;

	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;

	efi.reset_system             = xen_efi_reset_system;



	efi_systab_xen.tables = info->cfg.addr;

	efi_systab_xen.nr_tables = info->cfg.nent;

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