efi: Prevent GICv3 WARN() by mapping the memreserve table before first use (976b4891) · Commits · 戴 / test

Mapping the MEMRESERVE EFI configuration table from an early initcall is too late: the GICv3 ITS code that creates persistent reservations for the boot CPU's LPI tables is invoked from init_IRQ(), which runs much earlier than the handling of the initcalls. This results in a WARN() splat because the LPI tables cannot be reserved persistently, which will result in silent memory corruption after a kexec reboot. So instead, invoke the initialization performed by the initcall from efi_mem_reserve_persistent() itself as well, but keep the initcall so that the init is guaranteed to have been called before SMP boot. Tested-by:

Marc Zyngier <marc.zyngier@arm.com> Tested-by:

Jan Glauber <jglauber@cavium.com> Tested-by:

John Garry <john.garry@huawei.com> Signed-off-by:

Ard 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: linux-efi@vger.kernel.org Fixes: ("efi: Permit calling efi_mem_reserve_persistent() ...") Link: http://lkml.kernel.org/r/20181123215132.7951-2-ard.biesheuvel@linaro.org Signed-off-by:

Ingo Molnar <mingo@kernel.org>

drivers/firmware/efi/efi.c

+26 −10

Original line number	Diff line number	Diff line
		@@ -969,13 +969,33 @@ bool efi_is_table_address(unsigned long phys_addr)
		static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
		static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;

		int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
		static int __init efi_memreserve_map_root(void)
		{
		if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
		return -ENODEV;

		efi_memreserve_root = memremap(efi.mem_reserve,
		sizeof(*efi_memreserve_root),
		MEMREMAP_WB);
		if (WARN_ON_ONCE(!efi_memreserve_root))
		return -ENOMEM;
		return 0;
		}

		int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
		{
		struct linux_efi_memreserve *rsv;
		int rc;

		if (!efi_memreserve_root)
		if (efi_memreserve_root == (void *)ULONG_MAX)
		return -ENODEV;

		if (!efi_memreserve_root) {
		rc = efi_memreserve_map_root();
		if (rc)
		return rc;
		}

		rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);
		if (!rsv)
		return -ENOMEM;
		@@ -993,14 +1013,10 @@ int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)

		static int __init efi_memreserve_root_init(void)
		{
		if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
		return -ENODEV;

		efi_memreserve_root = memremap(efi.mem_reserve,
		sizeof(*efi_memreserve_root),
		MEMREMAP_WB);
		if (!efi_memreserve_root)
		return -ENOMEM;
		if (efi_memreserve_root)
		return 0;
		if (efi_memreserve_map_root())
		efi_memreserve_root = (void *)ULONG_MAX;
		return 0;
		}
		early_initcall(efi_memreserve_root_init);

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