Commit 976b4891 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar

efi: Prevent GICv3 WARN() by mapping the memreserve table before first use

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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Tested-by: default avatarJan Glauber <jglauber@cavium.com>
Tested-by: default avatarJohn Garry <john.garry@huawei.com>
Signed-off-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: linux-efi@vger.kernel.org
Fixes: 63eb322d ("efi: Permit calling efi_mem_reserve_persistent() ...")
Link: http://lkml.kernel.org/r/20181123215132.7951-2-ard.biesheuvel@linaro.orgSigned-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
parent 2e6e902d
......@@ -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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