Commit-ID: 976b489120cdab2b1b3a41ffa14661db43d58190
Gitweb: https://git.kernel.org/tip/976b489120cdab2b1b3a41ffa14661db43d58190
Author: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
AuthorDate: Fri, 23 Nov 2018 22:51:32 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 27 Nov 2018 13:50:20 +0100
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: Marc Zyngier <marc.zyngier@xxxxxxx>
Tested-by: Jan Glauber <jglauber@xxxxxxxxxx>
Tested-by: John Garry <john.garry@xxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-efi@xxxxxxxxxxxxxxx
Fixes: 63eb322d89c8 ("efi: Permit calling efi_mem_reserve_persistent() ...")
Link: http://lkml.kernel.org/r/20181123215132.7951-2-ard.biesheuvel@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/firmware/efi/efi.c | 36 ++++++++++++++++++++++++++----------
1 file changed, 26 insertions(+), 10 deletions(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index fad7c62cfc0e..415849bab233 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -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);
|