From 8dbe33956d96c9d066ef15ca933ede30748198b2 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Mon, 14 Aug 2023 19:12:47 +0300 Subject: [PATCH] efi/unaccepted: Make sure unaccepted table is mapped Unaccepted table is now allocated from EFI_ACPI_RECLAIM_MEMORY. It translates into E820_TYPE_ACPI, which is not added to memblock and therefore not mapped in the direct mapping. This causes a crash on the first touch of the table. Use memblock_add() to make sure that the table is mapped in direct mapping. Align the range to the nearest page borders. Ranges smaller than page size are not mapped. Fixes: e7761d827e99 ("efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table") Reported-by: Hongyu Ning Signed-off-by: Kirill A. Shutemov Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/efi.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 1599f1176842..ce20a60676f0 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -623,6 +623,34 @@ static __init int match_config_table(const efi_guid_t *guid, return 0; } +/** + * reserve_unaccepted - Map and reserve unaccepted configuration table + * @unaccepted: Pointer to unaccepted memory table + * + * memblock_add() makes sure that the table is mapped in direct mapping. During + * normal boot it happens automatically because the table is allocated from + * usable memory. But during crashkernel boot only memory specifically reserved + * for crash scenario is mapped. memblock_add() forces the table to be mapped + * in crashkernel case. + * + * Align the range to the nearest page borders. Ranges smaller than page size + * are not going to be mapped. + * + * memblock_reserve() makes sure that future allocations will not touch the + * table. + */ + +static __init void reserve_unaccepted(struct efi_unaccepted_memory *unaccepted) +{ + phys_addr_t start, size; + + start = PAGE_ALIGN_DOWN(efi.unaccepted); + size = PAGE_ALIGN(sizeof(*unaccepted) + unaccepted->size); + + memblock_add(start, size); + memblock_reserve(start, size); +} + int __init efi_config_parse_tables(const efi_config_table_t *config_tables, int count, const efi_config_table_type_t *arch_tables) @@ -751,11 +779,9 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables, unaccepted = early_memremap(efi.unaccepted, sizeof(*unaccepted)); if (unaccepted) { - unsigned long size; if (unaccepted->version == 1) { - size = sizeof(*unaccepted) + unaccepted->size; - memblock_reserve(efi.unaccepted, size); + reserve_unaccepted(unaccepted); } else { efi.unaccepted = EFI_INVALID_TABLE_ADDR; } -- 2.34.1