diff options
| -rw-r--r-- | arch/x86/boot/compressed/efi.h | 10 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 40 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/mem.c | 41 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 6 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.h | 10 |
5 files changed, 95 insertions, 12 deletions
diff --git a/arch/x86/boot/compressed/efi.h b/arch/x86/boot/compressed/efi.h index 7db2f41b54cd..866c0af8b5b9 100644 --- a/arch/x86/boot/compressed/efi.h +++ b/arch/x86/boot/compressed/efi.h @@ -16,6 +16,7 @@ typedef guid_t efi_guid_t __aligned(__alignof__(u32)); #define ACPI_TABLE_GUID EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3, 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) #define ACPI_20_TABLE_GUID EFI_GUID(0x8868e871, 0xe4f1, 0x11d3, 0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81) #define EFI_CC_BLOB_GUID EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42) +#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31) #define EFI32_LOADER_SIGNATURE "EL32" #define EFI64_LOADER_SIGNATURE "EL64" @@ -32,6 +33,7 @@ typedef struct { } efi_table_hdr_t; #define EFI_CONVENTIONAL_MEMORY 7 +#define EFI_UNACCEPTED_MEMORY 15 #define EFI_MEMORY_MORE_RELIABLE \ ((u64)0x0000000000010000ULL) /* higher reliability */ @@ -104,6 +106,14 @@ struct efi_setup_data { u64 reserved[8]; }; +struct efi_unaccepted_memory { + u32 version; + u32 unit_size; + u64 phys_base; + u64 size; + unsigned long bitmap[]; +}; + static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right) { return memcmp(&left, &right, sizeof (efi_guid_t)); diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 454757fbdfe5..9193acf0e9cd 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -672,6 +672,33 @@ static bool process_mem_region(struct mem_vector *region, } #ifdef CONFIG_EFI + +/* + * Only EFI_CONVENTIONAL_MEMORY and EFI_UNACCEPTED_MEMORY (if supported) are + * guaranteed to be free. + * + * Pick free memory more conservatively than the EFI spec allows: according to + * the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also free memory and thus + * available to place the kernel image into, but in practice there's firmware + * where using that memory leads to crashes. Buggy vendor EFI code registers + * for an event that triggers on SetVirtualAddressMap(). The handler assumes + * that EFI_BOOT_SERVICES_DATA memory has not been touched by loader yet, which + * is probably true for Windows. + * + * Preserve EFI_BOOT_SERVICES_* regions until after SetVirtualAddressMap(). + */ +static inline bool memory_type_is_free(efi_memory_desc_t *md) +{ + if (md->type == EFI_CONVENTIONAL_MEMORY) + return true; + + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && + md->type == EFI_UNACCEPTED_MEMORY) + return true; + + return false; +} + /* * Returns true if we processed the EFI memmap, which we prefer over the E820 * table if it is available. @@ -716,18 +743,7 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) for (i = 0; i < nr_desc; i++) { md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); - /* - * Here we are more conservative in picking free memory than - * the EFI spec allows: - * - * According to the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also - * free memory and thus available to place the kernel image into, - * but in practice there's firmware where using that memory leads - * to crashes. - * - * Only EFI_CONVENTIONAL_MEMORY is guaranteed to be free. - */ - if (md->type != EFI_CONVENTIONAL_MEMORY) + if (!memory_type_is_free(md)) continue; if (efi_soft_reserve_enabled() && diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c index 67594fcb11d9..69038ed7a310 100644 --- a/arch/x86/boot/compressed/mem.c +++ b/arch/x86/boot/compressed/mem.c @@ -1,9 +1,50 @@ // SPDX-License-Identifier: GPL-2.0-only #include "error.h" +#include "misc.h" void arch_accept_memory(phys_addr_t start, phys_addr_t end) { /* Platform-specific memory-acceptance call goes here */ error("Cannot accept memory"); } + +bool init_unaccepted_memory(void) +{ + guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID; + struct efi_unaccepted_memory *table; + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + enum efi_type et; + int ret; + + et = efi_get_type(boot_params); + if (et == EFI_TYPE_NONE) + return false; + + ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len); + if (ret) { + warn("EFI config table not found."); + return false; + } + + table = (void *)efi_find_vendor_table(boot_params, cfg_table_pa, + cfg_table_len, guid); + if (!table) + return false; + + if (table->version != 1) + error("Unknown version of unaccepted memory table\n"); + + /* + * In many cases unaccepted_table is already set by EFI stub, but it + * has to be initialized again to cover cases when the table is not + * allocated by EFI stub or EFI stub copied the kernel image with + * efi_relocate_kernel() before the variable is set. + * + * It must be initialized before the first usage of accept_memory(). + */ + unaccepted_table = table; + + return true; +} diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 014ff222bf4b..94b7abcf624b 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -455,6 +455,12 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, #endif debug_putstr("\nDecompressing Linux... "); + + if (init_unaccepted_memory()) { + debug_putstr("Accepting memory... "); + accept_memory(__pa(output), __pa(output) + needed_size); + } + __decompress(input_data, input_len, NULL, NULL, output, output_len, NULL, error); entry_offset = parse_elf(output); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 2f155a0e3041..964fe903a1cd 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -247,4 +247,14 @@ static inline unsigned long efi_find_vendor_table(struct boot_params *bp, } #endif /* CONFIG_EFI */ +#ifdef CONFIG_UNACCEPTED_MEMORY +bool init_unaccepted_memory(void); +#else +static inline bool init_unaccepted_memory(void) { return false; } +#endif + +/* Defined in EFI stub */ +extern struct efi_unaccepted_memory *unaccepted_table; +void accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* BOOT_COMPRESSED_MISC_H */ |