From: Junichi Nomura j-nomura@ce.jp.nec.com
commit 0a23ebc66a46786769dd68bfdaa3102345819b9c upstream.
Commit
3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in boot_params")
broke kexec boot on EFI systems. efi_get_rsdp_addr() in the early parsing code tries to search RSDP from the EFI tables but that will crash because the table address is virtual when the kernel was booted by kexec (set_virtual_address_map() has run in the first kernel and cannot be run again in the second kernel).
In the case of kexec, the physical address of EFI tables is provided via efi_setup_data in boot_params, which is set up by kexec(1).
Factor out the table parsing code and use different pointers depending on whether the kernel is booted by kexec or not.
[ bp: Massage. ]
Fixes: 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in boot_params") Signed-off-by: Jun'ichi Nomura j-nomura@ce.jp.nec.com Signed-off-by: Borislav Petkov bp@suse.de Tested-by: Dirk van der Merwe dirk.vandermerwe@netronome.com Cc: Chao Fan fanc.fnst@cn.fujitsu.com Cc: Dave Young dyoung@redhat.com Link: https://lkml.kernel.org/r/20190408231011.GA5402@jeru.linux.bs1.fc.nec.co.jp Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/boot/compressed/acpi.c | 143 +++++++++++++++++++++++++++++----------- 1 file changed, 107 insertions(+), 36 deletions(-)
--- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -44,17 +44,109 @@ static acpi_physical_address get_acpi_rs return addr; }
-/* Search EFI system tables for RSDP. */ -static acpi_physical_address efi_get_rsdp_addr(void) +/* + * Search EFI system tables for RSDP. If both ACPI_20_TABLE_GUID and + * ACPI_TABLE_GUID are found, take the former, which has more features. + */ +static acpi_physical_address +__efi_get_rsdp_addr(unsigned long config_tables, unsigned int nr_tables, + bool efi_64) { acpi_physical_address rsdp_addr = 0;
#ifdef CONFIG_EFI - unsigned long systab, systab_tables, config_tables; + int i; + + /* Get EFI tables from systab. */ + for (i = 0; i < nr_tables; i++) { + acpi_physical_address table; + efi_guid_t guid; + + if (efi_64) { + efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables + i; + + guid = tbl->guid; + table = tbl->table; + + if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { + debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); + return 0; + } + } else { + efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables + i; + + guid = tbl->guid; + table = tbl->table; + } + + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) + rsdp_addr = table; + else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) + return table; + } +#endif + return rsdp_addr; +} + +/* EFI/kexec support is 64-bit only. */ +#ifdef CONFIG_X86_64 +static struct efi_setup_data *get_kexec_setup_data_addr(void) +{ + struct setup_data *data; + u64 pa_data; + + pa_data = boot_params->hdr.setup_data; + while (pa_data) { + data = (struct setup_data *)pa_data; + if (data->type == SETUP_EFI) + return (struct efi_setup_data *)(pa_data + sizeof(struct setup_data)); + + pa_data = data->next; + } + return NULL; +} + +static acpi_physical_address kexec_get_rsdp_addr(void) +{ + efi_system_table_64_t *systab; + struct efi_setup_data *esd; + struct efi_info *ei; + char *sig; + + esd = (struct efi_setup_data *)get_kexec_setup_data_addr(); + if (!esd) + return 0; + + if (!esd->tables) { + debug_putstr("Wrong kexec SETUP_EFI data.\n"); + return 0; + } + + ei = &boot_params->efi_info; + sig = (char *)&ei->efi_loader_signature; + if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { + debug_putstr("Wrong kexec EFI loader signature.\n"); + return 0; + } + + /* Get systab from boot params. */ + systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32)); + if (!systab) + error("EFI system table not found in kexec boot_params."); + + return __efi_get_rsdp_addr((unsigned long)esd->tables, systab->nr_tables, true); +} +#else +static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; } +#endif /* CONFIG_X86_64 */ + +static acpi_physical_address efi_get_rsdp_addr(void) +{ +#ifdef CONFIG_EFI + unsigned long systab, config_tables; unsigned int nr_tables; struct efi_info *ei; bool efi_64; - int size, i; char *sig;
ei = &boot_params->efi_info; @@ -88,49 +180,20 @@ static acpi_physical_address efi_get_rsd
config_tables = stbl->tables; nr_tables = stbl->nr_tables; - size = sizeof(efi_config_table_64_t); } else { efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab;
config_tables = stbl->tables; nr_tables = stbl->nr_tables; - size = sizeof(efi_config_table_32_t); }
if (!config_tables) error("EFI config tables not found.");
- /* Get EFI tables from systab. */ - for (i = 0; i < nr_tables; i++) { - acpi_physical_address table; - efi_guid_t guid; - - config_tables += size; - - if (efi_64) { - efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables; - - guid = tbl->guid; - table = tbl->table; - - if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { - debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); - return 0; - } - } else { - efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables; - - guid = tbl->guid; - table = tbl->table; - } - - if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) - rsdp_addr = table; - else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) - return table; - } + return __efi_get_rsdp_addr(config_tables, nr_tables, efi_64); +#else + return 0; #endif - return rsdp_addr; }
static u8 compute_checksum(u8 *buffer, u32 length) @@ -220,6 +283,14 @@ acpi_physical_address get_rsdp_addr(void if (!pa) pa = boot_params->acpi_rsdp_addr;
+ /* + * Try to get EFI data from setup_data. This can happen when we're a + * kexec'ed kernel and kexec(1) has passed all the required EFI info to + * us. + */ + if (!pa) + pa = kexec_get_rsdp_addr(); + if (!pa) pa = efi_get_rsdp_addr();