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x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels 

Commit

  3a63f70bf4 ("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: 3a63f70bf4 ("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
This commit is contained in:
Junichi Nomura 2019-04-11 15:49:32 +02:00 committed by Borislav Petkov
parent 6bbeb276b7
commit 0a23ebc66a
1 changed files with 107 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

143
arch/x86/boot/compressed/acpi.c
View File

@ -44,17 +44,109 @@ static acpi_physical_address get_acpi_rsdp(void)
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_rsdp_addr(void)
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();