summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firmware/efi')
-rw-r--r--drivers/firmware/efi/Kconfig43
-rw-r--r--drivers/firmware/efi/efi.c13
-rw-r--r--drivers/firmware/efi/libstub/arm32-stub.c3
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c15
-rw-r--r--drivers/firmware/efi/libstub/efi-stub.c2
-rw-r--r--drivers/firmware/efi/libstub/efistub.h84
-rw-r--r--drivers/firmware/efi/libstub/randomalloc.c11
-rw-r--r--drivers/firmware/efi/libstub/riscv-stub.c32
-rw-r--r--drivers/firmware/efi/libstub/x86-stub.c119
9 files changed, 302 insertions, 20 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 2c3dac5ecb36..4720ba98cec3 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -91,6 +91,18 @@ config EFI_SOFT_RESERVE
If unsure, say Y.
+config EFI_DXE_MEM_ATTRIBUTES
+ bool "Adjust memory attributes in EFISTUB"
+ depends on EFI && EFI_STUB && X86
+ default y
+ help
+ UEFI specification does not guarantee all memory to be
+ accessible for both write and execute as the kernel expects
+ it to be.
+ Use DXE services to check and alter memory protection
+ attributes during boot via EFISTUB to ensure that memory
+ ranges used by the kernel are writable and executable.
+
config EFI_PARAMS_FROM_FDT
bool
help
@@ -284,3 +296,34 @@ config EFI_CUSTOM_SSDT_OVERLAYS
See Documentation/admin-guide/acpi/ssdt-overlays.rst for more
information.
+
+config EFI_DISABLE_RUNTIME
+ bool "Disable EFI runtime services support by default"
+ default y if PREEMPT_RT
+ help
+ Allow to disable the EFI runtime services support by default. This can
+ already be achieved by using the efi=noruntime option, but it could be
+ useful to have this default without any kernel command line parameter.
+
+ The EFI runtime services are disabled by default when PREEMPT_RT is
+ enabled, because measurements have shown that some EFI functions calls
+ might take too much time to complete, causing large latencies which is
+ an issue for Real-Time kernels.
+
+ This default can be overridden by using the efi=runtime option.
+
+config EFI_COCO_SECRET
+ bool "EFI Confidential Computing Secret Area Support"
+ depends on EFI
+ help
+ Confidential Computing platforms (such as AMD SEV) allow the
+ Guest Owner to securely inject secrets during guest VM launch.
+ The secrets are placed in a designated EFI reserved memory area.
+
+ In order to use the secrets in the kernel, the location of the secret
+ area (as published in the EFI config table) must be kept.
+
+ If you say Y here, the address of the EFI secret area will be kept
+ for usage inside the kernel. This will allow the
+ virt/coco/efi_secret module to access the secrets, which in turn
+ allows userspace programs to access the injected secrets.
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5502e176d51b..860534bcfdac 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -46,6 +46,9 @@ struct efi __read_mostly efi = {
#ifdef CONFIG_LOAD_UEFI_KEYS
.mokvar_table = EFI_INVALID_TABLE_ADDR,
#endif
+#ifdef CONFIG_EFI_COCO_SECRET
+ .coco_secret = EFI_INVALID_TABLE_ADDR,
+#endif
};
EXPORT_SYMBOL(efi);
@@ -66,7 +69,7 @@ struct mm_struct efi_mm = {
struct workqueue_struct *efi_rts_wq;
-static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT);
+static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
static int __init setup_noefi(char *arg)
{
disable_runtime = true;
@@ -422,6 +425,11 @@ static int __init efisubsys_init(void)
if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
efi_debugfs_init();
+#ifdef CONFIG_EFI_COCO_SECRET
+ if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
+ platform_device_register_simple("efi_secret", 0, NULL, 0);
+#endif
+
return 0;
err_remove_group:
@@ -529,6 +537,9 @@ static const efi_config_table_type_t common_tables[] __initconst = {
#ifdef CONFIG_LOAD_UEFI_KEYS
{LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" },
#endif
+#ifdef CONFIG_EFI_COCO_SECRET
+ {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" },
+#endif
{},
};
diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index 4b5b2403b3a0..0131e3aaa605 100644
--- a/drivers/firmware/efi/libstub/arm32-stub.c
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -117,7 +117,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
- efi_loaded_image_t *image)
+ efi_loaded_image_t *image,
+ efi_handle_t image_handle)
{
const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 9cc556013d08..577173ee1f83 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -83,7 +83,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
- efi_loaded_image_t *image)
+ efi_loaded_image_t *image,
+ efi_handle_t image_handle)
{
efi_status_t status;
unsigned long kernel_size, kernel_memsize = 0;
@@ -100,7 +101,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
u64 min_kimg_align = efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
- if (!efi_nokaslr) {
+ efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
+ void *p;
+
+ if (efi_nokaslr) {
+ efi_info("KASLR disabled on kernel command line\n");
+ } else if (efi_bs_call(handle_protocol, image_handle,
+ &li_fixed_proto, &p) == EFI_SUCCESS) {
+ efi_info("Image placement fixed by loader\n");
+ } else {
status = efi_get_random_bytes(sizeof(phys_seed),
(u8 *)&phys_seed);
if (status == EFI_NOT_FOUND) {
@@ -111,8 +120,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
status);
efi_nokaslr = true;
}
- } else {
- efi_info("KASLR disabled on kernel command line\n");
}
}
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index da93864d7abc..f515394cce6e 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -198,7 +198,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
status = handle_kernel_image(&image_addr, &image_size,
&reserve_addr,
&reserve_size,
- image);
+ image, handle);
if (status != EFI_SUCCESS) {
efi_err("Failed to relocate kernel\n");
goto fail_free_screeninfo;
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index edb77b0621ea..b0ae0a454404 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -36,6 +36,9 @@ extern bool efi_novamap;
extern const efi_system_table_t *efi_system_table;
+typedef union efi_dxe_services_table efi_dxe_services_table_t;
+extern const efi_dxe_services_table_t *efi_dxe_table;
+
efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
efi_system_table_t *sys_table_arg);
@@ -44,6 +47,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
#define efi_is_native() (true)
#define efi_bs_call(func, ...) efi_system_table->boottime->func(__VA_ARGS__)
#define efi_rt_call(func, ...) efi_system_table->runtime->func(__VA_ARGS__)
+#define efi_dxe_call(func, ...) efi_dxe_table->func(__VA_ARGS__)
#define efi_table_attr(inst, attr) (inst->attr)
#define efi_call_proto(inst, func, ...) inst->func(inst, ##__VA_ARGS__)
@@ -329,6 +333,76 @@ union efi_boot_services {
} mixed_mode;
};
+typedef enum {
+ EfiGcdMemoryTypeNonExistent,
+ EfiGcdMemoryTypeReserved,
+ EfiGcdMemoryTypeSystemMemory,
+ EfiGcdMemoryTypeMemoryMappedIo,
+ EfiGcdMemoryTypePersistent,
+ EfiGcdMemoryTypeMoreReliable,
+ EfiGcdMemoryTypeMaximum
+} efi_gcd_memory_type_t;
+
+typedef struct {
+ efi_physical_addr_t base_address;
+ u64 length;
+ u64 capabilities;
+ u64 attributes;
+ efi_gcd_memory_type_t gcd_memory_type;
+ void *image_handle;
+ void *device_handle;
+} efi_gcd_memory_space_desc_t;
+
+/*
+ * EFI DXE Services table
+ */
+union efi_dxe_services_table {
+ struct {
+ efi_table_hdr_t hdr;
+ void *add_memory_space;
+ void *allocate_memory_space;
+ void *free_memory_space;
+ void *remove_memory_space;
+ efi_status_t (__efiapi *get_memory_space_descriptor)(efi_physical_addr_t,
+ efi_gcd_memory_space_desc_t *);
+ efi_status_t (__efiapi *set_memory_space_attributes)(efi_physical_addr_t,
+ u64, u64);
+ void *get_memory_space_map;
+ void *add_io_space;
+ void *allocate_io_space;
+ void *free_io_space;
+ void *remove_io_space;
+ void *get_io_space_descriptor;
+ void *get_io_space_map;
+ void *dispatch;
+ void *schedule;
+ void *trust;
+ void *process_firmware_volume;
+ void *set_memory_space_capabilities;
+ };
+ struct {
+ efi_table_hdr_t hdr;
+ u32 add_memory_space;
+ u32 allocate_memory_space;
+ u32 free_memory_space;
+ u32 remove_memory_space;
+ u32 get_memory_space_descriptor;
+ u32 set_memory_space_attributes;
+ u32 get_memory_space_map;
+ u32 add_io_space;
+ u32 allocate_io_space;
+ u32 free_io_space;
+ u32 remove_io_space;
+ u32 get_io_space_descriptor;
+ u32 get_io_space_map;
+ u32 dispatch;
+ u32 schedule;
+ u32 trust;
+ u32 process_firmware_volume;
+ u32 set_memory_space_capabilities;
+ } mixed_mode;
+};
+
typedef union efi_uga_draw_protocol efi_uga_draw_protocol_t;
union efi_uga_draw_protocol {
@@ -720,6 +794,13 @@ union efi_tcg2_protocol {
} mixed_mode;
};
+struct riscv_efi_boot_protocol {
+ u64 revision;
+
+ efi_status_t (__efiapi *get_boot_hartid)(struct riscv_efi_boot_protocol *,
+ unsigned long *boot_hartid);
+};
+
typedef union efi_load_file_protocol efi_load_file_protocol_t;
typedef union efi_load_file_protocol efi_load_file2_protocol_t;
@@ -865,7 +946,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
- efi_loaded_image_t *image);
+ efi_loaded_image_t *image,
+ efi_handle_t image_handle);
asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
unsigned long fdt_addr,
diff --git a/drivers/firmware/efi/libstub/randomalloc.c b/drivers/firmware/efi/libstub/randomalloc.c
index 724155b9e10d..715f37479154 100644
--- a/drivers/firmware/efi/libstub/randomalloc.c
+++ b/drivers/firmware/efi/libstub/randomalloc.c
@@ -56,6 +56,7 @@ efi_status_t efi_random_alloc(unsigned long size,
unsigned long random_seed)
{
unsigned long map_size, desc_size, total_slots = 0, target_slot;
+ unsigned long total_mirrored_slots = 0;
unsigned long buff_size;
efi_status_t status;
efi_memory_desc_t *memory_map;
@@ -86,8 +87,14 @@ efi_status_t efi_random_alloc(unsigned long size,
slots = get_entry_num_slots(md, size, ilog2(align));
MD_NUM_SLOTS(md) = slots;
total_slots += slots;
+ if (md->attribute & EFI_MEMORY_MORE_RELIABLE)
+ total_mirrored_slots += slots;
}
+ /* consider only mirrored slots for randomization if any exist */
+ if (total_mirrored_slots > 0)
+ total_slots = total_mirrored_slots;
+
/* find a random number between 0 and total_slots */
target_slot = (total_slots * (u64)(random_seed & U32_MAX)) >> 32;
@@ -107,6 +114,10 @@ efi_status_t efi_random_alloc(unsigned long size,
efi_physical_addr_t target;
unsigned long pages;
+ if (total_mirrored_slots > 0 &&
+ !(md->attribute & EFI_MEMORY_MORE_RELIABLE))
+ continue;
+
if (target_slot >= MD_NUM_SLOTS(md)) {
target_slot -= MD_NUM_SLOTS(md);
continue;
diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c
index 9c460843442f..9e85e58d1f27 100644
--- a/drivers/firmware/efi/libstub/riscv-stub.c
+++ b/drivers/firmware/efi/libstub/riscv-stub.c
@@ -21,9 +21,9 @@
#define MIN_KIMG_ALIGN SZ_4M
#endif
-typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long);
+typedef void __noreturn (*jump_kernel_func)(unsigned long, unsigned long);
-static u32 hartid;
+static unsigned long hartid;
static int get_boot_hartid_from_fdt(void)
{
@@ -47,14 +47,31 @@ static int get_boot_hartid_from_fdt(void)
return 0;
}
+static efi_status_t get_boot_hartid_from_efi(void)
+{
+ efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
+ struct riscv_efi_boot_protocol *boot_protocol;
+ efi_status_t status;
+
+ status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
+ (void **)&boot_protocol);
+ if (status != EFI_SUCCESS)
+ return status;
+ return efi_call_proto(boot_protocol, get_boot_hartid, &hartid);
+}
+
efi_status_t check_platform_features(void)
{
+ efi_status_t status;
int ret;
- ret = get_boot_hartid_from_fdt();
- if (ret) {
- efi_err("/chosen/boot-hartid missing or invalid!\n");
- return EFI_UNSUPPORTED;
+ status = get_boot_hartid_from_efi();
+ if (status != EFI_SUCCESS) {
+ ret = get_boot_hartid_from_fdt();
+ if (ret) {
+ efi_err("Failed to get boot hartid!\n");
+ return EFI_UNSUPPORTED;
+ }
}
return EFI_SUCCESS;
}
@@ -80,7 +97,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
- efi_loaded_image_t *image)
+ efi_loaded_image_t *image,
+ efi_handle_t image_handle)
{
unsigned long kernel_size = 0;
unsigned long preferred_addr;
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 01ddd4502e28..b14e88ccefca 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -22,6 +22,7 @@
#define MAXMEM_X86_64_4LEVEL (1ull << 46)
const efi_system_table_t *efi_system_table;
+const efi_dxe_services_table_t *efi_dxe_table;
extern u32 image_offset;
static efi_loaded_image_t *image = NULL;
@@ -211,9 +212,110 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
}
}
+static void
+adjust_memory_range_protection(unsigned long start, unsigned long size)
+{
+ efi_status_t status;
+ efi_gcd_memory_space_desc_t desc;
+ unsigned long end, next;
+ unsigned long rounded_start, rounded_end;
+ unsigned long unprotect_start, unprotect_size;
+ int has_system_memory = 0;
+
+ if (efi_dxe_table == NULL)
+ return;
+
+ rounded_start = rounddown(start, EFI_PAGE_SIZE);
+ rounded_end = roundup(start + size, EFI_PAGE_SIZE);
+
+ /*
+ * Don't modify memory region attributes, they are
+ * already suitable, to lower the possibility to
+ * encounter firmware bugs.
+ */
+
+ for (end = start + size; start < end; start = next) {
+
+ status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
+
+ if (status != EFI_SUCCESS)
+ return;
+
+ next = desc.base_address + desc.length;
+
+ /*
+ * Only system memory is suitable for trampoline/kernel image placement,
+ * so only this type of memory needs its attributes to be modified.
+ */
+
+ if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
+ (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
+ continue;
+
+ unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
+ unprotect_size = min(rounded_end, next) - unprotect_start;
+
+ status = efi_dxe_call(set_memory_space_attributes,
+ unprotect_start, unprotect_size,
+ EFI_MEMORY_WB);
+
+ if (status != EFI_SUCCESS) {
+ efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %d\n",
+ unprotect_start,
+ unprotect_start + unprotect_size,
+ (int)status);
+ }
+ }
+}
+
+/*
+ * Trampoline takes 2 pages and can be loaded in first megabyte of memory
+ * with its end placed between 128k and 640k where BIOS might start.
+ * (see arch/x86/boot/compressed/pgtable_64.c)
+ *
+ * We cannot find exact trampoline placement since memory map
+ * can be modified by UEFI, and it can alter the computed address.
+ */
+
+#define TRAMPOLINE_PLACEMENT_BASE ((128 - 8)*1024)
+#define TRAMPOLINE_PLACEMENT_SIZE (640*1024 - (128 - 8)*1024)
+
+void startup_32(struct boot_params *boot_params);
+
+static void
+setup_memory_protection(unsigned long image_base, unsigned long image_size)
+{
+ /*
+ * Allow execution of possible trampoline used
+ * for switching between 4- and 5-level page tables
+ * and relocated kernel image.
+ */
+
+ adjust_memory_range_protection(TRAMPOLINE_PLACEMENT_BASE,
+ TRAMPOLINE_PLACEMENT_SIZE);
+
+#ifdef CONFIG_64BIT
+ if (image_base != (unsigned long)startup_32)
+ adjust_memory_range_protection(image_base, image_size);
+#else
+ /*
+ * Clear protection flags on a whole range of possible
+ * addresses used for KASLR. We don't need to do that
+ * on x86_64, since KASLR/extraction is performed after
+ * dedicated identity page tables are built and we only
+ * need to remove possible protection on relocated image
+ * itself disregarding further relocations.
+ */
+ adjust_memory_range_protection(LOAD_PHYSICAL_ADDR,
+ KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR);
+#endif
+}
+
static const efi_char16_t apple[] = L"Apple";
-static void setup_quirks(struct boot_params *boot_params)
+static void setup_quirks(struct boot_params *boot_params,
+ unsigned long image_base,
+ unsigned long image_size)
{
efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
efi_table_attr(efi_system_table, fw_vendor);
@@ -222,6 +324,9 @@ static void setup_quirks(struct boot_params *boot_params)
if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
retrieve_apple_device_properties(boot_params);
}
+
+ if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES))
+ setup_memory_protection(image_base, image_size);
}
/*
@@ -341,8 +446,6 @@ static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
asm("hlt");
}
-void startup_32(struct boot_params *boot_params);
-
void __noreturn efi_stub_entry(efi_handle_t handle,
efi_system_table_t *sys_table_arg,
struct boot_params *boot_params);
@@ -677,11 +780,17 @@ unsigned long efi_main(efi_handle_t handle,
efi_status_t status;
efi_system_table = sys_table_arg;
-
/* Check if we were booted by the EFI firmware */
if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
efi_exit(handle, EFI_INVALID_PARAMETER);
+ efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
+ if (efi_dxe_table &&
+ efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
+ efi_warn("Ignoring DXE services table: invalid signature\n");
+ efi_dxe_table = NULL;
+ }
+
/*
* If the kernel isn't already loaded at a suitable address,
* relocate it.
@@ -791,7 +900,7 @@ unsigned long efi_main(efi_handle_t handle,
setup_efi_pci(boot_params);
- setup_quirks(boot_params);
+ setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start);
status = exit_boot(boot_params, handle);
if (status != EFI_SUCCESS) {
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-05 22:36:12 +0300