diff options
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/dmi_scan.c | 79 | ||||
| -rw-r--r-- | drivers/firmware/efi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/efi.c | 83 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm-stub.c | 15 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 62 | ||||
| -rw-r--r-- | drivers/firmware/efi/runtime-wrappers.c | 164 | ||||
| -rw-r--r-- | drivers/firmware/efi/vars.c | 61 |
7 files changed, 438 insertions, 28 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 17afc51f3054..c5f7b4e9eb6c 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -93,6 +93,12 @@ static void dmi_table(u8 *buf, int len, int num, const struct dmi_header *dm = (const struct dmi_header *)data; /* + * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0] + */ + if (dm->type == DMI_ENTRY_END_OF_TABLE) + break; + + /* * We want to know the total length (formatted area and * strings) before decoding to make sure we won't run off the * table in dmi_decode or dmi_string @@ -107,7 +113,7 @@ static void dmi_table(u8 *buf, int len, int num, } } -static u32 dmi_base; +static phys_addr_t dmi_base; static u16 dmi_len; static u16 dmi_num; @@ -467,7 +473,7 @@ static int __init dmi_present(const u8 *buf) if (memcmp(buf, "_SM_", 4) == 0 && buf[5] < 32 && dmi_checksum(buf, buf[5])) { - smbios_ver = (buf[6] << 8) + buf[7]; + smbios_ver = get_unaligned_be16(buf + 6); /* Some BIOS report weird SMBIOS version, fix that up */ switch (smbios_ver) { @@ -489,10 +495,9 @@ static int __init dmi_present(const u8 *buf) buf += 16; if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) { - dmi_num = (buf[13] << 8) | buf[12]; - dmi_len = (buf[7] << 8) | buf[6]; - dmi_base = (buf[11] << 24) | (buf[10] << 16) | - (buf[9] << 8) | buf[8]; + dmi_num = get_unaligned_le16(buf + 12); + dmi_len = get_unaligned_le16(buf + 6); + dmi_base = get_unaligned_le32(buf + 8); if (dmi_walk_early(dmi_decode) == 0) { if (smbios_ver) { @@ -514,12 +519,72 @@ static int __init dmi_present(const u8 *buf) return 1; } +/* + * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy + * 32-bit entry point, there is no embedded DMI header (_DMI_) in here. + */ +static int __init dmi_smbios3_present(const u8 *buf) +{ + if (memcmp(buf, "_SM3_", 5) == 0 && + buf[6] < 32 && dmi_checksum(buf, buf[6])) { + dmi_ver = get_unaligned_be16(buf + 7); + dmi_len = get_unaligned_le32(buf + 12); + dmi_base = get_unaligned_le64(buf + 16); + + /* + * The 64-bit SMBIOS 3.0 entry point no longer has a field + * containing the number of structures present in the table. + * Instead, it defines the table size as a maximum size, and + * relies on the end-of-table structure type (#127) to be used + * to signal the end of the table. + * So let's define dmi_num as an upper bound as well: each + * structure has a 4 byte header, so dmi_len / 4 is an upper + * bound for the number of structures in the table. + */ + dmi_num = dmi_len / 4; + + if (dmi_walk_early(dmi_decode) == 0) { + pr_info("SMBIOS %d.%d present.\n", + dmi_ver >> 8, dmi_ver & 0xFF); + dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string)); + pr_debug("DMI: %s\n", dmi_ids_string); + return 0; + } + } + return 1; +} + void __init dmi_scan_machine(void) { char __iomem *p, *q; char buf[32]; if (efi_enabled(EFI_CONFIG_TABLES)) { + /* + * According to the DMTF SMBIOS reference spec v3.0.0, it is + * allowed to define both the 64-bit entry point (smbios3) and + * the 32-bit entry point (smbios), in which case they should + * either both point to the same SMBIOS structure table, or the + * table pointed to by the 64-bit entry point should contain a + * superset of the table contents pointed to by the 32-bit entry + * point (section 5.2) + * This implies that the 64-bit entry point should have + * precedence if it is defined and supported by the OS. If we + * have the 64-bit entry point, but fail to decode it, fall + * back to the legacy one (if available) + */ + if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) { + p = dmi_early_remap(efi.smbios3, 32); + if (p == NULL) + goto error; + memcpy_fromio(buf, p, 32); + dmi_early_unmap(p, 32); + + if (!dmi_smbios3_present(buf)) { + dmi_available = 1; + goto out; + } + } if (efi.smbios == EFI_INVALID_TABLE_ADDR) goto error; @@ -552,7 +617,7 @@ void __init dmi_scan_machine(void) memset(buf, 0, 16); for (q = p; q < p + 0x10000; q += 16) { memcpy_fromio(buf + 16, q, 16); - if (!dmi_present(buf)) { + if (!dmi_smbios3_present(buf) || !dmi_present(buf)) { dmi_available = 1; dmi_early_unmap(p, 0x10000); goto out; diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index aef6a95adef5..d8be608a9f3b 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -7,4 +7,4 @@ obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o obj-$(CONFIG_UEFI_CPER) += cper.o obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o -obj-$(CONFIG_EFI_ARM_STUB) += libstub/ +obj-$(CONFIG_EFI_STUB) += libstub/ diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 64ecbb501c50..9035c1b74d58 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -30,6 +30,7 @@ struct efi __read_mostly efi = { .acpi = EFI_INVALID_TABLE_ADDR, .acpi20 = EFI_INVALID_TABLE_ADDR, .smbios = EFI_INVALID_TABLE_ADDR, + .smbios3 = EFI_INVALID_TABLE_ADDR, .sal_systab = EFI_INVALID_TABLE_ADDR, .boot_info = EFI_INVALID_TABLE_ADDR, .hcdp = EFI_INVALID_TABLE_ADDR, @@ -41,6 +42,28 @@ struct efi __read_mostly efi = { }; EXPORT_SYMBOL(efi); +static bool disable_runtime; +static int __init setup_noefi(char *arg) +{ + disable_runtime = true; + return 0; +} +early_param("noefi", setup_noefi); + +bool efi_runtime_disabled(void) +{ + return disable_runtime; +} + +static int __init parse_efi_cmdline(char *str) +{ + if (parse_option_str(str, "noruntime")) + disable_runtime = true; + + return 0; +} +early_param("efi", parse_efi_cmdline); + static struct kobject *efi_kobj; static struct kobject *efivars_kobj; @@ -64,6 +87,8 @@ static ssize_t systab_show(struct kobject *kobj, str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); if (efi.smbios != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); + if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3); if (efi.hcdp != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); if (efi.boot_info != EFI_INVALID_TABLE_ADDR) @@ -238,6 +263,7 @@ static __initdata efi_config_table_type_t common_tables[] = { {MPS_TABLE_GUID, "MPS", &efi.mps}, {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab}, {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios}, + {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3}, {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga}, {NULL_GUID, NULL, NULL}, }; @@ -423,3 +449,60 @@ int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose) return ret; } #endif /* CONFIG_EFI_PARAMS_FROM_FDT */ + +static __initdata char memory_type_name[][20] = { + "Reserved", + "Loader Code", + "Loader Data", + "Boot Code", + "Boot Data", + "Runtime Code", + "Runtime Data", + "Conventional Memory", + "Unusable Memory", + "ACPI Reclaim Memory", + "ACPI Memory NVS", + "Memory Mapped I/O", + "MMIO Port Space", + "PAL Code" +}; + +char * __init efi_md_typeattr_format(char *buf, size_t size, + const efi_memory_desc_t *md) +{ + char *pos; + int type_len; + u64 attr; + + pos = buf; + if (md->type >= ARRAY_SIZE(memory_type_name)) + type_len = snprintf(pos, size, "[type=%u", md->type); + else + type_len = snprintf(pos, size, "[%-*s", + (int)(sizeof(memory_type_name[0]) - 1), + memory_type_name[md->type]); + if (type_len >= size) + return buf; + + pos += type_len; + size -= type_len; + + attr = md->attribute; + if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | + EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP | + EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME)) + snprintf(pos, size, "|attr=0x%016llx]", + (unsigned long long)attr); + else + snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]", + attr & EFI_MEMORY_RUNTIME ? "RUN" : "", + attr & EFI_MEMORY_XP ? "XP" : "", + attr & EFI_MEMORY_RP ? "RP" : "", + attr & EFI_MEMORY_WP ? "WP" : "", + attr & EFI_MEMORY_UCE ? "UCE" : "", + attr & EFI_MEMORY_WB ? "WB" : "", + attr & EFI_MEMORY_WT ? "WT" : "", + attr & EFI_MEMORY_WC ? "WC" : "", + attr & EFI_MEMORY_UC ? "UC" : ""); + return buf; +} diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 480339b6b110..eb48a1a1a576 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -226,6 +226,10 @@ unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table, goto fail_free_image; } + status = efi_parse_options(cmdline_ptr); + if (status != EFI_SUCCESS) + pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n"); + /* * Unauthenticated device tree data is a security hazard, so * ignore 'dtb=' unless UEFI Secure Boot is disabled. @@ -243,9 +247,18 @@ unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table, goto fail_free_cmdline; } } - if (!fdt_addr) + + if (fdt_addr) { + pr_efi(sys_table, "Using DTB from command line\n"); + } else { /* Look for a device tree configuration table entry. */ fdt_addr = (uintptr_t)get_fdt(sys_table); + if (fdt_addr) + pr_efi(sys_table, "Using DTB from configuration table\n"); + } + + if (!fdt_addr) + pr_efi(sys_table, "Generating empty DTB\n"); status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", dram_base + SZ_512M, diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 32d5cca30f49..a920fec8fe88 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -15,8 +15,23 @@ #include "efistub.h" +/* + * Some firmware implementations have problems reading files in one go. + * A read chunk size of 1MB seems to work for most platforms. + * + * Unfortunately, reading files in chunks triggers *other* bugs on some + * platforms, so we provide a way to disable this workaround, which can + * be done by passing "efi=nochunk" on the EFI boot stub command line. + * + * If you experience issues with initrd images being corrupt it's worth + * trying efi=nochunk, but chunking is enabled by default because there + * are far more machines that require the workaround than those that + * break with it enabled. + */ #define EFI_READ_CHUNK_SIZE (1024 * 1024) +static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; + struct file_info { efi_file_handle_t *handle; u64 size; @@ -281,6 +296,49 @@ void efi_free(efi_system_table_t *sys_table_arg, unsigned long size, efi_call_early(free_pages, addr, nr_pages); } +/* + * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi= + * option, e.g. efi=nochunk. + * + * It should be noted that efi= is parsed in two very different + * environments, first in the early boot environment of the EFI boot + * stub, and subsequently during the kernel boot. + */ +efi_status_t efi_parse_options(char *cmdline) +{ + char *str; + + /* + * If no EFI parameters were specified on the cmdline we've got + * nothing to do. + */ + str = strstr(cmdline, "efi="); + if (!str) + return EFI_SUCCESS; + + /* Skip ahead to first argument */ + str += strlen("efi="); + + /* + * Remember, because efi= is also used by the kernel we need to + * skip over arguments we don't understand. + */ + while (*str) { + if (!strncmp(str, "nochunk", 7)) { + str += strlen("nochunk"); + __chunk_size = -1UL; + } + + /* Group words together, delimited by "," */ + while (*str && *str != ',') + str++; + + if (*str == ',') + str++; + } + + return EFI_SUCCESS; +} /* * Check the cmdline for a LILO-style file= arguments. @@ -423,8 +481,8 @@ efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg, size = files[j].size; while (size) { unsigned long chunksize; - if (size > EFI_READ_CHUNK_SIZE) - chunksize = EFI_READ_CHUNK_SIZE; + if (size > __chunk_size) + chunksize = __chunk_size; else chunksize = size; diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 10daa4bbb258..228bbf910461 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -14,11 +14,80 @@ * This file is released under the GPLv2. */ +#include <linux/bug.h> #include <linux/efi.h> -#include <linux/spinlock.h> /* spinlock_t */ +#include <linux/mutex.h> +#include <linux/spinlock.h> #include <asm/efi.h> /* + * According to section 7.1 of the UEFI spec, Runtime Services are not fully + * reentrant, and there are particular combinations of calls that need to be + * serialized. (source: UEFI Specification v2.4A) + * + * Table 31. Rules for Reentry Into Runtime Services + * +------------------------------------+-------------------------------+ + * | If previous call is busy in | Forbidden to call | + * +------------------------------------+-------------------------------+ + * | Any | SetVirtualAddressMap() | + * +------------------------------------+-------------------------------+ + * | ConvertPointer() | ConvertPointer() | + * +------------------------------------+-------------------------------+ + * | SetVariable() | ResetSystem() | + * | UpdateCapsule() | | + * | SetTime() | | + * | SetWakeupTime() | | + * | GetNextHighMonotonicCount() | | + * +------------------------------------+-------------------------------+ + * | GetVariable() | GetVariable() | + * | GetNextVariableName() | GetNextVariableName() | + * | SetVariable() | SetVariable() | + * | QueryVariableInfo() | QueryVariableInfo() | + * | UpdateCapsule() | UpdateCapsule() | + * | QueryCapsuleCapabilities() | QueryCapsuleCapabilities() | + * | GetNextHighMonotonicCount() | GetNextHighMonotonicCount() | + * +------------------------------------+-------------------------------+ + * | GetTime() | GetTime() | + * | SetTime() | SetTime() | + * | GetWakeupTime() | GetWakeupTime() | + * | SetWakeupTime() | SetWakeupTime() | + * +------------------------------------+-------------------------------+ + * + * Due to the fact that the EFI pstore may write to the variable store in + * interrupt context, we need to use a spinlock for at least the groups that + * contain SetVariable() and QueryVariableInfo(). That leaves little else, as + * none of the remaining functions are actually ever called at runtime. + * So let's just use a single spinlock to serialize all Runtime Services calls. + */ +static DEFINE_SPINLOCK(efi_runtime_lock); + +/* + * Some runtime services calls can be reentrant under NMI, even if the table + * above says they are not. (source: UEFI Specification v2.4A) + * + * Table 32. Functions that may be called after Machine Check, INIT and NMI + * +----------------------------+------------------------------------------+ + * | Function | Called after Machine Check, INIT and NMI | + * +----------------------------+------------------------------------------+ + * | GetTime() | Yes, even if previously busy. | + * | GetVariable() | Yes, even if previously busy | + * | GetNextVariableName() | Yes, even if previously busy | + * | QueryVariableInfo() | Yes, even if previously busy | + * | SetVariable() | Yes, even if previously busy | + * | UpdateCapsule() | Yes, even if previously busy | + * | QueryCapsuleCapabilities() | Yes, even if previously busy | + * | ResetSystem() | Yes, even if previously busy | + * +----------------------------+------------------------------------------+ + * + * In order to prevent deadlocks under NMI, the wrappers for these functions + * may only grab the efi_runtime_lock or rtc_lock spinlocks if !efi_in_nmi(). + * However, not all of the services listed are reachable through NMI code paths, + * so the the special handling as suggested by the UEFI spec is only implemented + * for QueryVariableInfo() and SetVariable(), as these can be reached in NMI + * context through efi_pstore_write(). + */ + +/* * As per commit ef68c8f87ed1 ("x86: Serialize EFI time accesses on rtc_lock"), * the EFI specification requires that callers of the time related runtime * functions serialize with other CMOS accesses in the kernel, as the EFI time @@ -32,7 +101,9 @@ static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) efi_status_t status; spin_lock_irqsave(&rtc_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(get_time, tm, tc); + spin_unlock(&efi_runtime_lock); spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -43,7 +114,9 @@ static efi_status_t virt_efi_set_time(efi_time_t *tm) efi_status_t status; spin_lock_irqsave(&rtc_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(set_time, tm); + spin_unlock(&efi_runtime_lock); spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -56,7 +129,9 @@ static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled, efi_status_t status; spin_lock_irqsave(&rtc_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(get_wakeup_time, enabled, pending, tm); + spin_unlock(&efi_runtime_lock); spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -67,7 +142,9 @@ static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) efi_status_t status; spin_lock_irqsave(&rtc_lock, flags); + spin_lock(&efi_runtime_lock); status = efi_call_virt(set_wakeup_time, enabled, tm); + spin_unlock(&efi_runtime_lock); spin_unlock_irqrestore(&rtc_lock, flags); return status; } @@ -78,14 +155,27 @@ static efi_status_t virt_efi_get_variable(efi_char16_t *name, unsigned long *data_size, void *data) { - return efi_call_virt(get_variable, name, vendor, attr, data_size, data); + unsigned long flags; + efi_status_t status; + + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(get_variable, name, vendor, attr, data_size, + data); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } static efi_status_t virt_efi_get_next_variable(unsigned long *name_size, efi_char16_t *name, efi_guid_t *vendor) { - return efi_call_virt(get_next_variable, name_size, name, vendor); + unsigned long flags; + efi_status_t status; + + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(get_next_variable, name_size, name, vendor); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } static efi_status_t virt_efi_set_variable(efi_char16_t *name, @@ -94,24 +184,61 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name, unsigned long data_size, void *data) { - return efi_call_virt(set_variable, name, vendor, attr, data_size, data); + unsigned long flags; + efi_status_t status; + + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(set_variable, name, vendor, attr, data_size, + data); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } +static efi_status_t +virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor, + u32 attr, unsigned long data_size, + void *data) +{ + unsigned long flags; + efi_status_t status; + + if (!spin_trylock_irqsave(&efi_runtime_lock, flags)) + return EFI_NOT_READY; + + status = efi_call_virt(set_variable, name, vendor, attr, data_size, + data); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; +} + + static efi_status_t virt_efi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { + unsigned long flags; + efi_status_t status; + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - return efi_call_virt(query_variable_info, attr, storage_space, - remaining_space, max_variable_size); + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(query_variable_info, attr, storage_space, + remaining_space, max_variable_size); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } static efi_status_t virt_efi_get_next_high_mono_count(u32 *count) { - return efi_call_virt(get_next_high_mono_count, count); + unsigned long flags; + efi_status_t status; + + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(get_next_high_mono_count, count); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } static void virt_efi_reset_system(int reset_type, @@ -119,17 +246,27 @@ static void virt_efi_reset_system(int reset_type, unsigned long data_size, efi_char16_t *data) { + unsigned long flags; + + spin_lock_irqsave(&efi_runtime_lock, flags); __efi_call_virt(reset_system, reset_type, status, data_size, data); + spin_unlock_irqrestore(&efi_runtime_lock, flags); } static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules, unsigned long count, unsigned long sg_list) { + unsigned long flags; + efi_status_t status; + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - return efi_call_virt(update_capsule, capsules, count, sg_list); + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(update_capsule, capsules, count, sg_list); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules, @@ -137,11 +274,17 @@ static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules, u64 *max_size, int *reset_type) { + unsigned long flags; + efi_status_t status; + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; - return efi_call_virt(query_capsule_caps, capsules, count, max_size, - reset_type); + spin_lock_irqsave(&efi_runtime_lock, flags); + status = efi_call_virt(query_capsule_caps, capsules, count, max_size, + reset_type); + spin_unlock_irqrestore(&efi_runtime_lock, flags); + return status; } void efi_native_runtime_setup(void) @@ -153,6 +296,7 @@ void efi_native_runtime_setup(void) efi.get_variable = virt_efi_get_variable; efi.get_next_variable = virt_efi_get_next_variable; efi.set_variable = virt_efi_set_variable; + efi.set_variable_nonblocking = virt_efi_set_variable_nonblocking; efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count; efi.reset_system = virt_efi_reset_system; efi.query_variable_info = virt_efi_query_variable_info; diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index 5abe943e3404..70a0fb10517f 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -321,11 +321,11 @@ static unsigned long var_name_strnsize(efi_char16_t *variable_name, * Print a warning when duplicate EFI variables are encountered and * disable the sysfs workqueue since the firmware is buggy. */ -static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, +static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid, unsigned long len16) { size_t i, len8 = len16 / sizeof(efi_char16_t); - char *s8; + char *str8; /* * Disable the workqueue since the algorithm it uses for @@ -334,16 +334,16 @@ static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, */ efivar_wq_enabled = false; - s8 = kzalloc(len8, GFP_KERNEL); - if (!s8) + str8 = kzalloc(len8, GFP_KERNEL); + if (!str8) return; for (i = 0; i < len8; i++) - s8[i] = s16[i]; + str8[i] = str16[i]; printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", - s8, vendor_guid); - kfree(s8); + str8, vendor_guid); + kfree(str8); } /** @@ -595,6 +595,39 @@ int efivar_entry_set(struct efivar_entry *entry, u32 attributes, } EXPORT_SYMBOL_GPL(efivar_entry_set); +/* + * efivar_entry_set_nonblocking - call set_variable_nonblocking() + * + * This function is guaranteed to not block and is suitable for calling + * from crash/panic handlers. + * + * Crucially, this function will not block if it cannot acquire + * __efivars->lock. Instead, it returns -EBUSY. + */ +static int +efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor, + u32 attributes, unsigned long size, void *data) +{ + const struct efivar_operations *ops = __efivars->ops; + unsigned long flags; + efi_status_t status; + + if (!spin_trylock_irqsave(&__efivars->lock, flags)) + return -EBUSY; + + status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); + if (status != EFI_SUCCESS) { + spin_unlock_irqrestore(&__efivars->lock, flags); + return -ENOSPC; + } + + status = ops->set_variable_nonblocking(name, &vendor, attributes, + size, data); + + spin_unlock_irqrestore(&__efivars->lock, flags); + return efi_status_to_err(status); +} + /** * efivar_entry_set_safe - call set_variable() if enough space in firmware * @name: buffer containing the variable name @@ -622,6 +655,20 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, if (!ops->query_variable_store) return -ENOSYS; + /* + * If the EFI variable backend provides a non-blocking + * ->set_variable() operation and we're in a context where we + * cannot block, then we need to use it to avoid live-locks, + * since the implication is that the regular ->set_variable() + * will block. + * + * If no ->set_variable_nonblocking() is provided then + * ->set_variable() is assumed to be non-blocking. + */ + if (!block && ops->set_variable_nonblocking) + return efivar_entry_set_nonblocking(name, vendor, attributes, + size, data); + if (!block) { if (!spin_trylock_irqsave(&__efivars->lock, flags)) return -EBUSY; |