summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firmware/efi')
-rw-r--r--drivers/firmware/efi/efi.c79
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c4
-rw-r--r--drivers/firmware/efi/libstub/efi-stub-helper.c62
-rw-r--r--drivers/firmware/efi/runtime-wrappers.c164
-rw-r--r--drivers/firmware/efi/vars.c61
5 files changed, 351 insertions, 19 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 64ecbb501c50..8590099ac148 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -41,6 +41,28 @@ 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;
@@ -423,3 +445,60 @@ 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..75ee05964cbc 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.
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;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-01 11:29:42 +0300