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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 #define pr_fmt(fmt) "efi: " fmt
 
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/time.h>
 #include <linux/types.h>
 #include <linux/efi.h>
 #include <linux/slab.h>
 #include <linux/memblock.h>
 #include <linux/acpi.h>
 #include <linux/dmi.h>
 
 #include <asm/e820/api.h>
 #include <asm/efi.h>
 #include <asm/uv/uv.h>
 #include <asm/cpu_device_id.h>
 #include <asm/realmode.h>
 #include <asm/reboot.h>
 
 #define EFI_MIN_RESERVE 5120
 
 #define EFI_DUMMY_GUID \
     EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
 
 #define QUARK_CSH_SIGNATURE     0x5f435348  /* _CSH */
 #define QUARK_SECURITY_HEADER_SIZE  0x400
 
 /*
  * Header prepended to the standard EFI capsule on Quark systems the are based
  * on Intel firmware BSP.
  * @csh_signature:  Unique identifier to sanity check signed module
  *          presence ("_CSH").
  * @version:        Current version of CSH used. Should be one for Quark A0.
  * @modulesize:     Size of the entire module including the module header
  *          and payload.
  * @security_version_number_index: Index of SVN to use for validation of signed
  *          module.
  * @security_version_number: Used to prevent against roll back of modules.
  * @rsvd_module_id: Currently unused for Clanton (Quark).
  * @rsvd_module_vendor: Vendor Identifier. For Intel products value is
  *          0x00008086.
  * @rsvd_date:      BCD representation of build date as yyyymmdd, where
  *          yyyy=4 digit year, mm=1-12, dd=1-31.
  * @headersize:     Total length of the header including including any
  *          padding optionally added by the signing tool.
  * @hash_algo:      What Hash is used in the module signing.
  * @cryp_algo:      What Crypto is used in the module signing.
  * @keysize:        Total length of the key data including including any
  *          padding optionally added by the signing tool.
  * @signaturesize:  Total length of the signature including including any
  *          padding optionally added by the signing tool.
  * @rsvd_next_header:   32-bit pointer to the next Secure Boot Module in the
  *          chain, if there is a next header.
  * @rsvd:       Reserved, padding structure to required size.
  *
  * See also QuartSecurityHeader_t in
  * Quark_EDKII_v1.2.1.1/QuarkPlatformPkg/Include/QuarkBootRom.h
  * from https://downloadcenter.intel.com/download/23197/Intel-Quark-SoC-X1000-Board-Support-Package-BSP
  */
 struct quark_security_header {
     u32 csh_signature;
     u32 version;
     u32 modulesize;
     u32 security_version_number_index;
     u32 security_version_number;
     u32 rsvd_module_id;
     u32 rsvd_module_vendor;
     u32 rsvd_date;
     u32 headersize;
     u32 hash_algo;
     u32 cryp_algo;
     u32 keysize;
     u32 signaturesize;
     u32 rsvd_next_header;
     u32 rsvd[2];
 };
 
 static const efi_char16_t efi_dummy_name[] = L"DUMMY";
 
 static bool efi_no_storage_paranoia;
 
 /*
  * Some firmware implementations refuse to boot if there's insufficient
  * space in the variable store. The implementation of garbage collection
  * in some FW versions causes stale (deleted) variables to take up space
  * longer than intended and space is only freed once the store becomes
  * almost completely full.
  *
  * Enabling this option disables the space checks in
  * efi_query_variable_store() and forces garbage collection.
  *
  * Only enable this option if deleting EFI variables does not free up
  * space in your variable store, e.g. if despite deleting variables
  * you're unable to create new ones.
  */
 static int __init setup_storage_paranoia(char *arg)
 {
     efi_no_storage_paranoia = true;
     return 0;
 }
 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
 
 /*
  * Deleting the dummy variable which kicks off garbage collection
 */
 void efi_delete_dummy_variable(void)
 {
     efi.set_variable_nonblocking((efi_char16_t *)efi_dummy_name,
                      &EFI_DUMMY_GUID,
                      EFI_VARIABLE_NON_VOLATILE |
                      EFI_VARIABLE_BOOTSERVICE_ACCESS |
                      EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
 }
 
 /*
  * In the nonblocking case we do not attempt to perform garbage
  * collection if we do not have enough free space. Rather, we do the
  * bare minimum check and give up immediately if the available space
  * is below EFI_MIN_RESERVE.
  *
  * This function is intended to be small and simple because it is
  * invoked from crash handler paths.
  */
 static efi_status_t
 query_variable_store_nonblocking(u32 attributes, unsigned long size)
 {
     efi_status_t status;
     u64 storage_size, remaining_size, max_size;
 
     status = efi.query_variable_info_nonblocking(attributes, &storage_size,
                              &remaining_size,
                              &max_size);
     if (status != EFI_SUCCESS)
         return status;
 
     if (remaining_size - size < EFI_MIN_RESERVE)
         return EFI_OUT_OF_RESOURCES;
 
     return EFI_SUCCESS;
 }
 
 /*
  * Some firmware implementations refuse to boot if there's insufficient space
  * in the variable store. Ensure that we never use more than a safe limit.
  *
  * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
  * store.
  */
 efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
                       bool nonblocking)
 {
     efi_status_t status;
     u64 storage_size, remaining_size, max_size;
 
     if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
         return 0;
 
     if (nonblocking)
         return query_variable_store_nonblocking(attributes, size);
 
     status = efi.query_variable_info(attributes, &storage_size,
                      &remaining_size, &max_size);
     if (status != EFI_SUCCESS)
         return status;
 
     /*
      * We account for that by refusing the write if permitting it would
      * reduce the available space to under 5KB. This figure was provided by
      * Samsung, so should be safe.
      */
     if ((remaining_size - size < EFI_MIN_RESERVE) &&
         !efi_no_storage_paranoia) {
 
         /*
          * Triggering garbage collection may require that the firmware
          * generate a real EFI_OUT_OF_RESOURCES error. We can force
          * that by attempting to use more space than is available.
          */
         unsigned long dummy_size = remaining_size + 1024;
         void *dummy = kzalloc(dummy_size, GFP_KERNEL);
 
         if (!dummy)
             return EFI_OUT_OF_RESOURCES;
 
         status = efi.set_variable((efi_char16_t *)efi_dummy_name,
                       &EFI_DUMMY_GUID,
                       EFI_VARIABLE_NON_VOLATILE |
                       EFI_VARIABLE_BOOTSERVICE_ACCESS |
                       EFI_VARIABLE_RUNTIME_ACCESS,
                       dummy_size, dummy);
 
         if (status == EFI_SUCCESS) {
             /*
              * This should have failed, so if it didn't make sure
              * that we delete it...
              */
             efi_delete_dummy_variable();
         }
 
         kfree(dummy);
 
         /*
          * The runtime code may now have triggered a garbage collection
          * run, so check the variable info again
          */
         status = efi.query_variable_info(attributes, &storage_size,
                          &remaining_size, &max_size);
 
         if (status != EFI_SUCCESS)
             return status;
 
         /*
          * There still isn't enough room, so return an error
          */
         if (remaining_size - size < EFI_MIN_RESERVE)
             return EFI_OUT_OF_RESOURCES;
     }
 
     return EFI_SUCCESS;
 }
 EXPORT_SYMBOL_GPL(efi_query_variable_store);
 
 /*
  * The UEFI specification makes it clear that the operating system is
  * free to do whatever it wants with boot services code after
  * ExitBootServices() has been called. Ignoring this recommendation a
  * significant bunch of EFI implementations continue calling into boot
  * services code (SetVirtualAddressMap). In order to work around such
  * buggy implementations we reserve boot services region during EFI
  * init and make sure it stays executable. Then, after
  * SetVirtualAddressMap(), it is discarded.
  *
  * However, some boot services regions contain data that is required
  * by drivers, so we need to track which memory ranges can never be
  * freed. This is done by tagging those regions with the
  * EFI_MEMORY_RUNTIME attribute.
  *
  * Any driver that wants to mark a region as reserved must use
  * efi_mem_reserve() which will insert a new EFI memory descriptor
  * into efi.memmap (splitting existing regions if necessary) and tag
  * it with EFI_MEMORY_RUNTIME.
  */
 void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
 {
     struct efi_memory_map_data data = { 0 };
     struct efi_mem_range mr;
     efi_memory_desc_t md;
     int num_entries;
     void *new;
 
     if (efi_mem_desc_lookup(addr, &md) ||
         md.type != EFI_BOOT_SERVICES_DATA) {
         pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
         return;
     }
 
     if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) {
         pr_err("Region spans EFI memory descriptors, %pa\n", &addr);
         return;
     }
 
     size += addr % EFI_PAGE_SIZE;
     size = round_up(size, EFI_PAGE_SIZE);
     addr = round_down(addr, EFI_PAGE_SIZE);
 
     mr.range.start = addr;
     mr.range.end = addr + size - 1;
     mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
 
     num_entries = efi_memmap_split_count(&md, &mr.range);
     num_entries += efi.memmap.nr_map;
 
     if (efi_memmap_alloc(num_entries, &data) != 0) {
         pr_err("Could not allocate boot services memmap\n");
         return;
     }
 
     new = early_memremap_prot(data.phys_map, data.size,
                   pgprot_val(pgprot_encrypted(FIXMAP_PAGE_NORMAL)));
     if (!new) {
         pr_err("Failed to map new boot services memmap\n");
         return;
     }
 
     efi_memmap_insert(&efi.memmap, new, &mr);
     early_memunmap(new, data.size);
 
     efi_memmap_install(&data);
     e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
     e820__update_table(e820_table);
 }
 
 /*
  * Helper function for efi_reserve_boot_services() to figure out if we
  * can free regions in efi_free_boot_services().
  *
  * Use this function to ensure we do not free regions owned by somebody
  * else. We must only reserve (and then free) regions:
  *
  * - Not within any part of the kernel
  * - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc)
  */
 static __init bool can_free_region(u64 start, u64 size)
 {
     if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end))
         return false;
 
     if (!e820__mapped_all(start, start+size, E820_TYPE_RAM))
         return false;
 
     return true;
 }
 
 void __init efi_reserve_boot_services(void)
 {
     efi_memory_desc_t *md;
 
     if (!efi_enabled(EFI_MEMMAP))
         return;
 
     for_each_efi_memory_desc(md) {
         u64 start = md->phys_addr;
         u64 size = md->num_pages << EFI_PAGE_SHIFT;
         bool already_reserved;
 
         if (md->type != EFI_BOOT_SERVICES_CODE &&
             md->type != EFI_BOOT_SERVICES_DATA)
             continue;
 
         already_reserved = memblock_is_region_reserved(start, size);
 
         /*
          * Because the following memblock_reserve() is paired
          * with memblock_free_late() for this region in
          * efi_free_boot_services(), we must be extremely
          * careful not to reserve, and subsequently free,
          * critical regions of memory (like the kernel image) or
          * those regions that somebody else has already
          * reserved.
          *
          * A good example of a critical region that must not be
          * freed is page zero (first 4Kb of memory), which may
          * contain boot services code/data but is marked
          * E820_TYPE_RESERVED by trim_bios_range().
          */
         if (!already_reserved) {
             memblock_reserve(start, size);
 
             /*
              * If we are the first to reserve the region, no
              * one else cares about it. We own it and can
              * free it later.
              */
             if (can_free_region(start, size))
                 continue;
         }
 
         /*
          * We don't own the region. We must not free it.
          *
          * Setting this bit for a boot services region really
          * doesn't make sense as far as the firmware is
          * concerned, but it does provide us with a way to tag
          * those regions that must not be paired with
          * memblock_free_late().
          */
         md->attribute |= EFI_MEMORY_RUNTIME;
     }
 }
 
 /*
  * Apart from having VA mappings for EFI boot services code/data regions,
  * (duplicate) 1:1 mappings were also created as a quirk for buggy firmware. So,
  * unmap both 1:1 and VA mappings.
  */
 static void __init efi_unmap_pages(efi_memory_desc_t *md)
 {
     pgd_t *pgd = efi_mm.pgd;
     u64 pa = md->phys_addr;
     u64 va = md->virt_addr;
 
     /*
      * EFI mixed mode has all RAM mapped to access arguments while making
      * EFI runtime calls, hence don't unmap EFI boot services code/data
      * regions.
      */
     if (efi_is_mixed())
         return;
 
     if (kernel_unmap_pages_in_pgd(pgd, pa, md->num_pages))
         pr_err("Failed to unmap 1:1 mapping for 0x%llx\n", pa);
 
     if (kernel_unmap_pages_in_pgd(pgd, va, md->num_pages))
         pr_err("Failed to unmap VA mapping for 0x%llx\n", va);
 }
 
 void __init efi_free_boot_services(void)
 {
     struct efi_memory_map_data data = { 0 };
     efi_memory_desc_t *md;
     int num_entries = 0;
     void *new, *new_md;
 
     /* Keep all regions for /sys/kernel/debug/efi */
     if (efi_enabled(EFI_DBG))
         return;
 
     for_each_efi_memory_desc(md) {
         unsigned long long start = md->phys_addr;
         unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
         size_t rm_size;
 
         if (md->type != EFI_BOOT_SERVICES_CODE &&
             md->type != EFI_BOOT_SERVICES_DATA) {
             num_entries++;
             continue;
         }
 
         /* Do not free, someone else owns it: */
         if (md->attribute & EFI_MEMORY_RUNTIME) {
             num_entries++;
             continue;
         }
 
         /*
          * Before calling set_virtual_address_map(), EFI boot services
          * code/data regions were mapped as a quirk for buggy firmware.
          * Unmap them from efi_pgd before freeing them up.
          */
         efi_unmap_pages(md);
 
         /*
          * Nasty quirk: if all sub-1MB memory is used for boot
          * services, we can get here without having allocated the
          * real mode trampoline.  It's too late to hand boot services
          * memory back to the memblock allocator, so instead
          * try to manually allocate the trampoline if needed.
          *
          * I've seen this on a Dell XPS 13 9350 with firmware
          * 1.4.4 with SGX enabled booting Linux via Fedora 24's
          * grub2-efi on a hard disk.  (And no, I don't know why
          * this happened, but Linux should still try to boot rather
          * panicking early.)
          */
         rm_size = real_mode_size_needed();
         if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
             set_real_mode_mem(start);
             start += rm_size;
             size -= rm_size;
         }
 
         /*
          * Don't free memory under 1M for two reasons:
          * - BIOS might clobber it
          * - Crash kernel needs it to be reserved
          */
         if (start + size < SZ_1M)
             continue;
         if (start < SZ_1M) {
             size -= (SZ_1M - start);
             start = SZ_1M;
         }
 
         memblock_free_late(start, size);
     }
 
     if (!num_entries)
         return;
 
     if (efi_memmap_alloc(num_entries, &data) != 0) {
         pr_err("Failed to allocate new EFI memmap\n");
         return;
     }
 
     new = memremap(data.phys_map, data.size, MEMREMAP_WB);
     if (!new) {
         pr_err("Failed to map new EFI memmap\n");
         return;
     }
 
     /*
      * Build a new EFI memmap that excludes any boot services
      * regions that are not tagged EFI_MEMORY_RUNTIME, since those
      * regions have now been freed.
      */
     new_md = new;
     for_each_efi_memory_desc(md) {
         if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
             (md->type == EFI_BOOT_SERVICES_CODE ||
              md->type == EFI_BOOT_SERVICES_DATA))
             continue;
 
         memcpy(new_md, md, efi.memmap.desc_size);
         new_md += efi.memmap.desc_size;
     }
 
     memunmap(new);
 
     if (efi_memmap_install(&data) != 0) {
         pr_err("Could not install new EFI memmap\n");
         return;
     }
 }
 
 /*
  * A number of config table entries get remapped to virtual addresses
  * after entering EFI virtual mode. However, the kexec kernel requires
  * their physical addresses therefore we pass them via setup_data and
  * correct those entries to their respective physical addresses here.
  *
  * Currently only handles smbios which is necessary for some firmware
  * implementation.
  */
 int __init efi_reuse_config(u64 tables, int nr_tables)
 {
     int i, sz, ret = 0;
     void *p, *tablep;
     struct efi_setup_data *data;
 
     if (nr_tables == 0)
         return 0;
 
     if (!efi_setup)
         return 0;
 
     if (!efi_enabled(EFI_64BIT))
         return 0;
 
     data = early_memremap(efi_setup, sizeof(*data));
     if (!data) {
         ret = -ENOMEM;
         goto out;
     }
 
     if (!data->smbios)
         goto out_memremap;
 
     sz = sizeof(efi_config_table_64_t);
 
     p = tablep = early_memremap(tables, nr_tables * sz);
     if (!p) {
         pr_err("Could not map Configuration table!\n");
         ret = -ENOMEM;
         goto out_memremap;
     }
 
     for (i = 0; i < nr_tables; i++) {
         efi_guid_t guid;
 
         guid = ((efi_config_table_64_t *)p)->guid;
 
         if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
             ((efi_config_table_64_t *)p)->table = data->smbios;
         p += sz;
     }
     early_memunmap(tablep, nr_tables * sz);
 
 out_memremap:
     early_memunmap(data, sizeof(*data));
 out:
     return ret;
 }
 
 void __init efi_apply_memmap_quirks(void)
 {
     /*
      * Once setup is done earlier, unmap the EFI memory map on mismatched
      * firmware/kernel architectures since there is no support for runtime
      * services.
      */
     if (!efi_runtime_supported()) {
         pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
         efi_memmap_unmap();
     }
 }
 
 /*
  * For most modern platforms the preferred method of powering off is via
  * ACPI. However, there are some that are known to require the use of
  * EFI runtime services and for which ACPI does not work at all.
  *
  * Using EFI is a last resort, to be used only if no other option
  * exists.
  */
 bool efi_reboot_required(void)
 {
     if (!acpi_gbl_reduced_hardware)
         return false;
 
     efi_reboot_quirk_mode = EFI_RESET_WARM;
     return true;
 }
 
 bool efi_poweroff_required(void)
 {
     return acpi_gbl_reduced_hardware || acpi_no_s5;
 }
 
 #ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
 
 static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
                   size_t hdr_bytes)
 {
     struct quark_security_header *csh = *pkbuff;
 
     /* Only process data block that is larger than the security header */
     if (hdr_bytes < sizeof(struct quark_security_header))
         return 0;
 
     if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
         csh->headersize != QUARK_SECURITY_HEADER_SIZE)
         return 1;
 
     /* Only process data block if EFI header is included */
     if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
             sizeof(efi_capsule_header_t))
         return 0;
 
     pr_debug("Quark security header detected\n");
 
     if (csh->rsvd_next_header != 0) {
         pr_err("multiple Quark security headers not supported\n");
         return -EINVAL;
     }
 
     *pkbuff += csh->headersize;
     cap_info->total_size = csh->headersize;
 
     /*
      * Update the first page pointer to skip over the CSH header.
      */
     cap_info->phys[0] += csh->headersize;
 
     /*
      * cap_info->capsule should point at a virtual mapping of the entire
      * capsule, starting at the capsule header. Our image has the Quark
      * security header prepended, so we cannot rely on the default vmap()
      * mapping created by the generic capsule code.
      * Given that the Quark firmware does not appear to care about the
      * virtual mapping, let's just point cap_info->capsule at our copy
      * of the capsule header.
      */
     cap_info->capsule = &cap_info->header;
 
     return 1;
 }
 
 static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
     X86_MATCH_VENDOR_FAM_MODEL(INTEL, 5, INTEL_FAM5_QUARK_X1000,
                    &qrk_capsule_setup_info),
     { }
 };
 
 int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
                size_t hdr_bytes)
 {
     int (*quirk_handler)(struct capsule_info *, void **, size_t);
     const struct x86_cpu_id *id;
     int ret;
 
     if (hdr_bytes < sizeof(efi_capsule_header_t))
         return 0;
 
     cap_info->total_size = 0;
 
     id = x86_match_cpu(efi_capsule_quirk_ids);
     if (id) {
         /*
          * The quirk handler is supposed to return
          *  - a value > 0 if the setup should continue, after advancing
          *    kbuff as needed
          *  - 0 if not enough hdr_bytes are available yet
          *  - a negative error code otherwise
          */
         quirk_handler = (typeof(quirk_handler))id->driver_data;
         ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
         if (ret <= 0)
             return ret;
     }
 
     memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
 
     cap_info->total_size += cap_info->header.imagesize;
 
     return __efi_capsule_setup_info(cap_info);
 }
 
 #endif
 
 /*
  * If any access by any efi runtime service causes a page fault, then,
  * 1. If it's efi_reset_system(), reboot through BIOS.
  * 2. If any other efi runtime service, then
  *    a. Return error status to the efi caller process.
  *    b. Disable EFI Runtime Services forever and
  *    c. Freeze efi_rts_wq and schedule new process.
  *
  * @return: Returns, if the page fault is not handled. This function
  * will never return if the page fault is handled successfully.
  */
 void efi_crash_gracefully_on_page_fault(unsigned long phys_addr)
 {
     if (!IS_ENABLED(CONFIG_X86_64))
         return;
 
     /*
      * If we get an interrupt/NMI while processing an EFI runtime service
      * then this is a regular OOPS, not an EFI failure.
      */
     if (in_interrupt())
         return;
 
     /*
      * Make sure that an efi runtime service caused the page fault.
      * READ_ONCE() because we might be OOPSing in a different thread,
      * and we don't want to trip KTSAN while trying to OOPS.
      */
     if (READ_ONCE(efi_rts_work.efi_rts_id) == EFI_NONE ||
         current_work() != &efi_rts_work.work)
         return;
 
     /*
      * Address range 0x0000 - 0x0fff is always mapped in the efi_pgd, so
      * page faulting on these addresses isn't expected.
      */
     if (phys_addr <= 0x0fff)
         return;
 
     /*
      * Print stack trace as it might be useful to know which EFI Runtime
      * Service is buggy.
      */
     WARN(1, FW_BUG "Page fault caused by firmware at PA: 0x%lx\n",
          phys_addr);
 
     /*
      * Buggy efi_reset_system() is handled differently from other EFI
      * Runtime Services as it doesn't use efi_rts_wq. Although,
      * native_machine_emergency_restart() says that machine_real_restart()
      * could fail, it's better not to complicate this fault handler
      * because this case occurs *very* rarely and hence could be improved
      * on a need by basis.
      */
     if (efi_rts_work.efi_rts_id == EFI_RESET_SYSTEM) {
         pr_info("efi_reset_system() buggy! Reboot through BIOS\n");
         machine_real_restart(MRR_BIOS);
         return;
     }
 
     /*
      * Before calling EFI Runtime Service, the kernel has switched the
      * calling process to efi_mm. Hence, switch back to task_mm.
      */
     arch_efi_call_virt_teardown();
 
     /* Signal error status to the efi caller process */
     efi_rts_work.status = EFI_ABORTED;
     complete(&efi_rts_work.efi_rts_comp);
 
     clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
     pr_info("Froze efi_rts_wq and disabled EFI Runtime Services\n");
 
     /*
      * Call schedule() in an infinite loop, so that any spurious wake ups
      * will never run efi_rts_wq again.
      */
     for (;;) {
         set_current_state(TASK_IDLE);
         schedule();
     }
 }

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