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Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
-rw-r--r--arch/x86/kernel/machine_kexec_64.c621
1 files changed, 533 insertions, 88 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 4eabc160696f..201137b98fb8 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -1,11 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* handle transition of Linux booting another kernel
* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
*/
+#define pr_fmt(fmt) "kexec: " fmt
+
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/string.h>
@@ -15,39 +15,186 @@
#include <linux/ftrace.h>
#include <linux/io.h>
#include <linux/suspend.h>
+#include <linux/vmalloc.h>
+#include <linux/efi.h>
+#include <linux/cc_platform.h>
#include <asm/init.h>
-#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
+#include <asm/io_apic.h>
#include <asm/debugreg.h>
+#include <asm/kexec-bzimage64.h>
+#include <asm/setup.h>
+#include <asm/set_memory.h>
+#include <asm/cpu.h>
+#include <asm/efi.h>
+#include <asm/processor.h>
+
+#ifdef CONFIG_ACPI
+/*
+ * Used while adding mapping for ACPI tables.
+ * Can be reused when other iomem regions need be mapped
+ */
+struct init_pgtable_data {
+ struct x86_mapping_info *info;
+ pgd_t *level4p;
+};
+
+static int mem_region_callback(struct resource *res, void *arg)
+{
+ struct init_pgtable_data *data = arg;
+
+ return kernel_ident_mapping_init(data->info, data->level4p,
+ res->start, res->end + 1);
+}
+
+static int
+map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p)
+{
+ struct init_pgtable_data data;
+ unsigned long flags;
+ int ret;
+
+ data.info = info;
+ data.level4p = level4p;
+ flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+ ret = walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1,
+ &data, mem_region_callback);
+ if (ret && ret != -EINVAL)
+ return ret;
+
+ /* ACPI tables could be located in ACPI Non-volatile Storage region */
+ ret = walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1,
+ &data, mem_region_callback);
+ if (ret && ret != -EINVAL)
+ return ret;
+
+ return 0;
+}
+#else
+static int map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) { return 0; }
+#endif
+
+static int map_mmio_serial(struct x86_mapping_info *info, pgd_t *level4p)
+{
+ unsigned long mstart, mend;
+
+ if (!kexec_debug_8250_mmio32)
+ return 0;
+
+ mstart = kexec_debug_8250_mmio32 & PAGE_MASK;
+ mend = (kexec_debug_8250_mmio32 + PAGE_SIZE + 23) & PAGE_MASK;
+ pr_info("Map PCI serial at %lx - %lx\n", mstart, mend);
+ return kernel_ident_mapping_init(info, level4p, mstart, mend);
+}
+
+#ifdef CONFIG_KEXEC_FILE
+const struct kexec_file_ops * const kexec_file_loaders[] = {
+ &kexec_bzImage64_ops,
+ NULL
+};
+#endif
+
+static int
+map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p)
+{
+#ifdef CONFIG_EFI
+ unsigned long mstart, mend;
+ void *kaddr;
+ int ret;
+
+ if (!efi_enabled(EFI_BOOT))
+ return 0;
+
+ mstart = (boot_params.efi_info.efi_systab |
+ ((u64)boot_params.efi_info.efi_systab_hi<<32));
+
+ if (efi_enabled(EFI_64BIT))
+ mend = mstart + sizeof(efi_system_table_64_t);
+ else
+ mend = mstart + sizeof(efi_system_table_32_t);
+
+ if (!mstart)
+ return 0;
+
+ ret = kernel_ident_mapping_init(info, level4p, mstart, mend);
+ if (ret)
+ return ret;
+
+ kaddr = memremap(mstart, mend - mstart, MEMREMAP_WB);
+ if (!kaddr) {
+ pr_err("Could not map UEFI system table\n");
+ return -ENOMEM;
+ }
+
+ mstart = efi_config_table;
+
+ if (efi_enabled(EFI_64BIT)) {
+ efi_system_table_64_t *stbl = (efi_system_table_64_t *)kaddr;
+
+ mend = mstart + sizeof(efi_config_table_64_t) * stbl->nr_tables;
+ } else {
+ efi_system_table_32_t *stbl = (efi_system_table_32_t *)kaddr;
+
+ mend = mstart + sizeof(efi_config_table_32_t) * stbl->nr_tables;
+ }
+
+ memunmap(kaddr);
+
+ return kernel_ident_mapping_init(info, level4p, mstart, mend);
+#endif
+ return 0;
+}
static void free_transition_pgtable(struct kimage *image)
{
+ free_page((unsigned long)image->arch.p4d);
+ image->arch.p4d = NULL;
free_page((unsigned long)image->arch.pud);
+ image->arch.pud = NULL;
free_page((unsigned long)image->arch.pmd);
+ image->arch.pmd = NULL;
free_page((unsigned long)image->arch.pte);
+ image->arch.pte = NULL;
}
-static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
+static int init_transition_pgtable(struct kimage *image, pgd_t *pgd,
+ unsigned long control_page)
{
+ pgprot_t prot = PAGE_KERNEL_EXEC_NOENC;
+ unsigned long vaddr, paddr;
+ int result = -ENOMEM;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- unsigned long vaddr, paddr;
- int result = -ENOMEM;
- vaddr = (unsigned long)relocate_kernel;
- paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE);
+ /*
+ * For the transition to the identity mapped page tables, the control
+ * code page also needs to be mapped at the virtual address it starts
+ * off running from.
+ */
+ vaddr = (unsigned long)__va(control_page);
+ paddr = control_page;
pgd += pgd_index(vaddr);
if (!pgd_present(*pgd)) {
+ p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL);
+ if (!p4d)
+ goto err;
+ image->arch.p4d = p4d;
+ set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE));
+ }
+ p4d = p4d_offset(pgd, vaddr);
+ if (!p4d_present(*p4d)) {
pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
if (!pud)
goto err;
image->arch.pud = pud;
- set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+ set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));
}
- pud = pud_offset(pgd, vaddr);
+ pud = pud_offset(p4d, vaddr);
if (!pud_present(*pud)) {
pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
if (!pmd)
@@ -64,10 +211,13 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
}
pte = pte_offset_kernel(pmd, vaddr);
- set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
+
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ prot = PAGE_KERNEL_EXEC;
+
+ set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
return 0;
err:
- free_transition_pgtable(image);
return result;
}
@@ -86,26 +236,36 @@ static void *alloc_pgt_page(void *data)
return p;
}
-static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
+static int init_pgtable(struct kimage *image, unsigned long control_page)
{
struct x86_mapping_info info = {
.alloc_pgt_page = alloc_pgt_page,
.context = image,
- .pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
+ .page_flag = __PAGE_KERNEL_LARGE_EXEC,
+ .kernpg_flag = _KERNPG_TABLE_NOENC,
};
unsigned long mstart, mend;
- pgd_t *level4p;
int result;
int i;
- level4p = (pgd_t *)__va(start_pgtable);
- clear_page(level4p);
+ image->arch.pgd = alloc_pgt_page(image);
+ if (!image->arch.pgd)
+ return -ENOMEM;
+
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
+ info.page_flag |= _PAGE_ENC;
+ info.kernpg_flag |= _PAGE_ENC;
+ }
+
+ if (direct_gbpages)
+ info.direct_gbpages = true;
+
for (i = 0; i < nr_pfn_mapped; i++) {
mstart = pfn_mapped[i].start << PAGE_SHIFT;
mend = pfn_mapped[i].end << PAGE_SHIFT;
- result = kernel_ident_mapping_init(&info,
- level4p, mstart, mend);
+ result = kernel_ident_mapping_init(&info, image->arch.pgd,
+ mstart, mend);
if (result)
return result;
}
@@ -120,44 +280,35 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
mstart = image->segment[i].mem;
mend = mstart + image->segment[i].memsz;
- result = kernel_ident_mapping_init(&info,
- level4p, mstart, mend);
+ result = kernel_ident_mapping_init(&info, image->arch.pgd,
+ mstart, mend);
if (result)
return result;
}
- return init_transition_pgtable(image, level4p);
-}
-
-static void set_idt(void *newidt, u16 limit)
-{
- struct desc_ptr curidt;
-
- /* x86-64 supports unaliged loads & stores */
- curidt.size = limit;
- curidt.address = (unsigned long)newidt;
-
- __asm__ __volatile__ (
- "lidtq %0\n"
- : : "m" (curidt)
- );
-};
-
+ /*
+ * Prepare EFI systab and ACPI tables for kexec kernel since they are
+ * not covered by pfn_mapped.
+ */
+ result = map_efi_systab(&info, image->arch.pgd);
+ if (result)
+ return result;
-static void set_gdt(void *newgdt, u16 limit)
-{
- struct desc_ptr curgdt;
+ result = map_acpi_tables(&info, image->arch.pgd);
+ if (result)
+ return result;
- /* x86-64 supports unaligned loads & stores */
- curgdt.size = limit;
- curgdt.address = (unsigned long)newgdt;
+ result = map_mmio_serial(&info, image->arch.pgd);
+ if (result)
+ return result;
- __asm__ __volatile__ (
- "lgdtq %0\n"
- : : "m" (curgdt)
- );
-};
+ /*
+ * This must be last because the intermediate page table pages it
+ * allocates will not be control pages and may overlap the image.
+ */
+ return init_transition_pgtable(image, image->arch.pgd, control_page);
+}
static void load_segments(void)
{
@@ -171,24 +322,74 @@ static void load_segments(void)
);
}
+static void prepare_debug_idt(unsigned long control_page, unsigned long vec_ofs)
+{
+ gate_desc idtentry = { 0 };
+ int i;
+
+ idtentry.bits.p = 1;
+ idtentry.bits.type = GATE_TRAP;
+ idtentry.segment = __KERNEL_CS;
+ idtentry.offset_low = (control_page & 0xFFFF) + vec_ofs;
+ idtentry.offset_middle = (control_page >> 16) & 0xFFFF;
+ idtentry.offset_high = control_page >> 32;
+
+ for (i = 0; i < 16; i++) {
+ kexec_debug_idt[i] = idtentry;
+ idtentry.offset_low += KEXEC_DEBUG_EXC_HANDLER_SIZE;
+ }
+}
+
int machine_kexec_prepare(struct kimage *image)
{
- unsigned long start_pgtable;
+ void *control_page = page_address(image->control_code_page);
+ unsigned long reloc_start = (unsigned long)__relocate_kernel_start;
+ unsigned long reloc_end = (unsigned long)__relocate_kernel_end;
int result;
- /* Calculate the offsets */
- start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
+ /*
+ * Some early TDX-capable platforms have an erratum. A kernel
+ * partial write (a write transaction of less than cacheline
+ * lands at memory controller) to TDX private memory poisons that
+ * memory, and a subsequent read triggers a machine check.
+ *
+ * On those platforms the old kernel must reset TDX private
+ * memory before jumping to the new kernel otherwise the new
+ * kernel may see unexpected machine check. For simplicity
+ * just fail kexec/kdump on those platforms.
+ */
+ if (boot_cpu_has_bug(X86_BUG_TDX_PW_MCE)) {
+ pr_info_once("Not allowed on platform with tdx_pw_mce bug\n");
+ return -EOPNOTSUPP;
+ }
/* Setup the identity mapped 64bit page table */
- result = init_pgtable(image, start_pgtable);
+ result = init_pgtable(image, __pa(control_page));
if (result)
return result;
+ kexec_va_control_page = (unsigned long)control_page;
+ kexec_pa_table_page = (unsigned long)__pa(image->arch.pgd);
+
+ if (image->type == KEXEC_TYPE_DEFAULT)
+ kexec_pa_swap_page = page_to_pfn(image->swap_page) << PAGE_SHIFT;
+
+ prepare_debug_idt((unsigned long)__pa(control_page),
+ (unsigned long)kexec_debug_exc_vectors - reloc_start);
+
+ __memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start);
+
+ set_memory_rox((unsigned long)control_page, 1);
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
+ void *control_page = page_address(image->control_code_page);
+
+ set_memory_nx((unsigned long)control_page, 1);
+ set_memory_rw((unsigned long)control_page, 1);
+
free_transition_pgtable(image);
}
@@ -196,11 +397,13 @@ void machine_kexec_cleanup(struct kimage *image)
* Do not allocate memory (or fail in any way) in machine_kexec().
* We are past the point of no return, committed to rebooting now.
*/
-void machine_kexec(struct kimage *image)
+void __nocfi machine_kexec(struct kimage *image)
{
- unsigned long page_list[PAGES_NR];
- void *control_page;
+ unsigned long reloc_start = (unsigned long)__relocate_kernel_start;
+ relocate_kernel_fn *relocate_kernel_ptr;
+ unsigned int relocate_kernel_flags;
int save_ftrace_enabled;
+ void *control_page;
#ifdef CONFIG_KEXEC_JUMP
if (image->preserve_context)
@@ -212,31 +415,39 @@ void machine_kexec(struct kimage *image)
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
hw_breakpoint_disable();
+ cet_disable();
if (image->preserve_context) {
#ifdef CONFIG_X86_IO_APIC
/*
* We need to put APICs in legacy mode so that we can
* get timer interrupts in second kernel. kexec/kdump
- * paths already have calls to disable_IO_APIC() in
- * one form or other. kexec jump path also need
- * one.
+ * paths already have calls to restore_boot_irq_mode()
+ * in one form or other. kexec jump path also need one.
*/
- disable_IO_APIC();
+ clear_IO_APIC();
+ restore_boot_irq_mode();
#endif
}
- control_page = page_address(image->control_code_page) + PAGE_SIZE;
- memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
+ control_page = page_address(image->control_code_page);
- page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
- page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
- page_list[PA_TABLE_PAGE] =
- (unsigned long)__pa(page_address(image->control_code_page));
+ /*
+ * Allow for the possibility that relocate_kernel might not be at
+ * the very start of the page.
+ */
+ relocate_kernel_ptr = control_page + (unsigned long)relocate_kernel - reloc_start;
- if (image->type == KEXEC_TYPE_DEFAULT)
- page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
- << PAGE_SHIFT);
+ relocate_kernel_flags = 0;
+ if (image->preserve_context)
+ relocate_kernel_flags |= RELOC_KERNEL_PRESERVE_CONTEXT;
+
+ /*
+ * This must be done before load_segments() since it resets
+ * GS to 0 and percpu data needs the correct GS to work.
+ */
+ if (this_cpu_read(cache_state_incoherent))
+ relocate_kernel_flags |= RELOC_KERNEL_CACHE_INCOHERENT;
/*
* The segment registers are funny things, they have both a
@@ -245,22 +456,21 @@ void machine_kexec(struct kimage *image)
* with from a table in memory. At no other time is the
* descriptor table in memory accessed.
*
- * I take advantage of this here by force loading the
- * segments, before I zap the gdt with an invalid value.
+ * Take advantage of this here by force loading the segments,
+ * before the GDT is zapped with an invalid value.
+ *
+ * load_segments() resets GS to 0. Don't make any function call
+ * after here since call depth tracking uses percpu variables to
+ * operate (relocate_kernel() is explicitly ignored by call depth
+ * tracking).
*/
load_segments();
- /*
- * The gdt & idt are now invalid.
- * If you want to load them you must set up your own idt & gdt.
- */
- set_gdt(phys_to_virt(0), 0);
- set_idt(phys_to_virt(0), 0);
/* now call it */
- image->start = relocate_kernel((unsigned long)image->head,
- (unsigned long)page_list,
- image->start,
- image->preserve_context);
+ image->start = relocate_kernel_ptr((unsigned long)image->head,
+ virt_to_phys(control_page),
+ image->start,
+ relocate_kernel_flags);
#ifdef CONFIG_KEXEC_JUMP
if (image->preserve_context)
@@ -269,15 +479,250 @@ void machine_kexec(struct kimage *image)
__ftrace_enabled_restore(save_ftrace_enabled);
}
+/*
+ * Handover to the next kernel, no CFI concern.
+ */
+ANNOTATE_NOCFI_SYM(machine_kexec);
+
+/* arch-dependent functionality related to kexec file-based syscall */
-void arch_crash_save_vmcoreinfo(void)
+#ifdef CONFIG_KEXEC_FILE
+/*
+ * Apply purgatory relocations.
+ *
+ * @pi: Purgatory to be relocated.
+ * @section: Section relocations applying to.
+ * @relsec: Section containing RELAs.
+ * @symtabsec: Corresponding symtab.
+ *
+ * TODO: Some of the code belongs to generic code. Move that in kexec.c.
+ */
+int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+ Elf_Shdr *section, const Elf_Shdr *relsec,
+ const Elf_Shdr *symtabsec)
{
- VMCOREINFO_SYMBOL(phys_base);
- VMCOREINFO_SYMBOL(init_level4_pgt);
+ unsigned int i;
+ Elf64_Rela *rel;
+ Elf64_Sym *sym;
+ void *location;
+ unsigned long address, sec_base, value;
+ const char *strtab, *name, *shstrtab;
+ const Elf_Shdr *sechdrs;
+
+ /* String & section header string table */
+ sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
+ strtab = (char *)pi->ehdr + sechdrs[symtabsec->sh_link].sh_offset;
+ shstrtab = (char *)pi->ehdr + sechdrs[pi->ehdr->e_shstrndx].sh_offset;
+
+ rel = (void *)pi->ehdr + relsec->sh_offset;
-#ifdef CONFIG_NUMA
- VMCOREINFO_SYMBOL(node_data);
- VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
+ pr_debug("Applying relocate section %s to %u\n",
+ shstrtab + relsec->sh_name, relsec->sh_info);
+
+ for (i = 0; i < relsec->sh_size / sizeof(*rel); i++) {
+
+ /*
+ * rel[i].r_offset contains byte offset from beginning
+ * of section to the storage unit affected.
+ *
+ * This is location to update. This is temporary buffer
+ * where section is currently loaded. This will finally be
+ * loaded to a different address later, pointed to by
+ * ->sh_addr. kexec takes care of moving it
+ * (kexec_load_segment()).
+ */
+ location = pi->purgatory_buf;
+ location += section->sh_offset;
+ location += rel[i].r_offset;
+
+ /* Final address of the location */
+ address = section->sh_addr + rel[i].r_offset;
+
+ /*
+ * rel[i].r_info contains information about symbol table index
+ * w.r.t which relocation must be made and type of relocation
+ * to apply. ELF64_R_SYM() and ELF64_R_TYPE() macros get
+ * these respectively.
+ */
+ sym = (void *)pi->ehdr + symtabsec->sh_offset;
+ sym += ELF64_R_SYM(rel[i].r_info);
+
+ if (sym->st_name)
+ name = strtab + sym->st_name;
+ else
+ name = shstrtab + sechdrs[sym->st_shndx].sh_name;
+
+ pr_debug("Symbol: %s info: %02x shndx: %02x value=%llx size: %llx\n",
+ name, sym->st_info, sym->st_shndx, sym->st_value,
+ sym->st_size);
+
+ if (sym->st_shndx == SHN_UNDEF) {
+ pr_err("Undefined symbol: %s\n", name);
+ return -ENOEXEC;
+ }
+
+ if (sym->st_shndx == SHN_COMMON) {
+ pr_err("symbol '%s' in common section\n", name);
+ return -ENOEXEC;
+ }
+
+ if (sym->st_shndx == SHN_ABS)
+ sec_base = 0;
+ else if (sym->st_shndx >= pi->ehdr->e_shnum) {
+ pr_err("Invalid section %d for symbol %s\n",
+ sym->st_shndx, name);
+ return -ENOEXEC;
+ } else
+ sec_base = pi->sechdrs[sym->st_shndx].sh_addr;
+
+ value = sym->st_value;
+ value += sec_base;
+ value += rel[i].r_addend;
+
+ switch (ELF64_R_TYPE(rel[i].r_info)) {
+ case R_X86_64_NONE:
+ break;
+ case R_X86_64_64:
+ *(u64 *)location = value;
+ break;
+ case R_X86_64_32:
+ *(u32 *)location = value;
+ if (value != *(u32 *)location)
+ goto overflow;
+ break;
+ case R_X86_64_32S:
+ *(s32 *)location = value;
+ if ((s64)value != *(s32 *)location)
+ goto overflow;
+ break;
+ case R_X86_64_PC32:
+ case R_X86_64_PLT32:
+ value -= (u64)address;
+ *(u32 *)location = value;
+ break;
+ default:
+ pr_err("Unknown rela relocation: %llu\n",
+ ELF64_R_TYPE(rel[i].r_info));
+ return -ENOEXEC;
+ }
+ }
+ return 0;
+
+overflow:
+ pr_err("Overflow in relocation type %d value 0x%lx\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), value);
+ return -ENOEXEC;
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+ vfree(image->elf_headers);
+ image->elf_headers = NULL;
+ image->elf_headers_sz = 0;
+
+ return kexec_image_post_load_cleanup_default(image);
+}
+#endif /* CONFIG_KEXEC_FILE */
+
+#ifdef CONFIG_CRASH_DUMP
+
+static int
+kexec_mark_range(unsigned long start, unsigned long end, bool protect)
+{
+ struct page *page;
+ unsigned int nr_pages;
+
+ /*
+ * For physical range: [start, end]. We must skip the unassigned
+ * crashk resource with zero-valued "end" member.
+ */
+ if (!end || start > end)
+ return 0;
+
+ page = pfn_to_page(start >> PAGE_SHIFT);
+ nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
+ if (protect)
+ return set_pages_ro(page, nr_pages);
+ else
+ return set_pages_rw(page, nr_pages);
+}
+
+static void kexec_mark_crashkres(bool protect)
+{
+ unsigned long control;
+
+ kexec_mark_range(crashk_low_res.start, crashk_low_res.end, protect);
+
+ /* Don't touch the control code page used in crash_kexec().*/
+ control = PFN_PHYS(page_to_pfn(kexec_crash_image->control_code_page));
+ kexec_mark_range(crashk_res.start, control - 1, protect);
+ control += KEXEC_CONTROL_PAGE_SIZE;
+ kexec_mark_range(control, crashk_res.end, protect);
+}
+
+/* make the memory storing dm crypt keys in/accessible */
+static void kexec_mark_dm_crypt_keys(bool protect)
+{
+ unsigned long start_paddr, end_paddr;
+ unsigned int nr_pages;
+
+ if (kexec_crash_image->dm_crypt_keys_addr) {
+ start_paddr = kexec_crash_image->dm_crypt_keys_addr;
+ end_paddr = start_paddr + kexec_crash_image->dm_crypt_keys_sz - 1;
+ nr_pages = (PAGE_ALIGN(end_paddr) - PAGE_ALIGN_DOWN(start_paddr))/PAGE_SIZE;
+ if (protect)
+ set_memory_np((unsigned long)phys_to_virt(start_paddr), nr_pages);
+ else
+ __set_memory_prot(
+ (unsigned long)phys_to_virt(start_paddr),
+ nr_pages,
+ __pgprot(_PAGE_PRESENT | _PAGE_NX | _PAGE_RW));
+ }
+}
+
+void arch_kexec_protect_crashkres(void)
+{
+ kexec_mark_crashkres(true);
+ kexec_mark_dm_crypt_keys(true);
+}
+
+void arch_kexec_unprotect_crashkres(void)
+{
+ kexec_mark_dm_crypt_keys(false);
+ kexec_mark_crashkres(false);
+}
#endif
+
+/*
+ * During a traditional boot under SME, SME will encrypt the kernel,
+ * so the SME kexec kernel also needs to be un-encrypted in order to
+ * replicate a normal SME boot.
+ *
+ * During a traditional boot under SEV, the kernel has already been
+ * loaded encrypted, so the SEV kexec kernel needs to be encrypted in
+ * order to replicate a normal SEV boot.
+ */
+int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
+{
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ return 0;
+
+ /*
+ * If host memory encryption is active we need to be sure that kexec
+ * pages are not encrypted because when we boot to the new kernel the
+ * pages won't be accessed encrypted (initially).
+ */
+ return set_memory_decrypted((unsigned long)vaddr, pages);
}
+void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages)
+{
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ return;
+
+ /*
+ * If host memory encryption is active we need to reset the pages back
+ * to being an encrypted mapping before freeing them.
+ */
+ set_memory_encrypted((unsigned long)vaddr, pages);
+}