Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 240 insertions, 0 deletions

diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
new file mode 100644
index 000000000..1b373d79c
--- /dev/null
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * handle transition of Linux booting another kernel
+ * Copyright (C) 2002-2005 Eric Biederman  <ebiederm@xmission.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <linux/numa.h>
+#include <linux/ftrace.h>
+#include <linux/suspend.h>
+#include <linux/gfp.h>
+#include <linux/io.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/apic.h>
+#include <asm/io_apic.h>
+#include <asm/cpufeature.h>
+#include <asm/desc.h>
+#include <asm/set_memory.h>
+#include <asm/debugreg.h>
+
+static void load_segments(void)
+{
+#define __STR(X) #X
+#define STR(X) __STR(X)
+
+	__asm__ __volatile__ (
+		"\tljmp $"STR(__KERNEL_CS)",$1f\n"
+		"\t1:\n"
+		"\tmovl $"STR(__KERNEL_DS)",%%eax\n"
+		"\tmovl %%eax,%%ds\n"
+		"\tmovl %%eax,%%es\n"
+		"\tmovl %%eax,%%ss\n"
+		: : : "eax", "memory");
+#undef STR
+#undef __STR
+}
+
+static void machine_kexec_free_page_tables(struct kimage *image)
+{
+	free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER);
+	image->arch.pgd = NULL;
+#ifdef CONFIG_X86_PAE
+	free_page((unsigned long)image->arch.pmd0);
+	image->arch.pmd0 = NULL;
+	free_page((unsigned long)image->arch.pmd1);
+	image->arch.pmd1 = NULL;
+#endif
+	free_page((unsigned long)image->arch.pte0);
+	image->arch.pte0 = NULL;
+	free_page((unsigned long)image->arch.pte1);
+	image->arch.pte1 = NULL;
+}
+
+static int machine_kexec_alloc_page_tables(struct kimage *image)
+{
+	image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+						    PGD_ALLOCATION_ORDER);
+#ifdef CONFIG_X86_PAE
+	image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
+	image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
+#endif
+	image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL);
+	image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL);
+	if (!image->arch.pgd ||
+#ifdef CONFIG_X86_PAE
+	    !image->arch.pmd0 || !image->arch.pmd1 ||
+#endif
+	    !image->arch.pte0 || !image->arch.pte1) {
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static void machine_kexec_page_table_set_one(
+	pgd_t *pgd, pmd_t *pmd, pte_t *pte,
+	unsigned long vaddr, unsigned long paddr)
+{
+	p4d_t *p4d;
+	pud_t *pud;
+
+	pgd += pgd_index(vaddr);
+#ifdef CONFIG_X86_PAE
+	if (!(pgd_val(*pgd) & _PAGE_PRESENT))
+		set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
+#endif
+	p4d = p4d_offset(pgd, vaddr);
+	pud = pud_offset(p4d, vaddr);
+	pmd = pmd_offset(pud, vaddr);
+	if (!(pmd_val(*pmd) & _PAGE_PRESENT))
+		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
+	pte = pte_offset_kernel(pmd, vaddr);
+	set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
+}
+
+static void machine_kexec_prepare_page_tables(struct kimage *image)
+{
+	void *control_page;
+	pmd_t *pmd = NULL;
+
+	control_page = page_address(image->control_code_page);
+#ifdef CONFIG_X86_PAE
+	pmd = image->arch.pmd0;
+#endif
+	machine_kexec_page_table_set_one(
+		image->arch.pgd, pmd, image->arch.pte0,
+		(unsigned long)control_page, __pa(control_page));
+#ifdef CONFIG_X86_PAE
+	pmd = image->arch.pmd1;
+#endif
+	machine_kexec_page_table_set_one(
+		image->arch.pgd, pmd, image->arch.pte1,
+		__pa(control_page), __pa(control_page));
+}
+
+/*
+ * A architecture hook called to validate the
+ * proposed image and prepare the control pages
+ * as needed.  The pages for KEXEC_CONTROL_PAGE_SIZE
+ * have been allocated, but the segments have yet
+ * been copied into the kernel.
+ *
+ * Do what every setup is needed on image and the
+ * reboot code buffer to allow us to avoid allocations
+ * later.
+ *
+ * - Make control page executable.
+ * - Allocate page tables
+ * - Setup page tables
+ */
+int machine_kexec_prepare(struct kimage *image)
+{
+	int error;
+
+	set_memory_x((unsigned long)page_address(image->control_code_page), 1);
+	error = machine_kexec_alloc_page_tables(image);
+	if (error)
+		return error;
+	machine_kexec_prepare_page_tables(image);
+	return 0;
+}
+
+/*
+ * Undo anything leftover by machine_kexec_prepare
+ * when an image is freed.
+ */
+void machine_kexec_cleanup(struct kimage *image)
+{
+	set_memory_nx((unsigned long)page_address(image->control_code_page), 1);
+	machine_kexec_free_page_tables(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)
+{
+	unsigned long page_list[PAGES_NR];
+	void *control_page;
+	int save_ftrace_enabled;
+	asmlinkage unsigned long
+		(*relocate_kernel_ptr)(unsigned long indirection_page,
+				       unsigned long control_page,
+				       unsigned long start_address,
+				       unsigned int has_pae,
+				       unsigned int preserve_context);
+
+#ifdef CONFIG_KEXEC_JUMP
+	if (image->preserve_context)
+		save_processor_state();
+#endif
+
+	save_ftrace_enabled = __ftrace_enabled_save();
+
+	/* Interrupts aren't acceptable while we reboot */
+	local_irq_disable();
+	hw_breakpoint_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 restore_boot_irq_mode()
+		 * in one form or other. kexec jump path also need one.
+		 */
+		clear_IO_APIC();
+		restore_boot_irq_mode();
+#endif
+	}
+
+	control_page = page_address(image->control_code_page);
+	memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
+
+	relocate_kernel_ptr = control_page;
+	page_list[PA_CONTROL_PAGE] = __pa(control_page);
+	page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
+	page_list[PA_PGD] = __pa(image->arch.pgd);
+
+	if (image->type == KEXEC_TYPE_DEFAULT)
+		page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
+						<< PAGE_SHIFT);
+
+	/*
+	 * The segment registers are funny things, they have both a
+	 * visible and an invisible part.  Whenever the visible part is
+	 * set to a specific selector, the invisible part is loaded
+	 * 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.
+	 */
+	load_segments();
+	/*
+	 * The gdt & idt are now invalid.
+	 * If you want to load them you must set up your own idt & gdt.
+	 */
+	native_idt_invalidate();
+	native_gdt_invalidate();
+
+	/* now call it */
+	image->start = relocate_kernel_ptr((unsigned long)image->head,
+					   (unsigned long)page_list,
+					   image->start,
+					   boot_cpu_has(X86_FEATURE_PAE),
+					   image->preserve_context);
+
+#ifdef CONFIG_KEXEC_JUMP
+	if (image->preserve_context)
+		restore_processor_state();
+#endif
+
+	__ftrace_enabled_restore(save_ftrace_enabled);
+}