Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 491 insertions, 0 deletions

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
new file mode 100644
index 000000000..88dc38b4a
--- /dev/null
+++ b/arch/x86/kernel/head64.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  prepare to run common code
+ *
+ *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+/* cpu_feature_enabled() cannot be used this early */
+#define USE_EARLY_PGTABLE_L5
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/percpu.h>
+#include <linux/start_kernel.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/mem_encrypt.h>
+
+#include <asm/processor.h>
+#include <asm/proto.h>
+#include <asm/smp.h>
+#include <asm/setup.h>
+#include <asm/desc.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/kdebug.h>
+#include <asm/e820/api.h>
+#include <asm/bios_ebda.h>
+#include <asm/bootparam_utils.h>
+#include <asm/microcode.h>
+#include <asm/kasan.h>
+#include <asm/fixmap.h>
+
+/*
+ * Manage page tables very early on.
+ */
+extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
+static unsigned int __initdata next_early_pgt;
+pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
+
+#ifdef CONFIG_X86_5LEVEL
+unsigned int __pgtable_l5_enabled __ro_after_init;
+unsigned int pgdir_shift __ro_after_init = 39;
+EXPORT_SYMBOL(pgdir_shift);
+unsigned int ptrs_per_p4d __ro_after_init = 1;
+EXPORT_SYMBOL(ptrs_per_p4d);
+#endif
+
+#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
+unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
+EXPORT_SYMBOL(page_offset_base);
+unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
+EXPORT_SYMBOL(vmalloc_base);
+unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
+EXPORT_SYMBOL(vmemmap_base);
+#endif
+
+#define __head	__section(.head.text)
+
+static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
+{
+	return ptr - (void *)_text + (void *)physaddr;
+}
+
+static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
+{
+	return fixup_pointer(ptr, physaddr);
+}
+
+#ifdef CONFIG_X86_5LEVEL
+static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
+{
+	return fixup_pointer(ptr, physaddr);
+}
+
+static bool __head check_la57_support(unsigned long physaddr)
+{
+	/*
+	 * 5-level paging is detected and enabled at kernel decomression
+	 * stage. Only check if it has been enabled there.
+	 */
+	if (!(native_read_cr4() & X86_CR4_LA57))
+		return false;
+
+	*fixup_int(&__pgtable_l5_enabled, physaddr) = 1;
+	*fixup_int(&pgdir_shift, physaddr) = 48;
+	*fixup_int(&ptrs_per_p4d, physaddr) = 512;
+	*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
+	*fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
+	*fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
+
+	return true;
+}
+#else
+static bool __head check_la57_support(unsigned long physaddr)
+{
+	return false;
+}
+#endif
+
+/* Code in __startup_64() can be relocated during execution, but the compiler
+ * doesn't have to generate PC-relative relocations when accessing globals from
+ * that function. Clang actually does not generate them, which leads to
+ * boot-time crashes. To work around this problem, every global pointer must
+ * be adjusted using fixup_pointer().
+ */
+unsigned long __head __startup_64(unsigned long physaddr,
+				  struct boot_params *bp)
+{
+	unsigned long vaddr, vaddr_end;
+	unsigned long load_delta, *p;
+	unsigned long pgtable_flags;
+	pgdval_t *pgd;
+	p4dval_t *p4d;
+	pudval_t *pud;
+	pmdval_t *pmd, pmd_entry;
+	pteval_t *mask_ptr;
+	bool la57;
+	int i;
+	unsigned int *next_pgt_ptr;
+
+	la57 = check_la57_support(physaddr);
+
+	/* Is the address too large? */
+	if (physaddr >> MAX_PHYSMEM_BITS)
+		for (;;);
+
+	/*
+	 * Compute the delta between the address I am compiled to run at
+	 * and the address I am actually running at.
+	 */
+	load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);
+
+	/* Is the address not 2M aligned? */
+	if (load_delta & ~PMD_PAGE_MASK)
+		for (;;);
+
+	/* Activate Secure Memory Encryption (SME) if supported and enabled */
+	sme_enable(bp);
+
+	/* Include the SME encryption mask in the fixup value */
+	load_delta += sme_get_me_mask();
+
+	/* Fixup the physical addresses in the page table */
+
+	pgd = fixup_pointer(&early_top_pgt, physaddr);
+	p = pgd + pgd_index(__START_KERNEL_map);
+	if (la57)
+		*p = (unsigned long)level4_kernel_pgt;
+	else
+		*p = (unsigned long)level3_kernel_pgt;
+	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
+
+	if (la57) {
+		p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
+		p4d[511] += load_delta;
+	}
+
+	pud = fixup_pointer(&level3_kernel_pgt, physaddr);
+	pud[510] += load_delta;
+	pud[511] += load_delta;
+
+	pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
+	for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--)
+		pmd[i] += load_delta;
+
+	/*
+	 * Set up the identity mapping for the switchover.  These
+	 * entries should *NOT* have the global bit set!  This also
+	 * creates a bunch of nonsense entries but that is fine --
+	 * it avoids problems around wraparound.
+	 */
+
+	next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
+	pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
+	pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
+
+	pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
+
+	if (la57) {
+		p4d = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++],
+				    physaddr);
+
+		i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
+		pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
+		pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
+
+		i = physaddr >> P4D_SHIFT;
+		p4d[(i + 0) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
+		p4d[(i + 1) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
+	} else {
+		i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
+		pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
+		pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
+	}
+
+	i = physaddr >> PUD_SHIFT;
+	pud[(i + 0) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
+	pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
+
+	pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
+	/* Filter out unsupported __PAGE_KERNEL_* bits: */
+	mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
+	pmd_entry &= *mask_ptr;
+	pmd_entry += sme_get_me_mask();
+	pmd_entry +=  physaddr;
+
+	for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
+		int idx = i + (physaddr >> PMD_SHIFT);
+
+		pmd[idx % PTRS_PER_PMD] = pmd_entry + i * PMD_SIZE;
+	}
+
+	/*
+	 * Fixup the kernel text+data virtual addresses. Note that
+	 * we might write invalid pmds, when the kernel is relocated
+	 * cleanup_highmap() fixes this up along with the mappings
+	 * beyond _end.
+	 *
+	 * Only the region occupied by the kernel image has so far
+	 * been checked against the table of usable memory regions
+	 * provided by the firmware, so invalidate pages outside that
+	 * region. A page table entry that maps to a reserved area of
+	 * memory would allow processor speculation into that area,
+	 * and on some hardware (particularly the UV platform) even
+	 * speculative access to some reserved areas is caught as an
+	 * error, causing the BIOS to halt the system.
+	 */
+
+	pmd = fixup_pointer(level2_kernel_pgt, physaddr);
+
+	/* invalidate pages before the kernel image */
+	for (i = 0; i < pmd_index((unsigned long)_text); i++)
+		pmd[i] &= ~_PAGE_PRESENT;
+
+	/* fixup pages that are part of the kernel image */
+	for (; i <= pmd_index((unsigned long)_end); i++)
+		if (pmd[i] & _PAGE_PRESENT)
+			pmd[i] += load_delta;
+
+	/* invalidate pages after the kernel image */
+	for (; i < PTRS_PER_PMD; i++)
+		pmd[i] &= ~_PAGE_PRESENT;
+
+	/*
+	 * Fixup phys_base - remove the memory encryption mask to obtain
+	 * the true physical address.
+	 */
+	*fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
+
+	/* Encrypt the kernel and related (if SME is active) */
+	sme_encrypt_kernel(bp);
+
+	/*
+	 * Clear the memory encryption mask from the .bss..decrypted section.
+	 * The bss section will be memset to zero later in the initialization so
+	 * there is no need to zero it after changing the memory encryption
+	 * attribute.
+	 */
+	if (mem_encrypt_active()) {
+		vaddr = (unsigned long)__start_bss_decrypted;
+		vaddr_end = (unsigned long)__end_bss_decrypted;
+		for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
+			i = pmd_index(vaddr);
+			pmd[i] -= sme_get_me_mask();
+		}
+	}
+
+	/*
+	 * Return the SME encryption mask (if SME is active) to be used as a
+	 * modifier for the initial pgdir entry programmed into CR3.
+	 */
+	return sme_get_me_mask();
+}
+
+unsigned long __startup_secondary_64(void)
+{
+	/*
+	 * Return the SME encryption mask (if SME is active) to be used as a
+	 * modifier for the initial pgdir entry programmed into CR3.
+	 */
+	return sme_get_me_mask();
+}
+
+/* Wipe all early page tables except for the kernel symbol map */
+static void __init reset_early_page_tables(void)
+{
+	memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
+	next_early_pgt = 0;
+	write_cr3(__sme_pa_nodebug(early_top_pgt));
+}
+
+/* Create a new PMD entry */
+int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
+{
+	unsigned long physaddr = address - __PAGE_OFFSET;
+	pgdval_t pgd, *pgd_p;
+	p4dval_t p4d, *p4d_p;
+	pudval_t pud, *pud_p;
+	pmdval_t *pmd_p;
+
+	/* Invalid address or early pgt is done ?  */
+	if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
+		return -1;
+
+again:
+	pgd_p = &early_top_pgt[pgd_index(address)].pgd;
+	pgd = *pgd_p;
+
+	/*
+	 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
+	 * critical -- __PAGE_OFFSET would point us back into the dynamic
+	 * range and we might end up looping forever...
+	 */
+	if (!pgtable_l5_enabled())
+		p4d_p = pgd_p;
+	else if (pgd)
+		p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
+	else {
+		if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
+			reset_early_page_tables();
+			goto again;
+		}
+
+		p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++];
+		memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
+		*pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
+	}
+	p4d_p += p4d_index(address);
+	p4d = *p4d_p;
+
+	if (p4d)
+		pud_p = (pudval_t *)((p4d & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
+	else {
+		if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
+			reset_early_page_tables();
+			goto again;
+		}
+
+		pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
+		memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
+		*p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
+	}
+	pud_p += pud_index(address);
+	pud = *pud_p;
+
+	if (pud)
+		pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
+	else {
+		if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
+			reset_early_page_tables();
+			goto again;
+		}
+
+		pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
+		memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
+		*pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
+	}
+	pmd_p[pmd_index(address)] = pmd;
+
+	return 0;
+}
+
+int __init early_make_pgtable(unsigned long address)
+{
+	unsigned long physaddr = address - __PAGE_OFFSET;
+	pmdval_t pmd;
+
+	pmd = (physaddr & PMD_MASK) + early_pmd_flags;
+
+	return __early_make_pgtable(address, pmd);
+}
+
+/* Don't add a printk in there. printk relies on the PDA which is not initialized 
+   yet. */
+static void __init clear_bss(void)
+{
+	memset(__bss_start, 0,
+	       (unsigned long) __bss_stop - (unsigned long) __bss_start);
+}
+
+static unsigned long get_cmd_line_ptr(void)
+{
+	unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+	cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
+
+	return cmd_line_ptr;
+}
+
+static void __init copy_bootdata(char *real_mode_data)
+{
+	char * command_line;
+	unsigned long cmd_line_ptr;
+
+	/*
+	 * If SME is active, this will create decrypted mappings of the
+	 * boot data in advance of the copy operations.
+	 */
+	sme_map_bootdata(real_mode_data);
+
+	memcpy(&boot_params, real_mode_data, sizeof boot_params);
+	sanitize_boot_params(&boot_params);
+	cmd_line_ptr = get_cmd_line_ptr();
+	if (cmd_line_ptr) {
+		command_line = __va(cmd_line_ptr);
+		memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
+	}
+
+	/*
+	 * The old boot data is no longer needed and won't be reserved,
+	 * freeing up that memory for use by the system. If SME is active,
+	 * we need to remove the mappings that were created so that the
+	 * memory doesn't remain mapped as decrypted.
+	 */
+	sme_unmap_bootdata(real_mode_data);
+}
+
+asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
+{
+	/*
+	 * Build-time sanity checks on the kernel image and module
+	 * area mappings. (these are purely build-time and produce no code)
+	 */
+	BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map);
+	BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE);
+	BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
+	BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
+	BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
+	BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
+	MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
+				(__START_KERNEL & PGDIR_MASK)));
+	BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
+
+	cr4_init_shadow();
+
+	/* Kill off the identity-map trampoline */
+	reset_early_page_tables();
+
+	clear_bss();
+
+	clear_page(init_top_pgt);
+
+	/*
+	 * SME support may update early_pmd_flags to include the memory
+	 * encryption mask, so it needs to be called before anything
+	 * that may generate a page fault.
+	 */
+	sme_early_init();
+
+	kasan_early_init();
+
+	idt_setup_early_handler();
+
+	copy_bootdata(__va(real_mode_data));
+
+	/*
+	 * Load microcode early on BSP.
+	 */
+	load_ucode_bsp();
+
+	/* set init_top_pgt kernel high mapping*/
+	init_top_pgt[511] = early_top_pgt[511];
+
+	x86_64_start_reservations(real_mode_data);
+}
+
+void __init x86_64_start_reservations(char *real_mode_data)
+{
+	/* version is always not zero if it is copied */
+	if (!boot_params.hdr.version)
+		copy_bootdata(__va(real_mode_data));
+
+	x86_early_init_platform_quirks();
+
+	switch (boot_params.hdr.hardware_subarch) {
+	case X86_SUBARCH_INTEL_MID:
+		x86_intel_mid_early_setup();
+		break;
+	default:
+		break;
+	}
+
+	start_kernel();
+}