Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 471 insertions, 0 deletions

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
new file mode 100644
index 000000000..e1b599ecb
--- /dev/null
+++ b/arch/x86/mm/dump_pagetables.c
@@ -0,0 +1,471 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Debug helper to dump the current kernel pagetables of the system
+ * so that we can see what the various memory ranges are set to.
+ *
+ * (C) Copyright 2008 Intel Corporation
+ *
+ * Author: Arjan van de Ven <arjan@linux.intel.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/kasan.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/highmem.h>
+#include <linux/pci.h>
+#include <linux/ptdump.h>
+
+#include <asm/e820/types.h>
+
+/*
+ * The dumper groups pagetable entries of the same type into one, and for
+ * that it needs to keep some state when walking, and flush this state
+ * when a "break" in the continuity is found.
+ */
+struct pg_state {
+	struct ptdump_state ptdump;
+	int level;
+	pgprotval_t current_prot;
+	pgprotval_t effective_prot;
+	pgprotval_t prot_levels[5];
+	unsigned long start_address;
+	const struct addr_marker *marker;
+	unsigned long lines;
+	bool to_dmesg;
+	bool check_wx;
+	unsigned long wx_pages;
+	struct seq_file *seq;
+};
+
+struct addr_marker {
+	unsigned long start_address;
+	const char *name;
+	unsigned long max_lines;
+};
+
+/* Address space markers hints */
+
+#ifdef CONFIG_X86_64
+
+enum address_markers_idx {
+	USER_SPACE_NR = 0,
+	KERNEL_SPACE_NR,
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+	LDT_NR,
+#endif
+	LOW_KERNEL_NR,
+	VMALLOC_START_NR,
+	VMEMMAP_START_NR,
+#ifdef CONFIG_KASAN
+	KASAN_SHADOW_START_NR,
+	KASAN_SHADOW_END_NR,
+#endif
+	CPU_ENTRY_AREA_NR,
+#ifdef CONFIG_X86_ESPFIX64
+	ESPFIX_START_NR,
+#endif
+#ifdef CONFIG_EFI
+	EFI_END_NR,
+#endif
+	HIGH_KERNEL_NR,
+	MODULES_VADDR_NR,
+	MODULES_END_NR,
+	FIXADDR_START_NR,
+	END_OF_SPACE_NR,
+};
+
+static struct addr_marker address_markers[] = {
+	[USER_SPACE_NR]		= { 0,			"User Space" },
+	[KERNEL_SPACE_NR]	= { (1UL << 63),	"Kernel Space" },
+	[LOW_KERNEL_NR]		= { 0UL,		"Low Kernel Mapping" },
+	[VMALLOC_START_NR]	= { 0UL,		"vmalloc() Area" },
+	[VMEMMAP_START_NR]	= { 0UL,		"Vmemmap" },
+#ifdef CONFIG_KASAN
+	/*
+	 * These fields get initialized with the (dynamic)
+	 * KASAN_SHADOW_{START,END} values in pt_dump_init().
+	 */
+	[KASAN_SHADOW_START_NR]	= { 0UL,		"KASAN shadow" },
+	[KASAN_SHADOW_END_NR]	= { 0UL,		"KASAN shadow end" },
+#endif
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+	[LDT_NR]		= { 0UL,		"LDT remap" },
+#endif
+	[CPU_ENTRY_AREA_NR]	= { CPU_ENTRY_AREA_BASE,"CPU entry Area" },
+#ifdef CONFIG_X86_ESPFIX64
+	[ESPFIX_START_NR]	= { ESPFIX_BASE_ADDR,	"ESPfix Area", 16 },
+#endif
+#ifdef CONFIG_EFI
+	[EFI_END_NR]		= { EFI_VA_END,		"EFI Runtime Services" },
+#endif
+	[HIGH_KERNEL_NR]	= { __START_KERNEL_map,	"High Kernel Mapping" },
+	[MODULES_VADDR_NR]	= { MODULES_VADDR,	"Modules" },
+	[MODULES_END_NR]	= { MODULES_END,	"End Modules" },
+	[FIXADDR_START_NR]	= { FIXADDR_START,	"Fixmap Area" },
+	[END_OF_SPACE_NR]	= { -1,			NULL }
+};
+
+#define INIT_PGD	((pgd_t *) &init_top_pgt)
+
+#else /* CONFIG_X86_64 */
+
+enum address_markers_idx {
+	USER_SPACE_NR = 0,
+	KERNEL_SPACE_NR,
+	VMALLOC_START_NR,
+	VMALLOC_END_NR,
+#ifdef CONFIG_HIGHMEM
+	PKMAP_BASE_NR,
+#endif
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+	LDT_NR,
+#endif
+	CPU_ENTRY_AREA_NR,
+	FIXADDR_START_NR,
+	END_OF_SPACE_NR,
+};
+
+static struct addr_marker address_markers[] = {
+	[USER_SPACE_NR]		= { 0,			"User Space" },
+	[KERNEL_SPACE_NR]	= { PAGE_OFFSET,	"Kernel Mapping" },
+	[VMALLOC_START_NR]	= { 0UL,		"vmalloc() Area" },
+	[VMALLOC_END_NR]	= { 0UL,		"vmalloc() End" },
+#ifdef CONFIG_HIGHMEM
+	[PKMAP_BASE_NR]		= { 0UL,		"Persistent kmap() Area" },
+#endif
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+	[LDT_NR]		= { 0UL,		"LDT remap" },
+#endif
+	[CPU_ENTRY_AREA_NR]	= { 0UL,		"CPU entry area" },
+	[FIXADDR_START_NR]	= { 0UL,		"Fixmap area" },
+	[END_OF_SPACE_NR]	= { -1,			NULL }
+};
+
+#define INIT_PGD	(swapper_pg_dir)
+
+#endif /* !CONFIG_X86_64 */
+
+/* Multipliers for offsets within the PTEs */
+#define PTE_LEVEL_MULT (PAGE_SIZE)
+#define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT)
+#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
+#define P4D_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)
+#define PGD_LEVEL_MULT (PTRS_PER_P4D * P4D_LEVEL_MULT)
+
+#define pt_dump_seq_printf(m, to_dmesg, fmt, args...)		\
+({								\
+	if (to_dmesg)					\
+		printk(KERN_INFO fmt, ##args);			\
+	else							\
+		if (m)						\
+			seq_printf(m, fmt, ##args);		\
+})
+
+#define pt_dump_cont_printf(m, to_dmesg, fmt, args...)		\
+({								\
+	if (to_dmesg)					\
+		printk(KERN_CONT fmt, ##args);			\
+	else							\
+		if (m)						\
+			seq_printf(m, fmt, ##args);		\
+})
+
+/*
+ * Print a readable form of a pgprot_t to the seq_file
+ */
+static void printk_prot(struct seq_file *m, pgprotval_t pr, int level, bool dmsg)
+{
+	static const char * const level_name[] =
+		{ "pgd", "p4d", "pud", "pmd", "pte" };
+
+	if (!(pr & _PAGE_PRESENT)) {
+		/* Not present */
+		pt_dump_cont_printf(m, dmsg, "                              ");
+	} else {
+		if (pr & _PAGE_USER)
+			pt_dump_cont_printf(m, dmsg, "USR ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+		if (pr & _PAGE_RW)
+			pt_dump_cont_printf(m, dmsg, "RW ");
+		else
+			pt_dump_cont_printf(m, dmsg, "ro ");
+		if (pr & _PAGE_PWT)
+			pt_dump_cont_printf(m, dmsg, "PWT ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+		if (pr & _PAGE_PCD)
+			pt_dump_cont_printf(m, dmsg, "PCD ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+
+		/* Bit 7 has a different meaning on level 3 vs 4 */
+		if (level <= 3 && pr & _PAGE_PSE)
+			pt_dump_cont_printf(m, dmsg, "PSE ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+		if ((level == 4 && pr & _PAGE_PAT) ||
+		    ((level == 3 || level == 2) && pr & _PAGE_PAT_LARGE))
+			pt_dump_cont_printf(m, dmsg, "PAT ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+		if (pr & _PAGE_GLOBAL)
+			pt_dump_cont_printf(m, dmsg, "GLB ");
+		else
+			pt_dump_cont_printf(m, dmsg, "    ");
+		if (pr & _PAGE_NX)
+			pt_dump_cont_printf(m, dmsg, "NX ");
+		else
+			pt_dump_cont_printf(m, dmsg, "x  ");
+	}
+	pt_dump_cont_printf(m, dmsg, "%s\n", level_name[level]);
+}
+
+static void note_wx(struct pg_state *st, unsigned long addr)
+{
+	unsigned long npages;
+
+	npages = (addr - st->start_address) / PAGE_SIZE;
+
+#ifdef CONFIG_PCI_BIOS
+	/*
+	 * If PCI BIOS is enabled, the PCI BIOS area is forced to WX.
+	 * Inform about it, but avoid the warning.
+	 */
+	if (pcibios_enabled && st->start_address >= PAGE_OFFSET + BIOS_BEGIN &&
+	    addr <= PAGE_OFFSET + BIOS_END) {
+		pr_warn_once("x86/mm: PCI BIOS W+X mapping %lu pages\n", npages);
+		return;
+	}
+#endif
+	/* Account the WX pages */
+	st->wx_pages += npages;
+	WARN_ONCE(__supported_pte_mask & _PAGE_NX,
+		  "x86/mm: Found insecure W+X mapping at address %pS\n",
+		  (void *)st->start_address);
+}
+
+static void effective_prot(struct ptdump_state *pt_st, int level, u64 val)
+{
+	struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
+	pgprotval_t prot = val & PTE_FLAGS_MASK;
+	pgprotval_t effective;
+
+	if (level > 0) {
+		pgprotval_t higher_prot = st->prot_levels[level - 1];
+
+		effective = (higher_prot & prot & (_PAGE_USER | _PAGE_RW)) |
+			    ((higher_prot | prot) & _PAGE_NX);
+	} else {
+		effective = prot;
+	}
+
+	st->prot_levels[level] = effective;
+}
+
+/*
+ * This function gets called on a break in a continuous series
+ * of PTE entries; the next one is different so we need to
+ * print what we collected so far.
+ */
+static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
+		      u64 val)
+{
+	struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
+	pgprotval_t new_prot, new_eff;
+	pgprotval_t cur, eff;
+	static const char units[] = "BKMGTPE";
+	struct seq_file *m = st->seq;
+
+	new_prot = val & PTE_FLAGS_MASK;
+	if (!val)
+		new_eff = 0;
+	else
+		new_eff = st->prot_levels[level];
+
+	/*
+	 * If we have a "break" in the series, we need to flush the state that
+	 * we have now. "break" is either changing perms, levels or
+	 * address space marker.
+	 */
+	cur = st->current_prot;
+	eff = st->effective_prot;
+
+	if (st->level == -1) {
+		/* First entry */
+		st->current_prot = new_prot;
+		st->effective_prot = new_eff;
+		st->level = level;
+		st->marker = address_markers;
+		st->lines = 0;
+		pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
+				   st->marker->name);
+	} else if (new_prot != cur || new_eff != eff || level != st->level ||
+		   addr >= st->marker[1].start_address) {
+		const char *unit = units;
+		unsigned long delta;
+		int width = sizeof(unsigned long) * 2;
+
+		if (st->check_wx && (eff & _PAGE_RW) && !(eff & _PAGE_NX))
+			note_wx(st, addr);
+
+		/*
+		 * Now print the actual finished series
+		 */
+		if (!st->marker->max_lines ||
+		    st->lines < st->marker->max_lines) {
+			pt_dump_seq_printf(m, st->to_dmesg,
+					   "0x%0*lx-0x%0*lx   ",
+					   width, st->start_address,
+					   width, addr);
+
+			delta = addr - st->start_address;
+			while (!(delta & 1023) && unit[1]) {
+				delta >>= 10;
+				unit++;
+			}
+			pt_dump_cont_printf(m, st->to_dmesg, "%9lu%c ",
+					    delta, *unit);
+			printk_prot(m, st->current_prot, st->level,
+				    st->to_dmesg);
+		}
+		st->lines++;
+
+		/*
+		 * We print markers for special areas of address space,
+		 * such as the start of vmalloc space etc.
+		 * This helps in the interpretation.
+		 */
+		if (addr >= st->marker[1].start_address) {
+			if (st->marker->max_lines &&
+			    st->lines > st->marker->max_lines) {
+				unsigned long nskip =
+					st->lines - st->marker->max_lines;
+				pt_dump_seq_printf(m, st->to_dmesg,
+						   "... %lu entr%s skipped ... \n",
+						   nskip,
+						   nskip == 1 ? "y" : "ies");
+			}
+			st->marker++;
+			st->lines = 0;
+			pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
+					   st->marker->name);
+		}
+
+		st->start_address = addr;
+		st->current_prot = new_prot;
+		st->effective_prot = new_eff;
+		st->level = level;
+	}
+}
+
+static void ptdump_walk_pgd_level_core(struct seq_file *m,
+				       struct mm_struct *mm, pgd_t *pgd,
+				       bool checkwx, bool dmesg)
+{
+	const struct ptdump_range ptdump_ranges[] = {
+#ifdef CONFIG_X86_64
+	{0, PTRS_PER_PGD * PGD_LEVEL_MULT / 2},
+	{GUARD_HOLE_END_ADDR, ~0UL},
+#else
+	{0, ~0UL},
+#endif
+	{0, 0}
+};
+
+	struct pg_state st = {
+		.ptdump = {
+			.note_page	= note_page,
+			.effective_prot = effective_prot,
+			.range		= ptdump_ranges
+		},
+		.level = -1,
+		.to_dmesg	= dmesg,
+		.check_wx	= checkwx,
+		.seq		= m
+	};
+
+	ptdump_walk_pgd(&st.ptdump, mm, pgd);
+
+	if (!checkwx)
+		return;
+	if (st.wx_pages)
+		pr_info("x86/mm: Checked W+X mappings: FAILED, %lu W+X pages found.\n",
+			st.wx_pages);
+	else
+		pr_info("x86/mm: Checked W+X mappings: passed, no W+X pages found.\n");
+}
+
+void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm)
+{
+	ptdump_walk_pgd_level_core(m, mm, mm->pgd, false, true);
+}
+
+void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,
+				   bool user)
+{
+	pgd_t *pgd = mm->pgd;
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	if (user && boot_cpu_has(X86_FEATURE_PTI))
+		pgd = kernel_to_user_pgdp(pgd);
+#endif
+	ptdump_walk_pgd_level_core(m, mm, pgd, false, false);
+}
+EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs);
+
+void ptdump_walk_user_pgd_level_checkwx(void)
+{
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	pgd_t *pgd = INIT_PGD;
+
+	if (!(__supported_pte_mask & _PAGE_NX) ||
+	    !boot_cpu_has(X86_FEATURE_PTI))
+		return;
+
+	pr_info("x86/mm: Checking user space page tables\n");
+	pgd = kernel_to_user_pgdp(pgd);
+	ptdump_walk_pgd_level_core(NULL, &init_mm, pgd, true, false);
+#endif
+}
+
+void ptdump_walk_pgd_level_checkwx(void)
+{
+	ptdump_walk_pgd_level_core(NULL, &init_mm, INIT_PGD, true, false);
+}
+
+static int __init pt_dump_init(void)
+{
+	/*
+	 * Various markers are not compile-time constants, so assign them
+	 * here.
+	 */
+#ifdef CONFIG_X86_64
+	address_markers[LOW_KERNEL_NR].start_address = PAGE_OFFSET;
+	address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
+	address_markers[VMEMMAP_START_NR].start_address = VMEMMAP_START;
+#ifdef CONFIG_MODIFY_LDT_SYSCALL
+	address_markers[LDT_NR].start_address = LDT_BASE_ADDR;
+#endif
+#ifdef CONFIG_KASAN
+	address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START;
+	address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END;
+#endif
+#endif
+#ifdef CONFIG_X86_32
+	address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
+	address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
+# ifdef CONFIG_HIGHMEM
+	address_markers[PKMAP_BASE_NR].start_address = PKMAP_BASE;
+# endif
+	address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
+	address_markers[CPU_ENTRY_AREA_NR].start_address = CPU_ENTRY_AREA_BASE;
+# ifdef CONFIG_MODIFY_LDT_SYSCALL
+	address_markers[LDT_NR].start_address = LDT_BASE_ADDR;
+# endif
+#endif
+	return 0;
+}
+__initcall(pt_dump_init);