Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 453 insertions, 0 deletions

diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
new file mode 100644
index 000000000..e9a9b7b61
--- /dev/null
+++ b/arch/s390/mm/kasan_init.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kasan.h>
+#include <linux/sched/task.h>
+#include <linux/memblock.h>
+#include <linux/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/kasan.h>
+#include <asm/mem_detect.h>
+#include <asm/processor.h>
+#include <asm/sclp.h>
+#include <asm/facility.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/uv.h>
+
+unsigned long kasan_vmax;
+static unsigned long segment_pos __initdata;
+static unsigned long segment_low __initdata;
+static unsigned long pgalloc_pos __initdata;
+static unsigned long pgalloc_low __initdata;
+static unsigned long pgalloc_freeable __initdata;
+static bool has_edat __initdata;
+static bool has_nx __initdata;
+
+#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
+
+static pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+
+static void __init kasan_early_panic(const char *reason)
+{
+	sclp_early_printk("The Linux kernel failed to boot with the KernelAddressSanitizer:\n");
+	sclp_early_printk(reason);
+	disabled_wait();
+}
+
+static void * __init kasan_early_alloc_segment(void)
+{
+	segment_pos -= _SEGMENT_SIZE;
+
+	if (segment_pos < segment_low)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	return (void *)segment_pos;
+}
+
+static void * __init kasan_early_alloc_pages(unsigned int order)
+{
+	pgalloc_pos -= (PAGE_SIZE << order);
+
+	if (pgalloc_pos < pgalloc_low)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	return (void *)pgalloc_pos;
+}
+
+static void * __init kasan_early_crst_alloc(unsigned long val)
+{
+	unsigned long *table;
+
+	table = kasan_early_alloc_pages(CRST_ALLOC_ORDER);
+	if (table)
+		crst_table_init(table, val);
+	return table;
+}
+
+static pte_t * __init kasan_early_pte_alloc(void)
+{
+	static void *pte_leftover;
+	pte_t *pte;
+
+	BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
+
+	if (!pte_leftover) {
+		pte_leftover = kasan_early_alloc_pages(0);
+		pte = pte_leftover + _PAGE_TABLE_SIZE;
+	} else {
+		pte = pte_leftover;
+		pte_leftover = NULL;
+	}
+	memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
+	return pte;
+}
+
+enum populate_mode {
+	POPULATE_ONE2ONE,
+	POPULATE_MAP,
+	POPULATE_ZERO_SHADOW,
+	POPULATE_SHALLOW
+};
+static void __init kasan_early_vmemmap_populate(unsigned long address,
+						unsigned long end,
+						enum populate_mode mode)
+{
+	unsigned long pgt_prot_zero, pgt_prot, sgt_prot;
+	pgd_t *pg_dir;
+	p4d_t *p4_dir;
+	pud_t *pu_dir;
+	pmd_t *pm_dir;
+	pte_t *pt_dir;
+
+	pgt_prot_zero = pgprot_val(PAGE_KERNEL_RO);
+	if (!has_nx)
+		pgt_prot_zero &= ~_PAGE_NOEXEC;
+	pgt_prot = pgprot_val(PAGE_KERNEL);
+	sgt_prot = pgprot_val(SEGMENT_KERNEL);
+	if (!has_nx || mode == POPULATE_ONE2ONE) {
+		pgt_prot &= ~_PAGE_NOEXEC;
+		sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
+	}
+
+	/*
+	 * The first 1MB of 1:1 mapping is mapped with 4KB pages
+	 */
+	while (address < end) {
+		pg_dir = pgd_offset_k(address);
+		if (pgd_none(*pg_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, PGDIR_SIZE) &&
+			    end - address >= PGDIR_SIZE) {
+				pgd_populate(&init_mm, pg_dir,
+						kasan_early_shadow_p4d);
+				address = (address + PGDIR_SIZE) & PGDIR_MASK;
+				continue;
+			}
+			p4_dir = kasan_early_crst_alloc(_REGION2_ENTRY_EMPTY);
+			pgd_populate(&init_mm, pg_dir, p4_dir);
+		}
+
+		if (IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING) &&
+		    mode == POPULATE_SHALLOW) {
+			address = (address + P4D_SIZE) & P4D_MASK;
+			continue;
+		}
+
+		p4_dir = p4d_offset(pg_dir, address);
+		if (p4d_none(*p4_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, P4D_SIZE) &&
+			    end - address >= P4D_SIZE) {
+				p4d_populate(&init_mm, p4_dir,
+						kasan_early_shadow_pud);
+				address = (address + P4D_SIZE) & P4D_MASK;
+				continue;
+			}
+			pu_dir = kasan_early_crst_alloc(_REGION3_ENTRY_EMPTY);
+			p4d_populate(&init_mm, p4_dir, pu_dir);
+		}
+
+		if (!IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING) &&
+		    mode == POPULATE_SHALLOW) {
+			address = (address + PUD_SIZE) & PUD_MASK;
+			continue;
+		}
+
+		pu_dir = pud_offset(p4_dir, address);
+		if (pud_none(*pu_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, PUD_SIZE) &&
+			    end - address >= PUD_SIZE) {
+				pud_populate(&init_mm, pu_dir,
+						kasan_early_shadow_pmd);
+				address = (address + PUD_SIZE) & PUD_MASK;
+				continue;
+			}
+			pm_dir = kasan_early_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+			pud_populate(&init_mm, pu_dir, pm_dir);
+		}
+
+		pm_dir = pmd_offset(pu_dir, address);
+		if (pmd_none(*pm_dir)) {
+			if (IS_ALIGNED(address, PMD_SIZE) &&
+			    end - address >= PMD_SIZE) {
+				if (mode == POPULATE_ZERO_SHADOW) {
+					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
+				} else if (has_edat && address) {
+					void *page;
+
+					if (mode == POPULATE_ONE2ONE) {
+						page = (void *)address;
+					} else {
+						page = kasan_early_alloc_segment();
+						memset(page, 0, _SEGMENT_SIZE);
+					}
+					pmd_val(*pm_dir) = __pa(page) | sgt_prot;
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
+				}
+			}
+			pt_dir = kasan_early_pte_alloc();
+			pmd_populate(&init_mm, pm_dir, pt_dir);
+		} else if (pmd_large(*pm_dir)) {
+			address = (address + PMD_SIZE) & PMD_MASK;
+			continue;
+		}
+
+		pt_dir = pte_offset_kernel(pm_dir, address);
+		if (pte_none(*pt_dir)) {
+			void *page;
+
+			switch (mode) {
+			case POPULATE_ONE2ONE:
+				page = (void *)address;
+				pte_val(*pt_dir) = __pa(page) | pgt_prot;
+				break;
+			case POPULATE_MAP:
+				page = kasan_early_alloc_pages(0);
+				memset(page, 0, PAGE_SIZE);
+				pte_val(*pt_dir) = __pa(page) | pgt_prot;
+				break;
+			case POPULATE_ZERO_SHADOW:
+				page = kasan_early_shadow_page;
+				pte_val(*pt_dir) = __pa(page) | pgt_prot_zero;
+				break;
+			case POPULATE_SHALLOW:
+				/* should never happen */
+				break;
+			}
+		}
+		address += PAGE_SIZE;
+	}
+}
+
+static void __init kasan_set_pgd(pgd_t *pgd, unsigned long asce_type)
+{
+	unsigned long asce_bits;
+
+	asce_bits = asce_type | _ASCE_TABLE_LENGTH;
+	S390_lowcore.kernel_asce = (__pa(pgd) & PAGE_MASK) | asce_bits;
+	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
+
+	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
+}
+
+static void __init kasan_enable_dat(void)
+{
+	psw_t psw;
+
+	psw.mask = __extract_psw();
+	psw_bits(psw).dat = 1;
+	psw_bits(psw).as = PSW_BITS_AS_HOME;
+	__load_psw_mask(psw.mask);
+}
+
+static void __init kasan_early_detect_facilities(void)
+{
+	if (test_facility(8)) {
+		has_edat = true;
+		__ctl_set_bit(0, 23);
+	}
+	if (!noexec_disabled && test_facility(130)) {
+		has_nx = true;
+		__ctl_set_bit(0, 20);
+	}
+}
+
+static bool __init has_uv_sec_stor_limit(void)
+{
+	/*
+	 * keep these conditions in line with setup_uv()
+	 */
+	if (!is_prot_virt_host())
+		return false;
+
+	if (is_prot_virt_guest())
+		return false;
+
+	if (!test_facility(158))
+		return false;
+
+	return !!uv_info.max_sec_stor_addr;
+}
+
+void __init kasan_early_init(void)
+{
+	unsigned long untracked_mem_end;
+	unsigned long shadow_alloc_size;
+	unsigned long vmax_unlimited;
+	unsigned long initrd_end;
+	unsigned long asce_type;
+	unsigned long memsize;
+	unsigned long pgt_prot = pgprot_val(PAGE_KERNEL_RO);
+	pte_t pte_z;
+	pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
+	pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
+	p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
+
+	kasan_early_detect_facilities();
+	if (!has_nx)
+		pgt_prot &= ~_PAGE_NOEXEC;
+	pte_z = __pte(__pa(kasan_early_shadow_page) | pgt_prot);
+
+	memsize = get_mem_detect_end();
+	if (!memsize)
+		kasan_early_panic("cannot detect physical memory size\n");
+	/* respect mem= cmdline parameter */
+	if (memory_end_set && memsize > memory_end)
+		memsize = memory_end;
+	if (IS_ENABLED(CONFIG_CRASH_DUMP) && OLDMEM_BASE)
+		memsize = min(memsize, OLDMEM_SIZE);
+	memsize = min(memsize, KASAN_SHADOW_START);
+
+	if (IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING)) {
+		/* 4 level paging */
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, P4D_SIZE));
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, P4D_SIZE));
+		crst_table_init((unsigned long *)early_pg_dir,
+				_REGION2_ENTRY_EMPTY);
+		untracked_mem_end = kasan_vmax = vmax_unlimited = _REGION1_SIZE;
+		if (has_uv_sec_stor_limit())
+			kasan_vmax = min(vmax_unlimited, uv_info.max_sec_stor_addr);
+		asce_type = _ASCE_TYPE_REGION2;
+	} else {
+		/* 3 level paging */
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PUD_SIZE));
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PUD_SIZE));
+		crst_table_init((unsigned long *)early_pg_dir,
+				_REGION3_ENTRY_EMPTY);
+		untracked_mem_end = kasan_vmax = vmax_unlimited = _REGION2_SIZE;
+		asce_type = _ASCE_TYPE_REGION3;
+	}
+
+	/* init kasan zero shadow */
+	crst_table_init((unsigned long *)kasan_early_shadow_p4d,
+				p4d_val(p4d_z));
+	crst_table_init((unsigned long *)kasan_early_shadow_pud,
+				pud_val(pud_z));
+	crst_table_init((unsigned long *)kasan_early_shadow_pmd,
+				pmd_val(pmd_z));
+	memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);
+
+	shadow_alloc_size = memsize >> KASAN_SHADOW_SCALE_SHIFT;
+	pgalloc_low = round_up((unsigned long)_end, _SEGMENT_SIZE);
+	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD)) {
+		initrd_end =
+		    round_up(INITRD_START + INITRD_SIZE, _SEGMENT_SIZE);
+		pgalloc_low = max(pgalloc_low, initrd_end);
+	}
+
+	if (pgalloc_low + shadow_alloc_size > memsize)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	if (has_edat) {
+		segment_pos = round_down(memsize, _SEGMENT_SIZE);
+		segment_low = segment_pos - shadow_alloc_size;
+		pgalloc_pos = segment_low;
+	} else {
+		pgalloc_pos = memsize;
+	}
+	init_mm.pgd = early_pg_dir;
+	/*
+	 * Current memory layout:
+	 * +- 0 -------------+	   +- shadow start -+
+	 * | 1:1 ram mapping |	  /| 1/8 ram	    |
+	 * |		     |	 / |		    |
+	 * +- end of ram ----+	/  +----------------+
+	 * | ... gap ...     | /   |		    |
+	 * |		     |/    |	kasan	    |
+	 * +- shadow start --+	   |	zero	    |
+	 * | 1/8 addr space  |	   |	page	    |
+	 * +- shadow end    -+	   |	mapping	    |
+	 * | ... gap ...     |\    |  (untracked)   |
+	 * +- vmalloc area  -+ \   |		    |
+	 * | vmalloc_size    |	\  |		    |
+	 * +- modules vaddr -+	 \ +----------------+
+	 * | 2Gb	     |	  \|	  unmapped  | allocated per module
+	 * +-----------------+	   +- shadow end ---+
+	 *
+	 * Current memory layout (KASAN_VMALLOC):
+	 * +- 0 -------------+	   +- shadow start -+
+	 * | 1:1 ram mapping |	  /| 1/8 ram	    |
+	 * |		     |	 / |		    |
+	 * +- end of ram ----+	/  +----------------+
+	 * | ... gap ...     | /   |	kasan	    |
+	 * |		     |/    |	zero	    |
+	 * +- shadow start --+	   |	page	    |
+	 * | 1/8 addr space  |	   |	mapping     |
+	 * +- shadow end    -+	   |  (untracked)   |
+	 * | ... gap ...     |\    |		    |
+	 * +- vmalloc area  -+ \   +- vmalloc area -+
+	 * | vmalloc_size    |	\  |shallow populate|
+	 * +- modules vaddr -+	 \ +- modules area -+
+	 * | 2Gb	     |	  \|shallow populate|
+	 * +-----------------+	   +- shadow end ---+
+	 */
+	/* populate kasan shadow (for identity mapping and zero page mapping) */
+	kasan_early_vmemmap_populate(__sha(0), __sha(memsize), POPULATE_MAP);
+	if (IS_ENABLED(CONFIG_MODULES))
+		untracked_mem_end = kasan_vmax - MODULES_LEN;
+	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
+		untracked_mem_end = kasan_vmax - vmalloc_size - MODULES_LEN;
+		/* shallowly populate kasan shadow for vmalloc and modules */
+		kasan_early_vmemmap_populate(__sha(untracked_mem_end),
+					     __sha(kasan_vmax), POPULATE_SHALLOW);
+	}
+	/* populate kasan shadow for untracked memory */
+	kasan_early_vmemmap_populate(__sha(max_physmem_end),
+				     __sha(untracked_mem_end),
+				     POPULATE_ZERO_SHADOW);
+	kasan_early_vmemmap_populate(__sha(kasan_vmax),
+				     __sha(vmax_unlimited),
+				     POPULATE_ZERO_SHADOW);
+	/* memory allocated for identity mapping structs will be freed later */
+	pgalloc_freeable = pgalloc_pos;
+	/* populate identity mapping */
+	kasan_early_vmemmap_populate(0, memsize, POPULATE_ONE2ONE);
+	kasan_set_pgd(early_pg_dir, asce_type);
+	kasan_enable_dat();
+	/* enable kasan */
+	init_task.kasan_depth = 0;
+	memblock_reserve(pgalloc_pos, memsize - pgalloc_pos);
+	sclp_early_printk("KernelAddressSanitizer initialized\n");
+}
+
+void __init kasan_copy_shadow(pgd_t *pg_dir)
+{
+	/*
+	 * At this point we are still running on early pages setup early_pg_dir,
+	 * while swapper_pg_dir has just been initialized with identity mapping.
+	 * Carry over shadow memory region from early_pg_dir to swapper_pg_dir.
+	 */
+
+	pgd_t *pg_dir_src;
+	pgd_t *pg_dir_dst;
+	p4d_t *p4_dir_src;
+	p4d_t *p4_dir_dst;
+	pud_t *pu_dir_src;
+	pud_t *pu_dir_dst;
+
+	pg_dir_src = pgd_offset_raw(early_pg_dir, KASAN_SHADOW_START);
+	pg_dir_dst = pgd_offset_raw(pg_dir, KASAN_SHADOW_START);
+	p4_dir_src = p4d_offset(pg_dir_src, KASAN_SHADOW_START);
+	p4_dir_dst = p4d_offset(pg_dir_dst, KASAN_SHADOW_START);
+	if (!p4d_folded(*p4_dir_src)) {
+		/* 4 level paging */
+		memcpy(p4_dir_dst, p4_dir_src,
+		       (KASAN_SHADOW_SIZE >> P4D_SHIFT) * sizeof(p4d_t));
+		return;
+	}
+	/* 3 level paging */
+	pu_dir_src = pud_offset(p4_dir_src, KASAN_SHADOW_START);
+	pu_dir_dst = pud_offset(p4_dir_dst, KASAN_SHADOW_START);
+	memcpy(pu_dir_dst, pu_dir_src,
+	       (KASAN_SHADOW_SIZE >> PUD_SHIFT) * sizeof(pud_t));
+}
+
+void __init kasan_free_early_identity(void)
+{
+	memblock_free(pgalloc_pos, pgalloc_freeable - pgalloc_pos);
+}