From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/s390/mm/dump_pagetables.c | 315 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 315 insertions(+) create mode 100644 arch/s390/mm/dump_pagetables.c (limited to 'arch/s390/mm/dump_pagetables.c') diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c new file mode 100644 index 000000000..ba5f80268 --- /dev/null +++ b/arch/s390/mm/dump_pagetables.c @@ -0,0 +1,315 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned long max_addr; + +struct addr_marker { + unsigned long start_address; + const char *name; +}; + +enum address_markers_idx { + IDENTITY_BEFORE_NR = 0, + IDENTITY_BEFORE_END_NR, + AMODE31_START_NR, + AMODE31_END_NR, + KERNEL_START_NR, + KERNEL_END_NR, +#ifdef CONFIG_KFENCE + KFENCE_START_NR, + KFENCE_END_NR, +#endif + IDENTITY_AFTER_NR, + IDENTITY_AFTER_END_NR, + VMEMMAP_NR, + VMEMMAP_END_NR, + VMALLOC_NR, + VMALLOC_END_NR, + MODULES_NR, + MODULES_END_NR, + ABS_LOWCORE_NR, + ABS_LOWCORE_END_NR, + MEMCPY_REAL_NR, + MEMCPY_REAL_END_NR, +#ifdef CONFIG_KASAN + KASAN_SHADOW_START_NR, + KASAN_SHADOW_END_NR, +#endif +}; + +static struct addr_marker address_markers[] = { + [IDENTITY_BEFORE_NR] = {0, "Identity Mapping Start"}, + [IDENTITY_BEFORE_END_NR] = {(unsigned long)_stext, "Identity Mapping End"}, + [AMODE31_START_NR] = {0, "Amode31 Area Start"}, + [AMODE31_END_NR] = {0, "Amode31 Area End"}, + [KERNEL_START_NR] = {(unsigned long)_stext, "Kernel Image Start"}, + [KERNEL_END_NR] = {(unsigned long)_end, "Kernel Image End"}, +#ifdef CONFIG_KFENCE + [KFENCE_START_NR] = {0, "KFence Pool Start"}, + [KFENCE_END_NR] = {0, "KFence Pool End"}, +#endif + [IDENTITY_AFTER_NR] = {(unsigned long)_end, "Identity Mapping Start"}, + [IDENTITY_AFTER_END_NR] = {0, "Identity Mapping End"}, + [VMEMMAP_NR] = {0, "vmemmap Area Start"}, + [VMEMMAP_END_NR] = {0, "vmemmap Area End"}, + [VMALLOC_NR] = {0, "vmalloc Area Start"}, + [VMALLOC_END_NR] = {0, "vmalloc Area End"}, + [MODULES_NR] = {0, "Modules Area Start"}, + [MODULES_END_NR] = {0, "Modules Area End"}, + [ABS_LOWCORE_NR] = {0, "Lowcore Area Start"}, + [ABS_LOWCORE_END_NR] = {0, "Lowcore Area End"}, + [MEMCPY_REAL_NR] = {0, "Real Memory Copy Area Start"}, + [MEMCPY_REAL_END_NR] = {0, "Real Memory Copy Area End"}, +#ifdef CONFIG_KASAN + [KASAN_SHADOW_START_NR] = {KASAN_SHADOW_START, "Kasan Shadow Start"}, + [KASAN_SHADOW_END_NR] = {KASAN_SHADOW_END, "Kasan Shadow End"}, +#endif + { -1, NULL } +}; + +struct pg_state { + struct ptdump_state ptdump; + struct seq_file *seq; + int level; + unsigned int current_prot; + bool check_wx; + unsigned long wx_pages; + unsigned long start_address; + const struct addr_marker *marker; +}; + +#define pt_dump_seq_printf(m, fmt, args...) \ +({ \ + struct seq_file *__m = (m); \ + \ + if (__m) \ + seq_printf(__m, fmt, ##args); \ +}) + +#define pt_dump_seq_puts(m, fmt) \ +({ \ + struct seq_file *__m = (m); \ + \ + if (__m) \ + seq_printf(__m, fmt); \ +}) + +static void print_prot(struct seq_file *m, unsigned int pr, int level) +{ + static const char * const level_name[] = + { "ASCE", "PGD", "PUD", "PMD", "PTE" }; + + pt_dump_seq_printf(m, "%s ", level_name[level]); + if (pr & _PAGE_INVALID) { + pt_dump_seq_printf(m, "I\n"); + return; + } + pt_dump_seq_puts(m, (pr & _PAGE_PROTECT) ? "RO " : "RW "); + pt_dump_seq_puts(m, (pr & _PAGE_NOEXEC) ? "NX\n" : "X\n"); +} + +static void note_prot_wx(struct pg_state *st, unsigned long addr) +{ +#ifdef CONFIG_DEBUG_WX + if (!st->check_wx) + return; + if (st->current_prot & _PAGE_INVALID) + return; + if (st->current_prot & _PAGE_PROTECT) + return; + if (st->current_prot & _PAGE_NOEXEC) + return; + /* + * The first lowcore page is W+X if spectre mitigations are using + * trampolines or the BEAR enhancements facility is not installed, + * in which case we have two lpswe instructions in lowcore that need + * to be executable. + */ + if (addr == PAGE_SIZE && (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear))) + return; + WARN_ONCE(1, "s390/mm: Found insecure W+X mapping at address %pS\n", + (void *)st->start_address); + st->wx_pages += (addr - st->start_address) / PAGE_SIZE; +#endif /* CONFIG_DEBUG_WX */ +} + +static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val) +{ + int width = sizeof(unsigned long) * 2; + static const char units[] = "KMGTPE"; + const char *unit = units; + unsigned long delta; + struct pg_state *st; + struct seq_file *m; + unsigned int prot; + + st = container_of(pt_st, struct pg_state, ptdump); + m = st->seq; + prot = val & (_PAGE_PROTECT | _PAGE_NOEXEC); + if (level == 4 && (val & _PAGE_INVALID)) + prot = _PAGE_INVALID; + /* For pmd_none() & friends val gets passed as zero. */ + if (level != 4 && !val) + prot = _PAGE_INVALID; + /* Final flush from generic code. */ + if (level == -1) + addr = max_addr; + if (st->level == -1) { + pt_dump_seq_printf(m, "---[ %s ]---\n", st->marker->name); + st->start_address = addr; + st->current_prot = prot; + st->level = level; + } else if (prot != st->current_prot || level != st->level || + addr >= st->marker[1].start_address) { + note_prot_wx(st, addr); + pt_dump_seq_printf(m, "0x%0*lx-0x%0*lx ", + width, st->start_address, + width, addr); + delta = (addr - st->start_address) >> 10; + while (!(delta & 0x3ff) && unit[1]) { + delta >>= 10; + unit++; + } + pt_dump_seq_printf(m, "%9lu%c ", delta, *unit); + print_prot(m, st->current_prot, st->level); + while (addr >= st->marker[1].start_address) { + st->marker++; + pt_dump_seq_printf(m, "---[ %s ]---\n", st->marker->name); + } + st->start_address = addr; + st->current_prot = prot; + st->level = level; + } +} + +#ifdef CONFIG_DEBUG_WX +void ptdump_check_wx(void) +{ + struct pg_state st = { + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {.start = 0, .end = max_addr}, + {.start = 0, .end = 0}, + } + }, + .seq = NULL, + .level = -1, + .current_prot = 0, + .check_wx = true, + .wx_pages = 0, + .start_address = 0, + .marker = (struct addr_marker[]) { + { .start_address = 0, .name = NULL}, + { .start_address = -1, .name = NULL}, + }, + }; + + if (!MACHINE_HAS_NX) + return; + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); + if (st.wx_pages) + pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n", st.wx_pages); + else + pr_info("Checked W+X mappings: passed, no %sW+X pages found\n", + (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) ? + "unexpected " : ""); +} +#endif /* CONFIG_DEBUG_WX */ + +#ifdef CONFIG_PTDUMP_DEBUGFS +static int ptdump_show(struct seq_file *m, void *v) +{ + struct pg_state st = { + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {.start = 0, .end = max_addr}, + {.start = 0, .end = 0}, + } + }, + .seq = m, + .level = -1, + .current_prot = 0, + .check_wx = false, + .wx_pages = 0, + .start_address = 0, + .marker = address_markers, + }; + + get_online_mems(); + mutex_lock(&cpa_mutex); + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); + mutex_unlock(&cpa_mutex); + put_online_mems(); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(ptdump); +#endif /* CONFIG_PTDUMP_DEBUGFS */ + +/* + * Heapsort from lib/sort.c is not a stable sorting algorithm, do a simple + * insertion sort to preserve the original order of markers with the same + * start address. + */ +static void sort_address_markers(void) +{ + struct addr_marker tmp; + int i, j; + + for (i = 1; i < ARRAY_SIZE(address_markers) - 1; i++) { + tmp = address_markers[i]; + for (j = i - 1; j >= 0 && address_markers[j].start_address > tmp.start_address; j--) + address_markers[j + 1] = address_markers[j]; + address_markers[j + 1] = tmp; + } +} + +static int pt_dump_init(void) +{ +#ifdef CONFIG_KFENCE + unsigned long kfence_start = (unsigned long)__kfence_pool; +#endif + /* + * Figure out the maximum virtual address being accessible with the + * kernel ASCE. We need this to keep the page table walker functions + * from accessing non-existent entries. + */ + max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2; + max_addr = 1UL << (max_addr * 11 + 31); + address_markers[IDENTITY_AFTER_END_NR].start_address = ident_map_size; + address_markers[AMODE31_START_NR].start_address = __samode31; + address_markers[AMODE31_END_NR].start_address = __eamode31; + address_markers[MODULES_NR].start_address = MODULES_VADDR; + address_markers[MODULES_END_NR].start_address = MODULES_END; + address_markers[ABS_LOWCORE_NR].start_address = __abs_lowcore; + address_markers[ABS_LOWCORE_END_NR].start_address = __abs_lowcore + ABS_LOWCORE_MAP_SIZE; + address_markers[MEMCPY_REAL_NR].start_address = __memcpy_real_area; + address_markers[MEMCPY_REAL_END_NR].start_address = __memcpy_real_area + PAGE_SIZE; + address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap; + address_markers[VMEMMAP_END_NR].start_address = (unsigned long)vmemmap + vmemmap_size; + address_markers[VMALLOC_NR].start_address = VMALLOC_START; + address_markers[VMALLOC_END_NR].start_address = VMALLOC_END; +#ifdef CONFIG_KFENCE + address_markers[KFENCE_START_NR].start_address = kfence_start; + address_markers[KFENCE_END_NR].start_address = kfence_start + KFENCE_POOL_SIZE; +#endif + sort_address_markers(); +#ifdef CONFIG_PTDUMP_DEBUGFS + debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops); +#endif /* CONFIG_PTDUMP_DEBUGFS */ + return 0; +} +device_initcall(pt_dump_init); -- cgit v1.2.3