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-rw-r--r--arch/riscv/mm/Makefile3
-rw-r--r--arch/riscv/mm/hugetlbpage.c6
-rw-r--r--arch/riscv/mm/init.c44
-rw-r--r--arch/riscv/mm/pageattr.c187
-rw-r--r--arch/riscv/mm/ptdump.c317
5 files changed, 552 insertions, 5 deletions
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index 50b7af58c566..363ef01c30b1 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -7,7 +7,7 @@ endif
obj-y += init.o
obj-y += extable.o
-obj-$(CONFIG_MMU) += fault.o
+obj-$(CONFIG_MMU) += fault.o pageattr.o
obj-y += cacheflush.o
obj-y += context.o
@@ -15,6 +15,7 @@ ifeq ($(CONFIG_MMU),y)
obj-$(CONFIG_SMP) += tlbflush.o
endif
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
obj-$(CONFIG_KASAN) += kasan_init.o
ifdef CONFIG_KASAN
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 0d4747e9d5b5..a6189ed36c5f 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -4,14 +4,12 @@
int pud_huge(pud_t pud)
{
- return pud_present(pud) &&
- (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+ return pud_leaf(pud);
}
int pmd_huge(pmd_t pmd)
{
- return pmd_present(pmd) &&
- (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+ return pmd_leaf(pmd);
}
static __init int setup_hugepagesz(char *opt)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index fab855963c73..b55be44ff9bd 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -12,6 +12,7 @@
#include <linux/sizes.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
+#include <linux/set_memory.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
@@ -477,6 +478,17 @@ static void __init setup_vm_final(void)
csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
local_flush_tlb_all();
}
+
+void free_initmem(void)
+{
+ unsigned long init_begin = (unsigned long)__init_begin;
+ unsigned long init_end = (unsigned long)__init_end;
+
+ /* Make the region as non-execuatble. */
+ set_memory_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
+ free_initmem_default(POISON_FREE_INITMEM);
+}
+
#else
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
@@ -488,6 +500,38 @@ static inline void setup_vm_final(void)
}
#endif /* CONFIG_MMU */
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void set_kernel_text_rw(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+
+ set_memory_rw(text_start, (text_end - text_start) >> PAGE_SHIFT);
+}
+
+void set_kernel_text_ro(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+
+ set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
+}
+
+void mark_rodata_ro(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+ unsigned long rodata_start = (unsigned long)__start_rodata;
+ unsigned long data_start = (unsigned long)_data;
+ unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
+
+ set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
+ set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
+ set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
+ set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
+}
+#endif
+
void __init paging_init(void)
{
setup_vm_final();
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
new file mode 100644
index 000000000000..728759eb530a
--- /dev/null
+++ b/arch/riscv/mm/pageattr.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 SiFive
+ */
+
+#include <linux/pagewalk.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/bitops.h>
+
+struct pageattr_masks {
+ pgprot_t set_mask;
+ pgprot_t clear_mask;
+};
+
+static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
+{
+ struct pageattr_masks *masks = walk->private;
+ unsigned long new_val = val;
+
+ new_val &= ~(pgprot_val(masks->clear_mask));
+ new_val |= (pgprot_val(masks->set_mask));
+
+ return new_val;
+}
+
+static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pgd_t val = READ_ONCE(*pgd);
+
+ if (pgd_leaf(val)) {
+ val = __pgd(set_pageattr_masks(pgd_val(val), walk));
+ set_pgd(pgd, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ p4d_t val = READ_ONCE(*p4d);
+
+ if (p4d_leaf(val)) {
+ val = __p4d(set_pageattr_masks(p4d_val(val), walk));
+ set_p4d(p4d, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pud_t val = READ_ONCE(*pud);
+
+ if (pud_leaf(val)) {
+ val = __pud(set_pageattr_masks(pud_val(val), walk));
+ set_pud(pud, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pmd_t val = READ_ONCE(*pmd);
+
+ if (pmd_leaf(val)) {
+ val = __pmd(set_pageattr_masks(pmd_val(val), walk));
+ set_pmd(pmd, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pte_t val = READ_ONCE(*pte);
+
+ val = __pte(set_pageattr_masks(pte_val(val), walk));
+ set_pte(pte, val);
+
+ return 0;
+}
+
+static int pageattr_pte_hole(unsigned long addr, unsigned long next,
+ int depth, struct mm_walk *walk)
+{
+ /* Nothing to do here */
+ return 0;
+}
+
+const static struct mm_walk_ops pageattr_ops = {
+ .pgd_entry = pageattr_pgd_entry,
+ .p4d_entry = pageattr_p4d_entry,
+ .pud_entry = pageattr_pud_entry,
+ .pmd_entry = pageattr_pmd_entry,
+ .pte_entry = pageattr_pte_entry,
+ .pte_hole = pageattr_pte_hole,
+};
+
+static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
+ pgprot_t clear_mask)
+{
+ int ret;
+ unsigned long start = addr;
+ unsigned long end = start + PAGE_SIZE * numpages;
+ struct pageattr_masks masks = {
+ .set_mask = set_mask,
+ .clear_mask = clear_mask
+ };
+
+ if (!numpages)
+ return 0;
+
+ down_read(&init_mm.mmap_sem);
+ ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
+ &masks);
+ up_read(&init_mm.mmap_sem);
+
+ flush_tlb_kernel_range(start, end);
+
+ return ret;
+}
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+ return __set_memory(addr, numpages, __pgprot(_PAGE_READ),
+ __pgprot(_PAGE_WRITE));
+}
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+ return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
+ __pgprot(0));
+}
+
+int set_memory_x(unsigned long addr, int numpages)
+{
+ return __set_memory(addr, numpages, __pgprot(_PAGE_EXEC), __pgprot(0));
+}
+
+int set_memory_nx(unsigned long addr, int numpages)
+{
+ return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
+}
+
+int set_direct_map_invalid_noflush(struct page *page)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ unsigned long end = start + PAGE_SIZE;
+ struct pageattr_masks masks = {
+ .set_mask = __pgprot(0),
+ .clear_mask = __pgprot(_PAGE_PRESENT)
+ };
+
+ return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
+}
+
+int set_direct_map_default_noflush(struct page *page)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ unsigned long end = start + PAGE_SIZE;
+ struct pageattr_masks masks = {
+ .set_mask = PAGE_KERNEL,
+ .clear_mask = __pgprot(0)
+ };
+
+ return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
+}
+
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+ if (!debug_pagealloc_enabled())
+ return;
+
+ if (enable)
+ __set_memory((unsigned long)page_address(page), numpages,
+ __pgprot(_PAGE_PRESENT), __pgprot(0));
+ else
+ __set_memory((unsigned long)page_address(page), numpages,
+ __pgprot(0), __pgprot(_PAGE_PRESENT));
+}
diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
new file mode 100644
index 000000000000..7eab76a93106
--- /dev/null
+++ b/arch/riscv/mm/ptdump.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 SiFive
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/ptdump.h>
+
+#include <asm/ptdump.h>
+#include <asm/pgtable.h>
+#include <asm/kasan.h>
+
+#define pt_dump_seq_printf(m, fmt, args...) \
+({ \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+})
+
+#define pt_dump_seq_puts(m, fmt) \
+({ \
+ if (m) \
+ seq_printf(m, fmt); \
+})
+
+/*
+ * The page dumper groups page table entries of the same type into a single
+ * description. It uses pg_state to track the range information while
+ * iterating over the pte entries. When the continuity is broken it then
+ * dumps out a description of the range.
+ */
+struct pg_state {
+ struct ptdump_state ptdump;
+ struct seq_file *seq;
+ const struct addr_marker *marker;
+ unsigned long start_address;
+ unsigned long start_pa;
+ unsigned long last_pa;
+ int level;
+ u64 current_prot;
+ bool check_wx;
+ unsigned long wx_pages;
+};
+
+/* Address marker */
+struct addr_marker {
+ unsigned long start_address;
+ const char *name;
+};
+
+static struct addr_marker address_markers[] = {
+#ifdef CONFIG_KASAN
+ {KASAN_SHADOW_START, "Kasan shadow start"},
+ {KASAN_SHADOW_END, "Kasan shadow end"},
+#endif
+ {FIXADDR_START, "Fixmap start"},
+ {FIXADDR_TOP, "Fixmap end"},
+ {PCI_IO_START, "PCI I/O start"},
+ {PCI_IO_END, "PCI I/O end"},
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+ {VMEMMAP_START, "vmemmap start"},
+ {VMEMMAP_END, "vmemmap end"},
+#endif
+ {VMALLOC_START, "vmalloc() area"},
+ {VMALLOC_END, "vmalloc() end"},
+ {PAGE_OFFSET, "Linear mapping"},
+ {-1, NULL},
+};
+
+/* Page Table Entry */
+struct prot_bits {
+ u64 mask;
+ u64 val;
+ const char *set;
+ const char *clear;
+};
+
+static const struct prot_bits pte_bits[] = {
+ {
+ .mask = _PAGE_SOFT,
+ .val = _PAGE_SOFT,
+ .set = "RSW",
+ .clear = " ",
+ }, {
+ .mask = _PAGE_DIRTY,
+ .val = _PAGE_DIRTY,
+ .set = "D",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_ACCESSED,
+ .val = _PAGE_ACCESSED,
+ .set = "A",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_GLOBAL,
+ .val = _PAGE_GLOBAL,
+ .set = "G",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_USER,
+ .val = _PAGE_USER,
+ .set = "U",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_EXEC,
+ .val = _PAGE_EXEC,
+ .set = "X",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_WRITE,
+ .val = _PAGE_WRITE,
+ .set = "W",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_READ,
+ .val = _PAGE_READ,
+ .set = "R",
+ .clear = ".",
+ }, {
+ .mask = _PAGE_PRESENT,
+ .val = _PAGE_PRESENT,
+ .set = "V",
+ .clear = ".",
+ }
+};
+
+/* Page Level */
+struct pg_level {
+ const char *name;
+ u64 mask;
+};
+
+static struct pg_level pg_level[] = {
+ { /* pgd */
+ .name = "PGD",
+ }, { /* p4d */
+ .name = (CONFIG_PGTABLE_LEVELS > 4) ? "P4D" : "PGD",
+ }, { /* pud */
+ .name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
+ }, { /* pmd */
+ .name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
+ }, { /* pte */
+ .name = "PTE",
+ },
+};
+
+static void dump_prot(struct pg_state *st)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(pte_bits); i++) {
+ const char *s;
+
+ if ((st->current_prot & pte_bits[i].mask) == pte_bits[i].val)
+ s = pte_bits[i].set;
+ else
+ s = pte_bits[i].clear;
+
+ if (s)
+ pt_dump_seq_printf(st->seq, " %s", s);
+ }
+}
+
+#ifdef CONFIG_64BIT
+#define ADDR_FORMAT "0x%016lx"
+#else
+#define ADDR_FORMAT "0x%08lx"
+#endif
+static void dump_addr(struct pg_state *st, unsigned long addr)
+{
+ static const char units[] = "KMGTPE";
+ const char *unit = units;
+ unsigned long delta;
+
+ pt_dump_seq_printf(st->seq, ADDR_FORMAT "-" ADDR_FORMAT " ",
+ st->start_address, addr);
+
+ pt_dump_seq_printf(st->seq, " " ADDR_FORMAT " ", st->start_pa);
+ delta = (addr - st->start_address) >> 10;
+
+ while (!(delta & 1023) && unit[1]) {
+ delta >>= 10;
+ unit++;
+ }
+
+ pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
+ pg_level[st->level].name);
+}
+
+static void note_prot_wx(struct pg_state *st, unsigned long addr)
+{
+ if (!st->check_wx)
+ return;
+
+ if ((st->current_prot & (_PAGE_WRITE | _PAGE_EXEC)) !=
+ (_PAGE_WRITE | _PAGE_EXEC))
+ return;
+
+ WARN_ONCE(1, "riscv/mm: Found insecure W+X mapping at address %p/%pS\n",
+ (void *)st->start_address, (void *)st->start_address);
+
+ st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
+}
+
+static void note_page(struct ptdump_state *pt_st, unsigned long addr,
+ int level, unsigned long val)
+{
+ struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
+ u64 pa = PFN_PHYS(pte_pfn(__pte(val)));
+ u64 prot = 0;
+
+ if (level >= 0)
+ prot = val & pg_level[level].mask;
+
+ if (st->level == -1) {
+ st->level = level;
+ st->current_prot = prot;
+ st->start_address = addr;
+ st->start_pa = pa;
+ st->last_pa = pa;
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ } else if (prot != st->current_prot ||
+ level != st->level || addr >= st->marker[1].start_address) {
+ if (st->current_prot) {
+ note_prot_wx(st, addr);
+ dump_addr(st, addr);
+ dump_prot(st);
+ pt_dump_seq_puts(st->seq, "\n");
+ }
+
+ while (addr >= st->marker[1].start_address) {
+ st->marker++;
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n",
+ st->marker->name);
+ }
+
+ st->start_address = addr;
+ st->start_pa = pa;
+ st->last_pa = pa;
+ st->current_prot = prot;
+ st->level = level;
+ } else {
+ st->last_pa = pa;
+ }
+}
+
+static void ptdump_walk(struct seq_file *s)
+{
+ struct pg_state st = {
+ .seq = s,
+ .marker = address_markers,
+ .level = -1,
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]) {
+ {KERN_VIRT_START, ULONG_MAX},
+ {0, 0}
+ }
+ }
+ };
+
+ ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
+}
+
+void ptdump_check_wx(void)
+{
+ struct pg_state st = {
+ .seq = NULL,
+ .marker = (struct addr_marker[]) {
+ {0, NULL},
+ {-1, NULL},
+ },
+ .level = -1,
+ .check_wx = true,
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]) {
+ {KERN_VIRT_START, ULONG_MAX},
+ {0, 0}
+ }
+ }
+ };
+
+ 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 W+X pages found\n");
+}
+
+static int ptdump_show(struct seq_file *m, void *v)
+{
+ ptdump_walk(m);
+
+ return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(ptdump);
+
+static int ptdump_init(void)
+{
+ unsigned int i, j;
+
+ for (i = 0; i < ARRAY_SIZE(pg_level); i++)
+ for (j = 0; j < ARRAY_SIZE(pte_bits); j++)
+ pg_level[i].mask |= pte_bits[j].mask;
+
+ debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
+ &ptdump_fops);
+
+ return 0;
+}
+
+device_initcall(ptdump_init);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 08:44:37 +0000