Merge tag 'riscv-for-linus-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains a handful of new features:

   - Partial support for the Kendryte K210.

     There are still a few outstanding issues that I have patches for,
     but I don't actually have a board to test them so they're not
     included yet.

   - SBI v0.2 support.

   - Fixes to support for building with LLVM-based toolchains. The
     resulting images are known not to boot yet.

  I don't anticipate a part two, but I'll probably have something early
  in the RCs to finish up the K210 support"

* tag 'riscv-for-linus-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (38 commits)
  riscv: create a loader.bin boot image for Kendryte SoC
  riscv: Kendryte K210 default config
  riscv: Add Kendryte K210 device tree
  riscv: Select required drivers for Kendryte SOC
  riscv: Add Kendryte K210 SoC support
  riscv: Add SOC early init support
  riscv: Unaligned load/store handling for M_MODE
  RISC-V: Support cpu hotplug
  RISC-V: Add supported for ordered booting method using HSM
  RISC-V: Add SBI HSM extension definitions
  RISC-V: Export SBI error to linux error mapping function
  RISC-V: Add cpu_ops and modify default booting method
  RISC-V: Move relocate and few other functions out of __init
  RISC-V: Implement new SBI v0.2 extensions
  RISC-V: Introduce a new config for SBI v0.1
  RISC-V: Add SBI v0.2 extension definitions
  RISC-V: Add basic support for SBI v0.2
  RISC-V: Mark existing SBI as 0.1 SBI.
  riscv: Use macro definition instead of magic number
  riscv: Add support to dump the kernel page tables
  ...

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);