Merge tag 'riscv-for-linus-5.11-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "We have a handful of new kernel features for 5.11:

   - Support for the contiguous memory allocator.

   - Support for IRQ Time Accounting

   - Support for stack tracing

   - Support for strict /dev/mem

   - Support for kernel section protection

  I'm being a bit conservative on the cutoff for this round due to the
  timing, so this is all the new development I'm going to take for this
  cycle (even if some of it probably normally would have been OK). There
  are, however, some fixes on the list that I will likely be sending
  along either later this week or early next week.

  There is one issue in here: one of my test configurations
  (PREEMPT{,_DEBUG}=y) fails to boot on QEMU 5.0.0 (from April) as of
  the .text.init alignment patch.

  With any luck we'll sort out the issue, but given how many bugs get
  fixed all over the place and how unrelated those features seem my
  guess is that we're just running into something that's been lurking
  for a while and has already been fixed in the newer QEMU (though I
  wouldn't be surprised if it's one of these implicit assumptions we
  have in the boot flow). If it was hardware I'd be strongly inclined to
  look more closely, but given that users can upgrade their simulators
  I'm less worried about it"

* tag 'riscv-for-linus-5.11-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  arm64: Use the generic devmem_is_allowed()
  arm: Use the generic devmem_is_allowed()
  RISC-V: Use the new generic devmem_is_allowed()
  lib: Add a generic version of devmem_is_allowed()
  riscv: Fixed kernel test robot warning
  riscv: kernel: Drop unused clean rule
  riscv: provide memmove implementation
  RISC-V: Move dynamic relocation section under __init
  RISC-V: Protect all kernel sections including init early
  RISC-V: Align the .init.text section
  RISC-V: Initialize SBI early
  riscv: Enable ARCH_STACKWALK
  riscv: Make stack walk callback consistent with generic code
  riscv: Cleanup stacktrace
  riscv: Add HAVE_IRQ_TIME_ACCOUNTING
  riscv: Enable CMA support
  riscv: Ignore Image.* and loader.bin
  riscv: Clean up boot dir
  riscv: Fix compressed Image formats build
  RISC-V: Add kernel image sections to the resource tree

32 files changed, 402 insertions, 177 deletions

diff --git a/Documentation/features/time/irq-time-acct/arch-support.txt b/Documentation/features/time/irq-time-acct/arch-support.txt
index d9082b91f10e..6fc03deb1c38 100644
--- a/Documentation/features/time/irq-time-acct/arch-support.txt
+++ b/Documentation/features/time/irq-time-acct/arch-support.txt
@@ -23,7 +23,7 @@
     |    openrisc: | TODO |
     |      parisc: |  ..  |
     |     powerpc: |  ok  |
-    |       riscv: | TODO |
+    |       riscv: |  ok  |
     |        s390: |  ..  |
     |          sh: | TODO |
     |       sparc: |  ..  |
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ba937d85cb6c..b8ade91281bc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -5,7 +5,6 @@ config ARM
 	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
-	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
@@ -57,6 +56,7 @@ config ARM
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
+	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index ab2b654084fa..fc748122f1e0 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -441,7 +441,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
-extern int devmem_is_allowed(unsigned long pfn);
 #endif
 
 /*
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index b8d912ac9e61..a0f8a0ca0788 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -165,25 +165,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
 {
 	return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
 }
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain
- * address is valid. The argument is a physical page number.
- * We mimic x86 here by disallowing access to system RAM as well as
- * device-exclusive MMIO regions. This effectively disable read()/write()
- * on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
-	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
-		return 0;
-	if (!page_is_ram(pfn))
-		return 1;
-	return 0;
-}
-
-#endif
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9f0139ba8a1d..81463eb537bb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -13,7 +13,6 @@ config ARM64
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE
-	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
 	select ARCH_HAS_FAST_MULTIPLIER
@@ -113,6 +112,7 @@ config ARM64
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
+	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
 	select GENERIC_PTDUMP
 	select GENERIC_SCHED_CLOCK
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index fd172c41df90..5ea8656a2030 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -201,6 +201,4 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
 
-extern int devmem_is_allowed(unsigned long pfn);
-
 #endif	/* __ASM_IO_H */
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index 3028bacbc4e9..07937b49cb88 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -47,24 +47,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
 {
 	return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
 }
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain address
- * is valid. The argument is a physical page number.  We mimic x86 here by
- * disallowing access to system RAM as well as device-exclusive MMIO regions.
- * This effectively disable read()/write() on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
-	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
-		return 0;
-	if (!page_is_ram(pfn))
-		return 1;
-	return 0;
-}
-
-#endif
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 880c2b3b65d0..81b76d44725d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -15,6 +15,7 @@ config RISCV
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
+	select ARCH_STACKWALK
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
@@ -43,6 +44,7 @@ config RISCV
 	select GENERIC_IOREMAP
 	select GENERIC_IRQ_MULTI_HANDLER
 	select GENERIC_IRQ_SHOW
+	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
 	select GENERIC_PTDUMP if MMU
 	select GENERIC_SCHED_CLOCK
@@ -68,6 +70,7 @@ config RISCV
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_GCC_PLUGINS
 	select HAVE_GENERIC_VDSO if MMU && 64BIT
+	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_PCI
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 0289a97325d1..8c29e553ef7f 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -96,5 +96,11 @@ $(BOOT_TARGETS): vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 	@$(kecho) '  Kernel: $(boot)/$@ is ready'
 
+Image.%: Image
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
 zinstall install:
 	$(Q)$(MAKE) $(build)=$(boot) $@
+
+archclean:
+	$(Q)$(MAKE) $(clean)=$(boot)
diff --git a/arch/riscv/boot/.gitignore b/arch/riscv/boot/.gitignore
index 574c10f8ff68..90e66adb7de5 100644
--- a/arch/riscv/boot/.gitignore
+++ b/arch/riscv/boot/.gitignore
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 Image
-Image.gz
+Image.*
 loader
 loader.lds
+loader.bin
diff --git a/arch/riscv/boot/Makefile b/arch/riscv/boot/Makefile
index c59fca695f9d..03404c84f971 100644
--- a/arch/riscv/boot/Makefile
+++ b/arch/riscv/boot/Makefile
@@ -18,7 +18,7 @@ KCOV_INSTRUMENT := n
 
 OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
 
-targets := Image loader
+targets := Image Image.* loader loader.o loader.lds loader.bin
 
 $(obj)/Image: vmlinux FORCE
 	$(call if_changed,objcopy)
diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
index 3a9971b1210f..1595c5b60cfd 100644
--- a/arch/riscv/include/asm/sections.h
+++ b/arch/riscv/include/asm/sections.h
@@ -9,5 +9,7 @@
 
 extern char _start[];
 extern char _start_kernel[];
+extern char __init_data_begin[], __init_data_end[];
+extern char __init_text_begin[], __init_text_end[];
 
 #endif /* __ASM_SECTIONS_H */
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index d690b08dff2a..211eb8244a45 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -15,11 +15,15 @@ int set_memory_ro(unsigned long addr, int numpages);
 int set_memory_rw(unsigned long addr, int numpages);
 int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
+int set_memory_rw_nx(unsigned long addr, int numpages);
+void protect_kernel_text_data(void);
 #else
 static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
+static inline void protect_kernel_text_data(void) {};
+static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
 #endif
 
 int set_direct_map_invalid_noflush(struct page *page);
diff --git a/arch/riscv/include/asm/stacktrace.h b/arch/riscv/include/asm/stacktrace.h
new file mode 100644
index 000000000000..470a65c4ccdc
--- /dev/null
+++ b/arch/riscv/include/asm/stacktrace.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_RISCV_STACKTRACE_H
+#define _ASM_RISCV_STACKTRACE_H
+
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+
+struct stackframe {
+	unsigned long fp;
+	unsigned long ra;
+};
+
+extern void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
+				    bool (*fn)(void *, unsigned long), void *arg);
+
+#endif /* _ASM_RISCV_STACKTRACE_H */
diff --git a/arch/riscv/include/asm/string.h b/arch/riscv/include/asm/string.h
index 924af13f8555..5477e7ecb6e1 100644
--- a/arch/riscv/include/asm/string.h
+++ b/arch/riscv/include/asm/string.h
@@ -12,16 +12,16 @@
 #define __HAVE_ARCH_MEMSET
 extern asmlinkage void *memset(void *, int, size_t);
 extern asmlinkage void *__memset(void *, int, size_t);
-
 #define __HAVE_ARCH_MEMCPY
 extern asmlinkage void *memcpy(void *, const void *, size_t);
 extern asmlinkage void *__memcpy(void *, const void *, size_t);
-
+#define __HAVE_ARCH_MEMMOVE
+extern asmlinkage void *memmove(void *, const void *, size_t);
+extern asmlinkage void *__memmove(void *, const void *, size_t);
 /* For those files which don't want to check by kasan. */
 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
-
 #define memcpy(dst, src, len) __memcpy(dst, src, len)
 #define memset(s, c, n) __memset(s, c, n)
-
+#define memmove(dst, src, len) __memmove(dst, src, len)
 #endif
 #endif /* _ASM_RISCV_STRING_H */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index fa896c5f7ccb..f6caf4d9ca15 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -56,5 +56,3 @@ obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 
 obj-$(CONFIG_EFI)		+= efi.o
-
-clean:
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index db203442c08f..b79ffa3561fd 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -11,6 +11,8 @@
 #include <asm/thread_info.h>
 #include <asm/ptrace.h>
 
+void asm_offsets(void);
+
 void asm_offsets(void)
 {
 	OFFSET(TASK_THREAD_RA, task_struct, thread.ra);
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 7e849797c9c3..16e9941900c4 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -182,7 +182,6 @@ setup_trap_vector:
 
 END(_start)
 
-	__INIT
 ENTRY(_start_kernel)
 	/* Mask all interrupts */
 	csrw CSR_IE, zero
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index cf190197a22f..0bb1854dce83 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -4,11 +4,7 @@
 #include <linux/perf_event.h>
 #include <linux/uaccess.h>
 
-/* Kernel callchain */
-struct stackframe {
-	unsigned long fp;
-	unsigned long ra;
-};
+#include <asm/stacktrace.h>
 
 /*
  * Get the return address for a single stackframe and return a pointer to the
@@ -74,13 +70,11 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
 		fp = user_backtrace(entry, fp, 0);
 }
 
-bool fill_callchain(unsigned long pc, void *entry)
+static bool fill_callchain(void *entry, unsigned long pc)
 {
 	return perf_callchain_store(entry, pc);
 }
 
-void notrace walk_stackframe(struct task_struct *task,
-	struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg);
 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 			   struct pt_regs *regs)
 {
diff --git a/arch/riscv/kernel/riscv_ksyms.c b/arch/riscv/kernel/riscv_ksyms.c
index 450492e1cb4e..5ab1c7e1a6ed 100644
--- a/arch/riscv/kernel/riscv_ksyms.c
+++ b/arch/riscv/kernel/riscv_ksyms.c
@@ -11,5 +11,7 @@
  */
 EXPORT_SYMBOL(memset);
 EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memmove);
 EXPORT_SYMBOL(__memset);
 EXPORT_SYMBOL(__memcpy);
+EXPORT_SYMBOL(__memmove);
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 117f3212a8e4..1d85e9bf783c 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -4,6 +4,8 @@
  *  Chen Liqin <liqin.chen@sunplusct.com>
  *  Lennox Wu <lennox.wu@sunplusct.com>
  * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2020 FORTH-ICS/CARV
+ *  Nick Kossifidis <mick@ics.forth.gr>
  */
 
 #include <linux/init.h>
@@ -22,6 +24,7 @@
 #include <asm/cpu_ops.h>
 #include <asm/early_ioremap.h>
 #include <asm/setup.h>
+#include <asm/set_memory.h>
 #include <asm/sections.h>
 #include <asm/sbi.h>
 #include <asm/tlbflush.h>
@@ -51,6 +54,163 @@ atomic_t hart_lottery __section(".sdata");
 unsigned long boot_cpu_hartid;
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
+/*
+ * Place kernel memory regions on the resource tree so that
+ * kexec-tools can retrieve them from /proc/iomem. While there
+ * also add "System RAM" regions for compatibility with other
+ * archs, and the rest of the known regions for completeness.
+ */
+static struct resource code_res = { .name = "Kernel code", };
+static struct resource data_res = { .name = "Kernel data", };
+static struct resource rodata_res = { .name = "Kernel rodata", };
+static struct resource bss_res = { .name = "Kernel bss", };
+
+static int __init add_resource(struct resource *parent,
+				struct resource *res)
+{
+	int ret = 0;
+
+	ret = insert_resource(parent, res);
+	if (ret < 0) {
+		pr_err("Failed to add a %s resource at %llx\n",
+			res->name, (unsigned long long) res->start);
+		return ret;
+	}
+
+	return 1;
+}
+
+static int __init add_kernel_resources(struct resource *res)
+{
+	int ret = 0;
+
+	/*
+	 * The memory region of the kernel image is continuous and
+	 * was reserved on setup_bootmem, find it here and register
+	 * it as a resource, then register the various segments of
+	 * the image as child nodes
+	 */
+	if (!(res->start <= code_res.start && res->end >= data_res.end))
+		return 0;
+
+	res->name = "Kernel image";
+	res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	/*
+	 * We removed a part of this region on setup_bootmem so
+	 * we need to expand the resource for the bss to fit in.
+	 */
+	res->end = bss_res.end;
+
+	ret = add_resource(&iomem_resource, res);
+	if (ret < 0)
+		return ret;
+
+	ret = add_resource(res, &code_res);
+	if (ret < 0)
+		return ret;
+
+	ret = add_resource(res, &rodata_res);
+	if (ret < 0)
+		return ret;
+
+	ret = add_resource(res, &data_res);
+	if (ret < 0)
+		return ret;
+
+	ret = add_resource(res, &bss_res);
+
+	return ret;
+}
+
+static void __init init_resources(void)
+{
+	struct memblock_region *region = NULL;
+	struct resource *res = NULL;
+	int ret = 0;
+
+	code_res.start = __pa_symbol(_text);
+	code_res.end = __pa_symbol(_etext) - 1;
+	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	rodata_res.start = __pa_symbol(__start_rodata);
+	rodata_res.end = __pa_symbol(__end_rodata) - 1;
+	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	data_res.start = __pa_symbol(_data);
+	data_res.end = __pa_symbol(_edata) - 1;
+	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	bss_res.start = __pa_symbol(__bss_start);
+	bss_res.end = __pa_symbol(__bss_stop) - 1;
+	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	/*
+	 * Start by adding the reserved regions, if they overlap
+	 * with /memory regions, insert_resource later on will take
+	 * care of it.
+	 */
+	for_each_reserved_mem_region(region) {
+		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
+		if (!res)
+			panic("%s: Failed to allocate %zu bytes\n", __func__,
+			      sizeof(struct resource));
+
+		res->name = "Reserved";
+		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
+		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
+
+		ret = add_kernel_resources(res);
+		if (ret < 0)
+			goto error;
+		else if (ret)
+			continue;
+
+		/*
+		 * Ignore any other reserved regions within
+		 * system memory.
+		 */
+		if (memblock_is_memory(res->start))
+			continue;
+
+		ret = add_resource(&iomem_resource, res);
+		if (ret < 0)
+			goto error;
+	}
+
+	/* Add /memory regions to the resource tree */
+	for_each_mem_region(region) {
+		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
+		if (!res)
+			panic("%s: Failed to allocate %zu bytes\n", __func__,
+			      sizeof(struct resource));
+
+		if (unlikely(memblock_is_nomap(region))) {
+			res->name = "Reserved";
+			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+		} else {
+			res->name = "System RAM";
+			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+		}
+
+		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
+		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
+
+		ret = add_resource(&iomem_resource, res);
+		if (ret < 0)
+			goto error;
+	}
+
+	return;
+
+ error:
+	memblock_free((phys_addr_t) res, sizeof(struct resource));
+	/* Better an empty resource tree than an inconsistent one */
+	release_child_resources(&iomem_resource);
+}
+
+
 static void __init parse_dtb(void)
 {
 	/* Early scan of device tree from init memory */
@@ -81,6 +241,7 @@ void __init setup_arch(char **cmdline_p)
 	efi_init();
 	setup_bootmem();
 	paging_init();
+	init_resources();
 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
 	unflatten_and_copy_device_tree();
 #else
@@ -90,6 +251,11 @@ void __init setup_arch(char **cmdline_p)
 		pr_err("No DTB found in kernel mappings\n");
 #endif
 
+	if (IS_ENABLED(CONFIG_RISCV_SBI))
+		sbi_init();
+
+	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
+		protect_kernel_text_data();
 #ifdef CONFIG_SWIOTLB
 	swiotlb_init(1);
 #endif
@@ -98,10 +264,6 @@ void __init setup_arch(char **cmdline_p)
 	kasan_init();
 #endif
 
-#if IS_ENABLED(CONFIG_RISCV_SBI)
-	sbi_init();
-#endif
-
 #ifdef CONFIG_SMP
 	setup_smp();
 #endif
@@ -123,3 +285,12 @@ static int __init topology_init(void)
 	return 0;
 }
 subsys_initcall(topology_init);
+
+void free_initmem(void)
+{
+	unsigned long init_begin = (unsigned long)__init_begin;
+	unsigned long init_end = (unsigned long)__init_end;
+
+	set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
+	free_initmem_default(POISON_FREE_INITMEM);
+}
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 595342910c3f..48b870a685b3 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -12,17 +12,14 @@
 #include <linux/stacktrace.h>
 #include <linux/ftrace.h>
 
+#include <asm/stacktrace.h>
+
 register unsigned long sp_in_global __asm__("sp");
 
 #ifdef CONFIG_FRAME_POINTER
 
-struct stackframe {
-	unsigned long fp;
-	unsigned long ra;
-};
-
 void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
-			     bool (*fn)(unsigned long, void *), void *arg)
+			     bool (*fn)(void *, unsigned long), void *arg)
 {
 	unsigned long fp, sp, pc;
 
@@ -46,7 +43,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 		unsigned long low, high;
 		struct stackframe *frame;
 
-		if (unlikely(!__kernel_text_address(pc) || fn(pc, arg)))
+		if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc)))
 			break;
 
 		/* Validate frame pointer */
@@ -66,7 +63,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 #else /* !CONFIG_FRAME_POINTER */
 
 void notrace walk_stackframe(struct task_struct *task,
-	struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg)
+	struct pt_regs *regs, bool (*fn)(void *, unsigned long), void *arg)
 {
 	unsigned long sp, pc;
 	unsigned long *ksp;
@@ -88,7 +85,7 @@ void notrace walk_stackframe(struct task_struct *task,
 
 	ksp = (unsigned long *)sp;
 	while (!kstack_end(ksp)) {
-		if (__kernel_text_address(pc) && unlikely(fn(pc, arg)))
+		if (__kernel_text_address(pc) && unlikely(!fn(arg, pc)))
 			break;
 		pc = (*ksp++) - 0x4;
 	}
@@ -96,13 +93,12 @@ void notrace walk_stackframe(struct task_struct *task,
 
 #endif /* CONFIG_FRAME_POINTER */
 
-
-static bool print_trace_address(unsigned long pc, void *arg)
+static bool print_trace_address(void *arg, unsigned long pc)
 {
 	const char *loglvl = arg;
 
 	print_ip_sym(loglvl, pc);
-	return false;
+	return true;
 }
 
 void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
@@ -111,14 +107,14 @@ void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
 	walk_stackframe(task, NULL, print_trace_address, (void *)loglvl);
 }
 
-static bool save_wchan(unsigned long pc, void *arg)
+static bool save_wchan(void *arg, unsigned long pc)
 {
 	if (!in_sched_functions(pc)) {
 		unsigned long *p = arg;
 		*p = pc;
-		return true;
+		return false;
 	}
-	return false;
+	return true;
 }
 
 unsigned long get_wchan(struct task_struct *task)
@@ -130,42 +126,12 @@ unsigned long get_wchan(struct task_struct *task)
 	return pc;
 }
 
-
 #ifdef CONFIG_STACKTRACE
 
-static bool __save_trace(unsigned long pc, void *arg, bool nosched)
-{
-	struct stack_trace *trace = arg;
-
-	if (unlikely(nosched && in_sched_functions(pc)))
-		return false;
-	if (unlikely(trace->skip > 0)) {
-		trace->skip--;
-		return false;
-	}
-
-	trace->entries[trace->nr_entries++] = pc;
-	return (trace->nr_entries >= trace->max_entries);
-}
-
-static bool save_trace(unsigned long pc, void *arg)
-{
-	return __save_trace(pc, arg, false);
-}
-
-/*
- * Save stack-backtrace addresses into a stack_trace buffer.
- */
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
-{
-	walk_stackframe(tsk, NULL, save_trace, trace);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
-
-void save_stack_trace(struct stack_trace *trace)
+void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
+		     struct task_struct *task, struct pt_regs *regs)
 {
-	save_stack_trace_tsk(NULL, trace);
+	walk_stackframe(task, regs, consume_entry, cookie);
 }
-EXPORT_SYMBOL_GPL(save_stack_trace);
 
 #endif /* CONFIG_STACKTRACE */
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index 3ffbd6cbdb86..de03cb22d0e9 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -29,8 +29,30 @@ SECTIONS
 	HEAD_TEXT_SECTION
 	. = ALIGN(PAGE_SIZE);
 
+	.text : {
+		_text = .;
+		_stext = .;
+		TEXT_TEXT
+		SCHED_TEXT
+		CPUIDLE_TEXT
+		LOCK_TEXT
+		KPROBES_TEXT
+		ENTRY_TEXT
+		IRQENTRY_TEXT
+		SOFTIRQENTRY_TEXT
+		*(.fixup)
+		_etext = .;
+	}
+
+	. = ALIGN(SECTION_ALIGN);
 	__init_begin = .;
-	INIT_TEXT_SECTION(PAGE_SIZE)
+	__init_text_begin = .;
+	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) ALIGN(SECTION_ALIGN) { \
+		_sinittext = .;						\
+		INIT_TEXT						\
+		_einittext = .;						\
+	}
+
 	. = ALIGN(8);
 	__soc_early_init_table : {
 		__soc_early_init_table_start = .;
@@ -47,35 +69,28 @@ SECTIONS
 	{
 		EXIT_TEXT
 	}
+
+	__init_text_end = .;
+	. = ALIGN(SECTION_ALIGN);
+#ifdef CONFIG_EFI
+	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
+	__pecoff_text_end = .;
+#endif
+	/* Start of init data section */
+	__init_data_begin = .;
+	INIT_DATA_SECTION(16)
 	.exit.data :
 	{
 		EXIT_DATA
 	}
 	PERCPU_SECTION(L1_CACHE_BYTES)
-	__init_end = .;
 
-	. = ALIGN(SECTION_ALIGN);
-	.text : {
-		_text = .;
-		_stext = .;
-		TEXT_TEXT
-		SCHED_TEXT
-		CPUIDLE_TEXT
-		LOCK_TEXT
-		KPROBES_TEXT
-		ENTRY_TEXT
-		IRQENTRY_TEXT
-		SOFTIRQENTRY_TEXT
-		*(.fixup)
-		_etext = .;
+	.rel.dyn : {
+		*(.rel.dyn*)
 	}
 
-#ifdef CONFIG_EFI
-	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
-	__pecoff_text_end = .;
-#endif
-
-	INIT_DATA_SECTION(16)
+	__init_data_end = .;
+	__init_end = .;
 
 	/* Start of data section */
 	_sdata = .;
@@ -105,10 +120,6 @@ SECTIONS
 
 	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
 
-	.rel.dyn : {
-		*(.rel.dyn*)
-	}
-
 #ifdef CONFIG_EFI
 	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
 	__pecoff_data_virt_size = ABSOLUTE(. - __pecoff_text_end);
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 47e7a8204460..ac6171e9c19e 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -2,5 +2,6 @@
 lib-y			+= delay.o
 lib-y			+= memcpy.o
 lib-y			+= memset.o
+lib-y			+= memmove.o
 lib-$(CONFIG_MMU)	+= uaccess.o
 lib-$(CONFIG_64BIT)	+= tishift.o
diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
new file mode 100644
index 000000000000..07d1d2152ba5
--- /dev/null
+++ b/arch/riscv/lib/memmove.S
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+
+ENTRY(__memmove)
+WEAK(memmove)
+        move    t0, a0
+        move    t1, a1
+
+        beq     a0, a1, exit_memcpy
+        beqz    a2, exit_memcpy
+        srli    t2, a2, 0x2
+
+        slt     t3, a0, a1
+        beqz    t3, do_reverse
+
+        andi    a2, a2, 0x3
+        li      t4, 1
+        beqz    t2, byte_copy
+
+word_copy:
+        lw      t3, 0(a1)
+        addi    t2, t2, -1
+        addi    a1, a1, 4
+        sw      t3, 0(a0)
+        addi    a0, a0, 4
+        bnez    t2, word_copy
+        beqz    a2, exit_memcpy
+        j       byte_copy
+
+do_reverse:
+        add     a0, a0, a2
+        add     a1, a1, a2
+        andi    a2, a2, 0x3
+        li      t4, -1
+        beqz    t2, reverse_byte_copy
+
+reverse_word_copy:
+        addi    a1, a1, -4
+        addi    t2, t2, -1
+        lw      t3, 0(a1)
+        addi    a0, a0, -4
+        sw      t3, 0(a0)
+        bnez    t2, reverse_word_copy
+        beqz    a2, exit_memcpy
+
+reverse_byte_copy:
+        addi    a0, a0, -1
+        addi    a1, a1, -1
+
+byte_copy:
+        lb      t3, 0(a1)
+        addi    a2, a2, -1
+        sb      t3, 0(a0)
+        add     a1, a1, t4
+        add     a0, a0, t4
+        bnez    a2, byte_copy
+
+exit_memcpy:
+        move a0, t0
+        move a1, t1
+        ret
+END(__memmove)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 8e577f14f120..13ba533f462b 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -13,6 +13,7 @@
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
 #include <linux/set_memory.h>
+#include <linux/dma-map-ops.h>
 
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
@@ -41,13 +42,14 @@ struct pt_alloc_ops {
 #endif
 };
 
+static phys_addr_t dma32_phys_limit __ro_after_init;
+
 static void __init zone_sizes_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
 
 #ifdef CONFIG_ZONE_DMA32
-	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
-			(unsigned long) PFN_PHYS(max_low_pfn)));
+	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 
@@ -181,6 +183,7 @@ void __init setup_bootmem(void)
 
 	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
 	max_low_pfn = max_pfn;
+	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
 	set_max_mapnr(max_low_pfn);
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -194,6 +197,7 @@ void __init setup_bootmem(void)
 	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
 
 	early_init_fdt_scan_reserved_mem();
+	dma_contiguous_reserve(dma32_phys_limit);
 	memblock_allow_resize();
 	memblock_dump_all();
 }
@@ -618,48 +622,33 @@ static inline void setup_vm_final(void)
 #endif /* CONFIG_MMU */
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
-void mark_rodata_ro(void)
+void protect_kernel_text_data(void)
 {
-	unsigned long text_start = (unsigned long)_text;
-	unsigned long text_end = (unsigned long)_etext;
+	unsigned long text_start = (unsigned long)_start;
+	unsigned long init_text_start = (unsigned long)__init_text_begin;
+	unsigned long init_data_start = (unsigned long)__init_data_begin;
 	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_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT);
+	set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT);
+	set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT);
+	/* rodata section is marked readonly in mark_rodata_ro */
 	set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
 	set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
-
-	debug_checkwx();
 }
-#endif
 
-static void __init resource_init(void)
+void mark_rodata_ro(void)
 {
-	struct memblock_region *region;
-
-	for_each_mem_region(region) {
-		struct resource *res;
-
-		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
-		if (!res)
-			panic("%s: Failed to allocate %zu bytes\n", __func__,
-			      sizeof(struct resource));
+	unsigned long rodata_start = (unsigned long)__start_rodata;
+	unsigned long data_start = (unsigned long)_data;
 
-		if (memblock_is_nomap(region)) {
-			res->name = "reserved";
-			res->flags = IORESOURCE_MEM;
-		} else {
-			res->name = "System RAM";
-			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
-		}
-		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
-		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
+	set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
 
-		request_resource(&iomem_resource, res);
-	}
+	debug_checkwx();
 }
+#endif
 
 void __init paging_init(void)
 {
@@ -667,7 +656,6 @@ void __init paging_init(void)
 	sparse_init();
 	setup_zero_page();
 	zone_sizes_init();
-	resource_init();
 }
 
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 87ba5a68bbb8..5e49e4b4a4cc 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -128,6 +128,12 @@ static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
 	return ret;
 }
 
+int set_memory_rw_nx(unsigned long addr, int numpages)
+{
+	return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
+			    __pgprot(_PAGE_EXEC));
+}
+
 int set_memory_ro(unsigned long addr, int numpages)
 {
 	return __set_memory(addr, numpages, __pgprot(_PAGE_READ),
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 9ea83d80eb6f..c6af40ce03be 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1137,6 +1137,10 @@ static inline void memcpy_toio(volatile void __iomem *addr, const void *buffer,
 }
 #endif
 
+#ifndef CONFIG_GENERIC_DEVMEM_IS_ALLOWED
+extern int devmem_is_allowed(unsigned long pfn);
+#endif
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASM_GENERIC_IO_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index b46a9fd122c8..46806332a8cc 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -686,6 +686,9 @@ config GENERIC_LIB_CMPDI2
 config GENERIC_LIB_UCMPDI2
 	bool
 
+config GENERIC_LIB_DEVMEM_IS_ALLOWED
+	bool
+
 config PLDMFW
 	bool
 	default n
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7d7097c5dc58..e6e58b26e888 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1676,7 +1676,7 @@ config ARCH_HAS_DEVMEM_IS_ALLOWED
 config STRICT_DEVMEM
 	bool "Filter access to /dev/mem"
 	depends on MMU && DEVMEM
-	depends on ARCH_HAS_DEVMEM_IS_ALLOWED
+	depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
 	default y if PPC || X86 || ARM64
 	help
 	  If this option is disabled, you allow userspace (root) access to all
diff --git a/lib/Makefile b/lib/Makefile
index 8598e8796edf..afeff05fa8c5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -354,3 +354,5 @@ obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
 obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
 obj-$(CONFIG_BITS_TEST) += test_bits.o
 obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o
+
+obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c
new file mode 100644
index 000000000000..c0d67c541849
--- /dev/null
+++ b/lib/devmem_is_allowed.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * A generic version of devmem_is_allowed.
+ *
+ * Based on arch/arm64/mm/mmap.c
+ *
+ * Copyright (C) 2020 Google, Inc.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/mm.h>
+#include <linux/ioport.h>
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.  We mimic x86 here by
+ * disallowing access to system RAM as well as device-exclusive MMIO regions.
+ * This effectively disable read()/write() on /dev/mem.
+ */
+int devmem_is_allowed(unsigned long pfn)
+{
+	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
+		return 0;
+	if (!page_is_ram(pfn))
+		return 1;
+	return 0;
+}