15 files changed, 254 insertions, 16 deletions

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0f3cd7c3a436..4871220061c4 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -92,6 +92,7 @@ config RISCV
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_CPU_DEVICES
+	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_ENTRY
 	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
diff --git a/arch/riscv/include/asm/fence.h b/arch/riscv/include/asm/fence.h
index 6bcd80325dfc..182db7930edc 100644
--- a/arch/riscv/include/asm/fence.h
+++ b/arch/riscv/include/asm/fence.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 #ifndef _ASM_RISCV_FENCE_H
 #define _ASM_RISCV_FENCE_H
 
diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index 8e10a94430a2..8330d16b05b5 100644
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -12,6 +12,11 @@
 
 #include <asm-generic/irq.h>
 
+#ifdef CONFIG_SMP
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
+#endif
+
 void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
 
 struct fwnode_handle *riscv_get_intc_hwnode(void);
diff --git a/arch/riscv/include/asm/vmalloc.h b/arch/riscv/include/asm/vmalloc.h
index 51f6dfe19745..fefe94dc98e2 100644
--- a/arch/riscv/include/asm/vmalloc.h
+++ b/arch/riscv/include/asm/vmalloc.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 #ifndef _ASM_RISCV_VMALLOC_H
 #define _ASM_RISCV_VMALLOC_H
 
diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
index 11c0d2e0becf..3c37661801f9 100644
--- a/arch/riscv/kernel/elf_kexec.c
+++ b/arch/riscv/kernel/elf_kexec.c
@@ -451,6 +451,12 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 			*(u32 *)loc = CLEAN_IMM(CJTYPE, *(u32 *)loc) |
 				 ENCODE_CJTYPE_IMM(val - addr);
 			break;
+		case R_RISCV_ADD16:
+			*(u16 *)loc += val;
+			break;
+		case R_RISCV_SUB16:
+			*(u16 *)loc -= val;
+			break;
 		case R_RISCV_ADD32:
 			*(u32 *)loc += val;
 			break;
diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile
index 50bc5ef7dd2f..d5bf1bc7de62 100644
--- a/arch/riscv/kernel/pi/Makefile
+++ b/arch/riscv/kernel/pi/Makefile
@@ -5,6 +5,7 @@ KBUILD_CFLAGS	:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \
 		   -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \
 		   $(call cc-option,-mbranch-protection=none) \
 		   -I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
+		   -include $(srctree)/include/linux/hidden.h \
 		   -D__DISABLE_EXPORTS -ffreestanding \
 		   -fno-asynchronous-unwind-tables -fno-unwind-tables \
 		   $(call cc-option,-fno-addrsig)
@@ -16,6 +17,7 @@ KBUILD_CFLAGS	+= -mcmodel=medany
 
 CFLAGS_cmdline_early.o += -D__NO_FORTIFY
 CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY
+CFLAGS_fdt_early.o += -D__NO_FORTIFY
 
 $(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \
 			       --remove-section=.note.gnu.property \
@@ -32,5 +34,5 @@ $(obj)/string.o: $(srctree)/lib/string.c FORCE
 $(obj)/ctype.o: $(srctree)/lib/ctype.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
-obj-y		:= cmdline_early.pi.o fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o
+obj-y		:= cmdline_early.pi.o fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o archrandom_early.pi.o
 extra-y		:= $(patsubst %.pi.o,%.o,$(obj-y))
diff --git a/arch/riscv/kernel/pi/archrandom_early.c b/arch/riscv/kernel/pi/archrandom_early.c
new file mode 100644
index 000000000000..3f05d3cf3b7b
--- /dev/null
+++ b/arch/riscv/kernel/pi/archrandom_early.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/csr.h>
+#include <linux/processor.h>
+
+#include "pi.h"
+
+/*
+ * To avoid rewriting code include asm/archrandom.h and create macros
+ * for the functions that won't be included.
+ */
+#undef riscv_has_extension_unlikely
+#define riscv_has_extension_likely(...) false
+#undef pr_err_once
+#define pr_err_once(...)
+
+#include <asm/archrandom.h>
+
+u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa)
+{
+	unsigned long seed = 0;
+
+	if (!fdt_early_match_extension_isa((const void *)dtb_pa, "zkr"))
+		return 0;
+
+	if (!csr_seed_long(&seed))
+		return 0;
+
+	return seed;
+}
diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c
index f6d4dedffb84..fbcdc9e4e143 100644
--- a/arch/riscv/kernel/pi/cmdline_early.c
+++ b/arch/riscv/kernel/pi/cmdline_early.c
@@ -6,15 +6,9 @@
 #include <asm/pgtable.h>
 #include <asm/setup.h>
 
-static char early_cmdline[COMMAND_LINE_SIZE];
+#include "pi.h"
 
-/*
- * Declare the functions that are exported (but prefixed) here so that LLVM
- * does not complain it lacks the 'static' keyword (which, if added, makes
- * LLVM complain because the function is actually unused in this file).
- */
-u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
-bool set_nokaslr_from_cmdline(uintptr_t dtb_pa);
+static char early_cmdline[COMMAND_LINE_SIZE];
 
 static char *get_early_cmdline(uintptr_t dtb_pa)
 {
diff --git a/arch/riscv/kernel/pi/fdt_early.c b/arch/riscv/kernel/pi/fdt_early.c
index 899610e042ab..9bdee2fafe47 100644
--- a/arch/riscv/kernel/pi/fdt_early.c
+++ b/arch/riscv/kernel/pi/fdt_early.c
@@ -2,13 +2,9 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/libfdt.h>
+#include <linux/ctype.h>
 
-/*
- * Declare the functions that are exported (but prefixed) here so that LLVM
- * does not complain it lacks the 'static' keyword (which, if added, makes
- * LLVM complain because the function is actually unused in this file).
- */
-u64 get_kaslr_seed(uintptr_t dtb_pa);
+#include "pi.h"
 
 u64 get_kaslr_seed(uintptr_t dtb_pa)
 {
@@ -28,3 +24,162 @@ u64 get_kaslr_seed(uintptr_t dtb_pa)
 	*prop = 0;
 	return ret;
 }
+
+/**
+ *  fdt_device_is_available - check if a device is available for use
+ *
+ * @fdt: pointer to the device tree blob
+ * @node: offset of the node whose property to find
+ *
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool fdt_device_is_available(const void *fdt, int node)
+{
+	const char *status;
+	int statlen;
+
+	status = fdt_getprop(fdt, node, "status", &statlen);
+	if (!status)
+		return true;
+
+	if (statlen > 0) {
+		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+			return true;
+	}
+
+	return false;
+}
+
+/* Copy of fdt_nodename_eq_ */
+static int fdt_node_name_eq(const void *fdt, int offset,
+			    const char *s)
+{
+	int olen;
+	int len = strlen(s);
+	const char *p = fdt_get_name(fdt, offset, &olen);
+
+	if (!p || olen < len)
+		/* short match */
+		return 0;
+
+	if (memcmp(p, s, len) != 0)
+		return 0;
+
+	if (p[len] == '\0')
+		return 1;
+	else if (!memchr(s, '@', len) && (p[len] == '@'))
+		return 1;
+	else
+		return 0;
+}
+
+/**
+ *  isa_string_contains - check if isa string contains an extension
+ *
+ * @isa_str: isa string to search
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the extension is in the given isa string,
+ *  false otherwise
+ */
+static bool isa_string_contains(const char *isa_str, const char *ext_name)
+{
+	size_t i, single_end, len = strlen(ext_name);
+	char ext_end;
+
+	/* Error must contain rv32/64 */
+	if (strlen(isa_str) < 4)
+		return false;
+
+	if (len == 1) {
+		single_end = strcspn(isa_str, "sSxXzZ");
+		/* Search for single chars between rv32/64 and multi-letter extensions */
+		for (i = 4; i < single_end; i++) {
+			if (tolower(isa_str[i]) == ext_name[0])
+				return true;
+		}
+		return false;
+	}
+
+	/* Skip to start of multi-letter extensions */
+	isa_str = strpbrk(isa_str, "sSxXzZ");
+	while (isa_str) {
+		if (strncasecmp(isa_str, ext_name, len) == 0) {
+			ext_end = isa_str[len];
+			/* Check if matches the whole extension. */
+			if (ext_end == '\0' || ext_end == '_')
+				return true;
+		}
+		/* Multi-letter extensions must be split from other multi-letter
+		 * extensions with an "_", the end of a multi-letter extension will
+		 * either be the null character or the "_" at the start of the next
+		 * multi-letter extension.
+		 */
+		isa_str = strchr(isa_str, '_');
+		if (isa_str)
+			isa_str++;
+	}
+
+	return false;
+}
+
+/**
+ *  early_cpu_isa_ext_available - check if cpu node has an extension
+ *
+ * @fdt: pointer to the device tree blob
+ * @node: offset of the cpu node
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the cpu node has the extension,
+ *  false otherwise
+ */
+static bool early_cpu_isa_ext_available(const void *fdt, int node, const char *ext_name)
+{
+	const void *prop;
+	int len;
+
+	prop = fdt_getprop(fdt, node, "riscv,isa-extensions", &len);
+	if (prop && fdt_stringlist_contains(prop, len, ext_name))
+		return true;
+
+	prop = fdt_getprop(fdt, node, "riscv,isa", &len);
+	if (prop && isa_string_contains(prop, ext_name))
+		return true;
+
+	return false;
+}
+
+/**
+ *  fdt_early_match_extension_isa - check if all cpu nodes have an extension
+ *
+ * @fdt: pointer to the device tree blob
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the all available the cpu nodes have the extension,
+ *  false otherwise
+ */
+bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name)
+{
+	int node, parent;
+	bool ret = false;
+
+	parent = fdt_path_offset(fdt, "/cpus");
+	if (parent < 0)
+		return false;
+
+	fdt_for_each_subnode(node, fdt, parent) {
+		if (!fdt_node_name_eq(fdt, node, "cpu"))
+			continue;
+
+		if (!fdt_device_is_available(fdt, node))
+			continue;
+
+		if (!early_cpu_isa_ext_available(fdt, node, ext_name))
+			return false;
+
+		ret = true;
+	}
+
+	return ret;
+}
diff --git a/arch/riscv/kernel/pi/pi.h b/arch/riscv/kernel/pi/pi.h
new file mode 100644
index 000000000000..21141d84fea6
--- /dev/null
+++ b/arch/riscv/kernel/pi/pi.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _RISCV_PI_H_
+#define _RISCV_PI_H_
+
+#include <linux/types.h>
+
+/*
+ * The following functions are exported (but prefixed). Declare them here so
+ * that LLVM does not complain it lacks the 'static' keyword (which, if
+ * added, makes LLVM complain because the function is unused).
+ */
+
+u64 get_kaslr_seed(uintptr_t dtb_pa);
+u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa);
+bool set_nokaslr_from_cmdline(uintptr_t dtb_pa);
+u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
+
+bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name);
+
+#endif /* _RISCV_PI_H_ */
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 8e6eb64459af..9b047899791c 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -21,6 +21,7 @@
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/irq_work.h>
+#include <linux/nmi.h>
 
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
@@ -33,6 +34,7 @@ enum ipi_message_type {
 	IPI_CPU_CRASH_STOP,
 	IPI_IRQ_WORK,
 	IPI_TIMER,
+	IPI_CPU_BACKTRACE,
 	IPI_MAX
 };
 
@@ -136,6 +138,9 @@ static irqreturn_t handle_IPI(int irq, void *data)
 		tick_receive_broadcast();
 		break;
 #endif
+	case IPI_CPU_BACKTRACE:
+		nmi_cpu_backtrace(get_irq_regs());
+		break;
 	default:
 		pr_warn("CPU%d: unhandled IPI%d\n", smp_processor_id(), ipi);
 		break;
@@ -203,6 +208,7 @@ static const char * const ipi_names[] = {
 	[IPI_CPU_CRASH_STOP]	= "CPU stop (for crash dump) interrupts",
 	[IPI_IRQ_WORK]		= "IRQ work interrupts",
 	[IPI_TIMER]		= "Timer broadcast interrupts",
+	[IPI_CPU_BACKTRACE]     = "CPU backtrace interrupts",
 };
 
 void show_ipi_stats(struct seq_file *p, int prec)
@@ -323,3 +329,13 @@ void arch_smp_send_reschedule(int cpu)
 	send_ipi_single(cpu, IPI_RESCHEDULE);
 }
 EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
+
+static void riscv_backtrace_ipi(cpumask_t *mask)
+{
+	send_ipi_mask(mask, IPI_CPU_BACKTRACE);
+}
+
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
+{
+	nmi_trigger_cpumask_backtrace(mask, exclude_cpu, riscv_backtrace_ipi);
+}
diff --git a/arch/riscv/lib/memset.S b/arch/riscv/lib/memset.S
index 35f358e70bdb..da23b8347e2d 100644
--- a/arch/riscv/lib/memset.S
+++ b/arch/riscv/lib/memset.S
@@ -111,3 +111,5 @@ SYM_FUNC_START(__memset)
 	ret
 SYM_FUNC_END(__memset)
 SYM_FUNC_ALIAS_WEAK(memset, __memset)
+SYM_FUNC_ALIAS(__pi_memset, __memset)
+SYM_FUNC_ALIAS(__pi___memset, __memset)
diff --git a/arch/riscv/lib/strcmp.S b/arch/riscv/lib/strcmp.S
index 687b2bea5c43..bc73325b2fd1 100644
--- a/arch/riscv/lib/strcmp.S
+++ b/arch/riscv/lib/strcmp.S
@@ -120,3 +120,4 @@ strcmp_zbb:
 .option pop
 #endif
 SYM_FUNC_END(strcmp)
+SYM_FUNC_ALIAS(__pi_strcmp, strcmp)
diff --git a/arch/riscv/lib/strncmp.S b/arch/riscv/lib/strncmp.S
index aba5b3148621..b36325a57f6a 100644
--- a/arch/riscv/lib/strncmp.S
+++ b/arch/riscv/lib/strncmp.S
@@ -136,3 +136,4 @@ strncmp_zbb:
 .option pop
 #endif
 SYM_FUNC_END(strncmp)
+SYM_FUNC_ALIAS(__pi_strncmp, strncmp)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 31b23f84494f..f43139db82a9 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1049,6 +1049,7 @@ static void __init pt_ops_set_late(void)
 #ifdef CONFIG_RANDOMIZE_BASE
 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
+extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa);
 
 static int __init print_nokaslr(char *p)
 {
@@ -1069,10 +1070,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 
 #ifdef CONFIG_RANDOMIZE_BASE
 	if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
-		u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
+		u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa);
 		u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
 		u32 nr_pos;
 
+		if (kaslr_seed == 0)
+			kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
 		/*
 		 * Compute the number of positions available: we are limited
 		 * by the early page table that only has one PUD and we must