7 files changed, 140 insertions, 1 deletions
diff --git a/arch/openrisc/kernel/Makefile b/arch/openrisc/kernel/Makefile
index 58e6a1b525b7..19e0eb94f2eb 100644
--- a/arch/openrisc/kernel/Makefile
+++ b/arch/openrisc/kernel/Makefile
@@ -9,9 +9,11 @@ obj-y	:= head.o setup.o or32_ksyms.o process.o dma.o \
 	   traps.o time.o irq.o entry.o ptrace.o signal.o \
 	   sys_call_table.o unwinder.o cacheinfo.o
 
+obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_SMP)		+= smp.o sync-timer.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_OF)		+= prom.o
+obj-y	+= patching.o
 
 clean:
diff --git a/arch/openrisc/kernel/asm-offsets.c b/arch/openrisc/kernel/asm-offsets.c
index 710651d5aaae..3cc826f2216b 100644
--- a/arch/openrisc/kernel/asm-offsets.c
+++ b/arch/openrisc/kernel/asm-offsets.c
@@ -18,6 +18,7 @@
  * compile this file to assembler, and then extract the
  * #defines from the assembly-language output.
  */
+#define COMPILE_OFFSETS
 
 #include <linux/signal.h>
 #include <linux/sched.h>
diff --git a/arch/openrisc/kernel/jump_label.c b/arch/openrisc/kernel/jump_label.c
new file mode 100644
index 000000000000..ab7137c23b46
--- /dev/null
+++ b/arch/openrisc/kernel/jump_label.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Chen Miao
+ *
+ * Based on arch/arm/kernel/jump_label.c
+ */
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <asm/bug.h>
+#include <asm/cacheflush.h>
+#include <asm/text-patching.h>
+
+bool arch_jump_label_transform_queue(struct jump_entry *entry,
+				     enum jump_label_type type)
+{
+	void *addr = (void *)jump_entry_code(entry);
+	u32 insn;
+
+	if (type == JUMP_LABEL_JMP) {
+		long offset;
+
+		offset = jump_entry_target(entry) - jump_entry_code(entry);
+		/*
+		 * The actual maximum range of the l.j instruction's offset is -134,217,728
+		 * ~ 134,217,724 (sign 26-bit imm).
+		 * For the original jump range, we need to right-shift N by 2 to obtain the
+		 * instruction's offset.
+		 */
+		WARN_ON_ONCE(offset < -134217728 || offset > 134217724);
+
+		/* 26bit imm mask */
+		offset = (offset >> 2) & 0x03ffffff;
+
+		insn = offset;
+	} else {
+		insn = OPENRISC_INSN_NOP;
+	}
+
+	if (early_boot_irqs_disabled)
+		copy_to_kernel_nofault(addr, &insn, sizeof(insn));
+	else
+		patch_insn_write(addr, insn);
+
+	return true;
+}
+
+void arch_jump_label_transform_apply(void)
+{
+	kick_all_cpus_sync();
+}
diff --git a/arch/openrisc/kernel/module.c b/arch/openrisc/kernel/module.c
index c9ff4c4a0b29..4ac4fbaa827c 100644
--- a/arch/openrisc/kernel/module.c
+++ b/arch/openrisc/kernel/module.c
@@ -55,6 +55,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			value |= *location & 0xfc000000;
 			*location = value;
 			break;
+		case R_OR1K_32_PCREL:
+			value -= (uint32_t)location;
+			*location = value;
+			break;
 		case R_OR1K_AHI16:
 			/* Adjust the operand to match with a signed LO16.  */
 			value += 0x8000;
diff --git a/arch/openrisc/kernel/patching.c b/arch/openrisc/kernel/patching.c
new file mode 100644
index 000000000000..d186172beb33
--- /dev/null
+++ b/arch/openrisc/kernel/patching.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2020 SiFive
+ * Copyright (C) 2025 Chen Miao
+ */
+
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+#include <asm/insn-def.h>
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+#include <asm/fixmap.h>
+#include <asm/text-patching.h>
+#include <asm/sections.h>
+
+static DEFINE_RAW_SPINLOCK(patch_lock);
+
+static __always_inline void *patch_map(void *addr, int fixmap)
+{
+	uintptr_t uaddr = (uintptr_t) addr;
+	phys_addr_t phys;
+
+	if (core_kernel_text(uaddr)) {
+		phys = __pa_symbol(addr);
+	} else {
+		struct page *page = vmalloc_to_page(addr);
+		BUG_ON(!page);
+		phys = page_to_phys(page) + offset_in_page(addr);
+	}
+
+	return (void *)set_fixmap_offset(fixmap, phys);
+}
+
+static void patch_unmap(int fixmap)
+{
+	clear_fixmap(fixmap);
+}
+
+static int __patch_insn_write(void *addr, u32 insn)
+{
+	void *waddr = addr;
+	unsigned long flags = 0;
+	int ret;
+
+	raw_spin_lock_irqsave(&patch_lock, flags);
+
+	waddr = patch_map(addr, FIX_TEXT_POKE0);
+
+	ret = copy_to_kernel_nofault(waddr, &insn, OPENRISC_INSN_SIZE);
+	local_icache_range_inv((unsigned long)waddr,
+			       (unsigned long)waddr + OPENRISC_INSN_SIZE);
+
+	patch_unmap(FIX_TEXT_POKE0);
+
+	raw_spin_unlock_irqrestore(&patch_lock, flags);
+
+	return ret;
+}
+
+/*
+ * patch_insn_write - Write a single instruction to a specified memory location
+ * This API provides a single-instruction patching, primarily used for runtime
+ * code modification.
+ * By the way, the insn size must be 4 bytes.
+ */
+int patch_insn_write(void *addr, u32 insn)
+{
+	u32 *tp = addr;
+	int ret;
+
+	if ((uintptr_t) tp & 0x3)
+		return -EINVAL;
+
+	ret = __patch_insn_write(tp, insn);
+
+	return ret;
+}
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index eef99fee2110..73ffb9fa3118 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -165,7 +165,7 @@ extern asmlinkage void ret_from_fork(void);
 int
 copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *userregs;
diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index a9fb9cc6779e..000a9cc10e6f 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -249,6 +249,8 @@ void __init setup_arch(char **cmdline_p)
 		initrd_below_start_ok = 1;
 	}
 #endif
+	/* perform jump_table sorting before paging_init locks down read only memory */
+	jump_label_init();
 
 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();