Merge tag 'riscv-for-linus-5.15-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - support PC-relative instructions (auipc and branches) in kprobes

 - support for forced IRQ threading

 - support for the hlt/nohlt kernel command line options, via the
   generic idle loop

 - show the edge/level triggered behavior of interrupts
   in /proc/interrupts

 - a handful of cleanups to our address mapping mechanisms

 - support for allocating gigantic hugepages via CMA

 - support for the undefined behavior sanitizer (UBSAN)

 - a handful of cleanups to the VDSO that allow the kernel to build with
   LLD.

 - support for hugepage migration

* tag 'riscv-for-linus-5.15-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  riscv: add support for hugepage migration
  RISC-V: Fix VDSO build for !MMU
  riscv: use strscpy to replace strlcpy
  riscv: explicitly use symbol offsets for VDSO
  riscv: Enable Undefined Behavior Sanitizer UBSAN
  riscv: Keep the riscv Kconfig selects sorted
  riscv: Support allocating gigantic hugepages using CMA
  riscv: fix the global name pfn_base confliction error
  riscv: Move early fdt mapping creation in its own function
  riscv: Simplify BUILTIN_DTB device tree mapping handling
  riscv: Use __maybe_unused instead of #ifdefs around variable declarations
  riscv: Get rid of map_size parameter to create_kernel_page_table
  riscv: Introduce va_kernel_pa_offset for 32-bit kernel
  riscv: Optimize kernel virtual address conversion macro
  dt-bindings: riscv: add starfive jh7100 bindings
  riscv: Enable GENERIC_IRQ_SHOW_LEVEL
  riscv: Enable idle generic idle loop
  riscv: Allow forced irq threading
  riscv: Implement thread_struct whitelist for hardened usercopy
  riscv: kprobes: implement the branch instructions
  ...

6 files changed, 132 insertions, 24 deletions

diff --git a/arch/riscv/kernel/probes/decode-insn.c b/arch/riscv/kernel/probes/decode-insn.c
index 0ed043acc882..64f6183b4717 100644
--- a/arch/riscv/kernel/probes/decode-insn.c
+++ b/arch/riscv/kernel/probes/decode-insn.c
@@ -38,11 +38,10 @@ riscv_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
 	RISCV_INSN_REJECTED(c_ebreak,		insn);
 #endif
 
-	RISCV_INSN_REJECTED(auipc,		insn);
-	RISCV_INSN_REJECTED(branch,		insn);
-
 	RISCV_INSN_SET_SIMULATE(jal,		insn);
 	RISCV_INSN_SET_SIMULATE(jalr,		insn);
+	RISCV_INSN_SET_SIMULATE(auipc,		insn);
+	RISCV_INSN_SET_SIMULATE(branch,		insn);
 
 	return INSN_GOOD;
 }
diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c
index 2519ce26377d..d73e96f6ed7c 100644
--- a/arch/riscv/kernel/probes/simulate-insn.c
+++ b/arch/riscv/kernel/probes/simulate-insn.c
@@ -83,3 +83,115 @@ bool __kprobes simulate_jalr(u32 opcode, unsigned long addr, struct pt_regs *reg
 
 	return ret;
 }
+
+#define auipc_rd_idx(opcode) \
+	((opcode >> 7) & 0x1f)
+
+#define auipc_imm(opcode) \
+	((((opcode) >> 12) & 0xfffff) << 12)
+
+#if __riscv_xlen == 64
+#define auipc_offset(opcode)	sign_extend64(auipc_imm(opcode), 31)
+#elif __riscv_xlen == 32
+#define auipc_offset(opcode)	auipc_imm(opcode)
+#else
+#error "Unexpected __riscv_xlen"
+#endif
+
+bool __kprobes simulate_auipc(u32 opcode, unsigned long addr, struct pt_regs *regs)
+{
+	/*
+	 * auipc instruction:
+	 *  31        12 11 7 6      0
+	 * | imm[31:12] | rd | opcode |
+	 *        20       5     7
+	 */
+
+	u32 rd_idx = auipc_rd_idx(opcode);
+	unsigned long rd_val = addr + auipc_offset(opcode);
+
+	if (!rv_insn_reg_set_val(regs, rd_idx, rd_val))
+		return false;
+
+	instruction_pointer_set(regs, addr + 4);
+
+	return true;
+}
+
+#define branch_rs1_idx(opcode) \
+	(((opcode) >> 15) & 0x1f)
+
+#define branch_rs2_idx(opcode) \
+	(((opcode) >> 20) & 0x1f)
+
+#define branch_funct3(opcode) \
+	(((opcode) >> 12) & 0x7)
+
+#define branch_imm(opcode) \
+	(((((opcode) >>  8) & 0xf ) <<  1) | \
+	 ((((opcode) >> 25) & 0x3f) <<  5) | \
+	 ((((opcode) >>  7) & 0x1 ) << 11) | \
+	 ((((opcode) >> 31) & 0x1 ) << 12))
+
+#define branch_offset(opcode) \
+	sign_extend32((branch_imm(opcode)), 12)
+
+#define BRANCH_BEQ	0x0
+#define BRANCH_BNE	0x1
+#define BRANCH_BLT	0x4
+#define BRANCH_BGE	0x5
+#define BRANCH_BLTU	0x6
+#define BRANCH_BGEU	0x7
+
+bool __kprobes simulate_branch(u32 opcode, unsigned long addr, struct pt_regs *regs)
+{
+	/*
+	 * branch instructions:
+	 *      31    30       25 24 20 19 15 14    12 11       8    7      6      0
+	 * | imm[12] | imm[10:5] | rs2 | rs1 | funct3 | imm[4:1] | imm[11] | opcode |
+	 *     1           6        5     5      3         4         1         7
+	 *     imm[12|10:5]        rs2   rs1    000       imm[4:1|11]       1100011  BEQ
+	 *     imm[12|10:5]        rs2   rs1    001       imm[4:1|11]       1100011  BNE
+	 *     imm[12|10:5]        rs2   rs1    100       imm[4:1|11]       1100011  BLT
+	 *     imm[12|10:5]        rs2   rs1    101       imm[4:1|11]       1100011  BGE
+	 *     imm[12|10:5]        rs2   rs1    110       imm[4:1|11]       1100011  BLTU
+	 *     imm[12|10:5]        rs2   rs1    111       imm[4:1|11]       1100011  BGEU
+	 */
+
+	s32 offset;
+	s32 offset_tmp;
+	unsigned long rs1_val;
+	unsigned long rs2_val;
+
+	if (!rv_insn_reg_get_val(regs, branch_rs1_idx(opcode), &rs1_val) ||
+	    !rv_insn_reg_get_val(regs, branch_rs2_idx(opcode), &rs2_val))
+		return false;
+
+	offset_tmp = branch_offset(opcode);
+	switch (branch_funct3(opcode)) {
+	case BRANCH_BEQ:
+		offset = (rs1_val == rs2_val) ? offset_tmp : 4;
+		break;
+	case BRANCH_BNE:
+		offset = (rs1_val != rs2_val) ? offset_tmp : 4;
+		break;
+	case BRANCH_BLT:
+		offset = ((long)rs1_val < (long)rs2_val) ? offset_tmp : 4;
+		break;
+	case BRANCH_BGE:
+		offset = ((long)rs1_val >= (long)rs2_val) ? offset_tmp : 4;
+		break;
+	case BRANCH_BLTU:
+		offset = (rs1_val < rs2_val) ? offset_tmp : 4;
+		break;
+	case BRANCH_BGEU:
+		offset = (rs1_val >= rs2_val) ? offset_tmp : 4;
+		break;
+	default:
+		return false;
+	}
+
+	instruction_pointer_set(regs, addr + offset);
+
+	return true;
+}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 120b2f6f71bc..b9620e5f00ba 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -255,7 +255,7 @@ static void __init parse_dtb(void)
 
 	pr_err("No DTB passed to the kernel\n");
 #ifdef CONFIG_CMDLINE_FORCE
-	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+	strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
 #endif
 }
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 24d936c147cd..f2e065671e4d 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -23,10 +23,10 @@ ifneq ($(c-gettimeofday-y),)
 endif
 
 # Build rules
-targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-syms.S
+targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds
 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
 
-obj-y += vdso.o vdso-syms.o
+obj-y += vdso.o
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Disable -pg to prevent insert call site
@@ -36,6 +36,7 @@ CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
 GCOV_PROFILE := n
 KCOV_INSTRUMENT := n
 KASAN_SANITIZE := n
+UBSAN_SANITIZE := n
 
 # Force dependency
 $(obj)/vdso.o: $(obj)/vdso.so
@@ -43,20 +44,22 @@ $(obj)/vdso.o: $(obj)/vdso.so
 # link rule for the .so file, .lds has to be first
 $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
 	$(call if_changed,vdsold)
-LDFLAGS_vdso.so.dbg = -shared -s -soname=linux-vdso.so.1 \
+LDFLAGS_vdso.so.dbg = -shared -S -soname=linux-vdso.so.1 \
 	--build-id=sha1 --hash-style=both --eh-frame-hdr
 
-# We also create a special relocatable object that should mirror the symbol
-# table and layout of the linked DSO. With ld --just-symbols we can then
-# refer to these symbols in the kernel code rather than hand-coded addresses.
-$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE
-	$(call if_changed,so2s)
-
 # strip rule for the .so file
 $(obj)/%.so: OBJCOPYFLAGS := -S
 $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
+# Generate VDSO offsets using helper script
+gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
+quiet_cmd_vdsosym = VDSOSYM $@
+	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
+
+include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
+	$(call if_changed,vdsosym)
+
 # actual build commands
 # The DSO images are built using a special linker script
 # Make sure only to export the intended __vdso_xxx symbol offsets.
@@ -65,11 +68,6 @@ quiet_cmd_vdsold = VDSOLD  $@
                    $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
                    rm $@.tmp
 
-# Extracts symbol offsets from the VDSO, converting them into an assembly file
-# that contains the same symbols at the same offsets.
-quiet_cmd_so2s = SO2S    $@
-      cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@
-
 # install commands for the unstripped file
 quiet_cmd_vdso_install = INSTALL $@
       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
diff --git a/arch/riscv/kernel/vdso/gen_vdso_offsets.sh b/arch/riscv/kernel/vdso/gen_vdso_offsets.sh
new file mode 100755
index 000000000000..c2e5613f3495
--- /dev/null
+++ b/arch/riscv/kernel/vdso/gen_vdso_offsets.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+LC_ALL=C
+sed -n -e 's/^[0]\+\(0[0-9a-fA-F]*\) . \(__vdso_[a-zA-Z0-9_]*\)$/\#define \2_offset\t0x\1/p'
diff --git a/arch/riscv/kernel/vdso/so2s.sh b/arch/riscv/kernel/vdso/so2s.sh
deleted file mode 100755
index e64cb6d9440e..000000000000
--- a/arch/riscv/kernel/vdso/so2s.sh
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0+
-# Copyright 2020 Palmer Dabbelt <palmerdabbelt@google.com>
-
-sed 's!\([0-9a-f]*\) T \([a-z0-9_]*\)\(@@LINUX_4.15\)*!.global \2\n.set \2,0x\1!' \
-| grep '^\.'