Merge tag 'loongarch-fixes-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Some hw breakpoint fixes, an objtool build warnging fix, and a trivial
  cleanup"

* tag 'loongarch-fixes-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Remove an unneeded semicolon
  LoongArch: Fix multiple hardware watchpoint issues
  LoongArch: Trigger user-space watchpoints correctly
  LoongArch: Fix watchpoint setting error
  LoongArch: Only allow OBJTOOL & ORC unwinder if toolchain supports -mthin-add-sub

Author: torvalds

arch/loongarch/Kconfig

@@ -143,7 +143,7 @@ config LOONGARCH
 	select HAVE_LIVEPATCH
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
-	select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS
+	select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && !CC_IS_CLANG
 	select HAVE_PCI
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
@@ -261,6 +261,9 @@ config AS_HAS_EXPLICIT_RELOCS
 config AS_HAS_FCSR_CLASS
 	def_bool $(as-instr,movfcsr2gr \$t0$(comma)\$fcsr0)
 
+config AS_HAS_THIN_ADD_SUB
+	def_bool $(cc-option,-Wa$(comma)-mthin-add-sub)
+
 config AS_HAS_LSX_EXTENSION
 	def_bool $(as-instr,vld \$vr0$(comma)\$a0$(comma)0)
 

arch/loongarch/Kconfig.debug

@@ -28,6 +28,7 @@ config UNWINDER_PROLOGUE
 
 config UNWINDER_ORC
 	bool "ORC unwinder"
+	depends on HAVE_OBJTOOL
 	select OBJTOOL
 	help
 	  This option enables the ORC (Oops Rewind Capability) unwinder for

arch/loongarch/include/asm/hw_breakpoint.h

@@ -75,6 +75,8 @@ do {								\
 #define CSR_MWPC_NUM		0x3f
 
 #define CTRL_PLV_ENABLE		0x1e
+#define CTRL_PLV0_ENABLE	0x02
+#define CTRL_PLV3_ENABLE	0x10
 
 #define MWPnCFG3_LoadEn		8
 #define MWPnCFG3_StoreEn	9
@@ -101,7 +103,7 @@ struct perf_event;
 struct perf_event_attr;
 
 extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
-				  int *gen_len, int *gen_type, int *offset);
+				  int *gen_len, int *gen_type);
 extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
 extern int hw_breakpoint_arch_parse(struct perf_event *bp,
 				    const struct perf_event_attr *attr,

arch/loongarch/kernel/hw_breakpoint.c

@@ -174,11 +174,21 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 static int hw_breakpoint_control(struct perf_event *bp,
 				 enum hw_breakpoint_ops ops)
 {
-	u32 ctrl;
+	u32 ctrl, privilege;
 	int i, max_slots, enable;
+	struct pt_regs *regs;
 	struct perf_event **slots;
 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
 
+	if (arch_check_bp_in_kernelspace(info))
+		privilege = CTRL_PLV0_ENABLE;
+	else
+		privilege = CTRL_PLV3_ENABLE;
+
+	/*  Whether bp belongs to a task. */
+	if (bp->hw.target)
+		regs = task_pt_regs(bp->hw.target);
+
 	if (info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		slots = this_cpu_ptr(bp_on_reg);
@@ -197,31 +207,38 @@ static int hw_breakpoint_control(struct perf_event *bp,
 	switch (ops) {
 	case HW_BREAKPOINT_INSTALL:
 		/* Set the FWPnCFG/MWPnCFG 1~4 register. */
-		write_wb_reg(CSR_CFG_ADDR, i, 0, info->address);
-		write_wb_reg(CSR_CFG_ADDR, i, 1, info->address);
-		write_wb_reg(CSR_CFG_MASK, i, 0, info->mask);
-		write_wb_reg(CSR_CFG_MASK, i, 1, info->mask);
-		write_wb_reg(CSR_CFG_ASID, i, 0, 0);
-		write_wb_reg(CSR_CFG_ASID, i, 1, 0);
 		if (info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
-			write_wb_reg(CSR_CFG_CTRL, i, 0, CTRL_PLV_ENABLE);
+			write_wb_reg(CSR_CFG_ADDR, i, 0, info->address);
+			write_wb_reg(CSR_CFG_MASK, i, 0, info->mask);
+			write_wb_reg(CSR_CFG_ASID, i, 0, 0);
+			write_wb_reg(CSR_CFG_CTRL, i, 0, privilege);
 		} else {
+			write_wb_reg(CSR_CFG_ADDR, i, 1, info->address);
+			write_wb_reg(CSR_CFG_MASK, i, 1, info->mask);
+			write_wb_reg(CSR_CFG_ASID, i, 1, 0);
 			ctrl = encode_ctrl_reg(info->ctrl);
-			write_wb_reg(CSR_CFG_CTRL, i, 1, ctrl | CTRL_PLV_ENABLE);
+			write_wb_reg(CSR_CFG_CTRL, i, 1, ctrl | privilege);
 		}
 		enable = csr_read64(LOONGARCH_CSR_CRMD);
 		csr_write64(CSR_CRMD_WE | enable, LOONGARCH_CSR_CRMD);
+		if (bp->hw.target)
+			regs->csr_prmd |= CSR_PRMD_PWE;
 		break;
 	case HW_BREAKPOINT_UNINSTALL:
 		/* Reset the FWPnCFG/MWPnCFG 1~4 register. */
-		write_wb_reg(CSR_CFG_ADDR, i, 0, 0);
-		write_wb_reg(CSR_CFG_ADDR, i, 1, 0);
-		write_wb_reg(CSR_CFG_MASK, i, 0, 0);
-		write_wb_reg(CSR_CFG_MASK, i, 1, 0);
-		write_wb_reg(CSR_CFG_CTRL, i, 0, 0);
-		write_wb_reg(CSR_CFG_CTRL, i, 1, 0);
-		write_wb_reg(CSR_CFG_ASID, i, 0, 0);
-		write_wb_reg(CSR_CFG_ASID, i, 1, 0);
+		if (info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
+			write_wb_reg(CSR_CFG_ADDR, i, 0, 0);
+			write_wb_reg(CSR_CFG_MASK, i, 0, 0);
+			write_wb_reg(CSR_CFG_CTRL, i, 0, 0);
+			write_wb_reg(CSR_CFG_ASID, i, 0, 0);
+		} else {
+			write_wb_reg(CSR_CFG_ADDR, i, 1, 0);
+			write_wb_reg(CSR_CFG_MASK, i, 1, 0);
+			write_wb_reg(CSR_CFG_CTRL, i, 1, 0);
+			write_wb_reg(CSR_CFG_ASID, i, 1, 0);
+		}
+		if (bp->hw.target)
+			regs->csr_prmd &= ~CSR_PRMD_PWE;
 		break;
 	}
 
@@ -283,7 +300,7 @@ int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
  * to generic breakpoint descriptions.
  */
 int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
-			   int *gen_len, int *gen_type, int *offset)
+			   int *gen_len, int *gen_type)
 {
 	/* Type */
 	switch (ctrl.type) {
@@ -303,11 +320,6 @@ int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
 		return -EINVAL;
 	}
 
-	if (!ctrl.len)
-		return -EINVAL;
-
-	*offset = __ffs(ctrl.len);
-
 	/* Len */
 	switch (ctrl.len) {
 	case LOONGARCH_BREAKPOINT_LEN_1:
@@ -386,21 +398,17 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 			     struct arch_hw_breakpoint *hw)
 {
 	int ret;
-	u64 alignment_mask, offset;
+	u64 alignment_mask;
 
 	/* Build the arch_hw_breakpoint. */
 	ret = arch_build_bp_info(bp, attr, hw);
 	if (ret)
 		return ret;
 
-	if (hw->ctrl.type != LOONGARCH_BREAKPOINT_EXECUTE)
-		alignment_mask = 0x7;
-	else
+	if (hw->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
 		alignment_mask = 0x3;
-	offset = hw->address & alignment_mask;
-
-	hw->address &= ~alignment_mask;
-	hw->ctrl.len <<= offset;
+		hw->address &= ~alignment_mask;
+	}
 
 	return 0;
 }
@@ -471,12 +479,15 @@ void breakpoint_handler(struct pt_regs *regs)
 	slots = this_cpu_ptr(bp_on_reg);
 
 	for (i = 0; i < boot_cpu_data.watch_ireg_count; ++i) {
-		bp = slots[i];
-		if (bp == NULL)
-			continue;
-		perf_bp_event(bp, regs);
+		if ((csr_read32(LOONGARCH_CSR_FWPS) & (0x1 << i))) {
+			bp = slots[i];
+			if (bp == NULL)
+				continue;
+			perf_bp_event(bp, regs);
+			csr_write32(0x1 << i, LOONGARCH_CSR_FWPS);
+			update_bp_registers(regs, 0, 0);
+		}
 	}
-	update_bp_registers(regs, 0, 0);
 }
 NOKPROBE_SYMBOL(breakpoint_handler);
 
@@ -488,12 +499,15 @@ void watchpoint_handler(struct pt_regs *regs)
 	slots = this_cpu_ptr(wp_on_reg);
 
 	for (i = 0; i < boot_cpu_data.watch_dreg_count; ++i) {
-		wp = slots[i];
-		if (wp == NULL)
-			continue;
-		perf_bp_event(wp, regs);
+		if ((csr_read32(LOONGARCH_CSR_MWPS) & (0x1 << i))) {
+			wp = slots[i];
+			if (wp == NULL)
+				continue;
+			perf_bp_event(wp, regs);
+			csr_write32(0x1 << i, LOONGARCH_CSR_MWPS);
+			update_bp_registers(regs, 0, 1);
+		}
 	}
-	update_bp_registers(regs, 0, 1);
 }
 NOKPROBE_SYMBOL(watchpoint_handler);
 

arch/loongarch/kernel/ptrace.c

@@ -494,28 +494,14 @@ static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 				     struct arch_hw_breakpoint_ctrl ctrl,
 				     struct perf_event_attr *attr)
 {
-	int err, len, type, offset;
+	int err, len, type;
 
-	err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
+	err = arch_bp_generic_fields(ctrl, &len, &type);
 	if (err)
 		return err;
 
-	switch (note_type) {
-	case NT_LOONGARCH_HW_BREAK:
-		if ((type & HW_BREAKPOINT_X) != type)
-			return -EINVAL;
-		break;
-	case NT_LOONGARCH_HW_WATCH:
-		if ((type & HW_BREAKPOINT_RW) != type)
-			return -EINVAL;
-		break;
-	default:
-		return -EINVAL;
-	}
-
 	attr->bp_len	= len;
 	attr->bp_type	= type;
-	attr->bp_addr	+= offset;
 
 	return 0;
 }
@@ -609,10 +595,27 @@ static int ptrace_hbp_set_ctrl(unsigned int note_type,
 		return PTR_ERR(bp);
 
 	attr = bp->attr;
-	decode_ctrl_reg(uctrl, &ctrl);
-	err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
-	if (err)
-		return err;
+
+	switch (note_type) {
+	case NT_LOONGARCH_HW_BREAK:
+		ctrl.type = LOONGARCH_BREAKPOINT_EXECUTE;
+		ctrl.len = LOONGARCH_BREAKPOINT_LEN_4;
+		break;
+	case NT_LOONGARCH_HW_WATCH:
+		decode_ctrl_reg(uctrl, &ctrl);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (uctrl & CTRL_PLV_ENABLE) {
+		err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
+		if (err)
+			return err;
+		attr.disabled = 0;
+	} else {
+		attr.disabled = 1;
+	}
 
 	return modify_user_hw_breakpoint(bp, &attr);
 }
@@ -643,6 +646,10 @@ static int ptrace_hbp_set_addr(unsigned int note_type,
 	struct perf_event *bp;
 	struct perf_event_attr attr;
 
+	/* Kernel-space address cannot be monitored by user-space */
+	if ((unsigned long)addr >= XKPRANGE)
+		return -EINVAL;
+
 	bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 	if (IS_ERR(bp))
 		return PTR_ERR(bp);

arch/loongarch/kvm/exit.c

@@ -761,7 +761,7 @@ static void kvm_handle_service(struct kvm_vcpu *vcpu)
 	default:
 		ret = KVM_HCALL_INVALID_CODE;
 		break;
-	};
+	}
 
 	kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret);
 }