Merge tag 'loongarch-fixes-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:

 - only use SC.Q when supported by the assembler to fix a build failure

 - fix calling smp_processor_id() in preemptible code

 - make a BPF helper arch_protect_bpf_trampoline() return 0 to fix a
   kernel memory access failure

 - fix a typo issue in kvm_vm_init_features()

* tag 'loongarch-fixes-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Fix typo issue in kvm_vm_init_features()
  LoongArch: BPF: Make arch_protect_bpf_trampoline() return 0
  LoongArch: No need to flush icache if text copy failed
  LoongArch: Check return values for set_memory_{rw,rox}
  LoongArch: Give more information if kmem access failed
  LoongArch: Fix calling smp_processor_id() in preemptible code
  LoongArch: Only use SC.Q when supported by the assembler

Author: torvalds

arch/loongarch/Kconfig

@@ -304,6 +304,9 @@ config AS_HAS_LBT_EXTENSION
 config AS_HAS_LVZ_EXTENSION
 	def_bool $(as-instr,hvcl 0)
 
+config AS_HAS_SCQ_EXTENSION
+	def_bool $(as-instr,sc.q \$t0$(comma)\$t1$(comma)\$t2)
+
 config CC_HAS_ANNOTATE_TABLEJUMP
 	def_bool $(cc-option,-mannotate-tablejump)
 

arch/loongarch/include/asm/cmpxchg.h

@@ -238,6 +238,8 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, unsigned int
 	arch_cmpxchg((ptr), (o), (n));					\
   })
 
+#ifdef CONFIG_AS_HAS_SCQ_EXTENSION
+
 union __u128_halves {
 	u128 full;
 	struct {
@@ -290,6 +292,9 @@ union __u128_halves {
 	BUILD_BUG_ON(sizeof(*(ptr)) != 16);				\
 	__arch_cmpxchg128(ptr, o, n, "");				\
 })
+
+#endif /* CONFIG_AS_HAS_SCQ_EXTENSION */
+
 #else
 #include <asm-generic/cmpxchg-local.h>
 #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))

arch/loongarch/include/asm/uaccess.h

@@ -253,8 +253,13 @@ do {									\
 									\
 	__get_kernel_common(*((type *)(dst)), sizeof(type),		\
 			    (__force type *)(src));			\
-	if (unlikely(__gu_err))						\
+	if (unlikely(__gu_err))	{					\
+		pr_info("%s: memory access failed, ecode 0x%x\n",	\
+			__func__, read_csr_excode());			\
+		pr_info("%s: the caller is %pS\n",			\
+			__func__, __builtin_return_address(0));		\
 		goto err_label;						\
+	}								\
 } while (0)
 
 #define __put_kernel_nofault(dst, src, type, err_label)			\
@@ -264,8 +269,13 @@ do {									\
 									\
 	__pu_val = *(__force type *)(src);				\
 	__put_kernel_common(((type *)(dst)), sizeof(type));		\
-	if (unlikely(__pu_err))						\
+	if (unlikely(__pu_err))	{					\
+		pr_info("%s: memory access failed, ecode 0x%x\n",	\
+			__func__, read_csr_excode());			\
+		pr_info("%s: the caller is %pS\n",			\
+			__func__, __builtin_return_address(0));		\
 		goto err_label;						\
+	}								\
 } while (0)
 
 extern unsigned long __copy_user(void *to, const void *from, __kernel_size_t n);

arch/loongarch/kernel/inst.c

@@ -246,32 +246,51 @@ static int text_copy_cb(void *data)
 
 	if (smp_processor_id() == copy->cpu) {
 		ret = copy_to_kernel_nofault(copy->dst, copy->src, copy->len);
-		if (ret)
+		if (ret) {
 			pr_err("%s: operation failed\n", __func__);
+			return ret;
+		}
 	}
 
 	flush_icache_range((unsigned long)copy->dst, (unsigned long)copy->dst + copy->len);
 
-	return ret;
+	return 0;
 }
 
 int larch_insn_text_copy(void *dst, void *src, size_t len)
 {
 	int ret = 0;
+	int err = 0;
 	size_t start, end;
 	struct insn_copy copy = {
 		.dst = dst,
 		.src = src,
 		.len = len,
-		.cpu = smp_processor_id(),
+		.cpu = raw_smp_processor_id(),
 	};
 
+	/*
+	 * Ensure copy.cpu won't be hot removed before stop_machine.
+	 * If it is removed nobody will really update the text.
+	 */
+	lockdep_assert_cpus_held();
+
 	start = round_down((size_t)dst, PAGE_SIZE);
 	end   = round_up((size_t)dst + len, PAGE_SIZE);
 
-	set_memory_rw(start, (end - start) / PAGE_SIZE);
-	ret = stop_machine(text_copy_cb, &copy, cpu_online_mask);
-	set_memory_rox(start, (end - start) / PAGE_SIZE);
+	err = set_memory_rw(start, (end - start) / PAGE_SIZE);
+	if (err) {
+		pr_info("%s: set_memory_rw() failed\n", __func__);
+		return err;
+	}
+
+	ret = stop_machine_cpuslocked(text_copy_cb, &copy, cpu_online_mask);
+
+	err = set_memory_rox(start, (end - start) / PAGE_SIZE);
+	if (err) {
+		pr_info("%s: set_memory_rox() failed\n", __func__);
+		return err;
+	}
 
 	return ret;
 }

arch/loongarch/kvm/vm.c

@@ -49,8 +49,8 @@ static void kvm_vm_init_features(struct kvm *kvm)
 		kvm->arch.kvm_features |= BIT(KVM_LOONGARCH_VM_FEAT_PMU);
 
 	/* Enable all PV features by default */
-	kvm->arch.pv_features = BIT(KVM_FEATURE_IPI);
-	kvm->arch.kvm_features = BIT(KVM_LOONGARCH_VM_FEAT_PV_IPI);
+	kvm->arch.pv_features |= BIT(KVM_FEATURE_IPI);
+	kvm->arch.kvm_features |= BIT(KVM_LOONGARCH_VM_FEAT_PV_IPI);
 	if (kvm_pvtime_supported()) {
 		kvm->arch.pv_features |= BIT(KVM_FEATURE_PREEMPT);
 		kvm->arch.pv_features |= BIT(KVM_FEATURE_STEAL_TIME);

arch/loongarch/net/bpf_jit.c

@@ -1379,9 +1379,11 @@ void *bpf_arch_text_copy(void *dst, void *src, size_t len)
 {
 	int ret;
 
+	cpus_read_lock();
 	mutex_lock(&text_mutex);
 	ret = larch_insn_text_copy(dst, src, len);
 	mutex_unlock(&text_mutex);
+	cpus_read_unlock();
 
 	return ret ? ERR_PTR(-EINVAL) : dst;
 }
@@ -1429,10 +1431,12 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 	if (ret)
 		return ret;
 
+	cpus_read_lock();
 	mutex_lock(&text_mutex);
 	if (memcmp(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES))
 		ret = larch_insn_text_copy(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES);
 	mutex_unlock(&text_mutex);
+	cpus_read_unlock();
 
 	return ret;
 }
@@ -1450,10 +1454,12 @@ int bpf_arch_text_invalidate(void *dst, size_t len)
 	for (i = 0; i < (len / sizeof(u32)); i++)
 		inst[i] = INSN_BREAK;
 
+	cpus_read_lock();
 	mutex_lock(&text_mutex);
 	if (larch_insn_text_copy(dst, inst, len))
 		ret = -EINVAL;
 	mutex_unlock(&text_mutex);
+	cpus_read_unlock();
 
 	kvfree(inst);
 
@@ -1568,6 +1574,11 @@ void arch_free_bpf_trampoline(void *image, unsigned int size)
 	bpf_prog_pack_free(image, size);
 }
 
+int arch_protect_bpf_trampoline(void *image, unsigned int size)
+{
+	return 0;
+}
+
 /*
  * Sign-extend the register if necessary
  */