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Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Fri,  3 Jun 2022 00:43:31 +0000
In-Reply-To: <20220603004331.1523888-1-seanjc@google.com>
Message-Id: <20220603004331.1523888-145-seanjc@google.com>
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Subject: [PATCH v2 144/144] KVM: selftests: Sanity check input to ioctls() at
 build time
From:   Sean Christopherson <seanjc@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     kvm@vger.kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>,
        Andrew Jones <drjones@redhat.com>,
        David Matlack <dmatlack@google.com>,
        Ben Gardon <bgardon@google.com>,
        Oliver Upton <oupton@google.com>, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Add a static assert to the KVM/VM/vCPU ioctl() helpers to verify that the
size of the argument provided matches the expected size of the IOCTL.
Because ioctl() ultimately takes a "void *", it's all too easy to pass in
garbage and not detect the error until runtime.  E.g. while working on a
CPUID rework, selftests happily compiled when vcpu_set_cpuid()
unintentionally passed the cpuid() function as the parameter to ioctl()
(a local "cpuid" parameter was removed, but its use was not replaced with
"vcpu->cpuid" as intended).

Tweak a variety of benign issues that aren't compatible with the sanity
check, e.g. passing a non-pointer for ioctls().

Note, static_assert() requires a string on older versions of GCC.  Feed
it an empty string to make the compiler happy.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     | 61 +++++++++++++------
 .../selftests/kvm/lib/aarch64/processor.c     |  2 +-
 tools/testing/selftests/kvm/lib/guest_modes.c |  2 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    | 29 +--------
 tools/testing/selftests/kvm/s390x/resets.c    |  6 +-
 .../selftests/kvm/x86_64/mmio_warning_test.c  |  2 +-
 .../kvm/x86_64/pmu_event_filter_test.c        |  2 +-
 .../selftests/kvm/x86_64/xen_shinfo_test.c    |  6 +-
 8 files changed, 56 insertions(+), 54 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 04ddab322b6b..0eaf0c9b7612 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -180,29 +180,56 @@ static inline bool kvm_has_cap(long cap)
 #define __KVM_IOCTL_ERROR(_name, _ret)	__KVM_SYSCALL_ERROR(_name, _ret)
 #define KVM_IOCTL_ERROR(_ioctl, _ret) __KVM_IOCTL_ERROR(#_ioctl, _ret)
 
-#define __kvm_ioctl(kvm_fd, cmd, arg) \
-	ioctl(kvm_fd, cmd, arg)
+#define kvm_do_ioctl(fd, cmd, arg)						\
+({										\
+	static_assert(!_IOC_SIZE(cmd) || sizeof(*arg) == _IOC_SIZE(cmd), "");	\
+	ioctl(fd, cmd, arg);							\
+})
 
-static inline void _kvm_ioctl(int kvm_fd, unsigned long cmd, const char *name,
-			      void *arg)
-{
-	int ret = __kvm_ioctl(kvm_fd, cmd, arg);
+#define __kvm_ioctl(kvm_fd, cmd, arg)						\
+	kvm_do_ioctl(kvm_fd, cmd, arg)
 
-	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));
-}
+
+#define _kvm_ioctl(kvm_fd, cmd, name, arg)					\
+({										\
+	int ret = __kvm_ioctl(kvm_fd, cmd, arg);				\
+										\
+	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));			\
+})
 
 #define kvm_ioctl(kvm_fd, cmd, arg) \
 	_kvm_ioctl(kvm_fd, cmd, #cmd, arg)
 
-int __vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg);
-void _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, const char *name, void *arg);
-#define vm_ioctl(vm, cmd, arg) _vm_ioctl(vm, cmd, #cmd, arg)
-
-int __vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long cmd,
-		 void *arg);
-void _vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long cmd,
-		 const char *name, void *arg);
-#define vcpu_ioctl(vcpu, cmd, arg) \
+#define __vm_ioctl(vm, cmd, arg)						\
+({										\
+	static_assert(sizeof(*(vm)) == sizeof(struct kvm_vm), "");		\
+	kvm_do_ioctl((vm)->fd, cmd, arg);					\
+})
+
+#define _vm_ioctl(vcpu, cmd, name, arg)						\
+({										\
+	int ret = __vm_ioctl(vcpu, cmd, arg);					\
+										\
+	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));			\
+})
+
+#define vm_ioctl(vm, cmd, arg)							\
+	_vm_ioctl(vm, cmd, #cmd, arg)
+
+#define __vcpu_ioctl(vcpu, cmd, arg)						\
+({										\
+	static_assert(sizeof(*(vcpu)) == sizeof(struct kvm_vcpu), "");		\
+	kvm_do_ioctl((vcpu)->fd, cmd, arg);					\
+})
+
+#define _vcpu_ioctl(vcpu, cmd, name, arg)					\
+({										\
+	int ret = __vcpu_ioctl(vcpu, cmd, arg);					\
+										\
+	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));			\
+})
+
+#define vcpu_ioctl(vcpu, cmd, arg)						\
 	_vcpu_ioctl(vcpu, cmd, #cmd, arg)
 
 /*
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 6bd27782f00c..6f5551368944 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -472,7 +472,7 @@ void aarch64_get_supported_page_sizes(uint32_t ipa,
 	};
 
 	kvm_fd = open_kvm_dev_path_or_exit();
-	vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, ipa);
+	vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, (void *)(unsigned long)ipa);
 	TEST_ASSERT(vm_fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VM, vm_fd));
 
 	vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
diff --git a/tools/testing/selftests/kvm/lib/guest_modes.c b/tools/testing/selftests/kvm/lib/guest_modes.c
index 0be56c63aed6..99a575bbbc52 100644
--- a/tools/testing/selftests/kvm/lib/guest_modes.c
+++ b/tools/testing/selftests/kvm/lib/guest_modes.c
@@ -65,7 +65,7 @@ void guest_modes_append_default(void)
 		struct kvm_s390_vm_cpu_processor info;
 
 		kvm_fd = open_kvm_dev_path_or_exit();
-		vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, 0);
+		vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, NULL);
 		kvm_device_attr_get(vm_fd, KVM_S390_VM_CPU_MODEL,
 				    KVM_S390_VM_CPU_PROCESSOR, &info);
 		close(vm_fd);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 603a6d529357..f0300767df16 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -72,7 +72,7 @@ unsigned int kvm_check_cap(long cap)
 	int kvm_fd;
 
 	kvm_fd = open_kvm_dev_path_or_exit();
-	ret = __kvm_ioctl(kvm_fd, KVM_CHECK_EXTENSION, cap);
+	ret = __kvm_ioctl(kvm_fd, KVM_CHECK_EXTENSION, (void *)cap);
 	TEST_ASSERT(ret >= 0, KVM_IOCTL_ERROR(KVM_CHECK_EXTENSION, ret));
 
 	close(kvm_fd);
@@ -92,7 +92,7 @@ static void vm_open(struct kvm_vm *vm)
 
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_IMMEDIATE_EXIT));
 
-	vm->fd = __kvm_ioctl(vm->kvm_fd, KVM_CREATE_VM, vm->type);
+	vm->fd = __kvm_ioctl(vm->kvm_fd, KVM_CREATE_VM, (void *)vm->type);
 	TEST_ASSERT(vm->fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VM, vm->fd));
 }
 
@@ -1449,19 +1449,6 @@ struct kvm_reg_list *vcpu_get_reg_list(struct kvm_vcpu *vcpu)
 	return reg_list;
 }
 
-int __vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long cmd, void *arg)
-{
-	return ioctl(vcpu->fd, cmd, arg);
-}
-
-void _vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long cmd, const char *name,
-		 void *arg)
-{
-	int ret = __vcpu_ioctl(vcpu, cmd, arg);
-
-	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));
-}
-
 void *vcpu_map_dirty_ring(struct kvm_vcpu *vcpu)
 {
 	uint32_t page_size = vcpu->vm->page_size;
@@ -1491,18 +1478,6 @@ void *vcpu_map_dirty_ring(struct kvm_vcpu *vcpu)
 	return vcpu->dirty_gfns;
 }
 
-int __vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg)
-{
-	return ioctl(vm->fd, cmd, arg);
-}
-
-void _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, const char *name, void *arg)
-{
-	int ret = __vm_ioctl(vm, cmd, arg);
-
-	TEST_ASSERT(!ret, __KVM_IOCTL_ERROR(name, ret));
-}
-
 /*
  * Device Ioctl
  */
diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
index 4ba866047401..359fd18f473b 100644
--- a/tools/testing/selftests/kvm/s390x/resets.c
+++ b/tools/testing/selftests/kvm/s390x/resets.c
@@ -224,7 +224,7 @@ static void test_normal(void)
 
 	inject_irq(vcpu);
 
-	vcpu_ioctl(vcpu, KVM_S390_NORMAL_RESET, 0);
+	vcpu_ioctl(vcpu, KVM_S390_NORMAL_RESET, NULL);
 
 	/* must clears */
 	assert_normal(vcpu);
@@ -247,7 +247,7 @@ static void test_initial(void)
 
 	inject_irq(vcpu);
 
-	vcpu_ioctl(vcpu, KVM_S390_INITIAL_RESET, 0);
+	vcpu_ioctl(vcpu, KVM_S390_INITIAL_RESET, NULL);
 
 	/* must clears */
 	assert_normal(vcpu);
@@ -270,7 +270,7 @@ static void test_clear(void)
 
 	inject_irq(vcpu);
 
-	vcpu_ioctl(vcpu, KVM_S390_CLEAR_RESET, 0);
+	vcpu_ioctl(vcpu, KVM_S390_CLEAR_RESET, NULL);
 
 	/* must clears */
 	assert_normal(vcpu);
diff --git a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
index 0e4590afd0e1..fb02581953a3 100644
--- a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
+++ b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
@@ -59,7 +59,7 @@ void test(void)
 
 	kvm = open("/dev/kvm", O_RDWR);
 	TEST_ASSERT(kvm != -1, "failed to open /dev/kvm");
-	kvmvm = __kvm_ioctl(kvm, KVM_CREATE_VM, 0);
+	kvmvm = __kvm_ioctl(kvm, KVM_CREATE_VM, NULL);
 	TEST_ASSERT(kvmvm > 0, KVM_IOCTL_ERROR(KVM_CREATE_VM, kvmvm));
 	kvmcpu = ioctl(kvmvm, KVM_CREATE_VCPU, 0);
 	TEST_ASSERT(kvmcpu != -1, KVM_IOCTL_ERROR(KVM_CREATE_VCPU, kvmcpu));
diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
index de9ee00d84cf..66930384ef97 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
@@ -266,7 +266,7 @@ static void test_without_filter(struct kvm_vcpu *vcpu)
 static uint64_t test_with_filter(struct kvm_vcpu *vcpu,
 				 struct kvm_pmu_event_filter *f)
 {
-	vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, (void *)f);
+	vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f);
 	return run_vcpu_to_sync(vcpu);
 }
 
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index bdcb28186ccc..a4a78637c35a 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -472,7 +472,7 @@ int main(int argc, char *argv[])
 		irq_routes.entries[1].u.xen_evtchn.vcpu = vcpu->id;
 		irq_routes.entries[1].u.xen_evtchn.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
 
-		vm_ioctl(vm, KVM_SET_GSI_ROUTING, &irq_routes);
+		vm_ioctl(vm, KVM_SET_GSI_ROUTING, &irq_routes.info);
 
 		struct kvm_irqfd ifd = { };
 
@@ -716,7 +716,7 @@ int main(int argc, char *argv[])
 				if (verbose)
 					printf("Testing restored oneshot timer\n");
 
-				tmr.u.timer.expires_ns = rs->state_entry_time + 100000000,
+				tmr.u.timer.expires_ns = rs->state_entry_time + 100000000;
 				vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &tmr);
 				evtchn_irq_expected = true;
 				alarm(1);
@@ -743,7 +743,7 @@ int main(int argc, char *argv[])
 				if (verbose)
 					printf("Testing SCHEDOP_poll wake on masked event\n");
 
-				tmr.u.timer.expires_ns = rs->state_entry_time + 100000000,
+				tmr.u.timer.expires_ns = rs->state_entry_time + 100000000;
 				vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &tmr);
 				alarm(1);
 				break;
-- 
2.36.1.255.ge46751e96f-goog