Commit fcba483e authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: selftests: Sanity check input to ioctls() at build time 



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: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5321270b

tools/testing/selftests/kvm/include/kvm_util_base.h

+43 −16
Original line number Diff line number Diff line
@@ -180,28 +180,55 @@ 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_do_ioctl(fd, cmd, arg)						\

({										\

	static_assert(!_IOC_SIZE(cmd) || sizeof(*arg) == _IOC_SIZE(cmd), "");	\

	ioctl(fd, cmd, arg);							\

})



#define __kvm_ioctl(kvm_fd, cmd, arg)						\

	ioctl(kvm_fd, cmd, arg)

	kvm_do_ioctl(kvm_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);



	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)

#define __vm_ioctl(vm, cmd, arg)						\

({										\

	static_assert(sizeof(*(vm)) == sizeof(struct kvm_vm), "");		\

	kvm_do_ioctl((vm)->fd, cmd, arg);					\

})



#define _vm_ioctl(vm, cmd, name, arg)						\

({										\

	int ret = __vm_ioctl(vm, 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));			\

})



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)						\

	_vcpu_ioctl(vcpu, cmd, #cmd, arg)

tools/testing/selftests/kvm/lib/aarch64/processor.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

tools/testing/selftests/kvm/lib/guest_modes.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

tools/testing/selftests/kvm/lib/kvm_util.c

+2 −27
Original line number Diff line number Diff line
@@ -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));

}
@@ -1450,19 +1450,6 @@ 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;
@@ -1492,18 +1479,6 @@ 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

 */

tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c

+3 −3
Original line number Diff line number Diff line
@@ -103,9 +103,9 @@ void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vc 
		 * Override the vCPU to run perf_test_l1_guest_code() which will

		 * bounce it into L2 before calling perf_test_guest_code().

		 */

		vcpu_regs_get(vm, vcpus[vcpu_id]->id, &regs);

		vcpu_regs_get(vcpus[vcpu_id], &regs);

		regs.rip = (unsigned long) perf_test_l1_guest_code;

		vcpu_regs_set(vm, vcpus[vcpu_id]->id, &regs);

		vcpu_args_set(vm, vcpus[vcpu_id]->id, 2, vmx_gva, vcpu_id);

		vcpu_regs_set(vcpus[vcpu_id], &regs);

		vcpu_args_set(vcpus[vcpu_id], 2, vmx_gva, vcpu_id);

	}

}