1*4d495c6eSApple OSS Distributions /* 2*4d495c6eSApple OSS Distributions * Copyright (c) 2021 Apple Inc. All rights reserved. 3*4d495c6eSApple OSS Distributions * 4*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5*4d495c6eSApple OSS Distributions * 6*4d495c6eSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code 7*4d495c6eSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License 8*4d495c6eSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in 9*4d495c6eSApple OSS Distributions * compliance with the License. The rights granted to you under the License 10*4d495c6eSApple OSS Distributions * may not be used to create, or enable the creation or redistribution of, 11*4d495c6eSApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to 12*4d495c6eSApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any 13*4d495c6eSApple OSS Distributions * terms of an Apple operating system software license agreement. 14*4d495c6eSApple OSS Distributions * 15*4d495c6eSApple OSS Distributions * Please obtain a copy of the License at 16*4d495c6eSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file. 17*4d495c6eSApple OSS Distributions * 18*4d495c6eSApple OSS Distributions * The Original Code and all software distributed under the License are 19*4d495c6eSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20*4d495c6eSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21*4d495c6eSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22*4d495c6eSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23*4d495c6eSApple OSS Distributions * Please see the License for the specific language governing rights and 24*4d495c6eSApple OSS Distributions * limitations under the License. 25*4d495c6eSApple OSS Distributions * 26*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27*4d495c6eSApple OSS Distributions */ 28*4d495c6eSApple OSS Distributions 29*4d495c6eSApple OSS Distributions #include "context_helpers.h" 30*4d495c6eSApple OSS Distributions #include <darwintest.h> 31*4d495c6eSApple OSS Distributions #include <sys/types.h> 32*4d495c6eSApple OSS Distributions #include <sys/sysctl.h> 33*4d495c6eSApple OSS Distributions #include <stdbool.h> 34*4d495c6eSApple OSS Distributions #include <unistd.h> 35*4d495c6eSApple OSS Distributions 36*4d495c6eSApple OSS Distributions T_GLOBAL_META( 37*4d495c6eSApple OSS Distributions T_META_NAMESPACE("xnu.arm"), 38*4d495c6eSApple OSS Distributions T_META_RADAR_COMPONENT_NAME("xnu"), 39*4d495c6eSApple OSS Distributions T_META_RADAR_COMPONENT_VERSION("arm"), 40*4d495c6eSApple OSS Distributions T_META_OWNER("joster"), 41*4d495c6eSApple OSS Distributions T_META_RUN_CONCURRENTLY(true), 42*4d495c6eSApple OSS Distributions T_META_TAG_VM_PREFERRED); 43*4d495c6eSApple OSS Distributions 44*4d495c6eSApple OSS Distributions T_DECL(x18_unentitled, 45*4d495c6eSApple OSS Distributions "Test that x18 is trashed when unentitled.") 46*4d495c6eSApple OSS Distributions { 47*4d495c6eSApple OSS Distributions #ifndef __arm64__ 48*4d495c6eSApple OSS Distributions T_SKIP("Running on non-arm64 target, skipping..."); 49*4d495c6eSApple OSS Distributions #else 50*4d495c6eSApple OSS Distributions bool did_csw = false; 51*4d495c6eSApple OSS Distributions uint64_t x18_val; 52*4d495c6eSApple OSS Distributions 53*4d495c6eSApple OSS Distributions for (uint64_t i = 0xFEEDB0B000000000ULL; i < 0xFEEDB0B000000000ULL + 10000; ++i) { 54*4d495c6eSApple OSS Distributions asm volatile ("mov x18, %0" : : "r"(i)); 55*4d495c6eSApple OSS Distributions int32_t const nr_csw = get_csw_count(); 56*4d495c6eSApple OSS Distributions int const rc = usleep(10); 57*4d495c6eSApple OSS Distributions int32_t const nr_csw_after = get_csw_count(); 58*4d495c6eSApple OSS Distributions 59*4d495c6eSApple OSS Distributions // There isn't any guarantee usleep() will actually context switch so this is a best effort way 60*4d495c6eSApple OSS Distributions // to see if we've switched at least once in all these iterations. 61*4d495c6eSApple OSS Distributions did_csw = did_csw || (nr_csw_after > nr_csw); 62*4d495c6eSApple OSS Distributions T_QUIET; T_ASSERT_EQ(0, rc, "usleep"); 63*4d495c6eSApple OSS Distributions asm volatile ("mov %0, x18" : "=r"(x18_val)); 64*4d495c6eSApple OSS Distributions T_QUIET; T_ASSERT_EQ(x18_val, 0ULL, "check that x18 is cleared after yield"); 65*4d495c6eSApple OSS Distributions } 66*4d495c6eSApple OSS Distributions 67*4d495c6eSApple OSS Distributions T_QUIET; T_ASSERT_TRUE(did_csw, "did not context switch, but should have."); 68*4d495c6eSApple OSS Distributions #endif 69*4d495c6eSApple OSS Distributions } 70