1 // SPDX-License-Identifier: GPL-2.0-only
3  * sigreturn.c - tests that x86 avoids Intel SYSRET pitfalls
4  * Copyright (c) 2014-2016 Andrew Lutomirski
45 	if (rip != ctx->uc_mcontext.gregs[REG_RIP]) {  in sigsegv_for_sigreturn_test()
47 		       rip, (unsigned long)ctx->uc_mcontext.gregs[REG_RIP]);  in sigsegv_for_sigreturn_test()
49 		_exit(1);  in sigsegv_for_sigreturn_test()
52 	memcpy(&ctx->uc_mcontext.gregs, &initial_regs, sizeof(gregset_t));  in sigsegv_for_sigreturn_test()
61 	memcpy(&initial_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t));  in sigusr1()
64 	ctx->uc_mcontext.gregs[REG_RIP] = rip;  in sigusr1()
65 	ctx->uc_mcontext.gregs[REG_RCX] = rip;  in sigusr1()
68 	assert(ctx->uc_mcontext.gregs[REG_EFL] ==  in sigusr1()
69 	       ctx->uc_mcontext.gregs[REG_R11]);  in sigusr1()
89 	if (rip != ctx->uc_mcontext.gregs[REG_RIP]) {  in sigsegv_for_fallthrough()
91 		       rip, (unsigned long)ctx->uc_mcontext.gregs[REG_RIP]);  in sigsegv_for_fallthrough()
93 		_exit(1);  in sigsegv_for_fallthrough()
96 	siglongjmp(jmpbuf, 1);  in sigsegv_for_fallthrough()
101 	void *new_address = (void *)(ip - 4096);  in test_syscall_fallthrough_to()
109 		if (ip <= (1UL << 47) - PAGE_SIZE) {  in test_syscall_fallthrough_to()
110 			err(1, "mremap to %p", new_address);  in test_syscall_fallthrough_to()
118 		errx(1, "mremap malfunctioned: asked for %p but got %p\n",  in test_syscall_fallthrough_to()
124 	if (sigsetjmp(jmpbuf, 1) == 0) {  in test_syscall_fallthrough_to()
126 			      [syscall_insn] "rm" (ip - 2));  in test_syscall_fallthrough_to()
127 		errx(1, "[FAIL]\tSyscall trampoline returned");  in test_syscall_fallthrough_to()
136 	 * When the kernel returns from a slow-path syscall, it will  in main()
142 	for (int i = 47; i < 64; i++)  in main()
143 		test_sigreturn_to(1UL<<i);  in main()
150 	test_syscall_fallthrough_to((1UL << 47) - 2*PAGE_SIZE);  in main()
153 	for (int i = 47; i < 64; i++) {  in main()
154 		test_syscall_fallthrough_to((1UL<<i) - PAGE_SIZE);  in main()
155 		test_syscall_fallthrough_to(1UL<<i);  in main()