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
43 		err(1, "sigaction");  in sethandler()
53 		err(1, "sigaction");  in clearhandler()
65 	if (rip != ctx->uc_mcontext.gregs[REG_RIP]) {  in sigsegv_for_sigreturn_test()
67 		       rip, (unsigned long)ctx->uc_mcontext.gregs[REG_RIP]);  in sigsegv_for_sigreturn_test()
69 		_exit(1);  in sigsegv_for_sigreturn_test()
72 	memcpy(&ctx->uc_mcontext.gregs, &initial_regs, sizeof(gregset_t));  in sigsegv_for_sigreturn_test()
81 	memcpy(&initial_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t));  in sigusr1()
84 	ctx->uc_mcontext.gregs[REG_RIP] = rip;  in sigusr1()
85 	ctx->uc_mcontext.gregs[REG_RCX] = rip;  in sigusr1()
88 	assert(ctx->uc_mcontext.gregs[REG_EFL] ==  in sigusr1()
89 	       ctx->uc_mcontext.gregs[REG_R11]);  in sigusr1()
109 	if (rip != ctx->uc_mcontext.gregs[REG_RIP]) {  in sigsegv_for_fallthrough()
111 		       rip, (unsigned long)ctx->uc_mcontext.gregs[REG_RIP]);  in sigsegv_for_fallthrough()
113 		_exit(1);  in sigsegv_for_fallthrough()
116 	siglongjmp(jmpbuf, 1);  in sigsegv_for_fallthrough()
121 	void *new_address = (void *)(ip - 4096);  in test_syscall_fallthrough_to()
129 		if (ip <= (1UL << 47) - PAGE_SIZE) {  in test_syscall_fallthrough_to()
130 			err(1, "mremap to %p", new_address);  in test_syscall_fallthrough_to()
138 		errx(1, "mremap malfunctioned: asked for %p but got %p\n",  in test_syscall_fallthrough_to()
144 	if (sigsetjmp(jmpbuf, 1) == 0) {  in test_syscall_fallthrough_to()
146 			      [syscall_insn] "rm" (ip - 2));  in test_syscall_fallthrough_to()
147 		errx(1, "[FAIL]\tSyscall trampoline returned");  in test_syscall_fallthrough_to()
156 	 * When the kernel returns from a slow-path syscall, it will  in main()
162 	for (int i = 47; i < 64; i++)  in main()
163 		test_sigreturn_to(1UL<<i);  in main()
170 	test_syscall_fallthrough_to((1UL << 47) - 2*PAGE_SIZE);  in main()
173 	for (int i = 47; i < 64; i++) {  in main()
174 		test_syscall_fallthrough_to((1UL<<i) - PAGE_SIZE);  in main()
175 		test_syscall_fallthrough_to(1UL<<i);  in main()