6  * using an alternate signal stack, with the default pkey (pkey 0) disabled.
128 	/* After we disable MPK 0, we can't access the stack to return */  in thread_segv_pkuerr_stack()
134 	stack_t *stack = ptr;  in thread_segv_maperr_ptr()  local
138 	 * Setup alternate signal stack, which should be pkey_mprotect()ed by  in thread_segv_maperr_ptr()
139 	 * MPK 0. The thread's stack cannot be used for signals because it is  in thread_segv_maperr_ptr()
142 	syscall_raw(SYS_sigaltstack, (long)stack, 0, 0, 0, 0, 0);  in thread_segv_maperr_ptr()
155  * Note that the new thread stack and the alternate signal stack is
193  * Note that the new thread stack and the alternate signal stack is
231  * Verify that the sigsegv handler that uses an alternate signal stack
233  * its own stack, and disables all other MPKs (including 0).
239 	void *stack;  in test_sigsegv_handler_with_different_pkey_for_stack()  local
254 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,  in test_sigsegv_handler_with_different_pkey_for_stack()
257 	assert(stack != MAP_FAILED);  in test_sigsegv_handler_with_different_pkey_for_stack()
262 	/* Protect the new stack with MPK 1 */  in test_sigsegv_handler_with_different_pkey_for_stack()
264 	pkey_mprotect(stack, STACK_SIZE, PROT_READ | PROT_WRITE, pkey);  in test_sigsegv_handler_with_different_pkey_for_stack()
266 	/* Set up alternate signal stack that will use the default MPK */  in test_sigsegv_handler_with_different_pkey_for_stack()
280 			       (long) ((char *)(stack) + STACK_SIZE),  in test_sigsegv_handler_with_different_pkey_for_stack()
342 	 * the stack and the code could access it via an offset from the program  in thread_sigusr2_self()
343 	 * counter. This makes sure it's on the function's stack frame.  in thread_sigusr2_self()
349 	stack_t *stack = ptr;  in thread_sigusr2_self()  local
352 	 * Setup alternate signal stack, which should be pkey_mprotect()ed by  in thread_sigusr2_self()
353 	 * MPK 0. The thread's stack cannot be used for signals because it is  in thread_sigusr2_self()
356 	syscall(SYS_sigaltstack, (long)stack, 0, 0, 0, 0, 0);  in thread_sigusr2_self()
368 	 * will attempt to use a %rbp value which is on the stack  in thread_sigusr2_self()
383 	void *stack;  in test_pkru_sigreturn()  local
410 	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,  in test_pkru_sigreturn()
413 	assert(stack != MAP_FAILED);  in test_pkru_sigreturn()
417 	 * later in this flow) will have its stack protected by MPK 2, whereas  in test_pkru_sigreturn()
418 	 * the current thread's stack is protected by the default MPK 0. Hence  in test_pkru_sigreturn()
423 	/* Protect the stack with MPK 2 */  in test_pkru_sigreturn()
425 	pkey_mprotect(stack, STACK_SIZE, PROT_READ | PROT_WRITE, pkey);  in test_pkru_sigreturn()
427 	/* Set up alternate signal stack that will use the default MPK */  in test_pkru_sigreturn()
439 			       (long) ((char *)(stack) + STACK_SIZE),  in test_pkru_sigreturn()