1 // SPDX-License-Identifier: GPL-2.0+
8 #include <sys/wait.h>
13  * Child subroutine that performs a load on the address, then traps
24  * Child subroutine that performs a load on the first address, then a load on
126 	attr->type		= PERF_TYPE_BREAKPOINT;  in perf_user_event_attr_set()
127 	attr->size		= sizeof(struct perf_event_attr);  in perf_user_event_attr_set()
128 	attr->bp_type		= HW_BREAKPOINT_R;  in perf_user_event_attr_set()
129 	attr->bp_addr		= (u64)addr;  in perf_user_event_attr_set()
130 	attr->bp_len		= len;  in perf_user_event_attr_set()
131 	attr->exclude_kernel	= 1;  in perf_user_event_attr_set()
132 	attr->exclude_hv	= 1;  in perf_user_event_attr_set()
140 	return perf_event_open(&attr, child_pid, -1, -1, 0);  in perf_watchpoint_open()
146 	 * A perf counter is retrieved by the read() syscall. It contains  in perf_read_counter()
149 	ssize_t len = read(perf_fd, count, sizeof(*count));  in perf_read_counter()
152 		return -1;  in perf_read_counter()
160 	info->version = 1;  in ppc_ptrace_init_breakpoint()
161 	info->trigger_type = type;  in ppc_ptrace_init_breakpoint()
162 	info->condition_mode = PPC_BREAKPOINT_CONDITION_NONE;  in ppc_ptrace_init_breakpoint()
163 	info->addr = (u64)addr;  in ppc_ptrace_init_breakpoint()
164 	info->addr2 = (u64)addr + len;  in ppc_ptrace_init_breakpoint()
165 	info->condition_value = 0;  in ppc_ptrace_init_breakpoint()
167 		info->addr_mode = PPC_BREAKPOINT_MODE_EXACT;  in ppc_ptrace_init_breakpoint()
169 		info->addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE;  in ppc_ptrace_init_breakpoint()
173  * Checks if we can place at least 2 watchpoints on the child process
187  * ptrace-ing. Both the parent and child return from this, though
203 		/* Synchronise on child SIGSTOP */  in ptrace_fork_child()
204 		FAIL_IF_MSG(waitpid(*pid, &status, 0) == -1, "Failed to wait for child");  in ptrace_fork_child()
214  * We expect ptrace to take 'priority', as it is has before-execute
217  * The perf counter should not be incremented yet because perf has after-execute
234 	unsigned long value;	/* Dummy value to be read/written to by child */  in same_watch_addr_test()
250 	/* Place a perf watchpoint counter on value */  in same_watch_addr_test()
254 	/* Place a ptrace watchpoint on value */  in same_watch_addr_test()
259 	/* Let the child run. It should stop on the ptrace watchpoint */  in same_watch_addr_test()
262 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
265 	FAIL_IF_MSG(pc != same_watch_addr_load, "Child did not stop on load instruction");  in same_watch_addr_test()
271 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
277 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
281 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
285 	 * Set up a ptrace watchpoint on the value again and trigger it.  in same_watch_addr_test()
295 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
298 	FAIL_IF_MSG(pc != same_watch_addr_load, "Child did not stop on load trap");  in same_watch_addr_test()
299 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
305 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
308 	FAIL_IF_MSG(pc != same_watch_addr_trap, "Child did not stop on end trap");  in same_watch_addr_test()
309 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
314 	 * we should reach the end trap (because ptrace is one-shot) and have  in same_watch_addr_test()
320 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
323 	FAIL_IF_MSG(pc != same_watch_addr_trap, "Child did not stop on end trap");  in same_watch_addr_test()
324 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
329 	 * watchpoint on the load, then continue, we should immediately get  in same_watch_addr_test()
338 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
341 	FAIL_IF_MSG(pc != same_watch_addr_load, "Child did not stop on load instruction");  in same_watch_addr_test()
342 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
346 	 * If we change the PC while stopped on the load instruction, we should  in same_watch_addr_test()
347 	 * not increment the perf counter (because ptrace is before-execute,  in same_watch_addr_test()
348 	 * perf is after-execute).  in same_watch_addr_test()
353 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in same_watch_addr_test()
356 	FAIL_IF_MSG(pc != same_watch_addr_trap, "Child did not stop on end trap");  in same_watch_addr_test()
357 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in same_watch_addr_test()
370  * 3. The perf value is read, then the ptrace value is read immediately after
419 	/* Let the child run. It should stop on the ptrace watchpoint */  in perf_then_ptrace_test()
422 	FAIL_IF_MSG(waitpid(pid, &status, 0) == -1, "Failed to wait for child");  in perf_then_ptrace_test()
425 	FAIL_IF_MSG(pc != perf_then_ptrace_load2, "Child did not stop on ptrace load");  in perf_then_ptrace_test()
428 	FAIL_IF_MSG(perf_read_counter(perf_fd, &perf_count), "Failed to read perf counter");  in perf_then_ptrace_test()