Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Stack trace management functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *  Copyright IBM Corp. 2006
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *  Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/unwind.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <asm/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 		     struct task_struct *task, struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	struct unwind_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	unsigned long addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	unwind_for_each_frame(&state, task, regs, 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 		addr = unwind_get_return_address(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 		if (!addr || !consume_entry(cookie, addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * This function returns an error if it detects any unreliable features of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  * stack.  Otherwise it guarantees that the stack trace is reliable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  * If the task is not 'current', the caller *must* ensure the task is inactive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 			     void *cookie, struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	struct unwind_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	unsigned long addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	unwind_for_each_frame(&state, task, NULL, 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		if (state.stack_info.type != STACK_TYPE_TASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 		if (state.regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		addr = unwind_get_return_address(&state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		if (!addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #ifdef CONFIG_KPROBES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		 * Mark stacktraces with kretprobed functions on them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		 * as unreliable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		if (state.ip == (unsigned long)kretprobe_trampoline)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		if (!consume_entry(cookie, addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 	/* Check for stack corruption */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	if (unwind_error(&state))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) }