xref: /optee_os/ldelf/ftrace.c (revision 03121b2ca443384ef046706498a11dbfb9dc931c)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2019, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <printk.h>
8 #include <sys/queue.h>
9 #include <types_ext.h>
10 #include <util.h>
11 #include <user_ta_header.h>
12 
13 #include "ftrace.h"
14 #include "ta_elf.h"
15 
16 #define MIN_FTRACE_BUF_SIZE	1024
17 #define MAX_HEADER_STRLEN	128
18 
19 static struct __ftrace_info *finfo;
20 static struct ftrace_buf *fbuf;
21 
22 bool ftrace_init(void)
23 {
24 	struct ta_elf *elf = TAILQ_FIRST(&main_elf_queue);
25 	TEE_Result res = TEE_SUCCESS;
26 	vaddr_t val = 0;
27 	int count = 0;
28 	size_t fbuf_size = 0;
29 
30 	res = ta_elf_resolve_sym("__ftrace_info", &val);
31 	if (res)
32 		return false;
33 
34 	finfo = (struct __ftrace_info *)val;
35 
36 	assert(elf && elf->is_main);
37 
38 	if (SUB_OVERFLOW(finfo->buf_end, finfo->buf_start, &fbuf_size))
39 		return false;
40 
41 	if (fbuf_size < MIN_FTRACE_BUF_SIZE) {
42 		DMSG("ftrace buffer too small");
43 		return false;
44 	}
45 
46 	fbuf = (struct ftrace_buf *)finfo->buf_start;
47 	fbuf->head_off = sizeof(struct ftrace_buf);
48 	count = snprintk((char *)fbuf + fbuf->head_off, MAX_HEADER_STRLEN,
49 			 "Function graph for TA: %pUl @ %lx\n",
50 			 (void *)&elf->uuid, elf->load_addr);
51 	assert(count < MAX_HEADER_STRLEN);
52 
53 	fbuf->ret_func_ptr = finfo->ret_ptr;
54 	fbuf->ret_idx = 0;
55 	fbuf->lr_idx = 0;
56 	fbuf->buf_off = fbuf->head_off + count;
57 	fbuf->curr_size = 0;
58 	fbuf->max_size = fbuf_size - sizeof(struct ftrace_buf) - count;
59 
60 	return true;
61 }
62 
63 void ftrace_copy_buf(void *pctx, void (*copy_func)(void *pctx, void *b,
64 						   size_t bl))
65 {
66 	if (fbuf) {
67 		struct ta_elf *elf = TAILQ_FIRST(&main_elf_queue);
68 		size_t dump_size = fbuf->buf_off - fbuf->head_off +
69 				   fbuf->curr_size;
70 
71 		assert(elf && elf->is_main);
72 		copy_func(pctx, (char *)fbuf + fbuf->head_off, dump_size);
73 	}
74 }
75 
76 void ftrace_map_lr(uint64_t *lr)
77 {
78 	if (fbuf) {
79 		if (*lr == fbuf->ret_func_ptr &&
80 		    fbuf->lr_idx < fbuf->ret_idx) {
81 			fbuf->lr_idx++;
82 			*lr = fbuf->ret_stack[fbuf->ret_idx - fbuf->lr_idx];
83 		}
84 	}
85 }
86