1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/stdarg.h>
4 #include <linux/string.h>
5 #include <linux/ctype.h>
6 #include <asm/stacktrace.h>
7 #include <asm/boot_data.h>
8 #include <asm/lowcore.h>
9 #include <asm/setup.h>
10 #include <asm/sclp.h>
11 #include <asm/uv.h>
12 #include "boot.h"
13
14 const char hex_asc[] = "0123456789abcdef";
15
16 static char *as_hex(char *dst, unsigned long val, int pad)
17 {
18 char *p, *end = p = dst + max(pad, (int)__fls(val | 1) / 4 + 1);
19
20 for (*p-- = 0; p >= dst; val >>= 4)
21 *p-- = hex_asc[val & 0x0f];
22 return end;
23 }
24
25 static char *symstart(char *p)
26 {
27 while (*p)
28 p--;
29 return p + 1;
30 }
31
32 static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
33 {
34 /* symbol entries are in a form "10000 c4 startup\0" */
35 char *a = _decompressor_syms_start;
36 char *b = _decompressor_syms_end;
37 unsigned long start;
38 unsigned long size;
39 char *pivot;
40 char *endp;
41
42 while (a < b) {
43 pivot = symstart(a + (b - a) / 2);
44 start = simple_strtoull(pivot, &endp, 16);
45 size = simple_strtoull(endp + 1, &endp, 16);
46 if (ip < start) {
47 b = pivot;
48 continue;
49 }
50 if (ip > start + size) {
51 a = pivot + strlen(pivot) + 1;
52 continue;
53 }
54 *off = ip - start;
55 *len = size;
56 return endp + 1;
57 }
58 return NULL;
59 }
60
61 static noinline char *strsym(void *ip)
62 {
63 static char buf[64];
64 unsigned short off;
65 unsigned short len;
66 char *p;
67
68 p = findsym((unsigned long)ip, &off, &len);
69 if (p) {
70 strncpy(buf, p, sizeof(buf));
71 /* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
72 p = buf + strnlen(buf, sizeof(buf) - 15);
73 strcpy(p, "+0x");
74 p = as_hex(p + 3, off, 0);
75 strcpy(p, "/0x");
76 as_hex(p + 3, len, 0);
77 } else {
78 as_hex(buf, (unsigned long)ip, 16);
79 }
80 return buf;
81 }
82
83 void boot_printk(const char *fmt, ...)
84 {
85 char buf[1024] = { 0 };
86 char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
87 unsigned long pad;
88 char *p = buf;
89 va_list args;
90
91 va_start(args, fmt);
92 for (; p < end && *fmt; fmt++) {
93 if (*fmt != '%') {
94 *p++ = *fmt;
95 continue;
96 }
97 pad = isdigit(*++fmt) ? simple_strtol(fmt, (char **)&fmt, 10) : 0;
98 switch (*fmt) {
99 case 's':
100 p = buf + strlcat(buf, va_arg(args, char *), sizeof(buf));
101 break;
102 case 'p':
103 if (*++fmt != 'S')
104 goto out;
105 p = buf + strlcat(buf, strsym(va_arg(args, void *)), sizeof(buf));
106 break;
107 case 'l':
108 if (*++fmt != 'x' || end - p <= max(sizeof(long) * 2, pad))
109 goto out;
110 p = as_hex(p, va_arg(args, unsigned long), pad);
111 break;
112 case 'x':
113 if (end - p <= max(sizeof(int) * 2, pad))
114 goto out;
115 p = as_hex(p, va_arg(args, unsigned int), pad);
116 break;
117 default:
118 goto out;
119 }
120 }
121 out:
122 va_end(args);
123 sclp_early_printk(buf);
124 }
125
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