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 decompressor_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
126 void print_stacktrace(unsigned long sp)
127 {
128 struct stack_info boot_stack = { STACK_TYPE_TASK, (unsigned long)_stack_start,
129 (unsigned long)_stack_end };
130 bool first = true;
131
132 decompressor_printk("Call Trace:\n");
133 while (!(sp & 0x7) && on_stack(&boot_stack, sp, sizeof(struct stack_frame))) {
134 struct stack_frame *sf = (struct stack_frame *)sp;
135
136 decompressor_printk(first ? "(sp:%016lx [<%016lx>] %pS)\n" :
137 " sp:%016lx [<%016lx>] %pS\n",
138 sp, sf->gprs[8], (void *)sf->gprs[8]);
139 if (sf->back_chain <= sp)
140 break;
141 sp = sf->back_chain;
142 first = false;
143 }
144 }
145
146 void print_pgm_check_info(void)
147 {
148 unsigned long *gpregs = (unsigned long *)get_lowcore()->gpregs_save_area;
149 struct psw_bits *psw = &psw_bits(get_lowcore()->psw_save_area);
150
151 decompressor_printk("Linux version %s\n", kernel_version);
152 if (!is_prot_virt_guest() && early_command_line[0])
153 decompressor_printk("Kernel command line: %s\n", early_command_line);
154 decompressor_printk("Kernel fault: interruption code %04x ilc:%x\n",
155 get_lowcore()->pgm_code, get_lowcore()->pgm_ilc >> 1);
156 if (kaslr_enabled()) {
157 decompressor_printk("Kernel random base: %lx\n", __kaslr_offset);
158 decompressor_printk("Kernel random base phys: %lx\n", __kaslr_offset_phys);
159 }
160 decompressor_printk("PSW : %016lx %016lx (%pS)\n",
161 get_lowcore()->psw_save_area.mask,
162 get_lowcore()->psw_save_area.addr,
163 (void *)get_lowcore()->psw_save_area.addr);
164 decompressor_printk(
165 " R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x P:%x AS:%x CC:%x PM:%x RI:%x EA:%x\n",
166 psw->per, psw->dat, psw->io, psw->ext, psw->key, psw->mcheck,
167 psw->wait, psw->pstate, psw->as, psw->cc, psw->pm, psw->ri,
168 psw->eaba);
169 decompressor_printk("GPRS: %016lx %016lx %016lx %016lx\n",
170 gpregs[0], gpregs[1], gpregs[2], gpregs[3]);
171 decompressor_printk(" %016lx %016lx %016lx %016lx\n",
172 gpregs[4], gpregs[5], gpregs[6], gpregs[7]);
173 decompressor_printk(" %016lx %016lx %016lx %016lx\n",
174 gpregs[8], gpregs[9], gpregs[10], gpregs[11]);
175 decompressor_printk(" %016lx %016lx %016lx %016lx\n",
176 gpregs[12], gpregs[13], gpregs[14], gpregs[15]);
177 print_stacktrace(get_lowcore()->gpregs_save_area[15]);
178 decompressor_printk("Last Breaking-Event-Address:\n");
179 decompressor_printk(" [<%016lx>] %pS\n", (unsigned long)get_lowcore()->pgm_last_break,
180 (void *)get_lowcore()->pgm_last_break);
181 }
182
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