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
14const char hex_asc[] = "0123456789abcdef";
15
16static 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
25static char *symstart(char *p)
26{
27	while (*p)
28		p--;
29	return p + 1;
30}
31
32static 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
61static 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
83void 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	}
121out:
122	va_end(args);
123	sclp_early_printk(buf);
124}
125
126void 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
146void print_pgm_check_info(void)
147{
148	unsigned long *gpregs = (unsigned long *)S390_lowcore.gpregs_save_area;
149	struct psw_bits *psw = &psw_bits(S390_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			    S390_lowcore.pgm_code, S390_lowcore.pgm_ilc >> 1);
156	if (kaslr_enabled())
157		decompressor_printk("Kernel random base: %lx\n", __kaslr_offset);
158	decompressor_printk("PSW : %016lx %016lx (%pS)\n",
159			    S390_lowcore.psw_save_area.mask,
160			    S390_lowcore.psw_save_area.addr,
161			    (void *)S390_lowcore.psw_save_area.addr);
162	decompressor_printk(
163		"      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",
164		psw->per, psw->dat, psw->io, psw->ext, psw->key, psw->mcheck,
165		psw->wait, psw->pstate, psw->as, psw->cc, psw->pm, psw->ri,
166		psw->eaba);
167	decompressor_printk("GPRS: %016lx %016lx %016lx %016lx\n",
168			    gpregs[0], gpregs[1], gpregs[2], gpregs[3]);
169	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
170			    gpregs[4], gpregs[5], gpregs[6], gpregs[7]);
171	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
172			    gpregs[8], gpregs[9], gpregs[10], gpregs[11]);
173	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
174			    gpregs[12], gpregs[13], gpregs[14], gpregs[15]);
175	print_stacktrace(S390_lowcore.gpregs_save_area[15]);
176	decompressor_printk("Last Breaking-Event-Address:\n");
177	decompressor_printk(" [<%016lx>] %pS\n", (unsigned long)S390_lowcore.pgm_last_break,
178			    (void *)S390_lowcore.pgm_last_break);
179}
180