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/sections.h>
9 #include <asm/lowcore.h>
10 #include <asm/setup.h>
11 #include <asm/sclp.h>
12 #include <asm/uv.h>
13 #include "boot.h"
14
15 int boot_console_loglevel = CONFIG_CONSOLE_LOGLEVEL_DEFAULT;
16 bool boot_ignore_loglevel;
17 char __bootdata(boot_rb)[PAGE_SIZE * 2];
18 bool __bootdata(boot_earlyprintk);
19 size_t __bootdata(boot_rb_off);
20 char __bootdata(bootdebug_filter)[128];
21 bool __bootdata(bootdebug);
22
boot_rb_add(const char * str,size_t len)23 static void boot_rb_add(const char *str, size_t len)
24 {
25 /* leave double '\0' in the end */
26 size_t avail = sizeof(boot_rb) - boot_rb_off - 1;
27
28 /* store strings separated by '\0' */
29 if (len + 1 > avail)
30 boot_rb_off = 0;
31 strcpy(boot_rb + boot_rb_off, str);
32 boot_rb_off += len + 1;
33 }
34
print_rb_entry(const char * str)35 static void print_rb_entry(const char *str)
36 {
37 sclp_early_printk(printk_skip_level(str));
38 }
39
debug_messages_printed(void)40 static bool debug_messages_printed(void)
41 {
42 return boot_earlyprintk && (boot_ignore_loglevel || boot_console_loglevel > LOGLEVEL_DEBUG);
43 }
44
boot_rb_dump(void)45 void boot_rb_dump(void)
46 {
47 if (debug_messages_printed())
48 return;
49 sclp_early_printk("Boot messages ring buffer:\n");
50 boot_rb_foreach(print_rb_entry);
51 }
52
53 const char hex_asc[] = "0123456789abcdef";
54
as_hex(char * dst,unsigned long val,int pad)55 static char *as_hex(char *dst, unsigned long val, int pad)
56 {
57 char *p = dst + max(pad, (int)__fls(val | 1) / 4 + 1);
58
59 for (*p-- = '\0'; p >= dst; val >>= 4)
60 *p-- = hex_asc[val & 0x0f];
61 return dst;
62 }
63
64 #define MAX_NUMLEN 21
as_dec(char * buf,unsigned long val,bool is_signed)65 static char *as_dec(char *buf, unsigned long val, bool is_signed)
66 {
67 bool negative = false;
68 char *p = buf + MAX_NUMLEN;
69
70 if (is_signed && (long)val < 0) {
71 val = (val == LONG_MIN ? LONG_MIN : -(long)val);
72 negative = true;
73 }
74
75 *--p = '\0';
76 do {
77 *--p = '0' + (val % 10);
78 val /= 10;
79 } while (val);
80
81 if (negative)
82 *--p = '-';
83 return p;
84 }
85
strpad(char * dst,size_t dst_size,const char * src,int _pad,bool zero_pad,bool decimal)86 static ssize_t strpad(char *dst, size_t dst_size, const char *src,
87 int _pad, bool zero_pad, bool decimal)
88 {
89 ssize_t len = strlen(src), pad = _pad;
90 char *p = dst;
91
92 if (max(len, abs(pad)) >= dst_size)
93 return -E2BIG;
94
95 if (pad > len) {
96 if (decimal && zero_pad && *src == '-') {
97 *p++ = '-';
98 src++;
99 len--;
100 pad--;
101 }
102 memset(p, zero_pad ? '0' : ' ', pad - len);
103 p += pad - len;
104 }
105 memcpy(p, src, len);
106 p += len;
107 if (pad < 0 && -pad > len) {
108 memset(p, ' ', -pad - len);
109 p += -pad - len;
110 }
111 *p = '\0';
112 return p - dst;
113 }
114
symstart(char * p)115 static char *symstart(char *p)
116 {
117 while (*p)
118 p--;
119 return p + 1;
120 }
121
findsym(unsigned long ip,unsigned short * off,unsigned short * len)122 static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
123 {
124 /* symbol entries are in a form "10000 c4 startup\0" */
125 char *a = _decompressor_syms_start;
126 char *b = _decompressor_syms_end;
127 unsigned long start;
128 unsigned long size;
129 char *pivot;
130 char *endp;
131
132 while (a < b) {
133 pivot = symstart(a + (b - a) / 2);
134 start = simple_strtoull(pivot, &endp, 16);
135 size = simple_strtoull(endp + 1, &endp, 16);
136 if (ip < start) {
137 b = pivot;
138 continue;
139 }
140 if (ip > start + size) {
141 a = pivot + strlen(pivot) + 1;
142 continue;
143 }
144 *off = ip - start;
145 *len = size;
146 return endp + 1;
147 }
148 return NULL;
149 }
150
151 #define MAX_SYMLEN 64
strsym(char * buf,void * ip)152 static noinline char *strsym(char *buf, void *ip)
153 {
154 unsigned short off;
155 unsigned short len;
156 char *p;
157
158 p = findsym((unsigned long)ip, &off, &len);
159 if (p) {
160 strncpy(buf, p, MAX_SYMLEN);
161 /* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
162 p = buf + strnlen(buf, MAX_SYMLEN - 15);
163 strcpy(p, "+0x");
164 as_hex(p + 3, off, 0);
165 strcat(p, "/0x");
166 as_hex(p + strlen(p), len, 0);
167 } else {
168 as_hex(buf, (unsigned long)ip, 16);
169 }
170 return buf;
171 }
172
printk_loglevel(const char * buf)173 static inline int printk_loglevel(const char *buf)
174 {
175 if (buf[0] == KERN_SOH_ASCII && buf[1]) {
176 switch (buf[1]) {
177 case '0' ... '7':
178 return buf[1] - '0';
179 }
180 }
181 return MESSAGE_LOGLEVEL_DEFAULT;
182 }
183
boot_console_earlyprintk(const char * buf)184 static void boot_console_earlyprintk(const char *buf)
185 {
186 int level = printk_loglevel(buf);
187
188 /* always print emergency messages */
189 if (level > LOGLEVEL_EMERG && !boot_earlyprintk)
190 return;
191 buf = printk_skip_level(buf);
192 /* print debug messages only when bootdebug is enabled */
193 if (level == LOGLEVEL_DEBUG && (!bootdebug || !bootdebug_filter_match(skip_timestamp(buf))))
194 return;
195 if (boot_ignore_loglevel || level < boot_console_loglevel)
196 sclp_early_printk(buf);
197 }
198
add_timestamp(char * buf)199 static char *add_timestamp(char *buf)
200 {
201 #ifdef CONFIG_PRINTK_TIME
202 union tod_clock *boot_clock = (union tod_clock *)&get_lowcore()->boot_clock;
203 unsigned long ns = tod_to_ns(get_tod_clock() - boot_clock->tod);
204 char ts[MAX_NUMLEN];
205
206 *buf++ = '[';
207 buf += strpad(buf, MAX_NUMLEN, as_dec(ts, ns / NSEC_PER_SEC, 0), 5, 0, 0);
208 *buf++ = '.';
209 buf += strpad(buf, MAX_NUMLEN, as_dec(ts, (ns % NSEC_PER_SEC) / NSEC_PER_USEC, 0), 6, 1, 0);
210 *buf++ = ']';
211 *buf++ = ' ';
212 #endif
213 return buf;
214 }
215
216 #define va_arg_len_type(args, lenmod, typemod) \
217 ((lenmod == 'l') ? va_arg(args, typemod long) : \
218 (lenmod == 'h') ? (typemod short)va_arg(args, typemod int) : \
219 (lenmod == 'H') ? (typemod char)va_arg(args, typemod int) : \
220 (lenmod == 'z') ? va_arg(args, typemod long) : \
221 va_arg(args, typemod int))
222
boot_printk(const char * fmt,...)223 int boot_printk(const char *fmt, ...)
224 {
225 char buf[1024] = { 0 };
226 char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
227 bool zero_pad, decimal;
228 char *strval, *p = buf;
229 char valbuf[MAX(MAX_SYMLEN, MAX_NUMLEN)];
230 va_list args;
231 char lenmod;
232 ssize_t len;
233 int pad;
234
235 *p++ = KERN_SOH_ASCII;
236 *p++ = printk_get_level(fmt) ?: '0' + MESSAGE_LOGLEVEL_DEFAULT;
237 p = add_timestamp(p);
238 fmt = printk_skip_level(fmt);
239
240 va_start(args, fmt);
241 for (; p < end && *fmt; fmt++) {
242 if (*fmt != '%') {
243 *p++ = *fmt;
244 continue;
245 }
246 if (*++fmt == '%') {
247 *p++ = '%';
248 continue;
249 }
250 zero_pad = (*fmt == '0');
251 pad = simple_strtol(fmt, (char **)&fmt, 10);
252 lenmod = (*fmt == 'h' || *fmt == 'l' || *fmt == 'z') ? *fmt++ : 0;
253 if (lenmod == 'h' && *fmt == 'h') {
254 lenmod = 'H';
255 fmt++;
256 }
257 decimal = false;
258 switch (*fmt) {
259 case 's':
260 if (lenmod)
261 goto out;
262 strval = va_arg(args, char *);
263 zero_pad = false;
264 break;
265 case 'p':
266 if (*++fmt != 'S' || lenmod)
267 goto out;
268 strval = strsym(valbuf, va_arg(args, void *));
269 zero_pad = false;
270 break;
271 case 'd':
272 case 'i':
273 strval = as_dec(valbuf, va_arg_len_type(args, lenmod, signed), 1);
274 decimal = true;
275 break;
276 case 'u':
277 strval = as_dec(valbuf, va_arg_len_type(args, lenmod, unsigned), 0);
278 break;
279 case 'x':
280 strval = as_hex(valbuf, va_arg_len_type(args, lenmod, unsigned), 0);
281 break;
282 default:
283 goto out;
284 }
285 len = strpad(p, end - p, strval, pad, zero_pad, decimal);
286 if (len == -E2BIG)
287 break;
288 p += len;
289 }
290 out:
291 va_end(args);
292 len = strlen(buf);
293 if (len) {
294 boot_rb_add(buf, len);
295 boot_console_earlyprintk(buf);
296 }
297 return len;
298 }
299