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