arch/s390/boot/pgm_check_info.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/string.h>
   4 #include <linux/ctype.h>
   5 #include <asm/stacktrace.h>
   6 #include <asm/boot_data.h>
   7 #include <asm/lowcore.h>
   8 #include <asm/setup.h>
   9 #include <asm/sclp.h>
  10 #include <asm/uv.h>
  11 #include <stdarg.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 extern char _decompressor_syms_start[], _decompressor_syms_end[];
  33 static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len)
  34 {
  35         /* symbol entries are in a form "10000 c4 startup\0" */
  36         char *a = _decompressor_syms_start;
  37         char *b = _decompressor_syms_end;
  38         unsigned long start;
  39         unsigned long size;
  40         char *pivot;
  41         char *endp;
  42
  43         while (a < b) {
  44                 pivot = symstart(a + (b - a) / 2);
  45                 start = simple_strtoull(pivot, &endp, 16);
  46                 size = simple_strtoull(endp + 1, &endp, 16);
  47                 if (ip < start) {
  48                         b = pivot;
  49                         continue;
  50                 }
  51                 if (ip > start + size) {
  52                         a = pivot + strlen(pivot) + 1;
  53                         continue;
  54                 }
  55                 *off = ip - start;
  56                 *len = size;
  57                 return endp + 1;
  58         }
  59         return NULL;
  60 }
  61
  62 static noinline char *strsym(void *ip)
  63 {
  64         static char buf[64];
  65         unsigned short off;
  66         unsigned short len;
  67         char *p;
  68
  69         p = findsym((unsigned long)ip, &off, &len);
  70         if (p) {
  71                 strncpy(buf, p, sizeof(buf));
  72                 /* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
  73                 p = buf + strnlen(buf, sizeof(buf) - 15);
  74                 strcpy(p, "+0x");
  75                 p = as_hex(p + 3, off, 0);
  76                 strcpy(p, "/0x");
  77                 as_hex(p + 3, len, 0);
  78         } else {
  79                 as_hex(buf, (unsigned long)ip, 16);
  80         }
  81         return buf;
  82 }
  83
  84 void decompressor_printk(const char *fmt, ...)
  85 {
  86         char buf[1024] = { 0 };
  87         char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */
  88         unsigned long pad;
  89         char *p = buf;
  90         va_list args;
  91
  92         va_start(args, fmt);
  93         for (; p < end && *fmt; fmt++) {
  94                 if (*fmt != '%') {
  95                         *p++ = *fmt;
  96                         continue;
  97                 }
  98                 pad = isdigit(*++fmt) ? simple_strtol(fmt, (char **)&fmt, 10) : 0;
  99                 switch (*fmt) {
 100                 case 's':
 101                         p = buf + strlcat(buf, va_arg(args, char *), sizeof(buf));
 102                         break;
 103                 case 'p':
 104                         if (*++fmt != 'S')
 105                                 goto out;
 106                         p = buf + strlcat(buf, strsym(va_arg(args, void *)), sizeof(buf));
 107                         break;
 108                 case 'l':
 109                         if (*++fmt != 'x' || end - p <= max(sizeof(long) * 2, pad))
 110                                 goto out;
 111                         p = as_hex(p, va_arg(args, unsigned long), pad);
 112                         break;
 113                 case 'x':
 114                         if (end - p <= max(sizeof(int) * 2, pad))
 115                                 goto out;
 116                         p = as_hex(p, va_arg(args, unsigned int), pad);
 117                         break;
 118                 default:
 119                         goto out;
 120                 }
 121         }
 122 out:
 123         va_end(args);
 124         sclp_early_printk(buf);
 125 }
 126
 127 static noinline void print_stacktrace(void)
 128 {
 129         struct stack_info boot_stack = { STACK_TYPE_TASK, BOOT_STACK_OFFSET,
 130                                          BOOT_STACK_OFFSET + BOOT_STACK_SIZE };
 131         unsigned long sp = S390_lowcore.gpregs_save_area[15];
 132         bool first = true;
 133
 134         decompressor_printk("Call Trace:\n");
 135         while (!(sp & 0x7) && on_stack(&boot_stack, sp, sizeof(struct stack_frame))) {
 136                 struct stack_frame *sf = (struct stack_frame *)sp;
 137
 138                 decompressor_printk(first ? "(sp:%016lx [<%016lx>] %pS)\n" :
 139                                             " sp:%016lx [<%016lx>] %pS\n",
 140                                     sp, sf->gprs[8], (void *)sf->gprs[8]);
 141                 if (sf->back_chain <= sp)
 142                         break;
 143                 sp = sf->back_chain;
 144                 first = false;
 145         }
 146 }
 147
 148 void print_pgm_check_info(void)
 149 {
 150         unsigned long *gpregs = (unsigned long *)S390_lowcore.gpregs_save_area;
 151         struct psw_bits *psw = &psw_bits(S390_lowcore.psw_save_area);
 152
 153         decompressor_printk("Linux version %s\n", kernel_version);
 154         if (!is_prot_virt_guest() && early_command_line[0])
 155                 decompressor_printk("Kernel command line: %s\n", early_command_line);
 156         decompressor_printk("Kernel fault: interruption code %04x ilc:%x\n",
 157                             S390_lowcore.pgm_code, S390_lowcore.pgm_ilc >> 1);
 158         if (kaslr_enabled)
 159                 decompressor_printk("Kernel random base: %lx\n", __kaslr_offset);
 160         decompressor_printk("PSW : %016lx %016lx (%pS)\n",
 161                             S390_lowcore.psw_save_area.mask,
 162                             S390_lowcore.psw_save_area.addr,
 163                             (void *)S390_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();
 178         decompressor_printk("Last Breaking-Event-Address:\n");
 179         decompressor_printk(" [<%016lx>] %pS\n", (unsigned long)S390_lowcore.breaking_event_addr,
 180                             (void *)S390_lowcore.breaking_event_addr);
 181 }