arch/s390/boot/ipl_parm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/init.h>
   4 #include <linux/ctype.h>
   5 #include <asm/ebcdic.h>
   6 #include <asm/sclp.h>
   7 #include <asm/sections.h>
   8 #include <asm/boot_data.h>
   9 #include <asm/facility.h>
  10 #include <asm/uv.h>
  11 #include "boot.h"
  12
  13 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
  14 struct ipl_parameter_block __bootdata_preserved(ipl_block);
  15 int __bootdata_preserved(ipl_block_valid);
  16
  17 unsigned long __bootdata(memory_end);
  18 int __bootdata(memory_end_set);
  19 int __bootdata(noexec_disabled);
  20
  21 int kaslr_enabled __section(.data);
  22
  23 static inline int __diag308(unsigned long subcode, void *addr)
  24 {
  25         register unsigned long _addr asm("0") = (unsigned long)addr;
  26         register unsigned long _rc asm("1") = 0;
  27         unsigned long reg1, reg2;
  28         psw_t old = S390_lowcore.program_new_psw;
  29
  30         asm volatile(
  31                 "       epsw    %0,%1\n"
  32                 "       st      %0,%[psw_pgm]\n"
  33                 "       st      %1,%[psw_pgm]+4\n"
  34                 "       larl    %0,1f\n"
  35                 "       stg     %0,%[psw_pgm]+8\n"
  36                 "       diag    %[addr],%[subcode],0x308\n"
  37                 "1:     nopr    %%r7\n"
  38                 : "=&d" (reg1), "=&a" (reg2),
  39                   [psw_pgm] "=Q" (S390_lowcore.program_new_psw),
  40                   [addr] "+d" (_addr), "+d" (_rc)
  41                 : [subcode] "d" (subcode)
  42                 : "cc", "memory");
  43         S390_lowcore.program_new_psw = old;
  44         return _rc;
  45 }
  46
  47 void store_ipl_parmblock(void)
  48 {
  49         int rc;
  50
  51         rc = __diag308(DIAG308_STORE, &ipl_block);
  52         if (rc == DIAG308_RC_OK &&
  53             ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
  54                 ipl_block_valid = 1;
  55 }
  56
  57 static size_t scpdata_length(const u8 *buf, size_t count)
  58 {
  59         while (count) {
  60                 if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
  61                         break;
  62                 count--;
  63         }
  64         return count;
  65 }
  66
  67 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
  68                                           const struct ipl_parameter_block *ipb)
  69 {
  70         size_t count;
  71         size_t i;
  72         int has_lowercase;
  73
  74         count = min(size - 1, scpdata_length(ipb->fcp.scp_data,
  75                                              ipb->fcp.scp_data_len));
  76         if (!count)
  77                 goto out;
  78
  79         has_lowercase = 0;
  80         for (i = 0; i < count; i++) {
  81                 if (!isascii(ipb->fcp.scp_data[i])) {
  82                         count = 0;
  83                         goto out;
  84                 }
  85                 if (!has_lowercase && islower(ipb->fcp.scp_data[i]))
  86                         has_lowercase = 1;
  87         }
  88
  89         if (has_lowercase)
  90                 memcpy(dest, ipb->fcp.scp_data, count);
  91         else
  92                 for (i = 0; i < count; i++)
  93                         dest[i] = tolower(ipb->fcp.scp_data[i]);
  94 out:
  95         dest[count] = '\0';
  96         return count;
  97 }
  98
  99 static void append_ipl_block_parm(void)
 100 {
 101         char *parm, *delim;
 102         size_t len, rc = 0;
 103
 104         len = strlen(early_command_line);
 105
 106         delim = early_command_line + len;    /* '\0' character position */
 107         parm = early_command_line + len + 1; /* append right after '\0' */
 108
 109         switch (ipl_block.pb0_hdr.pbt) {
 110         case IPL_PBT_CCW:
 111                 rc = ipl_block_get_ascii_vmparm(
 112                         parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
 113                 break;
 114         case IPL_PBT_FCP:
 115                 rc = ipl_block_get_ascii_scpdata(
 116                         parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
 117                 break;
 118         }
 119         if (rc) {
 120                 if (*parm == '=')
 121                         memmove(early_command_line, parm + 1, rc);
 122                 else
 123                         *delim = ' '; /* replace '\0' with space */
 124         }
 125 }
 126
 127 static inline int has_ebcdic_char(const char *str)
 128 {
 129         int i;
 130
 131         for (i = 0; str[i]; i++)
 132                 if (str[i] & 0x80)
 133                         return 1;
 134         return 0;
 135 }
 136
 137 void setup_boot_command_line(void)
 138 {
 139         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 140         /* convert arch command line to ascii if necessary */
 141         if (has_ebcdic_char(COMMAND_LINE))
 142                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 143         /* copy arch command line */
 144         strcpy(early_command_line, strim(COMMAND_LINE));
 145
 146         /* append IPL PARM data to the boot command line */
 147         if (!is_prot_virt_guest() && ipl_block_valid)
 148                 append_ipl_block_parm();
 149 }
 150
 151 static void modify_facility(unsigned long nr, bool clear)
 152 {
 153         if (clear)
 154                 __clear_facility(nr, S390_lowcore.stfle_fac_list);
 155         else
 156                 __set_facility(nr, S390_lowcore.stfle_fac_list);
 157 }
 158
 159 static void check_cleared_facilities(void)
 160 {
 161         unsigned long als[] = { FACILITIES_ALS };
 162         int i;
 163
 164         for (i = 0; i < ARRAY_SIZE(als); i++) {
 165                 if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
 166                         sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
 167                         print_missing_facilities();
 168                         break;
 169                 }
 170         }
 171 }
 172
 173 static void modify_fac_list(char *str)
 174 {
 175         unsigned long val, endval;
 176         char *endp;
 177         bool clear;
 178
 179         while (*str) {
 180                 clear = false;
 181                 if (*str == '!') {
 182                         clear = true;
 183                         str++;
 184                 }
 185                 val = simple_strtoull(str, &endp, 0);
 186                 if (str == endp)
 187                         break;
 188                 str = endp;
 189                 if (*str == '-') {
 190                         str++;
 191                         endval = simple_strtoull(str, &endp, 0);
 192                         if (str == endp)
 193                                 break;
 194                         str = endp;
 195                         while (val <= endval) {
 196                                 modify_facility(val, clear);
 197                                 val++;
 198                         }
 199                 } else {
 200                         modify_facility(val, clear);
 201                 }
 202                 if (*str != ',')
 203                         break;
 204                 str++;
 205         }
 206         check_cleared_facilities();
 207 }
 208
 209 static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);
 210 void parse_boot_command_line(void)
 211 {
 212         char *param, *val;
 213         bool enabled;
 214         char *args;
 215         int rc;
 216
 217         kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
 218         args = strcpy(command_line_buf, early_command_line);
 219         while (*args) {
 220                 args = next_arg(args, &param, &val);
 221
 222                 if (!strcmp(param, "mem")) {
 223                         memory_end = memparse(val, NULL);
 224                         memory_end_set = 1;
 225                 }
 226
 227                 if (!strcmp(param, "noexec")) {
 228                         rc = kstrtobool(val, &enabled);
 229                         if (!rc && !enabled)
 230                                 noexec_disabled = 1;
 231                 }
 232
 233                 if (!strcmp(param, "facilities"))
 234                         modify_fac_list(val);
 235
 236                 if (!strcmp(param, "nokaslr"))
 237                         kaslr_enabled = 0;
 238         }
 239 }
 240
 241 void setup_memory_end(void)
 242 {
 243 #ifdef CONFIG_CRASH_DUMP
 244         if (OLDMEM_BASE) {
 245                 kaslr_enabled = 0;
 246         } else if (ipl_block_valid &&
 247                    ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
 248                    ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP) {
 249                 kaslr_enabled = 0;
 250                 if (!sclp_early_get_hsa_size(&memory_end) && memory_end)
 251                         memory_end_set = 1;
 252         }
 253 #endif
 254 }