target/linux/generic/patches-3.18/330-MIPS-kexec-Accept-command-line-parameters-from-users.patch

   1 From d8582dcf1ed66eee88a11e4760f42c0d6c8822be Mon Sep 17 00:00:00 2001
   2 From: Yousong Zhou <yszhou4tech@gmail.com>
   3 Date: Sat, 31 Jan 2015 22:26:03 +0800
   4 Subject: [PATCH 331/331] MIPS: kexec: Accept command line parameters from
   5  userspace.
   6
   7 Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
   8 ---
   9  arch/mips/kernel/machine_kexec.c   |  153 +++++++++++++++++++++++++++++++-----
  10  arch/mips/kernel/machine_kexec.h   |   20 +++++
  11  arch/mips/kernel/relocate_kernel.S |   21 +++--
  12  3 files changed, 167 insertions(+), 27 deletions(-)
  13  create mode 100644 arch/mips/kernel/machine_kexec.h
  14
  15 --- a/arch/mips/kernel/machine_kexec.c
  16 +++ b/arch/mips/kernel/machine_kexec.c
  17 @@ -10,45 +10,145 @@
  18  #include <linux/mm.h>
  19  #include <linux/delay.h>
  20
  21 +#include <asm/bootinfo.h>
  22  #include <asm/cacheflush.h>
  23  #include <asm/page.h>
  24 -
  25 -extern const unsigned char relocate_new_kernel[];
  26 -extern const size_t relocate_new_kernel_size;
  27 -
  28 -extern unsigned long kexec_start_address;
  29 -extern unsigned long kexec_indirection_page;
  30 +#include <asm/uaccess.h>
  31 +#include "machine_kexec.h"
  32
  33  int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  34  void (*_machine_kexec_shutdown)(void) = NULL;
  35  void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
  36 +
  37  #ifdef CONFIG_SMP
  38  void (*relocated_kexec_smp_wait) (void *);
  39  atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
  40  #endif
  41
  42 -int
  43 -machine_kexec_prepare(struct kimage *kimage)
  44 +static void machine_kexec_print_args(void)
  45  {
  46 +       unsigned long argc = (int)kexec_args[0];
  47 +       int i;
  48 +
  49 +       pr_info("kexec_args[0] (argc): %lu\n", argc);
  50 +       pr_info("kexec_args[1] (argv): %p\n", (void *)kexec_args[1]);
  51 +       pr_info("kexec_args[2] (env ): %p\n", (void *)kexec_args[2]);
  52 +       pr_info("kexec_args[3] (desc): %p\n", (void *)kexec_args[3]);
  53 +
  54 +       for (i = 0; i < argc; i++) {
  55 +               pr_info("kexec_argv[%d] = %p, %s\n",
  56 +                               i, kexec_argv[i], kexec_argv[i]);
  57 +       }
  58 +}
  59 +
  60 +static void machine_kexec_init_argv(struct kimage *image)
  61 +{
  62 +       void __user *buf = NULL;
  63 +       size_t bufsz;
  64 +       size_t size;
  65 +       int i;
  66 +
  67 +       bufsz = 0;
  68 +       for (i = 0; i < image->nr_segments; i++) {
  69 +               struct kexec_segment *seg;
  70 +
  71 +               seg = &image->segment[i];
  72 +               if (seg->bufsz < 6)
  73 +                       continue;
  74 +
  75 +               if (strncmp((char *) seg->buf, "kexec ", 6))
  76 +                       continue;
  77 +
  78 +               buf = seg->buf;
  79 +               bufsz = seg->bufsz;
  80 +               break;
  81 +       }
  82 +
  83 +       if (!buf)
  84 +               return;
  85 +
  86 +       size = KEXEC_COMMAND_LINE_SIZE;
  87 +       size = min(size, bufsz);
  88 +       if (size < bufsz)
  89 +               pr_warn("kexec command line truncated to %zd bytes\n", size);
  90 +
  91 +       /* Copy to kernel space */
  92 +       copy_from_user(kexec_argv_buf, buf, size);
  93 +       kexec_argv_buf[size - 1] = 0;
  94 +}
  95 +
  96 +static void machine_kexec_parse_argv(struct kimage *image)
  97 +{
  98 +       char *reboot_code_buffer;
  99 +       int reloc_delta;
 100 +       char *ptr;
 101 +       int argc;
 102 +       int i;
 103 +
 104 +       ptr = kexec_argv_buf;
 105 +       argc = 0;
 106 +
 107 +       /*
 108 +        * convert command line string to array of parameters
 109 +        * (as bootloader does).
 110 +        */
 111 +       while (ptr && *ptr && (KEXEC_MAX_ARGC > argc)) {
 112 +               if (*ptr == ' ') {
 113 +                       *ptr++ = '\0';
 114 +                       continue;
 115 +               }
 116 +
 117 +               kexec_argv[argc++] = ptr;
 118 +               ptr = strchr(ptr, ' ');
 119 +       }
 120 +
 121 +       if (!argc)
 122 +               return;
 123 +
 124 +       kexec_args[0] = argc;
 125 +       kexec_args[1] = (unsigned long)kexec_argv;
 126 +       kexec_args[2] = 0;
 127 +       kexec_args[3] = 0;
 128 +
 129 +       reboot_code_buffer = page_address(image->control_code_page);
 130 +       reloc_delta = reboot_code_buffer - (char *)kexec_relocate_new_kernel;
 131 +
 132 +       kexec_args[1] += reloc_delta;
 133 +       for (i = 0; i < argc; i++)
 134 +               kexec_argv[i] += reloc_delta;
 135 +}
 136 +
 137 +int machine_kexec_prepare(struct kimage *kimage)
 138 +{
 139 +       /*
 140 +        * Whenever arguments passed from kexec-tools, Init the arguments as
 141 +        * the original ones to try avoiding booting failure.
 142 +        */
 143 +
 144 +       kexec_args[0] = fw_arg0;
 145 +       kexec_args[1] = fw_arg1;
 146 +       kexec_args[2] = fw_arg2;
 147 +       kexec_args[3] = fw_arg3;
 148 +
 149 +       machine_kexec_init_argv(kimage);
 150 +       machine_kexec_parse_argv(kimage);
 151 +
 152         if (_machine_kexec_prepare)
 153                 return _machine_kexec_prepare(kimage);
 154         return 0;
 155  }
 156
 157 -void
 158 -machine_kexec_cleanup(struct kimage *kimage)
 159 +void machine_kexec_cleanup(struct kimage *kimage)
 160  {
 161  }
 162
 163 -void
 164 -machine_shutdown(void)
 165 +void machine_shutdown(void)
 166  {
 167         if (_machine_kexec_shutdown)
 168                 _machine_kexec_shutdown();
 169  }
 170
 171 -void
 172 -machine_crash_shutdown(struct pt_regs *regs)
 173 +void machine_crash_shutdown(struct pt_regs *regs)
 174  {
 175         if (_machine_crash_shutdown)
 176                 _machine_crash_shutdown(regs);
 177 @@ -66,10 +166,12 @@ machine_kexec(struct kimage *image)
 178         unsigned long *ptr;
 179
 180         reboot_code_buffer =
 181 -         (unsigned long)page_address(image->control_code_page);
 182 +               (unsigned long)page_address(image->control_code_page);
 183 +       pr_info("reboot_code_buffer = %p\n", (void *)reboot_code_buffer);
 184
 185         kexec_start_address =
 186                 (unsigned long) phys_to_virt(image->start);
 187 +       pr_info("kexec_start_address = %p\n", (void *)kexec_start_address);
 188
 189         if (image->type == KEXEC_TYPE_DEFAULT) {
 190                 kexec_indirection_page =
 191 @@ -77,9 +179,19 @@ machine_kexec(struct kimage *image)
 192         } else {
 193                 kexec_indirection_page = (unsigned long)&image->head;
 194         }
 195 +       pr_info("kexec_indirection_page = %p\n", (void *)kexec_indirection_page);
 196
 197 -       memcpy((void*)reboot_code_buffer, relocate_new_kernel,
 198 -              relocate_new_kernel_size);
 199 +       pr_info("Where is memcpy: %p\n", memcpy);
 200 +       pr_info("kexec_relocate_new_kernel = %p, kexec_relocate_new_kernel_end = %p\n",
 201 +               (void *)kexec_relocate_new_kernel, &kexec_relocate_new_kernel_end);
 202 +       pr_info("Copy %lu bytes from %p to %p\n", KEXEC_RELOCATE_NEW_KERNEL_SIZE,
 203 +               (void *)kexec_relocate_new_kernel, (void *)reboot_code_buffer);
 204 +       memcpy((void*)reboot_code_buffer, kexec_relocate_new_kernel,
 205 +              KEXEC_RELOCATE_NEW_KERNEL_SIZE);
 206 +
 207 +       pr_info("Before _print_args().\n");
 208 +       machine_kexec_print_args();
 209 +       pr_info("Before eval loop.\n");
 210
 211         /*
 212          * The generic kexec code builds a page list with physical
 213 @@ -98,15 +210,16 @@ machine_kexec(struct kimage *image)
 214         /*
 215          * we do not want to be bothered.
 216          */
 217 +       pr_info("Before irq_disable.\n");
 218         local_irq_disable();
 219
 220 -       printk("Will call new kernel at %08lx\n", image->start);
 221 -       printk("Bye ...\n");
 222 +       pr_info("Will call new kernel at %08lx\n", image->start);
 223 +       pr_info("Bye ...\n");
 224         __flush_cache_all();
 225  #ifdef CONFIG_SMP
 226         /* All secondary cpus now may jump to kexec_wait cycle */
 227         relocated_kexec_smp_wait = reboot_code_buffer +
 228 -               (void *)(kexec_smp_wait - relocate_new_kernel);
 229 +               (void *)(kexec_smp_wait - kexec_relocate_new_kernel);
 230         smp_wmb();
 231         atomic_set(&kexec_ready_to_reboot, 1);
 232  #endif
 233 --- /dev/null
 234 +++ b/arch/mips/kernel/machine_kexec.h
 235 @@ -0,0 +1,20 @@
 236 +#ifndef _MACHINE_KEXEC_H
 237 +#define _MACHINE_KEXEC_H
 238 +
 239 +#ifndef __ASSEMBLY__
 240 +extern const unsigned char kexec_relocate_new_kernel[];
 241 +extern unsigned long kexec_relocate_new_kernel_end;
 242 +extern unsigned long kexec_start_address;
 243 +extern unsigned long kexec_indirection_page;
 244 +
 245 +extern char kexec_argv_buf[];
 246 +extern char *kexec_argv[];
 247 +
 248 +#define KEXEC_RELOCATE_NEW_KERNEL_SIZE ((unsigned long)&kexec_relocate_new_kernel_end - (unsigned long)kexec_relocate_new_kernel)
 249 +#endif /* !__ASSEMBLY__ */
 250 +
 251 +#define KEXEC_COMMAND_LINE_SIZE                256
 252 +#define KEXEC_ARGV_SIZE                        (KEXEC_COMMAND_LINE_SIZE / 16)
 253 +#define KEXEC_MAX_ARGC                 (KEXEC_ARGV_SIZE / sizeof(long))
 254 +
 255 +#endif
 256 --- a/arch/mips/kernel/relocate_kernel.S
 257 +++ b/arch/mips/kernel/relocate_kernel.S
 258 @@ -12,8 +12,9 @@
 259  #include <asm/mipsregs.h>
 260  #include <asm/stackframe.h>
 261  #include <asm/addrspace.h>
 262 +#include "machine_kexec.h"
 263
 264 -LEAF(relocate_new_kernel)
 265 +LEAF(kexec_relocate_new_kernel)
 266         PTR_L a0,       arg0
 267         PTR_L a1,       arg1
 268         PTR_L a2,       arg2
 269 @@ -98,7 +99,7 @@ done:
 270  #endif
 271         /* jump to kexec_start_address */
 272         j               s1
 273 -       END(relocate_new_kernel)
 274 +       END(kexec_relocate_new_kernel)
 275
 276  #ifdef CONFIG_SMP
 277  /*
 278 @@ -184,9 +185,15 @@ kexec_indirection_page:
 279         PTR             0
 280         .size           kexec_indirection_page, PTRSIZE
 281
 282 -relocate_new_kernel_end:
 283 +kexec_argv_buf:
 284 +       EXPORT(kexec_argv_buf)
 285 +       .skip           KEXEC_COMMAND_LINE_SIZE
 286 +       .size           kexec_argv_buf, KEXEC_COMMAND_LINE_SIZE
 287 +
 288 +kexec_argv:
 289 +       EXPORT(kexec_argv)
 290 +       .skip           KEXEC_ARGV_SIZE
 291 +       .size           kexec_argv, KEXEC_ARGV_SIZE
 292
 293 -relocate_new_kernel_size:
 294 -       EXPORT(relocate_new_kernel_size)
 295 -       PTR             relocate_new_kernel_end - relocate_new_kernel
 296 -       .size           relocate_new_kernel_size, PTRSIZE
 297 +kexec_relocate_new_kernel_end:
 298 +       EXPORT(kexec_relocate_new_kernel_end)