target/linux/generic/pending-4.9/330-MIPS-kexec-Accept-command-line-parameters-from-users.patch

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