target/linux/generic/pending-4.19/330-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 <linux/uaccess.h>
  28 +#include "machine_kexec.h"
  29
  30  int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  31  void (*_machine_kexec_shutdown)(void) = NULL;
  32 @@ -28,6 +25,99 @@ 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  static void kexec_image_info(const struct kimage *kimage)
 130  {
 131         unsigned long i;
 132 @@ -52,6 +142,18 @@ int
 133  machine_kexec_prepare(struct kimage *kimage)
 134  {
 135         kexec_image_info(kimage);
 136 +       /*
 137 +        * Whenever arguments passed from kexec-tools, Init the arguments as
 138 +        * the original ones to try avoiding booting failure.
 139 +        */
 140 +
 141 +       kexec_args[0] = fw_arg0;
 142 +       kexec_args[1] = fw_arg1;
 143 +       kexec_args[2] = fw_arg2;
 144 +       kexec_args[3] = fw_arg3;
 145 +
 146 +       machine_kexec_init_argv(kimage);
 147 +       machine_kexec_parse_argv(kimage);
 148
 149         if (_machine_kexec_prepare)
 150                 return _machine_kexec_prepare(kimage);
 151 @@ -89,10 +191,12 @@ machine_kexec(struct kimage *image)
 152         unsigned long *ptr;
 153
 154         reboot_code_buffer =
 155 -         (unsigned long)page_address(image->control_code_page);
 156 +               (unsigned long)page_address(image->control_code_page);
 157 +       pr_info("reboot_code_buffer = %p\n", (void *)reboot_code_buffer);
 158
 159         kexec_start_address =
 160                 (unsigned long) phys_to_virt(image->start);
 161 +       pr_info("kexec_start_address = %p\n", (void *)kexec_start_address);
 162
 163         if (image->type == KEXEC_TYPE_DEFAULT) {
 164                 kexec_indirection_page =
 165 @@ -100,9 +204,19 @@ machine_kexec(struct kimage *image)
 166         } else {
 167                 kexec_indirection_page = (unsigned long)&image->head;
 168         }
 169 +       pr_info("kexec_indirection_page = %p\n", (void *)kexec_indirection_page);
 170
 171 -       memcpy((void*)reboot_code_buffer, relocate_new_kernel,
 172 -              relocate_new_kernel_size);
 173 +       pr_info("Where is memcpy: %p\n", memcpy);
 174 +       pr_info("kexec_relocate_new_kernel = %p, kexec_relocate_new_kernel_end = %p\n",
 175 +               (void *)kexec_relocate_new_kernel, &kexec_relocate_new_kernel_end);
 176 +       pr_info("Copy %lu bytes from %p to %p\n", KEXEC_RELOCATE_NEW_KERNEL_SIZE,
 177 +               (void *)kexec_relocate_new_kernel, (void *)reboot_code_buffer);
 178 +       memcpy((void*)reboot_code_buffer, kexec_relocate_new_kernel,
 179 +              KEXEC_RELOCATE_NEW_KERNEL_SIZE);
 180 +
 181 +       pr_info("Before _print_args().\n");
 182 +       machine_kexec_print_args();
 183 +       pr_info("Before eval loop.\n");
 184
 185         /*
 186          * The generic kexec code builds a page list with physical
 187 @@ -124,15 +238,16 @@ machine_kexec(struct kimage *image)
 188         /*
 189          * we do not want to be bothered.
 190          */
 191 +       pr_info("Before irq_disable.\n");
 192         local_irq_disable();
 193
 194 -       printk("Will call new kernel at %08lx\n", image->start);
 195 -       printk("Bye ...\n");
 196 +       pr_info("Will call new kernel at %08lx\n", image->start);
 197 +       pr_info("Bye ...\n");
 198         __flush_cache_all();
 199  #ifdef CONFIG_SMP
 200         /* All secondary cpus now may jump to kexec_wait cycle */
 201         relocated_kexec_smp_wait = reboot_code_buffer +
 202 -               (void *)(kexec_smp_wait - relocate_new_kernel);
 203 +               (void *)(kexec_smp_wait - kexec_relocate_new_kernel);
 204         smp_wmb();
 205         atomic_set(&kexec_ready_to_reboot, 1);
 206  #endif
 207 --- /dev/null
 208 +++ b/arch/mips/kernel/machine_kexec.h
 209 @@ -0,0 +1,20 @@
 210 +#ifndef _MACHINE_KEXEC_H
 211 +#define _MACHINE_KEXEC_H
 212 +
 213 +#ifndef __ASSEMBLY__
 214 +extern const unsigned char kexec_relocate_new_kernel[];
 215 +extern unsigned long kexec_relocate_new_kernel_end;
 216 +extern unsigned long kexec_start_address;
 217 +extern unsigned long kexec_indirection_page;
 218 +
 219 +extern char kexec_argv_buf[];
 220 +extern char *kexec_argv[];
 221 +
 222 +#define KEXEC_RELOCATE_NEW_KERNEL_SIZE ((unsigned long)&kexec_relocate_new_kernel_end - (unsigned long)kexec_relocate_new_kernel)
 223 +#endif /* !__ASSEMBLY__ */
 224 +
 225 +#define KEXEC_COMMAND_LINE_SIZE                256
 226 +#define KEXEC_ARGV_SIZE                        (KEXEC_COMMAND_LINE_SIZE / 16)
 227 +#define KEXEC_MAX_ARGC                 (KEXEC_ARGV_SIZE / sizeof(long))
 228 +
 229 +#endif
 230 --- a/arch/mips/kernel/relocate_kernel.S
 231 +++ b/arch/mips/kernel/relocate_kernel.S
 232 @@ -12,8 +12,9 @@
 233  #include <asm/mipsregs.h>
 234  #include <asm/stackframe.h>
 235  #include <asm/addrspace.h>
 236 +#include "machine_kexec.h"
 237
 238 -LEAF(relocate_new_kernel)
 239 +LEAF(kexec_relocate_new_kernel)
 240         PTR_L a0,       arg0
 241         PTR_L a1,       arg1
 242         PTR_L a2,       arg2
 243 @@ -98,7 +99,7 @@ done:
 244  #endif
 245         /* jump to kexec_start_address */
 246         j               s1
 247 -       END(relocate_new_kernel)
 248 +       END(kexec_relocate_new_kernel)
 249
 250  #ifdef CONFIG_SMP
 251  /*
 252 @@ -184,9 +185,15 @@ kexec_indirection_page:
 253         PTR             0
 254         .size           kexec_indirection_page, PTRSIZE
 255
 256 -relocate_new_kernel_end:
 257 +kexec_argv_buf:
 258 +       EXPORT(kexec_argv_buf)
 259 +       .skip           KEXEC_COMMAND_LINE_SIZE
 260 +       .size           kexec_argv_buf, KEXEC_COMMAND_LINE_SIZE
 261 +
 262 +kexec_argv:
 263 +       EXPORT(kexec_argv)
 264 +       .skip           KEXEC_ARGV_SIZE
 265 +       .size           kexec_argv, KEXEC_ARGV_SIZE
 266
 267 -relocate_new_kernel_size:
 268 -       EXPORT(relocate_new_kernel_size)
 269 -       PTR             relocate_new_kernel_end - relocate_new_kernel
 270 -       .size           relocate_new_kernel_size, PTRSIZE
 271 +kexec_relocate_new_kernel_end:
 272 +       EXPORT(kexec_relocate_new_kernel_end)