kexec: support for kexec on panic using new system call

[linux.git] / arch / x86 / kernel / kexec-bzimage64.c

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index bcedd100192fe3c1acd4d95bb29902813033a2db..a8e646458a1074666c4f4d2a2b07156c8014f9fc 100644 (file)
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -21,6 +21,9 @@
 
 #include <asm/bootparam.h>
 #include <asm/setup.h>
+#include <asm/crash.h>
+
+#define MAX_ELFCOREHDR_STR_LEN 30      /* elfcorehdr=0x<64bit-value> */
 
 /*
  * Defines lowest physical address for various segments. Not sure where
@@ -58,18 +61,24 @@ static int setup_initrd(struct boot_params *params,
        return 0;
 }
 
-static int setup_cmdline(struct boot_params *params,
+static int setup_cmdline(struct kimage *image, struct boot_params *params,
                         unsigned long bootparams_load_addr,
                         unsigned long cmdline_offset, char *cmdline,
                         unsigned long cmdline_len)
 {
        char *cmdline_ptr = ((char *)params) + cmdline_offset;
-       unsigned long cmdline_ptr_phys;
+       unsigned long cmdline_ptr_phys, len;
        uint32_t cmdline_low_32, cmdline_ext_32;
 
        memcpy(cmdline_ptr, cmdline, cmdline_len);
+       if (image->type == KEXEC_TYPE_CRASH) {
+               len = sprintf(cmdline_ptr + cmdline_len - 1,
+                       " elfcorehdr=0x%lx", image->arch.elf_load_addr);
+               cmdline_len += len;
+       }
        cmdline_ptr[cmdline_len - 1] = '\0';
 
+       pr_debug("Final command line is: %s\n", cmdline_ptr);
        cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
        cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
        cmdline_ext_32 = cmdline_ptr_phys >> 32;
@@ -98,11 +107,12 @@ static int setup_memory_map_entries(struct boot_params *params)
        return 0;
 }
 
-static int setup_boot_parameters(struct boot_params *params)
+static int setup_boot_parameters(struct kimage *image,
+                                struct boot_params *params)
 {
        unsigned int nr_e820_entries;
        unsigned long long mem_k, start, end;
-       int i;
+       int i, ret = 0;
 
        /* Get subarch from existing bootparams */
        params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
@@ -125,7 +135,13 @@ static int setup_boot_parameters(struct boot_params *params)
        /* Default sysdesc table */
        params->sys_desc_table.length = 0;
 
-       setup_memory_map_entries(params);
+       if (image->type == KEXEC_TYPE_CRASH) {
+               ret = crash_setup_memmap_entries(image, params);
+               if (ret)
+                       return ret;
+       } else
+               setup_memory_map_entries(params);
+
        nr_e820_entries = params->e820_entries;
 
        for (i = 0; i < nr_e820_entries; i++) {
@@ -153,7 +169,7 @@ static int setup_boot_parameters(struct boot_params *params)
        memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
               EDD_MBR_SIG_MAX * sizeof(unsigned int));
 
-       return 0;
+       return ret;
 }
 
 int bzImage64_probe(const char *buf, unsigned long len)
@@ -240,6 +256,22 @@ void *bzImage64_load(struct kimage *image, char *kernel,
                return ERR_PTR(-EINVAL);
        }
 
+       /*
+        * In case of crash dump, we will append elfcorehdr=<addr> to
+        * command line. Make sure it does not overflow
+        */
+       if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
+               pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       /* Allocate and load backup region */
+       if (image->type == KEXEC_TYPE_CRASH) {
+               ret = crash_load_segments(image);
+               if (ret)
+                       return ERR_PTR(ret);
+       }
+
        /*
         * Load purgatory. For 64bit entry point, purgatory  code can be
         * anywhere.
@@ -254,7 +286,8 @@ void *bzImage64_load(struct kimage *image, char *kernel,
        pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
 
        /* Load Bootparams and cmdline */
-       params_cmdline_sz = sizeof(struct boot_params) + cmdline_len;
+       params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
+                               MAX_ELFCOREHDR_STR_LEN;
        params = kzalloc(params_cmdline_sz, GFP_KERNEL);
        if (!params)
                return ERR_PTR(-ENOMEM);
@@ -303,8 +336,8 @@ void *bzImage64_load(struct kimage *image, char *kernel,
                setup_initrd(params, initrd_load_addr, initrd_len);
        }
 
-       setup_cmdline(params, bootparam_load_addr, sizeof(struct boot_params),
-                     cmdline, cmdline_len);
+       setup_cmdline(image, params, bootparam_load_addr,
+                     sizeof(struct boot_params), cmdline, cmdline_len);
 
        /* bootloader info. Do we need a separate ID for kexec kernel loader? */
        params->hdr.type_of_loader = 0x0D << 4;
@@ -332,7 +365,9 @@ void *bzImage64_load(struct kimage *image, char *kernel,
        if (ret)
                goto out_free_params;
 
-       setup_boot_parameters(params);
+       ret = setup_boot_parameters(image, params);
+       if (ret)
+               goto out_free_params;
 
        /* Allocate loader specific data */
        ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);