root/trunk/patches/2.6.22/96-kexec-cmdline.patch

linux-2.6.21.5/kernel/ksysfs.c

@@ -49 +49 @@
 #endif
 
 #ifdef CONFIG_KEXEC
+
+#include <asm/setup.h>
+
+extern unsigned long kexec_boot_params;
+
+char kexec_cmdline[COMMAND_LINE_SIZE] = "";
+
+static void
+replace_cmdline_tag(void)
+{
+        char *t;
+        struct tag *real;
+        struct tag *copy;
+        struct tag *rend;
+        int i;
+
+/* TODO: check the return params */
+        t = kmalloc(KEXEC_BOOT_PARAMS_SIZE + COMMAND_LINE_SIZE, GFP_KERNEL);
+        memset((void *)t, 0, KEXEC_BOOT_PARAMS_SIZE + COMMAND_LINE_SIZE);
+
+/* TODO: validate that the boot params are ATAGS, in fact */
+
+        copy = (struct tag *)t;
+        real = (struct tag *)kexec_boot_params;
+        rend = (struct tag *)(kexec_boot_params + KEXEC_BOOT_PARAMS_SIZE);
+        while ((real->hdr.size) && (real < rend)) {
+                if (real->hdr.tag != ATAG_CMDLINE) {
+                        memcpy((void *)copy, (void *)real, real->hdr.size * 4);
+                        copy = tag_next(copy);
+                }
+                real = tag_next(real);
+        }
+
+/* TODO: validate that we have enough space in the buffer */
+        
+        i = strlen(kexec_cmdline);
+        if (i) {
+                copy->hdr.tag = ATAG_CMDLINE;
+                copy->hdr.size = (sizeof(struct tag_header) + i + 1 + 4) >> 2;
+                strcpy(copy->u.cmdline.cmdline, kexec_cmdline);
+                copy = tag_next(copy);
+        }
+
+        copy->hdr.tag = ATAG_NONE;            /* Empty tag ends list */
+        copy->hdr.size = 0;                   /* zero length */
+
+/* TODO: validate that the temporary buffer isn't too full */
+
+        memcpy((void *)kexec_boot_params, (void *)t, KEXEC_BOOT_PARAMS_SIZE);
+
+        kfree(t);  /* Don't forget to free the big buffer we used */
+}
+
+static ssize_t kexec_cmdline_show(struct kset *kset, char *page)
+{
+        return sprintf(page, "%s\n", kexec_cmdline);
+}
+
+static ssize_t kexec_cmdline_store(struct kset *kset, const char *page,
+                                   size_t count)
+{
+        if ((count + 1) > COMMAND_LINE_SIZE)
+                count = COMMAND_LINE_SIZE;
+        memcpy(kexec_cmdline, page, count);
+        kexec_cmdline[count] = '\0';
+        if (count && (kexec_cmdline[count - 1] == '\n'))
+                kexec_cmdline[count - 1] = '\0';
+        replace_cmdline_tag();
+        return count;
+}
+KERNEL_ATTR_RW(kexec_cmdline);
+
+static ssize_t kexec_boot_params_show(struct kset *kset, char *page)
+{
+        unsigned long *p;
+        char buf[PAGE_SIZE];
+        int keep_doing;
+
+        p = (unsigned long *)kexec_boot_params;
+
+        /* if this doesn't look like atags, just print first few words */
+        if (p[1] != ATAG_CORE)
+                return sprintf(page, "0x%lx 0x%lx 0x%lx 0x%lx\n",
+                               p[0], p[1], p[2], p[3]);
+
+        /* carefully walk the atag list, and print out the structure */
+        keep_doing = 1;
+        do {
+                switch (p[1]) {
+                case ATAG_CORE:
+                        /* watch out, core tag is permitted to be empty */
+                        if (p[0] == 5)
+                                sprintf(buf,
+                                        "CORE flg=%ld pgsz=%ld rdev=0x%lx\n",
+                                        p[2], p[3], p[4]);
+                        else
+                                sprintf(buf,"CORE\n");
+                        break;
+                case ATAG_MEM:
+                        sprintf(buf,"MEM  %ldM@0x%lx\n", p[2] / (1024 * 1024),
+                                p[3]);
+                        break;
+                case ATAG_VIDEOTEXT:
+                        sprintf(buf,"VIDEOTEXT sz=%ld\n", p[0]);
+                        break;
+                case ATAG_RAMDISK:
+                        sprintf(buf,"RAMDISK prmpt=%ld %ldK@0x%lx\n",
+                                p[2], p[3], p[4]);
+                        break;
+                case ATAG_INITRD2:
+                        sprintf(buf,"INITRD2 %ldK@0x%lx\n", p[3] / 1024, p[2]);
+                        break;
+                case ATAG_SERIAL:
+                        sprintf(buf,"SERIAL high=0x%08lx low=0x%08lx\n",
+                                p[3], p[2]);
+                        break;
+                case ATAG_REVISION:
+                        sprintf(buf,"REVISION rev=%ld\n", p[2]);
+                        break;
+                case ATAG_VIDEOLFB:
+                        sprintf(buf,"VIDEOLFB sz=%ld\n", p[0]);
+                        break;
+                case ATAG_CMDLINE:
+                        sprintf(buf,"CMD  \"%s\"\n", (char *)&p[2]);
+                        break;
+                case ATAG_NONE:
+                        sprintf(buf,"NONE\n");
+                        keep_doing = 0;
+                        break;
+                default:
+                        sprintf(buf,"-unknown- sz=%ld\n", p[0]);
+                        break;
+                }
+
+                /* carefully add to page */
+                if ((strlen(buf) + strlen(page)) < PAGE_SIZE) {
+                        strcat(page, buf);
+                } else {
+                        keep_doing = 0;
+                }
+
+                /* stop when we encounter a header length of 0 */
+                if (p[0] == 0)
+                        keep_doing = 0;
+
+                /* go to the next tag */
+                p += p[0];
+
+                /* stop if we walked off the end of the buffer */
+                if (p > (unsigned long *)(kexec_boot_params +
+                                          KEXEC_BOOT_PARAMS_SIZE))
+                        keep_doing = 0;
+
+        } while (keep_doing);
+
+        return (strlen(page));
+}
+KERNEL_ATTR_RO(kexec_boot_params);
+
 static ssize_t kexec_loaded_show(struct kset *kset, char *page)
 {
         return sprintf(page, "%d\n", !!kexec_image);
@@ -73 +233 @@
 #ifdef CONFIG_KEXEC
         &kexec_loaded_attr.attr,
         &kexec_crash_loaded_attr.attr,
+        &kexec_cmdline_attr.attr,
+        &kexec_boot_params_attr.attr,
 #endif
         NULL
 };