X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fkexec.c;h=2a59c8a01ae0010da5ef5b80b39fad2ec1da14ae;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=bf39d28e4c0e7b44313124d84681f012ca193713;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/kernel/kexec.c b/kernel/kexec.c
index bf39d28e4..2a59c8a01 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -20,6 +20,8 @@
 #include <linux/syscalls.h>
 #include <linux/ioport.h>
 #include <linux/hardirq.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
 
 #include <asm/page.h>
 #include <asm/uaccess.h>
@@ -40,7 +42,7 @@ struct resource crashk_res = {
 
 int kexec_should_crash(struct task_struct *p)
 {
-	if (in_interrupt() || !p->pid || p->pid == 1 || panic_on_oops)
+	if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops)
 		return 1;
 	return 0;
 }
@@ -108,11 +110,10 @@ static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
 
 	/* Allocate a controlling structure */
 	result = -ENOMEM;
-	image = kmalloc(sizeof(*image), GFP_KERNEL);
+	image = kzalloc(sizeof(*image), GFP_KERNEL);
 	if (!image)
 		goto out;
 
-	memset(image, 0, sizeof(*image));
 	image->head = 0;
 	image->entry = &image->head;
 	image->last_entry = &image->head;
@@ -851,6 +852,7 @@ static int kimage_load_crash_segment(struct kimage *image,
 			memset(ptr + uchunk, 0, mchunk - uchunk);
 		}
 		result = copy_from_user(ptr, buf, uchunk);
+		kexec_flush_icache_page(page);
 		kunmap(page);
 		if (result) {
 			result = (result < 0) ? result : -EIO;
@@ -902,14 +904,14 @@ static int kimage_load_segment(struct kimage *image,
  * kexec does not sync, or unmount filesystems so if you need
  * that to happen you need to do that yourself.
  */
-struct kimage *kexec_image = NULL;
-static struct kimage *kexec_crash_image = NULL;
+struct kimage *kexec_image;
+struct kimage *kexec_crash_image;
 /*
  * A home grown binary mutex.
  * Nothing can wait so this mutex is safe to use
  * in interrupt context :)
  */
-static int kexec_lock = 0;
+static int kexec_lock;
 
 asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
 				struct kexec_segment __user *segments,
@@ -995,7 +997,8 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
 	image = xchg(dest_image, image);
 
 out:
-	xchg(&kexec_lock, 0); /* Release the mutex */
+	locked = xchg(&kexec_lock, 0); /* Release the mutex */
+	BUG_ON(!locked);
 	kimage_free(image);
 
 	return result;
@@ -1042,7 +1045,6 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
 
 void crash_kexec(struct pt_regs *regs)
 {
-	struct kimage *image;
 	int locked;
 
 
@@ -1056,17 +1058,71 @@ void crash_kexec(struct pt_regs *regs)
 	 */
 	locked = xchg(&kexec_lock, 1);
 	if (!locked) {
-		image = xchg(&kexec_crash_image, NULL);
-		if (image) {
+		if (kexec_crash_image) {
 			struct pt_regs fixed_regs;
 			crash_setup_regs(&fixed_regs, regs);
 			machine_crash_shutdown(&fixed_regs);
-			machine_kexec(image);
+			machine_kexec(kexec_crash_image);
 		}
-		xchg(&kexec_lock, 0);
+		locked = xchg(&kexec_lock, 0);
+		BUG_ON(!locked);
 	}
 }
 
+static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
+			    size_t data_len)
+{
+	struct elf_note note;
+
+	note.n_namesz = strlen(name) + 1;
+	note.n_descsz = data_len;
+	note.n_type   = type;
+	memcpy(buf, &note, sizeof(note));
+	buf += (sizeof(note) + 3)/4;
+	memcpy(buf, name, note.n_namesz);
+	buf += (note.n_namesz + 3)/4;
+	memcpy(buf, data, note.n_descsz);
+	buf += (note.n_descsz + 3)/4;
+
+	return buf;
+}
+
+static void final_note(u32 *buf)
+{
+	struct elf_note note;
+
+	note.n_namesz = 0;
+	note.n_descsz = 0;
+	note.n_type   = 0;
+	memcpy(buf, &note, sizeof(note));
+}
+
+void crash_save_cpu(struct pt_regs *regs, int cpu)
+{
+	struct elf_prstatus prstatus;
+	u32 *buf;
+
+	if ((cpu < 0) || (cpu >= NR_CPUS))
+		return;
+
+	/* Using ELF notes here is opportunistic.
+	 * I need a well defined structure format
+	 * for the data I pass, and I need tags
+	 * on the data to indicate what information I have
+	 * squirrelled away.  ELF notes happen to provide
+	 * all of that, so there is no need to invent something new.
+	 */
+	buf = (u32*)per_cpu_ptr(crash_notes, cpu);
+	if (!buf)
+		return;
+	memset(&prstatus, 0, sizeof(prstatus));
+	prstatus.pr_pid = current->pid;
+	elf_core_copy_regs(&prstatus.pr_reg, regs);
+	buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
+				sizeof(prstatus));
+	final_note(buf);
+}
+
 static int __init crash_notes_memory_init(void)
 {
 	/* Allocate memory for saving cpu registers. */