W: http://www.cse.unsw.edu.au/~neilb/patches/linux-devel/
S: Maintained
+KEXEC
+P: Eric Biederman
+P: Randy Dunlap
+M: ebiederm@xmission.com
+M: rddunlap@osdl.org
+W: http://www.xmission.com/~ebiederm/files/kexec/
+W: http://developer.osdl.org/rddunlap/kexec/
+L: linux-kernel@vger.kernel.org
+L: fastboot@osdl.org
+S: Maintained
+
LANMEDIA WAN CARD DRIVER
P: Andrew Stanley-Jones
M: asj@lanmedia.com
help
Panic if the stack grows to within specified byte range.
+config KEXEC
+ bool "kexec system call (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel. It is like a reboot
+ but it is indepedent of the system firmware. And like a reboot
+ you can start any kernel with it, not just Linux.
+
+ The name comes from the similiarity to the exec system call.
+
+ It is an ongoing process to be certain the hardware in a machine
+ is properly shutdown, so do not be surprised if this code does not
+ initially work for you. It may help to enable device hotplugging
+ support. As of this writing the exact hardware interface is
+ strongly in flux, so no good recommendation can be made.
+
endmenu
obj-$(CONFIG_X86_MPPARSE) += mpparse.o
obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o
obj-$(CONFIG_X86_IO_APIC) += io_apic.o
+obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
obj-$(CONFIG_X86_NUMAQ) += numaq.o
obj-$(CONFIG_X86_SUMMIT_NUMA) += summit.o
obj-$(CONFIG_MODULES) += module.o
outb(0x70, 0x22);
outb(0x00, 0x23);
}
+ else {
+ /* Go back to Virtual Wire compatibility mode */
+ unsigned long value;
+
+ /* For the spurious interrupt use vector F, and enable it */
+ value = apic_read(APIC_SPIV);
+ value &= ~APIC_VECTOR_MASK;
+ value |= APIC_SPIV_APIC_ENABLED;
+ value |= 0xf;
+ apic_write_around(APIC_SPIV, value);
+
+ /* For LVT0 make it edge triggered, active high, external and enabled */
+ value = apic_read(APIC_LVT0);
+ value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
+ APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+ APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
+ value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+ value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXINT);
+ apic_write_around(APIC_LVT0, value);
+
+ /* For LVT1 make it edge triggered, active high, nmi and enabled */
+ value = apic_read(APIC_LVT1);
+ value &= ~(
+ APIC_MODE_MASK | APIC_SEND_PENDING |
+ APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+ APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
+ value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+ value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
+ apic_write_around(APIC_LVT1, value);
+ }
}
void disable_local_APIC(void)
.long sys_mq_timedreceive /* 280 */
.long sys_mq_notify
.long sys_mq_getsetattr
- .long sys_ni_syscall /* reserved for kexec */
+ .long sys_kexec_load
.long sys_ioprio_set
.long sys_ioprio_get /* 285 */
return 0;
}
+static int i8259A_shutdown(struct sys_device *dev)
+{
+ /* Put the i8259A into a quiescent state that
+ * the kernel initialization code can get it
+ * out of.
+ */
+ outb(0xff, 0x21); /* mask all of 8259A-1 */
+ outb(0xff, 0xA1); /* mask all of 8259A-1 */
+ return 0;
+}
+
static struct sysdev_class i8259_sysdev_class = {
set_kset_name("i8259"),
.resume = i8259A_resume,
+ .shutdown = i8259A_shutdown,
};
static struct sys_device device_i8259A = {
*/
void disable_IO_APIC(void)
{
+ int pin;
/*
* Clear the IO-APIC before rebooting:
*/
clear_IO_APIC();
+ /*
+ * If the i82559 is routed through an IOAPIC
+ * Put that IOAPIC in virtual wire mode
+ * so legacy interrups can be delivered.
+ */
+ pin = find_isa_irq_pin(0, mp_ExtINT);
+ if (pin != -1) {
+ struct IO_APIC_route_entry entry;
+ unsigned long flags;
+
+ memset(&entry, 0, sizeof(entry));
+ entry.mask = 0; /* Enabled */
+ entry.trigger = 0; /* Edge */
+ entry.irr = 0;
+ entry.polarity = 0; /* High */
+ entry.delivery_status = 0;
+ entry.dest_mode = 0; /* Physical */
+ entry.delivery_mode = 7; /* ExtInt */
+ entry.vector = 0;
+ entry.dest.physical.physical_dest = 0;
+
+
+ /*
+ * Add it to the IO-APIC irq-routing table:
+ */
+ spin_lock_irqsave(&ioapic_lock, flags);
+ io_apic_write(0, 0x11+2*pin, *(((int *)&entry)+1));
+ io_apic_write(0, 0x10+2*pin, *(((int *)&entry)+0));
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+ }
disconnect_bsp_APIC();
}
--- /dev/null
+/*
+ * machine_kexec.c - handle transition of Linux booting another kernel
+ * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/cpufeature.h>
+
+static inline unsigned long read_cr3(void)
+{
+ unsigned long cr3;
+ asm volatile("movl %%cr3,%0": "=r"(cr3));
+ return cr3;
+}
+
+#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
+
+#define L0_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define L1_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define L2_ATTR (_PAGE_PRESENT)
+
+#define LEVEL0_SIZE (1UL << 12UL)
+
+#ifndef CONFIG_X86_PAE
+#define LEVEL1_SIZE (1UL << 22UL)
+static u32 pgtable_level1[1024] PAGE_ALIGNED;
+
+static void identity_map_page(unsigned long address)
+{
+ unsigned long level1_index, level2_index;
+ u32 *pgtable_level2;
+
+ /* Find the current page table */
+ pgtable_level2 = __va(read_cr3());
+
+ /* Find the indexes of the physical address to identity map */
+ level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
+ level2_index = address / LEVEL1_SIZE;
+
+ /* Identity map the page table entry */
+ pgtable_level1[level1_index] = address | L0_ATTR;
+ pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
+
+ /* Flush the tlb so the new mapping takes effect.
+ * Global tlb entries are not flushed but that is not an issue.
+ */
+ load_cr3(pgtable_level2);
+}
+
+#else
+#define LEVEL1_SIZE (1UL << 21UL)
+#define LEVEL2_SIZE (1UL << 30UL)
+static u64 pgtable_level1[512] PAGE_ALIGNED;
+static u64 pgtable_level2[512] PAGE_ALIGNED;
+
+static void identity_map_page(unsigned long address)
+{
+ unsigned long level1_index, level2_index, level3_index;
+ u64 *pgtable_level3;
+
+ /* Find the current page table */
+ pgtable_level3 = __va(read_cr3());
+
+ /* Find the indexes of the physical address to identity map */
+ level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
+ level2_index = (address % LEVEL2_SIZE)/LEVEL1_SIZE;
+ level3_index = address / LEVEL2_SIZE;
+
+ /* Identity map the page table entry */
+ pgtable_level1[level1_index] = address | L0_ATTR;
+ pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
+ set_64bit(&pgtable_level3[level3_index], __pa(pgtable_level2) | L2_ATTR);
+
+ /* Flush the tlb so the new mapping takes effect.
+ * Global tlb entries are not flushed but that is not an issue.
+ */
+ load_cr3(pgtable_level3);
+}
+#endif
+
+
+static void set_idt(void *newidt, __u16 limit)
+{
+ unsigned char curidt[6];
+
+ /* ia32 supports unaliged loads & stores */
+ (*(__u16 *)(curidt)) = limit;
+ (*(__u32 *)(curidt +2)) = (unsigned long)(newidt);
+
+ __asm__ __volatile__ (
+ "lidt %0\n"
+ : "=m" (curidt)
+ );
+};
+
+
+static void set_gdt(void *newgdt, __u16 limit)
+{
+ unsigned char curgdt[6];
+
+ /* ia32 supports unaligned loads & stores */
+ (*(__u16 *)(curgdt)) = limit;
+ (*(__u32 *)(curgdt +2)) = (unsigned long)(newgdt);
+
+ __asm__ __volatile__ (
+ "lgdt %0\n"
+ : "=m" (curgdt)
+ );
+};
+
+static void load_segments(void)
+{
+#define __STR(X) #X
+#define STR(X) __STR(X)
+
+ __asm__ __volatile__ (
+ "\tljmp $"STR(__KERNEL_CS)",$1f\n"
+ "\t1:\n"
+ "\tmovl $"STR(__KERNEL_DS)",%eax\n"
+ "\tmovl %eax,%ds\n"
+ "\tmovl %eax,%es\n"
+ "\tmovl %eax,%fs\n"
+ "\tmovl %eax,%gs\n"
+ "\tmovl %eax,%ss\n"
+ );
+#undef STR
+#undef __STR
+}
+
+typedef asmlinkage void (*relocate_new_kernel_t)(
+ unsigned long indirection_page, unsigned long reboot_code_buffer,
+ unsigned long start_address, unsigned int has_pae);
+
+const extern unsigned char relocate_new_kernel[];
+extern void relocate_new_kernel_end(void);
+const extern unsigned int relocate_new_kernel_size;
+
+/*
+ * Do what every setup is needed on image and the
+ * reboot code buffer to allow us to avoid allocations
+ * later. Currently nothing.
+ */
+int machine_kexec_prepare(struct kimage *image)
+{
+ return 0;
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+/*
+ * Do not allocate memory (or fail in any way) in machine_kexec().
+ * We are past the point of no return, committed to rebooting now.
+ */
+void machine_kexec(struct kimage *image)
+{
+ unsigned long indirection_page;
+ unsigned long reboot_code_buffer;
+ relocate_new_kernel_t rnk;
+
+ /* Interrupts aren't acceptable while we reboot */
+ local_irq_disable();
+
+ /* Compute some offsets */
+ reboot_code_buffer = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
+ indirection_page = image->head & PAGE_MASK;
+
+ /* Set up an identity mapping for the reboot_code_buffer */
+ identity_map_page(reboot_code_buffer);
+
+ /* copy it out */
+ memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size);
+
+ /* The segment registers are funny things, they are
+ * automatically loaded from a table, in memory wherever you
+ * set them to a specific selector, but this table is never
+ * accessed again you set the segment to a different selector.
+ *
+ * The more common model is are caches where the behide
+ * the scenes work is done, but is also dropped at arbitrary
+ * times.
+ *
+ * I take advantage of this here by force loading the
+ * segments, before I zap the gdt with an invalid value.
+ */
+ load_segments();
+ /* The gdt & idt are now invalid.
+ * If you want to load them you must set up your own idt & gdt.
+ */
+ set_gdt(phys_to_virt(0),0);
+ set_idt(phys_to_virt(0),0);
+
+ /* now call it */
+ rnk = (relocate_new_kernel_t) reboot_code_buffer;
+ (*rnk)(indirection_page, reboot_code_buffer, image->start, cpu_has_pae);
+}
int reboot_thru_bios;
#ifdef CONFIG_SMP
-int reboot_smp = 0;
static int reboot_cpu = -1;
/* shamelessly grabbed from lib/vsprintf.c for readability */
#define is_digit(c) ((c) >= '0' && (c) <= '9')
return 0;
}
-/*
- * Some machines require the "reboot=s" commandline option, this quirk makes that automatic.
- */
-static int __init set_smp_reboot(struct dmi_system_id *d)
-{
-#ifdef CONFIG_SMP
- if (!reboot_smp) {
- reboot_smp = 1;
- printk(KERN_INFO "%s series board detected. Selecting SMP-method for reboots.\n", d->ident);
- }
-#endif
- return 0;
-}
-
-/*
- * Some machines require the "reboot=b,s" commandline option, this quirk makes that automatic.
- */
-static int __init set_smp_bios_reboot(struct dmi_system_id *d)
-{
- set_smp_reboot(d);
- set_bios_reboot(d);
- return 0;
-}
-
static struct dmi_system_id __initdata reboot_dmi_table[] = {
{ /* Handle problems with rebooting on Dell 1300's */
- .callback = set_smp_bios_reboot,
+ .callback = set_bios_reboot,
.ident = "Dell PowerEdge 1300",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
}
-void machine_restart(char * __unused)
+void machine_shutdown(void)
{
#ifdef CONFIG_SMP
- int cpuid;
-
- cpuid = GET_APIC_ID(apic_read(APIC_ID));
-
- if (reboot_smp) {
-
- /* check to see if reboot_cpu is valid
- if its not, default to the BSP */
- if ((reboot_cpu == -1) ||
- (reboot_cpu > (NR_CPUS -1)) ||
- !physid_isset(cpuid, phys_cpu_present_map))
- reboot_cpu = boot_cpu_physical_apicid;
-
- reboot_smp = 0; /* use this as a flag to only go through this once*/
- /* re-run this function on the other CPUs
- it will fall though this section since we have
- cleared reboot_smp, and do the reboot if it is the
- correct CPU, otherwise it halts. */
- if (reboot_cpu != cpuid)
- smp_call_function((void *)machine_restart , NULL, 1, 0);
+ int reboot_cpu_id;
+
+ /* The boot cpu is always logical cpu 0 */
+ reboot_cpu_id = 0;
+
+ /* See if there has been given a command line override */
+ if ((reboot_cpu_id != -1) && (reboot_cpu < NR_CPUS) &&
+ cpu_isset(reboot_cpu, cpu_online_map)) {
+ reboot_cpu_id = reboot_cpu;
}
- /* if reboot_cpu is still -1, then we want a tradional reboot,
- and if we are not running on the reboot_cpu,, halt */
- if ((reboot_cpu != -1) && (cpuid != reboot_cpu)) {
- for (;;)
- __asm__ __volatile__ ("hlt");
+ /* Make certain the cpu I'm rebooting on is online */
+ if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
+ reboot_cpu_id = smp_processor_id();
}
- /*
- * Stop all CPUs and turn off local APICs and the IO-APIC, so
- * other OSs see a clean IRQ state.
+
+ /* Make certain I only run on the appropriate processor */
+ set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
+
+ /* O.K. Now that I'm on the appropriate processor, stop
+ * all of the others, and disable their local APICs.
*/
+
if (!netdump_mode)
smp_send_stop();
#elif defined(CONFIG_X86_LOCAL_APIC)
#ifdef CONFIG_X86_IO_APIC
disable_IO_APIC();
#endif
+}
+
+void machine_restart(char * __unused)
+{
+ machine_shutdown();
if (!reboot_thru_bios) {
if (efi_enabled) {
--- /dev/null
+/*
+ * relocate_kernel.S - put the kernel image in place to boot
+ * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/linkage.h>
+
+ /*
+ * Must be relocatable PIC code callable as a C function, that once
+ * it starts can not use the previous processes stack.
+ */
+ .globl relocate_new_kernel
+relocate_new_kernel:
+ /* read the arguments and say goodbye to the stack */
+ movl 4(%esp), %ebx /* indirection_page */
+ movl 8(%esp), %ebp /* reboot_code_buffer */
+ movl 12(%esp), %edx /* start address */
+ movl 16(%esp), %ecx /* cpu_has_pae */
+
+ /* zero out flags, and disable interrupts */
+ pushl $0
+ popfl
+
+ /* set a new stack at the bottom of our page... */
+ lea 4096(%ebp), %esp
+
+ /* store the parameters back on the stack */
+ pushl %edx /* store the start address */
+
+ /* Set cr0 to a known state:
+ * 31 0 == Paging disabled
+ * 18 0 == Alignment check disabled
+ * 16 0 == Write protect disabled
+ * 3 0 == No task switch
+ * 2 0 == Don't do FP software emulation.
+ * 0 1 == Proctected mode enabled
+ */
+ movl %cr0, %eax
+ andl $~((1<<31)|(1<<18)|(1<<16)|(1<<3)|(1<<2)), %eax
+ orl $(1<<0), %eax
+ movl %eax, %cr0
+
+ /* clear cr4 if applicable */
+ testl %ecx, %ecx
+ jz 1f
+ /* Set cr4 to a known state:
+ * Setting everything to zero seems safe.
+ */
+ movl %cr4, %eax
+ andl $0, %eax
+ movl %eax, %cr4
+
+ jmp 1f
+1:
+
+ /* Flush the TLB (needed?) */
+ xorl %eax, %eax
+ movl %eax, %cr3
+
+ /* Do the copies */
+ cld
+0: /* top, read another word for the indirection page */
+ movl %ebx, %ecx
+ movl (%ebx), %ecx
+ addl $4, %ebx
+ testl $0x1, %ecx /* is it a destination page */
+ jz 1f
+ movl %ecx, %edi
+ andl $0xfffff000, %edi
+ jmp 0b
+1:
+ testl $0x2, %ecx /* is it an indirection page */
+ jz 1f
+ movl %ecx, %ebx
+ andl $0xfffff000, %ebx
+ jmp 0b
+1:
+ testl $0x4, %ecx /* is it the done indicator */
+ jz 1f
+ jmp 2f
+1:
+ testl $0x8, %ecx /* is it the source indicator */
+ jz 0b /* Ignore it otherwise */
+ movl %ecx, %esi /* For every source page do a copy */
+ andl $0xfffff000, %esi
+
+ movl $1024, %ecx
+ rep ; movsl
+ jmp 0b
+
+2:
+
+ /* To be certain of avoiding problems with self-modifying code
+ * I need to execute a serializing instruction here.
+ * So I flush the TLB, it's handy, and not processor dependent.
+ */
+ xorl %eax, %eax
+ movl %eax, %cr3
+
+ /* set all of the registers to known values */
+ /* leave %esp alone */
+
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
+ xorl %edx, %edx
+ xorl %esi, %esi
+ xorl %edi, %edi
+ xorl %ebp, %ebp
+ ret
+relocate_new_kernel_end:
+
+ .globl relocate_new_kernel_size
+relocate_new_kernel_size:
+ .long relocate_new_kernel_end - relocate_new_kernel
return ioctx;
}
-static void use_mm(struct mm_struct *mm)
+void use_mm(struct mm_struct *mm)
{
struct mm_struct *active_mm;
#define APIC_LVT_REMOTE_IRR (1<<14)
#define APIC_INPUT_POLARITY (1<<13)
#define APIC_SEND_PENDING (1<<12)
+#define APIC_MODE_MASK 0x700
#define GET_APIC_DELIVERY_MODE(x) (((x)>>8)&0x7)
#define SET_APIC_DELIVERY_MODE(x,y) (((x)&~0x700)|((y)<<8))
#define APIC_MODE_FIXED 0x0
--- /dev/null
+#ifndef _I386_KEXEC_H
+#define _I386_KEXEC_H
+
+#include <asm/fixmap.h>
+
+/*
+ * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
+ * I.e. Maximum page that is mapped directly into kernel memory,
+ * and kmap is not required.
+ *
+ * Someone correct me if FIXADDR_START - PAGEOFFSET is not the correct
+ * calculation for the amount of memory directly mappable into the
+ * kernel memory space.
+ */
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+/* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+#endif /* _I386_KEXEC_H */
*/
#define IDT_ENTRIES 256
+#define KERN_PHYS_OFFSET (CONFIG_KERN_PHYS_OFFSET * 0x100000)
+
#endif
--- /dev/null
+#ifndef LINUX_KEXEC_H
+#define LINUX_KEXEC_H
+
+#ifdef CONFIG_KEXEC
+#include <linux/types.h>
+#include <linux/list.h>
+#include <asm/kexec.h>
+
+/*
+ * This structure is used to hold the arguments that are used when loading
+ * kernel binaries.
+ */
+
+typedef unsigned long kimage_entry_t;
+#define IND_DESTINATION 0x1
+#define IND_INDIRECTION 0x2
+#define IND_DONE 0x4
+#define IND_SOURCE 0x8
+
+#define KEXEC_SEGMENT_MAX 8
+struct kexec_segment {
+ void *buf;
+ size_t bufsz;
+ void *mem;
+ size_t memsz;
+};
+
+struct kimage {
+ kimage_entry_t head;
+ kimage_entry_t *entry;
+ kimage_entry_t *last_entry;
+
+ unsigned long destination;
+
+ unsigned long start;
+ struct page *control_code_page;
+
+ unsigned long nr_segments;
+ struct kexec_segment segment[KEXEC_SEGMENT_MAX];
+
+ struct list_head control_pages;
+ struct list_head dest_pages;
+ struct list_head unuseable_pages;
+};
+
+
+/* kexec interface functions */
+extern void machine_kexec(struct kimage *image);
+extern int machine_kexec_prepare(struct kimage *image);
+extern void machine_kexec_cleanup(struct kimage *image);
+extern asmlinkage long sys_kexec(unsigned long entry, long nr_segments,
+ struct kexec_segment *segments);
+extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order);
+extern struct kimage *kexec_image;
+#endif
+#endif /* LINUX_KEXEC_H */
extern void machine_halt(void);
extern void machine_power_off(void);
+extern void machine_shutdown(void);
+
#endif
#endif /* _LINUX_REBOOT_H */
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PM) += power/
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
+obj-$(CONFIG_KEXEC) += kexec.o
obj-$(CONFIG_COMPAT) += compat.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_IKCONFIG_PROC) += configs.o
--- /dev/null
+/*
+ * kexec.c - kexec system call
+ * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/kexec.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+#include <net/checksum.h>
+#include <asm/page.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/system.h>
+
+/*
+ * When kexec transitions to the new kernel there is a one-to-one
+ * mapping between physical and virtual addresses. On processors
+ * where you can disable the MMU this is trivial, and easy. For
+ * others it is still a simple predictable page table to setup.
+ *
+ * In that environment kexec copies the new kernel to its final
+ * resting place. This means I can only support memory whose
+ * physical address can fit in an unsigned long. In particular
+ * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
+ * If the assembly stub has more restrictive requirements
+ * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
+ * defined more restrictively in <asm/kexec.h>.
+ *
+ * The code for the transition from the current kernel to the
+ * the new kernel is placed in the control_code_buffer, whose size
+ * is given by KEXEC_CONTROL_CODE_SIZE. In the best case only a single
+ * page of memory is necessary, but some architectures require more.
+ * Because this memory must be identity mapped in the transition from
+ * virtual to physical addresses it must live in the range
+ * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
+ * modifiable.
+ *
+ * The assembly stub in the control code buffer is passed a linked list
+ * of descriptor pages detailing the source pages of the new kernel,
+ * and the destination addresses of those source pages. As this data
+ * structure is not used in the context of the current OS, it must
+ * be self-contained.
+ *
+ * The code has been made to work with highmem pages and will use a
+ * destination page in its final resting place (if it happens
+ * to allocate it). The end product of this is that most of the
+ * physical address space, and most of RAM can be used.
+ *
+ * Future directions include:
+ * - allocating a page table with the control code buffer identity
+ * mapped, to simplify machine_kexec and make kexec_on_panic more
+ * reliable.
+ */
+
+/*
+ * KIMAGE_NO_DEST is an impossible destination address..., for
+ * allocating pages whose destination address we do not care about.
+ */
+#define KIMAGE_NO_DEST (-1UL)
+
+static int kimage_is_destination_range(
+ struct kimage *image, unsigned long start, unsigned long end);
+static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mask, unsigned long dest);
+
+
+static int kimage_alloc(struct kimage **rimage,
+ unsigned long nr_segments, struct kexec_segment *segments)
+{
+ int result;
+ struct kimage *image;
+ size_t segment_bytes;
+ unsigned long i;
+
+ /* Allocate a controlling structure */
+ result = -ENOMEM;
+ image = kmalloc(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;
+
+ /* Initialize the list of control pages */
+ INIT_LIST_HEAD(&image->control_pages);
+
+ /* Initialize the list of destination pages */
+ INIT_LIST_HEAD(&image->dest_pages);
+
+ /* Initialize the list of unuseable pages */
+ INIT_LIST_HEAD(&image->unuseable_pages);
+
+ /* Read in the segments */
+ image->nr_segments = nr_segments;
+ segment_bytes = nr_segments * sizeof*segments;
+ result = copy_from_user(image->segment, segments, segment_bytes);
+ if (result)
+ goto out;
+
+ /*
+ * Verify we have good destination addresses. The caller is
+ * responsible for making certain we don't attempt to load
+ * the new image into invalid or reserved areas of RAM. This
+ * just verifies it is an address we can use.
+ */
+ result = -EADDRNOTAVAIL;
+ for (i = 0; i < nr_segments; i++) {
+ unsigned long mend;
+ mend = ((unsigned long)(image->segment[i].mem)) +
+ image->segment[i].memsz;
+ if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
+ goto out;
+ }
+
+ /*
+ * Find a location for the control code buffer, and add it
+ * the vector of segments so that it's pages will also be
+ * counted as destination pages.
+ */
+ result = -ENOMEM;
+ image->control_code_page = kimage_alloc_control_pages(image,
+ get_order(KEXEC_CONTROL_CODE_SIZE));
+ if (!image->control_code_page) {
+ printk(KERN_ERR "Could not allocate control_code_buffer\n");
+ goto out;
+ }
+
+ result = 0;
+ out:
+ if (result == 0) {
+ *rimage = image;
+ } else {
+ kfree(image);
+ }
+ return result;
+}
+
+static int kimage_is_destination_range(
+ struct kimage *image, unsigned long start, unsigned long end)
+{
+ unsigned long i;
+
+ for (i = 0; i < image->nr_segments; i++) {
+ unsigned long mstart, mend;
+ mstart = (unsigned long)image->segment[i].mem;
+ mend = mstart + image->segment[i].memsz;
+ if ((end > mstart) && (start < mend)) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static struct page *kimage_alloc_pages(unsigned int gfp_mask, unsigned int order)
+{
+ struct page *pages;
+ pages = alloc_pages(gfp_mask, order);
+ if (pages) {
+ unsigned int count, i;
+ pages->mapping = NULL;
+ pages->private = order;
+ count = 1 << order;
+ for(i = 0; i < count; i++) {
+ SetPageReserved(pages + i);
+ }
+ }
+ return pages;
+}
+
+static void kimage_free_pages(struct page *page)
+{
+ unsigned int order, count, i;
+ order = page->private;
+ count = 1 << order;
+ for(i = 0; i < count; i++) {
+ ClearPageReserved(page + i);
+ }
+ __free_pages(page, order);
+}
+
+static void kimage_free_page_list(struct list_head *list)
+{
+ struct list_head *pos, *next;
+ list_for_each_safe(pos, next, list) {
+ struct page *page;
+
+ page = list_entry(pos, struct page, lru);
+ list_del(&page->lru);
+
+ kimage_free_pages(page);
+ }
+}
+
+struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order)
+{
+ /* Control pages are special, they are the intermediaries
+ * that are needed while we copy the rest of the pages
+ * to their final resting place. As such they must
+ * not conflict with either the destination addresses
+ * or memory the kernel is already using.
+ *
+ * The only case where we really need more than one of
+ * these are for architectures where we cannot disable
+ * the MMU and must instead generate an identity mapped
+ * page table for all of the memory.
+ *
+ * At worst this runs in O(N) of the image size.
+ */
+ struct list_head extra_pages;
+ struct page *pages;
+ unsigned int count;
+
+ count = 1 << order;
+ INIT_LIST_HEAD(&extra_pages);
+
+ /* Loop while I can allocate a page and the page allocated
+ * is a destination page.
+ */
+ do {
+ unsigned long pfn, epfn, addr, eaddr;
+ pages = kimage_alloc_pages(GFP_KERNEL, order);
+ if (!pages)
+ break;
+ pfn = page_to_pfn(pages);
+ epfn = pfn + count;
+ addr = pfn << PAGE_SHIFT;
+ eaddr = epfn << PAGE_SHIFT;
+ if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
+ kimage_is_destination_range(image, addr, eaddr))
+ {
+ list_add(&pages->lru, &extra_pages);
+ pages = NULL;
+ }
+ } while(!pages);
+ if (pages) {
+ /* Remember the allocated page... */
+ list_add(&pages->lru, &image->control_pages);
+
+ /* Because the page is already in it's destination
+ * location we will never allocate another page at
+ * that address. Therefore kimage_alloc_pages
+ * will not return it (again) and we don't need
+ * to give it an entry in image->segment[].
+ */
+ }
+ /* Deal with the destination pages I have inadvertently allocated.
+ *
+ * Ideally I would convert multi-page allocations into single
+ * page allocations, and add everyting to image->dest_pages.
+ *
+ * For now it is simpler to just free the pages.
+ */
+ kimage_free_page_list(&extra_pages);
+ return pages;
+
+}
+
+static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
+{
+ if (*image->entry != 0) {
+ image->entry++;
+ }
+ if (image->entry == image->last_entry) {
+ kimage_entry_t *ind_page;
+ struct page *page;
+ page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
+ if (!page) {
+ return -ENOMEM;
+ }
+ ind_page = page_address(page);
+ *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
+ image->entry = ind_page;
+ image->last_entry =
+ ind_page + ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
+ }
+ *image->entry = entry;
+ image->entry++;
+ *image->entry = 0;
+ return 0;
+}
+
+static int kimage_set_destination(
+ struct kimage *image, unsigned long destination)
+{
+ int result;
+
+ destination &= PAGE_MASK;
+ result = kimage_add_entry(image, destination | IND_DESTINATION);
+ if (result == 0) {
+ image->destination = destination;
+ }
+ return result;
+}
+
+
+static int kimage_add_page(struct kimage *image, unsigned long page)
+{
+ int result;
+
+ page &= PAGE_MASK;
+ result = kimage_add_entry(image, page | IND_SOURCE);
+ if (result == 0) {
+ image->destination += PAGE_SIZE;
+ }
+ return result;
+}
+
+
+static void kimage_free_extra_pages(struct kimage *image)
+{
+ /* Walk through and free any extra destination pages I may have */
+ kimage_free_page_list(&image->dest_pages);
+
+ /* Walk through and free any unuseable pages I have cached */
+ kimage_free_page_list(&image->unuseable_pages);
+
+}
+static int kimage_terminate(struct kimage *image)
+{
+ int result;
+
+ result = kimage_add_entry(image, IND_DONE);
+ if (result == 0) {
+ /* Point at the terminating element */
+ image->entry--;
+ kimage_free_extra_pages(image);
+ }
+ return result;
+}
+
+#define for_each_kimage_entry(image, ptr, entry) \
+ for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
+ ptr = (entry & IND_INDIRECTION)? \
+ phys_to_virt((entry & PAGE_MASK)): ptr +1)
+
+static void kimage_free_entry(kimage_entry_t entry)
+{
+ struct page *page;
+
+ page = pfn_to_page(entry >> PAGE_SHIFT);
+ kimage_free_pages(page);
+}
+
+static void kimage_free(struct kimage *image)
+{
+ kimage_entry_t *ptr, entry;
+ kimage_entry_t ind = 0;
+
+ if (!image)
+ return;
+ kimage_free_extra_pages(image);
+ for_each_kimage_entry(image, ptr, entry) {
+ if (entry & IND_INDIRECTION) {
+ /* Free the previous indirection page */
+ if (ind & IND_INDIRECTION) {
+ kimage_free_entry(ind);
+ }
+ /* Save this indirection page until we are
+ * done with it.
+ */
+ ind = entry;
+ }
+ else if (entry & IND_SOURCE) {
+ kimage_free_entry(entry);
+ }
+ }
+ /* Free the final indirection page */
+ if (ind & IND_INDIRECTION) {
+ kimage_free_entry(ind);
+ }
+
+ /* Handle any machine specific cleanup */
+ machine_kexec_cleanup(image);
+
+ /* Free the kexec control pages... */
+ kimage_free_page_list(&image->control_pages);
+ kfree(image);
+}
+
+static kimage_entry_t *kimage_dst_used(struct kimage *image, unsigned long page)
+{
+ kimage_entry_t *ptr, entry;
+ unsigned long destination = 0;
+
+ for_each_kimage_entry(image, ptr, entry) {
+ if (entry & IND_DESTINATION) {
+ destination = entry & PAGE_MASK;
+ }
+ else if (entry & IND_SOURCE) {
+ if (page == destination) {
+ return ptr;
+ }
+ destination += PAGE_SIZE;
+ }
+ }
+ return 0;
+}
+
+static struct page *kimage_alloc_page(struct kimage *image, unsigned int gfp_mask, unsigned long destination)
+{
+ /*
+ * Here we implement safeguards to ensure that a source page
+ * is not copied to its destination page before the data on
+ * the destination page is no longer useful.
+ *
+ * To do this we maintain the invariant that a source page is
+ * either its own destination page, or it is not a
+ * destination page at all.
+ *
+ * That is slightly stronger than required, but the proof
+ * that no problems will not occur is trivial, and the
+ * implementation is simply to verify.
+ *
+ * When allocating all pages normally this algorithm will run
+ * in O(N) time, but in the worst case it will run in O(N^2)
+ * time. If the runtime is a problem the data structures can
+ * be fixed.
+ */
+ struct page *page;
+ unsigned long addr;
+
+ /*
+ * Walk through the list of destination pages, and see if I
+ * have a match.
+ */
+ list_for_each_entry(page, &image->dest_pages, lru) {
+ addr = page_to_pfn(page) << PAGE_SHIFT;
+ if (addr == destination) {
+ list_del(&page->lru);
+ return page;
+ }
+ }
+ page = NULL;
+ while (1) {
+ kimage_entry_t *old;
+
+ /* Allocate a page, if we run out of memory give up */
+ page = kimage_alloc_pages(gfp_mask, 0);
+ if (!page) {
+ return 0;
+ }
+ /* If the page cannot be used file it away */
+ if (page_to_pfn(page) > (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
+ list_add(&page->lru, &image->unuseable_pages);
+ continue;
+ }
+ addr = page_to_pfn(page) << PAGE_SHIFT;
+
+ /* If it is the destination page we want use it */
+ if (addr == destination)
+ break;
+
+ /* If the page is not a destination page use it */
+ if (!kimage_is_destination_range(image, addr, addr + PAGE_SIZE))
+ break;
+
+ /*
+ * I know that the page is someones destination page.
+ * See if there is already a source page for this
+ * destination page. And if so swap the source pages.
+ */
+ old = kimage_dst_used(image, addr);
+ if (old) {
+ /* If so move it */
+ unsigned long old_addr;
+ struct page *old_page;
+
+ old_addr = *old & PAGE_MASK;
+ old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
+ copy_highpage(page, old_page);
+ *old = addr | (*old & ~PAGE_MASK);
+
+ /* The old page I have found cannot be a
+ * destination page, so return it.
+ */
+ addr = old_addr;
+ page = old_page;
+ break;
+ }
+ else {
+ /* Place the page on the destination list I
+ * will use it later.
+ */
+ list_add(&page->lru, &image->dest_pages);
+ }
+ }
+ return page;
+}
+
+static int kimage_load_segment(struct kimage *image,
+ struct kexec_segment *segment)
+{
+ unsigned long mstart;
+ int result;
+ unsigned long offset;
+ unsigned long offset_end;
+ unsigned char *buf;
+
+ result = 0;
+ buf = segment->buf;
+ mstart = (unsigned long)segment->mem;
+
+ offset_end = segment->memsz;
+
+ result = kimage_set_destination(image, mstart);
+ if (result < 0) {
+ goto out;
+ }
+ for (offset = 0; offset < segment->memsz; offset += PAGE_SIZE) {
+ struct page *page;
+ char *ptr;
+ size_t size, leader;
+ page = kimage_alloc_page(image, GFP_HIGHUSER, mstart + offset);
+ if (page == 0) {
+ result = -ENOMEM;
+ goto out;
+ }
+ result = kimage_add_page(image, page_to_pfn(page) << PAGE_SHIFT);
+ if (result < 0) {
+ goto out;
+ }
+ ptr = kmap(page);
+ if (segment->bufsz < offset) {
+ /* We are past the end zero the whole page */
+ memset(ptr, 0, PAGE_SIZE);
+ kunmap(page);
+ continue;
+ }
+ size = PAGE_SIZE;
+ leader = 0;
+ if ((offset == 0)) {
+ leader = mstart & ~PAGE_MASK;
+ }
+ if (leader) {
+ /* We are on the first page zero the unused portion */
+ memset(ptr, 0, leader);
+ size -= leader;
+ ptr += leader;
+ }
+ if (size > (segment->bufsz - offset)) {
+ size = segment->bufsz - offset;
+ }
+ if (size < (PAGE_SIZE - leader)) {
+ /* zero the trailing part of the page */
+ memset(ptr + size, 0, (PAGE_SIZE - leader) - size);
+ }
+ result = copy_from_user(ptr, buf + offset, size);
+ kunmap(page);
+ if (result) {
+ result = (result < 0) ? result : -EIO;
+ goto out;
+ }
+ }
+ out:
+ return result;
+}
+
+/*
+ * Exec Kernel system call: for obvious reasons only root may call it.
+ *
+ * This call breaks up into three pieces.
+ * - A generic part which loads the new kernel from the current
+ * address space, and very carefully places the data in the
+ * allocated pages.
+ *
+ * - A generic part that interacts with the kernel and tells all of
+ * the devices to shut down. Preventing on-going dmas, and placing
+ * the devices in a consistent state so a later kernel can
+ * reinitialize them.
+ *
+ * - A machine specific part that includes the syscall number
+ * and the copies the image to it's final destination. And
+ * jumps into the image at entry.
+ *
+ * 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;
+
+asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
+ struct kexec_segment *segments, unsigned long flags)
+{
+ struct kimage *image;
+ int result;
+
+ /* We only trust the superuser with rebooting the system. */
+ if (!capable(CAP_SYS_BOOT))
+ return -EPERM;
+
+ /*
+ * In case we need just a little bit of special behavior for
+ * reboot on panic.
+ */
+ if (flags != 0)
+ return -EINVAL;
+
+ if (nr_segments > KEXEC_SEGMENT_MAX)
+ return -EINVAL;
+
+ image = NULL;
+ result = 0;
+
+ if (nr_segments > 0) {
+ unsigned long i;
+ result = kimage_alloc(&image, nr_segments, segments);
+ if (result) {
+ goto out;
+ }
+ result = machine_kexec_prepare(image);
+ if (result) {
+ goto out;
+ }
+ image->start = entry;
+ for (i = 0; i < nr_segments; i++) {
+ result = kimage_load_segment(image, &image->segment[i]);
+ if (result) {
+ goto out;
+ }
+ }
+ result = kimage_terminate(image);
+ if (result) {
+ goto out;
+ }
+ }
+
+ image = xchg(&kexec_image, image);
+
+ out:
+ kimage_free(image);
+ return result;
+}
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
#include <linux/workqueue.h>
#include <linux/device.h>
#include <linux/times.h>
machine_restart(buffer);
break;
+#ifdef CONFIG_KEXEC
+ case LINUX_REBOOT_CMD_KEXEC:
+ {
+ struct kimage *image;
+ image = xchg(&kexec_image, 0);
+ if (!image) {
+ unlock_kernel();
+ return -EINVAL;
+ }
+ notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
+ system_state = SYSTEM_RESTART;
+ device_shutdown();
+ system_state = SYSTEM_BOOTING;
+ printk(KERN_EMERG "Starting new kernel\n");
+ machine_shutdown();
+ machine_kexec(image);
+ break;
+ }
+#endif
#ifdef CONFIG_SOFTWARE_SUSPEND
case LINUX_REBOOT_CMD_SW_SUSPEND:
{
git://git.onelab.eu / linux-2.6.git / commitdiff