x86: Do not free zero sized per cpu areas

[safe/jmp/linux-2.6] / kernel / kexec.c

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 8a6d7b0..87ebe8a 100644 (file)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -21,7 +21,7 @@
 #include <linux/hardirq.h>
 #include <linux/elf.h>
 #include <linux/elfcore.h>
-#include <linux/utsrelease.h>
+#include <generated/utsrelease.h>
 #include <linux/utsname.h>
 #include <linux/numa.h>
 #include <linux/suspend.h>
@@ -31,6 +31,8 @@
 #include <linux/cpu.h>
 #include <linux/console.h>
 #include <linux/vmalloc.h>
+#include <linux/swap.h>
+#include <linux/kmsg_dump.h>
 
 #include <asm/page.h>
 #include <asm/uaccess.h>
@@ -39,10 +41,10 @@
 #include <asm/sections.h>
 
 /* Per cpu memory for storing cpu states in case of system crash. */
-note_buf_t* crash_notes;
+note_buf_t __percpu *crash_notes;
 
 /* vmcoreinfo stuff */
-unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
+static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
 u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 size_t vmcoreinfo_size;
 size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
@@ -1073,6 +1075,9 @@ void crash_kexec(struct pt_regs *regs)
        if (mutex_trylock(&kexec_mutex)) {
                if (kexec_crash_image) {
                        struct pt_regs fixed_regs;
+
+                       kmsg_dump(KMSG_DUMP_KEXEC);
+
                        crash_setup_regs(&fixed_regs, regs);
                        crash_save_vmcoreinfo();
                        machine_crash_shutdown(&fixed_regs);
@@ -1082,6 +1087,64 @@ void crash_kexec(struct pt_regs *regs)
        }
 }
 
+size_t crash_get_memory_size(void)
+{
+       size_t size;
+       mutex_lock(&kexec_mutex);
+       size = crashk_res.end - crashk_res.start + 1;
+       mutex_unlock(&kexec_mutex);
+       return size;
+}
+
+static void free_reserved_phys_range(unsigned long begin, unsigned long end)
+{
+       unsigned long addr;
+
+       for (addr = begin; addr < end; addr += PAGE_SIZE) {
+               ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
+               init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
+               free_page((unsigned long)__va(addr));
+               totalram_pages++;
+       }
+}
+
+int crash_shrink_memory(unsigned long new_size)
+{
+       int ret = 0;
+       unsigned long start, end;
+
+       mutex_lock(&kexec_mutex);
+
+       if (kexec_crash_image) {
+               ret = -ENOENT;
+               goto unlock;
+       }
+       start = crashk_res.start;
+       end = crashk_res.end;
+
+       if (new_size >= end - start + 1) {
+               ret = -EINVAL;
+               if (new_size == end - start + 1)
+                       ret = 0;
+               goto unlock;
+       }
+
+       start = roundup(start, PAGE_SIZE);
+       end = roundup(start + new_size, PAGE_SIZE);
+
+       free_reserved_phys_range(end, crashk_res.end);
+
+       if (start == end) {
+               crashk_res.end = end;
+               release_resource(&crashk_res);
+       } else
+               crashk_res.end = end - 1;
+
+unlock:
+       mutex_unlock(&kexec_mutex);
+       return ret;
+}
+
 static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
                            size_t data_len)
 {
@@ -1130,7 +1193,7 @@ void crash_save_cpu(struct pt_regs *regs, int cpu)
                return;
        memset(&prstatus, 0, sizeof(prstatus));
        prstatus.pr_pid = current->pid;
-       elf_core_copy_regs(&prstatus.pr_reg, regs);
+       elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
        buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
                              &prstatus, sizeof(prstatus));
        final_note(buf);
@@ -1228,7 +1291,7 @@ static int __init parse_crashkernel_mem(char                      *cmdline,
        } while (*cur++ == ',');
 
        if (*crash_size > 0) {
-               while (*cur != ' ' && *cur != '@')
+               while (*cur && *cur != ' ' && *cur != '@')
                        cur++;
                if (*cur == '@') {
                        cur++;
@@ -1409,6 +1472,7 @@ static int __init crash_save_vmcoreinfo_init(void)
        VMCOREINFO_OFFSET(list_head, prev);
        VMCOREINFO_OFFSET(vm_struct, addr);
        VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
+       log_buf_kexec_setup();
        VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
        VMCOREINFO_NUMBER(NR_FREE_PAGES);
        VMCOREINFO_NUMBER(PG_lru);
@@ -1447,22 +1511,25 @@ int kernel_kexec(void)
                        goto Restore_console;
                }
                suspend_console();
-               error = device_suspend(PMSG_FREEZE);
+               error = dpm_suspend_start(PMSG_FREEZE);
                if (error)
                        goto Resume_console;
-               error = disable_nonboot_cpus();
-               if (error)
-                       goto Resume_devices;
-               device_pm_lock();
-               local_irq_disable();
-               /* At this point, device_suspend() has been called,
-                * but *not* device_power_down(). We *must*
-                * device_power_down() now.  Otherwise, drivers for
+               /* At this point, dpm_suspend_start() has been called,
+                * but *not* dpm_suspend_noirq(). We *must* call
+                * dpm_suspend_noirq() now.  Otherwise, drivers for
                 * some devices (e.g. interrupt controllers) become
                 * desynchronized with the actual state of the
                 * hardware at resume time, and evil weirdness ensues.
                 */
-               error = device_power_down(PMSG_FREEZE);
+               error = dpm_suspend_noirq(PMSG_FREEZE);
+               if (error)
+                       goto Resume_devices;
+               error = disable_nonboot_cpus();
+               if (error)
+                       goto Enable_cpus;
+               local_irq_disable();
+               /* Suspend system devices */
+               error = sysdev_suspend(PMSG_FREEZE);
                if (error)
                        goto Enable_irqs;
        } else
@@ -1477,13 +1544,14 @@ int kernel_kexec(void)
 
 #ifdef CONFIG_KEXEC_JUMP
        if (kexec_image->preserve_context) {
-               device_power_up(PMSG_RESTORE);
+               sysdev_resume();
  Enable_irqs:
                local_irq_enable();
-               device_pm_unlock();
+ Enable_cpus:
                enable_nonboot_cpus();
+               dpm_resume_noirq(PMSG_RESTORE);
  Resume_devices:
-               device_resume(PMSG_RESTORE);
+               dpm_resume_end(PMSG_RESTORE);
  Resume_console:
                resume_console();
                thaw_processes();