Merge master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

[linux-2.6-block.git] / arch / i386 / kernel / crash.c

diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c
index a021681d21f8a61b5ad2ae180a9182c8a0f514ce..0248e084017ceddd74bcc7e92052cef801b897ff 100644 (file)
--- a/arch/i386/kernel/crash.c
+++ b/arch/i386/kernel/crash.c
@@ -11,10 +11,8 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/smp.h>
-#include <linux/irq.h>
 #include <linux/reboot.h>
 #include <linux/kexec.h>
-#include <linux/irq.h>
 #include <linux/delay.h>
 #include <linux/elf.h>
 #include <linux/elfcore.h>
@@ -31,10 +29,11 @@ note_buf_t crash_notes[NR_CPUS];
 /* This keeps a track of which one is crashing cpu. */
 static int crashing_cpu;
 
-static u32 *append_elf_note(u32 *buf,
-       char *name, unsigned type, void *data, size_t data_len)
+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;
@@ -44,26 +43,28 @@ static u32 *append_elf_note(u32 *buf,
        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));
 }
 
-
 static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
 {
        struct elf_prstatus prstatus;
        u32 *buf;
-       if ((cpu < 0) || (cpu >= NR_CPUS)) {
+
+       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
@@ -75,9 +76,8 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
        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));
-
+       buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
+                               sizeof(prstatus));
        final_note(buf);
 }
 
@@ -100,12 +100,31 @@ static void crash_get_current_regs(struct pt_regs *regs)
        regs->eip = (unsigned long)current_text_addr();
 }
 
-static void crash_save_self(void)
+/* CPU does not save ss and esp on stack if execution is already
+ * running in kernel mode at the time of NMI occurrence. This code
+ * fixes it.
+ */
+static void crash_setup_regs(struct pt_regs *newregs, struct pt_regs *oldregs)
+{
+       memcpy(newregs, oldregs, sizeof(*newregs));
+       newregs->esp = (unsigned long)&(oldregs->esp);
+       __asm__ __volatile__("xorl %eax, %eax;");
+       __asm__ __volatile__ ("movw %%ss, %%ax;" :"=a"(newregs->xss));
+}
+
+/* We may have saved_regs from where the error came from
+ * or it is NULL if via a direct panic().
+ */
+static void crash_save_self(struct pt_regs *saved_regs)
 {
        struct pt_regs regs;
        int cpu;
+
        cpu = smp_processor_id();
-       crash_get_current_regs(&regs);
+       if (saved_regs)
+               crash_setup_regs(&regs, saved_regs);
+       else
+               crash_get_current_regs(&regs);
        crash_save_this_cpu(&regs, cpu);
 }
 
@@ -124,23 +143,17 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu)
                return 1;
        local_irq_disable();
 
-       /* CPU does not save ss and esp on stack if execution is already
-        * running in kernel mode at the time of NMI occurrence. This code
-        * fixes it.
-        */
        if (!user_mode(regs)) {
-               memcpy(&fixed_regs, regs, sizeof(*regs));
-               fixed_regs.esp = (unsigned long)&(regs->esp);
-               __asm__ __volatile__("xorl %eax, %eax;");
-               __asm__ __volatile__ ("movw %%ss, %%ax;" :"=a"(fixed_regs.xss));
+               crash_setup_regs(&fixed_regs, regs);
                regs = &fixed_regs;
        }
        crash_save_this_cpu(regs, cpu);
        disable_local_APIC();
        atomic_dec(&waiting_for_crash_ipi);
        /* Assume hlt works */
-       __asm__("hlt");
+       halt();
        for(;;);
+
        return 1;
 }
 
@@ -157,8 +170,8 @@ static void smp_send_nmi_allbutself(void)
 static void nmi_shootdown_cpus(void)
 {
        unsigned long msecs;
-       atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 
+       atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
        /* Would it be better to replace the trap vector here? */
        set_nmi_callback(crash_nmi_callback);
        /* Ensure the new callback function is set before sending
@@ -184,7 +197,7 @@ static void nmi_shootdown_cpus(void)
 }
 #endif
 
-void machine_crash_shutdown(void)
+void machine_crash_shutdown(struct pt_regs *regs)
 {
        /* This function is only called after the system
         * has paniced or is otherwise in a critical state.
@@ -204,5 +217,5 @@ void machine_crash_shutdown(void)
 #if defined(CONFIG_X86_IO_APIC)
        disable_IO_APIC();
 #endif
-       crash_save_self();
+       crash_save_self(regs);
 }