Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq

[safe/jmp/linux-2.6] / arch / i386 / kernel / crash.c

diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c
index 3645ad7..2b0cfce 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>
@@ -27,12 +25,14 @@
 #include <mach_ipi.h>
 
 
-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;
@@ -42,69 +42,52 @@ 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
         * on the data to indicate what information I have
         * squirrelled away.  ELF notes happen to provide
-        * all of that that no need to invent something new.
+        * all of that, so there is no need to invent something new.
         */
-       buf = &crash_notes[cpu][0];
+       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));
-
+       buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
+                               sizeof(prstatus));
        final_note(buf);
 }
 
-static void crash_get_current_regs(struct pt_regs *regs)
-{
-       __asm__ __volatile__("movl %%ebx,%0" : "=m"(regs->ebx));
-       __asm__ __volatile__("movl %%ecx,%0" : "=m"(regs->ecx));
-       __asm__ __volatile__("movl %%edx,%0" : "=m"(regs->edx));
-       __asm__ __volatile__("movl %%esi,%0" : "=m"(regs->esi));
-       __asm__ __volatile__("movl %%edi,%0" : "=m"(regs->edi));
-       __asm__ __volatile__("movl %%ebp,%0" : "=m"(regs->ebp));
-       __asm__ __volatile__("movl %%eax,%0" : "=m"(regs->eax));
-       __asm__ __volatile__("movl %%esp,%0" : "=m"(regs->esp));
-       __asm__ __volatile__("movw %%ss, %%ax;" :"=a"(regs->xss));
-       __asm__ __volatile__("movw %%cs, %%ax;" :"=a"(regs->xcs));
-       __asm__ __volatile__("movw %%ds, %%ax;" :"=a"(regs->xds));
-       __asm__ __volatile__("movw %%es, %%ax;" :"=a"(regs->xes));
-       __asm__ __volatile__("pushfl; popl %0" :"=m"(regs->eflags));
-
-       regs->eip = (unsigned long)current_text_addr();
-}
-
-static void crash_save_self(void)
+static void crash_save_self(struct pt_regs *regs)
 {
-       struct pt_regs regs;
        int cpu;
+
        cpu = smp_processor_id();
-       crash_get_current_regs(&regs);
-       crash_save_this_cpu(&regs, cpu);
+       crash_save_this_cpu(regs, cpu);
 }
 
 #ifdef CONFIG_SMP
@@ -112,13 +95,27 @@ static atomic_t waiting_for_crash_ipi;
 
 static int crash_nmi_callback(struct pt_regs *regs, int cpu)
 {
+       struct pt_regs fixed_regs;
+
+       /* Don't do anything if this handler is invoked on crashing cpu.
+        * Otherwise, system will completely hang. Crashing cpu can get
+        * an NMI if system was initially booted with nmi_watchdog parameter.
+        */
+       if (cpu == crashing_cpu)
+               return 1;
        local_irq_disable();
+
+       if (!user_mode_vm(regs)) {
+               crash_fixup_ss_esp(&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;
 }
 
@@ -135,8 +132,8 @@ 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
@@ -162,7 +159,7 @@ 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.
@@ -174,10 +171,13 @@ void machine_crash_shutdown(void)
         */
        /* The kernel is broken so disable interrupts */
        local_irq_disable();
+
+       /* Make a note of crashing cpu. Will be used in NMI callback.*/
+       crashing_cpu = smp_processor_id();
        nmi_shootdown_cpus();
        lapic_shutdown();
 #if defined(CONFIG_X86_IO_APIC)
        disable_IO_APIC();
 #endif
-       crash_save_self();
+       crash_save_self(regs);
 }