x86: unify appropriate bits from dumpstack_32 and dumpstack_64

Impact: cleanup

As promised, now that dumpstack_32 and dumpstack_64 have so many bits
in common, we should merge the in-sync bits into a common file, to
prevent them from diverging again.

This patch removes bits which are common between dumpstack_32.c and
dumpstack_64.c and places them in a common dumpstack.c which is built
for both 32 and 64 bit arches.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 Makefile       |    2
 arch/x86/kernel/Makefile       |    2
 arch/x86/kernel/Makefile       |    2
 arch/x86/kernel/Makefile       |    2
 arch/x86/kernel/Makefile       |    2
 arch/x86/kernel/Makefile       |    2
 arch/x86/kernel/dumpstack.c    |  319 +++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/dumpstack.h    |   39 +++++
 arch/x86/kernel/dumpstack_32.c |  294 -------------------------------------
 arch/x86/kernel/dumpstack_64.c |  285 ------------------------------------
 5 files changed, 363 insertions(+), 576 deletions(-)

1 files changed, 319 insertions, 0 deletions

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
new file mode 100644
index 000000000000..5962176dfabb
--- /dev/null
+++ b/arch/x86/kernel/dumpstack.c
@@ -0,0 +1,319 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ */
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/utsname.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/kexec.h>
+#include <linux/bug.h>
+#include <linux/nmi.h>
+#include <linux/sysfs.h>
+
+#include <asm/stacktrace.h>
+
+#include "dumpstack.h"
+
+int panic_on_unrecovered_nmi;
+unsigned int code_bytes = 64;
+int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
+static int die_counter;
+
+void printk_address(unsigned long address, int reliable)
+{
+        printk(" [<%p>] %s%pS\n", (void *) address,
+                        reliable ? "" : "? ", (void *) address);
+}
+
+/*
+ * x86-64 can have up to three kernel stacks:
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
+ */
+
+static inline int valid_stack_ptr(struct thread_info *tinfo,
+                        void *p, unsigned int size, void *end)
+{
+        void *t = tinfo;
+        if (end) {
+                if (p < end && p >= (end-THREAD_SIZE))
+                        return 1;
+                else
+                        return 0;
+        }
+        return p > t && p < t + THREAD_SIZE - size;
+}
+
+unsigned long
+print_context_stack(struct thread_info *tinfo,
+                unsigned long *stack, unsigned long bp,
+                const struct stacktrace_ops *ops, void *data,
+                unsigned long *end)
+{
+        struct stack_frame *frame = (struct stack_frame *)bp;
+
+        while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
+                unsigned long addr;
+
+                addr = *stack;
+                if (__kernel_text_address(addr)) {
+                        if ((unsigned long) stack == bp + sizeof(long)) {
+                                ops->address(data, addr, 1);
+                                frame = frame->next_frame;
+                                bp = (unsigned long) frame;
+                        } else {
+                                ops->address(data, addr, bp == 0);
+                        }
+                }
+                stack++;
+        }
+        return bp;
+}
+
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+        printk(data);
+        print_symbol(msg, symbol);
+        printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+        printk("%s%s\n", (char *)data, msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+        printk("%s <%s> ", (char *)data, name);
+        return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+        touch_nmi_watchdog();
+        printk(data);
+        printk_address(addr, reliable);
+}
+
+static const struct stacktrace_ops print_trace_ops = {
+        .warning = print_trace_warning,
+        .warning_symbol = print_trace_warning_symbol,
+        .stack = print_trace_stack,
+        .address = print_trace_address,
+};
+
+void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+                unsigned long *stack, unsigned long bp, char *log_lvl)
+{
+        printk("%sCall Trace:\n", log_lvl);
+        dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
+}
+
+void show_trace(struct task_struct *task, struct pt_regs *regs,
+                unsigned long *stack, unsigned long bp)
+{
+        show_trace_log_lvl(task, regs, stack, bp, "");
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+        show_stack_log_lvl(task, NULL, sp, 0, "");
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+        unsigned long bp = 0;
+        unsigned long stack;
+
+#ifdef CONFIG_FRAME_POINTER
+        if (!bp)
+                get_bp(bp);
+#endif
+
+        printk("Pid: %d, comm: %.20s %s %s %.*s\n",
+                current->pid, current->comm, print_tainted(),
+                init_utsname()->release,
+                (int)strcspn(init_utsname()->version, " "),
+                init_utsname()->version);
+        show_trace(NULL, NULL, &stack, bp);
+}
+EXPORT_SYMBOL(dump_stack);
+
+static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
+static unsigned int die_nest_count;
+
+unsigned __kprobes long oops_begin(void)
+{
+        int cpu;
+        unsigned long flags;
+
+        oops_enter();
+
+        /* racy, but better than risking deadlock. */
+        raw_local_irq_save(flags);
+        cpu = smp_processor_id();
+        if (!__raw_spin_trylock(&die_lock)) {
+                if (cpu == die_owner)
+                        /* nested oops. should stop eventually */;
+                else
+                        __raw_spin_lock(&die_lock);
+        }
+        die_nest_count++;
+        die_owner = cpu;
+        console_verbose();
+        bust_spinlocks(1);
+        return flags;
+}
+
+void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
+{
+        if (regs && kexec_should_crash(current))
+                crash_kexec(regs);
+
+        bust_spinlocks(0);
+        die_owner = -1;
+        add_taint(TAINT_DIE);
+        die_nest_count--;
+        if (!die_nest_count)
+                /* Nest count reaches zero, release the lock. */
+                __raw_spin_unlock(&die_lock);
+        raw_local_irq_restore(flags);
+        oops_exit();
+
+        if (!signr)
+                return;
+        if (in_interrupt())
+                panic("Fatal exception in interrupt");
+        if (panic_on_oops)
+                panic("Fatal exception");
+        do_exit(signr);
+}
+
+int __kprobes __die(const char *str, struct pt_regs *regs, long err)
+{
+#ifdef CONFIG_X86_32
+        unsigned short ss;
+        unsigned long sp;
+#endif
+        printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
+#ifdef CONFIG_PREEMPT
+        printk("PREEMPT ");
+#endif
+#ifdef CONFIG_SMP
+        printk("SMP ");
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+        printk("DEBUG_PAGEALLOC");
+#endif
+        printk("\n");
+        sysfs_printk_last_file();
+        if (notify_die(DIE_OOPS, str, regs, err,
+                        current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
+                return 1;
+
+        show_registers(regs);
+#ifdef CONFIG_X86_32
+        sp = (unsigned long) (&regs->sp);
+        savesegment(ss, ss);
+        if (user_mode(regs)) {
+                sp = regs->sp;
+                ss = regs->ss & 0xffff;
+        }
+        printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
+        print_symbol("%s", regs->ip);
+        printk(" SS:ESP %04x:%08lx\n", ss, sp);
+#else
+        /* Executive summary in case the oops scrolled away */
+        printk(KERN_ALERT "RIP ");
+        printk_address(regs->ip, 1);
+        printk(" RSP <%016lx>\n", regs->sp);
+#endif
+        return 0;
+}
+
+/*
+ * This is gone through when something in the kernel has done something bad
+ * and is about to be terminated:
+ */
+void die(const char *str, struct pt_regs *regs, long err)
+{
+        unsigned long flags = oops_begin();
+        int sig = SIGSEGV;
+
+        if (!user_mode_vm(regs))
+                report_bug(regs->ip, regs);
+
+        if (__die(str, regs, err))
+                sig = 0;
+        oops_end(flags, regs, sig);
+}
+
+void notrace __kprobes
+die_nmi(char *str, struct pt_regs *regs, int do_panic)
+{
+        unsigned long flags;
+
+        if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
+                return;
+
+        /*
+         * We are in trouble anyway, lets at least try
+         * to get a message out.
+         */
+        flags = oops_begin();
+        printk(KERN_EMERG "%s", str);
+        printk(" on CPU%d, ip %08lx, registers:\n",
+                smp_processor_id(), regs->ip);
+        show_registers(regs);
+        oops_end(flags, regs, 0);
+        if (do_panic || panic_on_oops)
+                panic("Non maskable interrupt");
+        nmi_exit();
+        local_irq_enable();
+        do_exit(SIGBUS);
+}
+
+static int __init oops_setup(char *s)
+{
+        if (!s)
+                return -EINVAL;
+        if (!strcmp(s, "panic"))
+                panic_on_oops = 1;
+        return 0;
+}
+early_param("oops", oops_setup);
+
+static int __init kstack_setup(char *s)
+{
+        if (!s)
+                return -EINVAL;
+        kstack_depth_to_print = simple_strtoul(s, NULL, 0);
+        return 0;
+}
+early_param("kstack", kstack_setup);
+
+static int __init code_bytes_setup(char *s)
+{
+        code_bytes = simple_strtoul(s, NULL, 0);
+        if (code_bytes > 8192)
+                code_bytes = 8192;
+
+        return 1;
+}
+__setup("code_bytes=", code_bytes_setup);