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* [PATCH 0/2] x86: split out dumpstack code from traps_xx.c
@ 2008-09-30 11:12 Alexander van Heukelum
  2008-09-30 11:12 ` [PATCH 1/2] i386: split out dumpstack code from traps_32.c Alexander van Heukelum
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Alexander van Heukelum @ 2008-09-30 11:12 UTC (permalink / raw)
  To: Ingo Molnar, LKML; +Cc: Alexander van Heukelum

Hi Ingo,

I intend to keep looking for possibilities to bring traps_32.c
and traps_64.c closer to each-other. One trivial way (from my
point of view) is to split out code into separate files. These
two patches split out a large piece of code that has nothing to
do with hardware traps. Are you willing to take those two
patches? Or are they to intrusive?

Patches are against the current master branch of the tip tree.
The defconfigs compile fine and I ran some simple configs within
qemu.

Greetings,
	Alexander

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH 1/2] i386: split out dumpstack code from traps_32.c
  2008-09-30 11:12 [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Alexander van Heukelum
@ 2008-09-30 11:12 ` Alexander van Heukelum
  2008-09-30 11:12   ` [PATCH 2/2] x86_64: split out dumpstack code from traps_64.c Alexander van Heukelum
  2008-09-30 11:27 ` [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Ingo Molnar
  2008-09-30 11:44 ` Ingo Molnar
  2 siblings, 1 reply; 5+ messages in thread
From: Alexander van Heukelum @ 2008-09-30 11:12 UTC (permalink / raw)
  To: Ingo Molnar, LKML; +Cc: Alexander van Heukelum

The dumpstack code is logically quite independent from the
hardware traps. Split it out into its own file.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
---
 arch/x86/kernel/Makefile       |    2 +-
 arch/x86/kernel/dumpstack_32.c |  425 ++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/traps_32.c     |  407 --------------------------------------
 3 files changed, 426 insertions(+), 408 deletions(-)
 create mode 100644 arch/x86/kernel/dumpstack_32.c

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index c71722d..ed1af8a 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -29,7 +29,7 @@ obj-y			+= time_$(BITS).o ioport.o ldt.o
 obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
 obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o
 obj-$(CONFIG_X86_32)	+= probe_roms_32.o
-obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
+obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o dumpstack_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)	+= syscall_64.o vsyscall_64.o
 obj-y			+= bootflag.o e820.o
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
new file mode 100644
index 0000000..7378c0c
--- /dev/null
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -0,0 +1,425 @@
+/*
+ *  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 <asm/stacktrace.h>
+
+int panic_on_unrecovered_nmi;
+int kstack_depth_to_print = 24;
+static unsigned int code_bytes = 64;
+static int die_counter;
+
+void printk_address(unsigned long address, int reliable)
+{
+#ifdef CONFIG_KALLSYMS
+	unsigned long offset = 0;
+	unsigned long symsize;
+	const char *symname;
+	char *modname;
+	char *delim = ":";
+	char namebuf[KSYM_NAME_LEN];
+	char reliab[4] = "";
+
+	symname = kallsyms_lookup(address, &symsize, &offset,
+					&modname, namebuf);
+	if (!symname) {
+		printk(" [<%08lx>]\n", address);
+		return;
+	}
+	if (!reliable)
+		strcpy(reliab, "? ");
+
+	if (!modname)
+		modname = delim = "";
+	printk(" [<%08lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
+		address, reliab, delim, modname, delim, symname, offset, symsize);
+#else
+	printk(" [<%08lx>]\n", address);
+#endif
+}
+
+static inline int valid_stack_ptr(struct thread_info *tinfo,
+			void *p, unsigned int size)
+{
+	void *t = tinfo;
+	return	p > t && p <= t + THREAD_SIZE - size;
+}
+
+/* The form of the top of the frame on the stack */
+struct stack_frame {
+	struct stack_frame *next_frame;
+	unsigned long return_address;
+};
+
+static inline unsigned long
+print_context_stack(struct thread_info *tinfo,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data)
+{
+	struct stack_frame *frame = (struct stack_frame *)bp;
+
+	while (valid_stack_ptr(tinfo, stack, sizeof(*stack))) {
+		unsigned long addr;
+
+		addr = *stack;
+		if (__kernel_text_address(addr)) {
+			if ((unsigned long) stack == bp + 4) {
+				ops->address(data, addr, 1);
+				frame = frame->next_frame;
+				bp = (unsigned long) frame;
+			} else {
+				ops->address(data, addr, bp == 0);
+			}
+		}
+		stack++;
+	}
+	return bp;
+}
+
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data)
+{
+	if (!task)
+		task = current;
+
+	if (!stack) {
+		unsigned long dummy;
+		stack = &dummy;
+		if (task != current)
+			stack = (unsigned long *)task->thread.sp;
+	}
+
+#ifdef CONFIG_FRAME_POINTER
+	if (!bp) {
+		if (task == current) {
+			/* Grab bp right from our regs */
+			asm("movl %%ebp, %0" : "=r" (bp) :);
+		} else {
+			/* bp is the last reg pushed by switch_to */
+			bp = *(unsigned long *) task->thread.sp;
+		}
+	}
+#endif
+
+	for (;;) {
+		struct thread_info *context;
+
+		context = (struct thread_info *)
+			((unsigned long)stack & (~(THREAD_SIZE - 1)));
+		bp = print_context_stack(context, stack, bp, ops, data);
+		/*
+		 * Should be after the line below, but somewhere
+		 * in early boot context comes out corrupted and we
+		 * can't reference it:
+		 */
+		if (ops->stack(data, "IRQ") < 0)
+			break;
+		stack = (unsigned long *)context->previous_esp;
+		if (!stack)
+			break;
+		touch_nmi_watchdog();
+	}
+}
+EXPORT_SYMBOL(dump_trace);
+
+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)
+{
+	return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+	printk("%s [<%08lx>] ", (char *)data, addr);
+	if (!reliable)
+		printk("? ");
+	print_symbol("%s\n", addr);
+	touch_nmi_watchdog();
+}
+
+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,
+};
+
+static void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp, char *log_lvl)
+{
+	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
+	printk("%s =======================\n", 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, "");
+}
+
+static void
+show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		   unsigned long *sp, unsigned long bp, char *log_lvl)
+{
+	unsigned long *stack;
+	int i;
+
+	if (sp == NULL) {
+		if (task)
+			sp = (unsigned long *)task->thread.sp;
+		else
+			sp = (unsigned long *)&sp;
+	}
+
+	stack = sp;
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (kstack_end(stack))
+			break;
+		if (i && ((i % 8) == 0))
+			printk("\n%s       ", log_lvl);
+		printk("%08lx ", *stack++);
+	}
+	printk("\n%sCall Trace:\n", log_lvl);
+
+	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+	printk("       ");
+	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)
+		asm("movl %%ebp, %0" : "=r" (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(current, NULL, &stack, bp);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_registers(struct pt_regs *regs)
+{
+	int i;
+
+	print_modules();
+	__show_regs(regs, 0);
+
+	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
+		TASK_COMM_LEN, current->comm, task_pid_nr(current),
+		current_thread_info(), current, task_thread_info(current));
+	/*
+	 * When in-kernel, we also print out the stack and code at the
+	 * time of the fault..
+	 */
+	if (!user_mode_vm(regs)) {
+		unsigned int code_prologue = code_bytes * 43 / 64;
+		unsigned int code_len = code_bytes;
+		unsigned char c;
+		u8 *ip;
+
+		printk("\n" KERN_EMERG "Stack: ");
+		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);
+
+		printk(KERN_EMERG "Code: ");
+
+		ip = (u8 *)regs->ip - code_prologue;
+		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
+			/* try starting at EIP */
+			ip = (u8 *)regs->ip;
+			code_len = code_len - code_prologue + 1;
+		}
+		for (i = 0; i < code_len; i++, ip++) {
+			if (ip < (u8 *)PAGE_OFFSET ||
+					probe_kernel_address(ip, c)) {
+				printk(" Bad EIP value.");
+				break;
+			}
+			if (ip == (u8 *)regs->ip)
+				printk("<%02x> ", c);
+			else
+				printk("%02x ", c);
+		}
+	}
+	printk("\n");
+}
+
+int is_valid_bugaddr(unsigned long ip)
+{
+	unsigned short ud2;
+
+	if (ip < PAGE_OFFSET)
+		return 0;
+	if (probe_kernel_address((unsigned short *)ip, ud2))
+		return 0;
+
+	return ud2 == 0x0b0f;
+}
+
+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)
+{
+	unsigned long flags;
+
+	oops_enter();
+
+	if (die_owner != raw_smp_processor_id()) {
+		console_verbose();
+		raw_local_irq_save(flags);
+		__raw_spin_lock(&die_lock);
+		die_owner = smp_processor_id();
+		die_nest_count = 0;
+		bust_spinlocks(1);
+	} else {
+		raw_local_irq_save(flags);
+	}
+	die_nest_count++;
+	return flags;
+}
+
+void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
+{
+	bust_spinlocks(0);
+	die_owner = -1;
+	add_taint(TAINT_DIE);
+	__raw_spin_unlock(&die_lock);
+	raw_local_irq_restore(flags);
+
+	if (!regs)
+		return;
+
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+
+	if (in_nmi())
+		panic("Fatal exception in non-maskable interrupt");
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+
+	if (panic_on_oops)
+		panic("Fatal exception");
+
+	oops_exit();
+	do_exit(signr);
+}
+
+int __kprobes __die(const char *str, struct pt_regs *regs, long err)
+{
+	unsigned short ss;
+	unsigned long sp;
+
+	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");
+	if (notify_die(DIE_OOPS, str, regs, err,
+			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
+		return 1;
+
+	show_registers(regs);
+	/* Executive summary in case the oops scrolled away */
+	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);
+	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();
+
+	if (die_nest_count < 3) {
+		report_bug(regs->ip, regs);
+
+		if (__die(str, regs, err))
+			regs = NULL;
+	} else {
+		printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
+	}
+
+	oops_end(flags, regs, SIGSEGV);
+}
+
+static int __init kstack_setup(char *s)
+{
+	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
+
+	return 1;
+}
+__setup("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);
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 5457b93..2edab44 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -81,11 +81,7 @@ char ignore_fpu_irq;
 gate_desc idt_table[256]
 	__attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
 
-int panic_on_unrecovered_nmi;
-int kstack_depth_to_print = 24;
-static unsigned int code_bytes = 64;
 static int ignore_nmis;
-static int die_counter;
 
 static inline void conditional_sti(struct pt_regs *regs)
 {
@@ -93,391 +89,6 @@ static inline void conditional_sti(struct pt_regs *regs)
 		local_irq_enable();
 }
 
-void printk_address(unsigned long address, int reliable)
-{
-#ifdef CONFIG_KALLSYMS
-	unsigned long offset = 0;
-	unsigned long symsize;
-	const char *symname;
-	char *modname;
-	char *delim = ":";
-	char namebuf[KSYM_NAME_LEN];
-	char reliab[4] = "";
-
-	symname = kallsyms_lookup(address, &symsize, &offset,
-					&modname, namebuf);
-	if (!symname) {
-		printk(" [<%08lx>]\n", address);
-		return;
-	}
-	if (!reliable)
-		strcpy(reliab, "? ");
-
-	if (!modname)
-		modname = delim = "";
-	printk(" [<%08lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
-		address, reliab, delim, modname, delim, symname, offset, symsize);
-#else
-	printk(" [<%08lx>]\n", address);
-#endif
-}
-
-static inline int valid_stack_ptr(struct thread_info *tinfo,
-			void *p, unsigned int size)
-{
-	void *t = tinfo;
-	return	p > t && p <= t + THREAD_SIZE - size;
-}
-
-/* The form of the top of the frame on the stack */
-struct stack_frame {
-	struct stack_frame *next_frame;
-	unsigned long return_address;
-};
-
-static inline unsigned long
-print_context_stack(struct thread_info *tinfo,
-		unsigned long *stack, unsigned long bp,
-		const struct stacktrace_ops *ops, void *data)
-{
-	struct stack_frame *frame = (struct stack_frame *)bp;
-
-	while (valid_stack_ptr(tinfo, stack, sizeof(*stack))) {
-		unsigned long addr;
-
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			if ((unsigned long) stack == bp + 4) {
-				ops->address(data, addr, 1);
-				frame = frame->next_frame;
-				bp = (unsigned long) frame;
-			} else {
-				ops->address(data, addr, bp == 0);
-			}
-		}
-		stack++;
-	}
-	return bp;
-}
-
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp,
-		const struct stacktrace_ops *ops, void *data)
-{
-	if (!task)
-		task = current;
-
-	if (!stack) {
-		unsigned long dummy;
-		stack = &dummy;
-		if (task != current)
-			stack = (unsigned long *)task->thread.sp;
-	}
-
-#ifdef CONFIG_FRAME_POINTER
-	if (!bp) {
-		if (task == current) {
-			/* Grab bp right from our regs */
-			asm("movl %%ebp, %0" : "=r" (bp) :);
-		} else {
-			/* bp is the last reg pushed by switch_to */
-			bp = *(unsigned long *) task->thread.sp;
-		}
-	}
-#endif
-
-	for (;;) {
-		struct thread_info *context;
-
-		context = (struct thread_info *)
-			((unsigned long)stack & (~(THREAD_SIZE - 1)));
-		bp = print_context_stack(context, stack, bp, ops, data);
-		/*
-		 * Should be after the line below, but somewhere
-		 * in early boot context comes out corrupted and we
-		 * can't reference it:
-		 */
-		if (ops->stack(data, "IRQ") < 0)
-			break;
-		stack = (unsigned long *)context->previous_esp;
-		if (!stack)
-			break;
-		touch_nmi_watchdog();
-	}
-}
-EXPORT_SYMBOL(dump_trace);
-
-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)
-{
-	return 0;
-}
-
-/*
- * Print one address/symbol entries per line.
- */
-static void print_trace_address(void *data, unsigned long addr, int reliable)
-{
-	printk("%s [<%08lx>] ", (char *)data, addr);
-	if (!reliable)
-		printk("? ");
-	print_symbol("%s\n", addr);
-	touch_nmi_watchdog();
-}
-
-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,
-};
-
-static void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp, char *log_lvl)
-{
-	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
-	printk("%s =======================\n", 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, "");
-}
-
-static void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		   unsigned long *sp, unsigned long bp, char *log_lvl)
-{
-	unsigned long *stack;
-	int i;
-
-	if (sp == NULL) {
-		if (task)
-			sp = (unsigned long *)task->thread.sp;
-		else
-			sp = (unsigned long *)&sp;
-	}
-
-	stack = sp;
-	for (i = 0; i < kstack_depth_to_print; i++) {
-		if (kstack_end(stack))
-			break;
-		if (i && ((i % 8) == 0))
-			printk("\n%s       ", log_lvl);
-		printk("%08lx ", *stack++);
-	}
-	printk("\n%sCall Trace:\n", log_lvl);
-
-	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
-}
-
-void show_stack(struct task_struct *task, unsigned long *sp)
-{
-	printk("       ");
-	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)
-		asm("movl %%ebp, %0" : "=r" (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(current, NULL, &stack, bp);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-void show_registers(struct pt_regs *regs)
-{
-	int i;
-
-	print_modules();
-	__show_regs(regs, 0);
-
-	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
-		TASK_COMM_LEN, current->comm, task_pid_nr(current),
-		current_thread_info(), current, task_thread_info(current));
-	/*
-	 * When in-kernel, we also print out the stack and code at the
-	 * time of the fault..
-	 */
-	if (!user_mode_vm(regs)) {
-		unsigned int code_prologue = code_bytes * 43 / 64;
-		unsigned int code_len = code_bytes;
-		unsigned char c;
-		u8 *ip;
-
-		printk("\n" KERN_EMERG "Stack: ");
-		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);
-
-		printk(KERN_EMERG "Code: ");
-
-		ip = (u8 *)regs->ip - code_prologue;
-		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
-			/* try starting at EIP */
-			ip = (u8 *)regs->ip;
-			code_len = code_len - code_prologue + 1;
-		}
-		for (i = 0; i < code_len; i++, ip++) {
-			if (ip < (u8 *)PAGE_OFFSET ||
-					probe_kernel_address(ip, c)) {
-				printk(" Bad EIP value.");
-				break;
-			}
-			if (ip == (u8 *)regs->ip)
-				printk("<%02x> ", c);
-			else
-				printk("%02x ", c);
-		}
-	}
-	printk("\n");
-}
-
-int is_valid_bugaddr(unsigned long ip)
-{
-	unsigned short ud2;
-
-	if (ip < PAGE_OFFSET)
-		return 0;
-	if (probe_kernel_address((unsigned short *)ip, ud2))
-		return 0;
-
-	return ud2 == 0x0b0f;
-}
-
-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)
-{
-	unsigned long flags;
-
-	oops_enter();
-
-	if (die_owner != raw_smp_processor_id()) {
-		console_verbose();
-		raw_local_irq_save(flags);
-		__raw_spin_lock(&die_lock);
-		die_owner = smp_processor_id();
-		die_nest_count = 0;
-		bust_spinlocks(1);
-	} else {
-		raw_local_irq_save(flags);
-	}
-	die_nest_count++;
-	return flags;
-}
-
-void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
-{
-	bust_spinlocks(0);
-	die_owner = -1;
-	add_taint(TAINT_DIE);
-	__raw_spin_unlock(&die_lock);
-	raw_local_irq_restore(flags);
-
-	if (!regs)
-		return;
-
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-
-	if (in_nmi())
-		panic("Fatal exception in non-maskable interrupt");
-
-	if (in_interrupt())
-		panic("Fatal exception in interrupt");
-
-	if (panic_on_oops)
-		panic("Fatal exception");
-
-	oops_exit();
-	do_exit(signr);
-}
-
-int __kprobes __die(const char *str, struct pt_regs *regs, long err)
-{
-	unsigned short ss;
-	unsigned long sp;
-
-	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");
-	if (notify_die(DIE_OOPS, str, regs, err,
-			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
-		return 1;
-
-	show_registers(regs);
-	/* Executive summary in case the oops scrolled away */
-	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);
-	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();
-
-	if (die_nest_count < 3) {
-		report_bug(regs->ip, regs);
-
-		if (__die(str, regs, err))
-			regs = NULL;
-	} else {
-		printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
-	}
-
-	oops_end(flags, regs, SIGSEGV);
-}
-
 static inline void
 die_if_kernel(const char *str, struct pt_regs *regs, long err)
 {
@@ -1262,21 +873,3 @@ void __init trap_init(void)
 
 	trap_init_hook();
 }
-
-static int __init kstack_setup(char *s)
-{
-	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
-
-	return 1;
-}
-__setup("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);
-- 
1.5.4.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH 2/2] x86_64: split out dumpstack code from traps_64.c
  2008-09-30 11:12 ` [PATCH 1/2] i386: split out dumpstack code from traps_32.c Alexander van Heukelum
@ 2008-09-30 11:12   ` Alexander van Heukelum
  0 siblings, 0 replies; 5+ messages in thread
From: Alexander van Heukelum @ 2008-09-30 11:12 UTC (permalink / raw)
  To: Ingo Molnar, LKML; +Cc: Alexander van Heukelum

The dumpstack code is logically quite independent from the
hardware traps. Split it out into its own file.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
---
 arch/x86/kernel/Makefile       |    4 +-
 arch/x86/kernel/dumpstack_64.c |  567 ++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/traps_64.c     |  549 --------------------------------------
 3 files changed, 569 insertions(+), 551 deletions(-)
 create mode 100644 arch/x86/kernel/dumpstack_64.c

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index ed1af8a..6ccada6 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -24,12 +24,12 @@ CFLAGS_tsc.o		:= $(nostackp)
 CFLAGS_paravirt.o	:= $(nostackp)
 
 obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
-obj-y			+= traps_$(BITS).o irq_$(BITS).o
+obj-y			+= traps_$(BITS).o irq_$(BITS).o dumpstack_$(BITS).o
 obj-y			+= time_$(BITS).o ioport.o ldt.o
 obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
 obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o
 obj-$(CONFIG_X86_32)	+= probe_roms_32.o
-obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o dumpstack_32.o
+obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)	+= syscall_64.o vsyscall_64.o
 obj-y			+= bootflag.o e820.o
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
new file mode 100644
index 0000000..11f22d2
--- /dev/null
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -0,0 +1,567 @@
+/*
+ *  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 <asm/stacktrace.h>
+
+int panic_on_unrecovered_nmi;
+int kstack_depth_to_print = 12;
+static unsigned int code_bytes = 64;
+static int die_counter;
+
+void printk_address(unsigned long address, int reliable)
+{
+	printk(" [<%016lx>] %s%pS\n",
+			address, reliable ?	"" : "? ", (void *) address);
+}
+
+static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
+					unsigned *usedp, char **idp)
+{
+	static char ids[][8] = {
+		[DEBUG_STACK - 1] = "#DB",
+		[NMI_STACK - 1] = "NMI",
+		[DOUBLEFAULT_STACK - 1] = "#DF",
+		[STACKFAULT_STACK - 1] = "#SS",
+		[MCE_STACK - 1] = "#MC",
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+		[N_EXCEPTION_STACKS ...
+			N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
+#endif
+	};
+	unsigned k;
+
+	/*
+	 * Iterate over all exception stacks, and figure out whether
+	 * 'stack' is in one of them:
+	 */
+	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+		unsigned long end = per_cpu(orig_ist, cpu).ist[k];
+		/*
+		 * Is 'stack' above this exception frame's end?
+		 * If yes then skip to the next frame.
+		 */
+		if (stack >= end)
+			continue;
+		/*
+		 * Is 'stack' above this exception frame's start address?
+		 * If yes then we found the right frame.
+		 */
+		if (stack >= end - EXCEPTION_STKSZ) {
+			/*
+			 * Make sure we only iterate through an exception
+			 * stack once. If it comes up for the second time
+			 * then there's something wrong going on - just
+			 * break out and return NULL:
+			 */
+			if (*usedp & (1U << k))
+				break;
+			*usedp |= 1U << k;
+			*idp = ids[k];
+			return (unsigned long *)end;
+		}
+		/*
+		 * If this is a debug stack, and if it has a larger size than
+		 * the usual exception stacks, then 'stack' might still
+		 * be within the lower portion of the debug stack:
+		 */
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+		if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
+			unsigned j = N_EXCEPTION_STACKS - 1;
+
+			/*
+			 * Black magic. A large debug stack is composed of
+			 * multiple exception stack entries, which we
+			 * iterate through now. Dont look:
+			 */
+			do {
+				++j;
+				end -= EXCEPTION_STKSZ;
+				ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
+			} while (stack < end - EXCEPTION_STKSZ);
+			if (*usedp & (1U << j))
+				break;
+			*usedp |= 1U << j;
+			*idp = ids[j];
+			return (unsigned long *)end;
+		}
+#endif
+	}
+	return NULL;
+}
+
+/*
+ * 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;
+}
+
+/* The form of the top of the frame on the stack */
+struct stack_frame {
+	struct stack_frame *next_frame;
+	unsigned long return_address;
+};
+
+static inline 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 + 8) {
+				ops->address(data, addr, 1);
+				frame = frame->next_frame;
+				bp = (unsigned long) frame;
+			} else {
+				ops->address(data, addr, bp == 0);
+			}
+		}
+		stack++;
+	}
+	return bp;
+}
+
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data)
+{
+	const unsigned cpu = get_cpu();
+	unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
+	unsigned used = 0;
+	struct thread_info *tinfo;
+
+	if (!task)
+		task = current;
+
+	if (!stack) {
+		unsigned long dummy;
+		stack = &dummy;
+		if (task && task != current)
+			stack = (unsigned long *)task->thread.sp;
+	}
+
+#ifdef CONFIG_FRAME_POINTER
+	if (!bp) {
+		if (task == current) {
+			/* Grab bp right from our regs */
+			asm("movq %%rbp, %0" : "=r" (bp) : );
+		} else {
+			/* bp is the last reg pushed by switch_to */
+			bp = *(unsigned long *) task->thread.sp;
+		}
+	}
+#endif
+
+	/*
+	 * Print function call entries in all stacks, starting at the
+	 * current stack address. If the stacks consist of nested
+	 * exceptions
+	 */
+	tinfo = task_thread_info(task);
+	for (;;) {
+		char *id;
+		unsigned long *estack_end;
+		estack_end = in_exception_stack(cpu, (unsigned long)stack,
+						&used, &id);
+
+		if (estack_end) {
+			if (ops->stack(data, id) < 0)
+				break;
+
+			bp = print_context_stack(tinfo, stack, bp, ops,
+							data, estack_end);
+			ops->stack(data, "<EOE>");
+			/*
+			 * We link to the next stack via the
+			 * second-to-last pointer (index -2 to end) in the
+			 * exception stack:
+			 */
+			stack = (unsigned long *) estack_end[-2];
+			continue;
+		}
+		if (irqstack_end) {
+			unsigned long *irqstack;
+			irqstack = irqstack_end -
+				(IRQSTACKSIZE - 64) / sizeof(*irqstack);
+
+			if (stack >= irqstack && stack < irqstack_end) {
+				if (ops->stack(data, "IRQ") < 0)
+					break;
+				bp = print_context_stack(tinfo, stack, bp,
+						ops, data, irqstack_end);
+				/*
+				 * We link to the next stack (which would be
+				 * the process stack normally) the last
+				 * pointer (index -1 to end) in the IRQ stack:
+				 */
+				stack = (unsigned long *) (irqstack_end[-1]);
+				irqstack_end = NULL;
+				ops->stack(data, "EOI");
+				continue;
+			}
+		}
+		break;
+	}
+
+	/*
+	 * This handles the process stack:
+	 */
+	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
+	put_cpu();
+}
+EXPORT_SYMBOL(dump_trace);
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+	print_symbol(msg, symbol);
+	printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+	printk("%s\n", msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+	printk(" <%s> ", name);
+	return 0;
+}
+
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+	touch_nmi_watchdog();
+	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,
+};
+
+static void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp, char *log_lvl)
+{
+	printk("Call Trace:\n");
+	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, "");
+}
+
+static void
+show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *sp, unsigned long bp, char *log_lvl)
+{
+	unsigned long *stack;
+	int i;
+	const int cpu = smp_processor_id();
+	unsigned long *irqstack_end =
+		(unsigned long *) (cpu_pda(cpu)->irqstackptr);
+	unsigned long *irqstack =
+		(unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
+
+	/*
+	 * debugging aid: "show_stack(NULL, NULL);" prints the
+	 * back trace for this cpu.
+	 */
+
+	if (sp == NULL) {
+		if (task)
+			sp = (unsigned long *)task->thread.sp;
+		else
+			sp = (unsigned long *)&sp;
+	}
+
+	stack = sp;
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (stack >= irqstack && stack <= irqstack_end) {
+			if (stack == irqstack_end) {
+				stack = (unsigned long *) (irqstack_end[-1]);
+				printk(" <EOI> ");
+			}
+		} else {
+		if (((long) stack & (THREAD_SIZE-1)) == 0)
+			break;
+		}
+		if (i && ((i % 4) == 0))
+			printk("\n");
+		printk(" %016lx", *stack++);
+		touch_nmi_watchdog();
+	}
+	printk("\n");
+	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+}
+
+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)
+		asm("movq %%rbp, %0" : "=r" (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);
+
+void show_registers(struct pt_regs *regs)
+{
+	int i;
+	unsigned long sp;
+	const int cpu = smp_processor_id();
+	struct task_struct *cur = cpu_pda(cpu)->pcurrent;
+
+	sp = regs->sp;
+	printk("CPU %d ", cpu);
+	__show_regs(regs, 1);
+	printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
+		cur->comm, cur->pid, task_thread_info(cur), cur);
+
+	/*
+	 * When in-kernel, we also print out the stack and code at the
+	 * time of the fault..
+	 */
+	if (!user_mode(regs)) {
+		unsigned int code_prologue = code_bytes * 43 / 64;
+		unsigned int code_len = code_bytes;
+		unsigned char c;
+		u8 *ip;
+
+		printk("Stack: ");
+		show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
+				regs->bp, "");
+
+		printk(KERN_EMERG "Code: ");
+
+		ip = (u8 *)regs->ip - code_prologue;
+		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
+			/* try starting at RIP */
+			ip = (u8 *)regs->ip;
+			code_len = code_len - code_prologue + 1;
+		}
+		for (i = 0; i < code_len; i++, ip++) {
+			if (ip < (u8 *)PAGE_OFFSET ||
+					probe_kernel_address(ip, c)) {
+				printk(" Bad RIP value.");
+				break;
+			}
+			if (ip == (u8 *)regs->ip)
+				printk("<%02x> ", c);
+			else
+				printk("%02x ", c);
+		}
+	}
+	printk("\n");
+}
+
+int is_valid_bugaddr(unsigned long ip)
+{
+	unsigned short ud2;
+
+	if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
+		return 0;
+
+	return ud2 == 0x0b0f;
+}
+
+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)
+{
+	die_owner = -1;
+	bust_spinlocks(0);
+	die_nest_count--;
+	if (!die_nest_count)
+		/* Nest count reaches zero, release the lock. */
+		__raw_spin_unlock(&die_lock);
+	raw_local_irq_restore(flags);
+	if (!regs) {
+		oops_exit();
+		return;
+	}
+	if (in_nmi())
+		panic("Fatal exception in non-maskable interrupt");
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	oops_exit();
+	do_exit(signr);
+}
+
+int __kprobes __die(const char *str, struct pt_regs *regs, long err)
+{
+	printk(KERN_EMERG "%s: %04lx [%u] ", 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");
+	if (notify_die(DIE_OOPS, str, regs, err,
+			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
+		return 1;
+
+	show_registers(regs);
+	add_taint(TAINT_DIE);
+	/* Executive summary in case the oops scrolled away */
+	printk(KERN_ALERT "RIP ");
+	printk_address(regs->ip, 1);
+	printk(" RSP <%016lx>\n", regs->sp);
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+	return 0;
+}
+
+void die(const char *str, struct pt_regs *regs, long err)
+{
+	unsigned long flags = oops_begin();
+
+	if (!user_mode(regs))
+		report_bug(regs->ip, regs);
+
+	if (__die(str, regs, err))
+		regs = NULL;
+	oops_end(flags, regs, SIGSEGV);
+}
+
+notrace __kprobes void
+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;
+
+	flags = oops_begin();
+	/*
+	 * We are in trouble anyway, lets at least try
+	 * to get a message out.
+	 */
+	printk(KERN_EMERG "%s", str);
+	printk(" on CPU%d, ip %08lx, registers:\n",
+		smp_processor_id(), regs->ip);
+	show_registers(regs);
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+	if (do_panic || panic_on_oops)
+		panic("Non maskable interrupt");
+	oops_end(flags, NULL, SIGBUS);
+	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);
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index f9513d6..c47841e 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -55,11 +55,7 @@
 
 #include <mach_traps.h>
 
-int panic_on_unrecovered_nmi;
-int kstack_depth_to_print = 12;
-static unsigned int code_bytes = 64;
 static int ignore_nmis;
-static int die_counter;
 
 static inline void conditional_sti(struct pt_regs *regs)
 {
@@ -83,522 +79,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 	dec_preempt_count();
 }
 
-void printk_address(unsigned long address, int reliable)
-{
-	printk(" [<%016lx>] %s%pS\n",
-			address, reliable ?	"" : "? ", (void *) address);
-}
-
-static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
-					unsigned *usedp, char **idp)
-{
-	static char ids[][8] = {
-		[DEBUG_STACK - 1] = "#DB",
-		[NMI_STACK - 1] = "NMI",
-		[DOUBLEFAULT_STACK - 1] = "#DF",
-		[STACKFAULT_STACK - 1] = "#SS",
-		[MCE_STACK - 1] = "#MC",
-#if DEBUG_STKSZ > EXCEPTION_STKSZ
-		[N_EXCEPTION_STACKS ...
-			N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
-#endif
-	};
-	unsigned k;
-
-	/*
-	 * Iterate over all exception stacks, and figure out whether
-	 * 'stack' is in one of them:
-	 */
-	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
-		unsigned long end = per_cpu(orig_ist, cpu).ist[k];
-		/*
-		 * Is 'stack' above this exception frame's end?
-		 * If yes then skip to the next frame.
-		 */
-		if (stack >= end)
-			continue;
-		/*
-		 * Is 'stack' above this exception frame's start address?
-		 * If yes then we found the right frame.
-		 */
-		if (stack >= end - EXCEPTION_STKSZ) {
-			/*
-			 * Make sure we only iterate through an exception
-			 * stack once. If it comes up for the second time
-			 * then there's something wrong going on - just
-			 * break out and return NULL:
-			 */
-			if (*usedp & (1U << k))
-				break;
-			*usedp |= 1U << k;
-			*idp = ids[k];
-			return (unsigned long *)end;
-		}
-		/*
-		 * If this is a debug stack, and if it has a larger size than
-		 * the usual exception stacks, then 'stack' might still
-		 * be within the lower portion of the debug stack:
-		 */
-#if DEBUG_STKSZ > EXCEPTION_STKSZ
-		if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
-			unsigned j = N_EXCEPTION_STACKS - 1;
-
-			/*
-			 * Black magic. A large debug stack is composed of
-			 * multiple exception stack entries, which we
-			 * iterate through now. Dont look:
-			 */
-			do {
-				++j;
-				end -= EXCEPTION_STKSZ;
-				ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
-			} while (stack < end - EXCEPTION_STKSZ);
-			if (*usedp & (1U << j))
-				break;
-			*usedp |= 1U << j;
-			*idp = ids[j];
-			return (unsigned long *)end;
-		}
-#endif
-	}
-	return NULL;
-}
-
-/*
- * 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;
-}
-
-/* The form of the top of the frame on the stack */
-struct stack_frame {
-	struct stack_frame *next_frame;
-	unsigned long return_address;
-};
-
-static inline 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 + 8) {
-				ops->address(data, addr, 1);
-				frame = frame->next_frame;
-				bp = (unsigned long) frame;
-			} else {
-				ops->address(data, addr, bp == 0);
-			}
-		}
-		stack++;
-	}
-	return bp;
-}
-
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp,
-		const struct stacktrace_ops *ops, void *data)
-{
-	const unsigned cpu = get_cpu();
-	unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
-	unsigned used = 0;
-	struct thread_info *tinfo;
-
-	if (!task)
-		task = current;
-
-	if (!stack) {
-		unsigned long dummy;
-		stack = &dummy;
-		if (task && task != current)
-			stack = (unsigned long *)task->thread.sp;
-	}
-
-#ifdef CONFIG_FRAME_POINTER
-	if (!bp) {
-		if (task == current) {
-			/* Grab bp right from our regs */
-			asm("movq %%rbp, %0" : "=r" (bp) : );
-		} else {
-			/* bp is the last reg pushed by switch_to */
-			bp = *(unsigned long *) task->thread.sp;
-		}
-	}
-#endif
-
-	/*
-	 * Print function call entries in all stacks, starting at the
-	 * current stack address. If the stacks consist of nested
-	 * exceptions
-	 */
-	tinfo = task_thread_info(task);
-	for (;;) {
-		char *id;
-		unsigned long *estack_end;
-		estack_end = in_exception_stack(cpu, (unsigned long)stack,
-						&used, &id);
-
-		if (estack_end) {
-			if (ops->stack(data, id) < 0)
-				break;
-
-			bp = print_context_stack(tinfo, stack, bp, ops,
-							data, estack_end);
-			ops->stack(data, "<EOE>");
-			/*
-			 * We link to the next stack via the
-			 * second-to-last pointer (index -2 to end) in the
-			 * exception stack:
-			 */
-			stack = (unsigned long *) estack_end[-2];
-			continue;
-		}
-		if (irqstack_end) {
-			unsigned long *irqstack;
-			irqstack = irqstack_end -
-				(IRQSTACKSIZE - 64) / sizeof(*irqstack);
-
-			if (stack >= irqstack && stack < irqstack_end) {
-				if (ops->stack(data, "IRQ") < 0)
-					break;
-				bp = print_context_stack(tinfo, stack, bp,
-						ops, data, irqstack_end);
-				/*
-				 * We link to the next stack (which would be
-				 * the process stack normally) the last
-				 * pointer (index -1 to end) in the IRQ stack:
-				 */
-				stack = (unsigned long *) (irqstack_end[-1]);
-				irqstack_end = NULL;
-				ops->stack(data, "EOI");
-				continue;
-			}
-		}
-		break;
-	}
-
-	/*
-	 * This handles the process stack:
-	 */
-	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
-	put_cpu();
-}
-EXPORT_SYMBOL(dump_trace);
-
-static void
-print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
-{
-	print_symbol(msg, symbol);
-	printk("\n");
-}
-
-static void print_trace_warning(void *data, char *msg)
-{
-	printk("%s\n", msg);
-}
-
-static int print_trace_stack(void *data, char *name)
-{
-	printk(" <%s> ", name);
-	return 0;
-}
-
-static void print_trace_address(void *data, unsigned long addr, int reliable)
-{
-	touch_nmi_watchdog();
-	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,
-};
-
-static void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp, char *log_lvl)
-{
-	printk("Call Trace:\n");
-	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, "");
-}
-
-static void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *sp, unsigned long bp, char *log_lvl)
-{
-	unsigned long *stack;
-	int i;
-	const int cpu = smp_processor_id();
-	unsigned long *irqstack_end =
-		(unsigned long *) (cpu_pda(cpu)->irqstackptr);
-	unsigned long *irqstack =
-		(unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
-
-	/*
-	 * debugging aid: "show_stack(NULL, NULL);" prints the
-	 * back trace for this cpu.
-	 */
-
-	if (sp == NULL) {
-		if (task)
-			sp = (unsigned long *)task->thread.sp;
-		else
-			sp = (unsigned long *)&sp;
-	}
-
-	stack = sp;
-	for (i = 0; i < kstack_depth_to_print; i++) {
-		if (stack >= irqstack && stack <= irqstack_end) {
-			if (stack == irqstack_end) {
-				stack = (unsigned long *) (irqstack_end[-1]);
-				printk(" <EOI> ");
-			}
-		} else {
-		if (((long) stack & (THREAD_SIZE-1)) == 0)
-			break;
-		}
-		if (i && ((i % 4) == 0))
-			printk("\n");
-		printk(" %016lx", *stack++);
-		touch_nmi_watchdog();
-	}
-	printk("\n");
-	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
-}
-
-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)
-		asm("movq %%rbp, %0" : "=r" (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);
-
-void show_registers(struct pt_regs *regs)
-{
-	int i;
-	unsigned long sp;
-	const int cpu = smp_processor_id();
-	struct task_struct *cur = cpu_pda(cpu)->pcurrent;
-
-	sp = regs->sp;
-	printk("CPU %d ", cpu);
-	__show_regs(regs, 1);
-	printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
-		cur->comm, cur->pid, task_thread_info(cur), cur);
-
-	/*
-	 * When in-kernel, we also print out the stack and code at the
-	 * time of the fault..
-	 */
-	if (!user_mode(regs)) {
-		unsigned int code_prologue = code_bytes * 43 / 64;
-		unsigned int code_len = code_bytes;
-		unsigned char c;
-		u8 *ip;
-
-		printk("Stack: ");
-		show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
-				regs->bp, "");
-
-		printk(KERN_EMERG "Code: ");
-
-		ip = (u8 *)regs->ip - code_prologue;
-		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
-			/* try starting at RIP */
-			ip = (u8 *)regs->ip;
-			code_len = code_len - code_prologue + 1;
-		}
-		for (i = 0; i < code_len; i++, ip++) {
-			if (ip < (u8 *)PAGE_OFFSET ||
-					probe_kernel_address(ip, c)) {
-				printk(" Bad RIP value.");
-				break;
-			}
-			if (ip == (u8 *)regs->ip)
-				printk("<%02x> ", c);
-			else
-				printk("%02x ", c);
-		}
-	}
-	printk("\n");
-}
-
-int is_valid_bugaddr(unsigned long ip)
-{
-	unsigned short ud2;
-
-	if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
-		return 0;
-
-	return ud2 == 0x0b0f;
-}
-
-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)
-{
-	die_owner = -1;
-	bust_spinlocks(0);
-	die_nest_count--;
-	if (!die_nest_count)
-		/* Nest count reaches zero, release the lock. */
-		__raw_spin_unlock(&die_lock);
-	raw_local_irq_restore(flags);
-	if (!regs) {
-		oops_exit();
-		return;
-	}
-	if (in_nmi())
-		panic("Fatal exception in non-maskable interrupt");
-	if (in_interrupt())
-		panic("Fatal exception in interrupt");
-	if (panic_on_oops)
-		panic("Fatal exception");
-	oops_exit();
-	do_exit(signr);
-}
-
-int __kprobes __die(const char *str, struct pt_regs *regs, long err)
-{
-	printk(KERN_EMERG "%s: %04lx [%u] ", 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");
-	if (notify_die(DIE_OOPS, str, regs, err,
-			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
-		return 1;
-
-	show_registers(regs);
-	add_taint(TAINT_DIE);
-	/* Executive summary in case the oops scrolled away */
-	printk(KERN_ALERT "RIP ");
-	printk_address(regs->ip, 1);
-	printk(" RSP <%016lx>\n", regs->sp);
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-	return 0;
-}
-
-void die(const char *str, struct pt_regs *regs, long err)
-{
-	unsigned long flags = oops_begin();
-
-	if (!user_mode(regs))
-		report_bug(regs->ip, regs);
-
-	if (__die(str, regs, err))
-		regs = NULL;
-	oops_end(flags, regs, SIGSEGV);
-}
-
-notrace __kprobes void
-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;
-
-	flags = oops_begin();
-	/*
-	 * We are in trouble anyway, lets at least try
-	 * to get a message out.
-	 */
-	printk(KERN_EMERG "%s", str);
-	printk(" on CPU%d, ip %08lx, registers:\n",
-		smp_processor_id(), regs->ip);
-	show_registers(regs);
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-	if (do_panic || panic_on_oops)
-		panic("Non maskable interrupt");
-	oops_end(flags, NULL, SIGBUS);
-	nmi_exit();
-	local_irq_enable();
-	do_exit(SIGBUS);
-}
-
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 	long error_code, siginfo_t *info)
@@ -1187,32 +667,3 @@ void __init trap_init(void)
 	 */
 	cpu_init();
 }
-
-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);
-- 
1.5.4.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH 0/2] x86: split out dumpstack code from traps_xx.c
  2008-09-30 11:12 [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Alexander van Heukelum
  2008-09-30 11:12 ` [PATCH 1/2] i386: split out dumpstack code from traps_32.c Alexander van Heukelum
@ 2008-09-30 11:27 ` Ingo Molnar
  2008-09-30 11:44 ` Ingo Molnar
  2 siblings, 0 replies; 5+ messages in thread
From: Ingo Molnar @ 2008-09-30 11:27 UTC (permalink / raw)
  To: Alexander van Heukelum; +Cc: LKML, Thomas Gleixner, H. Peter Anvin


* Alexander van Heukelum <heukelum@fastmail.fm> wrote:

> Hi Ingo,
> 
> I intend to keep looking for possibilities to bring traps_32.c and 
> traps_64.c closer to each-other. One trivial way (from my point of 
> view) is to split out code into separate files. These two patches 
> split out a large piece of code that has nothing to do with hardware 
> traps. Are you willing to take those two patches? Or are they to 
> intrusive?

they are not intrusive at all! The right way to do such things is to 
keep them in reasonably small files.

> Patches are against the current master branch of the tip tree. The 
> defconfigs compile fine and I ran some simple configs within qemu.

would be nice to bring dumpstack_32.c and dumpstack_64.c together as 
well. While some of the details like IST stack logic (which dont exist 
on 32-bit) are special, most of the glue, the iterators, the boot 
parameters, and even the output should be unified some more.

	Ingo

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH 0/2] x86: split out dumpstack code from traps_xx.c
  2008-09-30 11:12 [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Alexander van Heukelum
  2008-09-30 11:12 ` [PATCH 1/2] i386: split out dumpstack code from traps_32.c Alexander van Heukelum
  2008-09-30 11:27 ` [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Ingo Molnar
@ 2008-09-30 11:44 ` Ingo Molnar
  2 siblings, 0 replies; 5+ messages in thread
From: Ingo Molnar @ 2008-09-30 11:44 UTC (permalink / raw)
  To: Alexander van Heukelum
  Cc: LKML, Vegard Nossum, H. Peter Anvin, Thomas Gleixner


* Alexander van Heukelum <heukelum@fastmail.fm> wrote:

> Patches are against the current master branch of the tip tree. The 
> defconfigs compile fine and I ran some simple configs within qemu.

applied to tip/x86/traps:

 # 9bb2b4f: x86_64: split out dumpstack code from traps_64.c
 # f616942: i386: split out dumpstack code from traps_32.c

there were some interactions with other branches:

 054efa5: Merge branch 'tracing/nmisafe' into x86/traps
 9ecb7cf: Merge branch 'kmemcheck' into x86/traps
 8955b63: Merge branch 'core/signal' into x86/traps
 ff1b7a8: Merge branch 'x86/signal' into x86/traps
 76b22d8: Merge commit 'v2.6.27-rc8' into x86/traps
 b58c936: Merge branch 'x86/core' into x86/traps

I hope i sorted them out right.

	Ingo

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2008-09-30 11:45 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-09-30 11:12 [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Alexander van Heukelum
2008-09-30 11:12 ` [PATCH 1/2] i386: split out dumpstack code from traps_32.c Alexander van Heukelum
2008-09-30 11:12   ` [PATCH 2/2] x86_64: split out dumpstack code from traps_64.c Alexander van Heukelum
2008-09-30 11:27 ` [PATCH 0/2] x86: split out dumpstack code from traps_xx.c Ingo Molnar
2008-09-30 11:44 ` Ingo Molnar

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