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-rw-r--r--arch/x86_64/kernel/stacktrace.c214
-rw-r--r--arch/x86_64/kernel/traps.c99
-rw-r--r--include/asm-x86_64/stacktrace.h18
3 files changed, 120 insertions, 211 deletions
diff --git a/arch/x86_64/kernel/stacktrace.c b/arch/x86_64/kernel/stacktrace.c
index 1c022af..6026b31 100644
--- a/arch/x86_64/kernel/stacktrace.c
+++ b/arch/x86_64/kernel/stacktrace.c
@@ -7,211 +7,49 @@
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
+#include <linux/module.h>
+#include <asm/stacktrace.h>
-#include <asm/smp.h>
-
-static inline int
-in_range(unsigned long start, unsigned long addr, unsigned long end)
+static void save_stack_warning(void *data, char *msg)
{
- return addr >= start && addr <= end;
}
-static unsigned long
-get_stack_end(struct task_struct *task, unsigned long stack)
+static void
+save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
{
- unsigned long stack_start, stack_end, flags;
- int i, cpu;
-
- /*
- * The most common case is that we are in the task stack:
- */
- stack_start = (unsigned long)task->thread_info;
- stack_end = stack_start + THREAD_SIZE;
-
- if (in_range(stack_start, stack, stack_end))
- return stack_end;
-
- /*
- * We are in an interrupt if irqstackptr is set:
- */
- raw_local_irq_save(flags);
- cpu = safe_smp_processor_id();
- stack_end = (unsigned long)cpu_pda(cpu)->irqstackptr;
-
- if (stack_end) {
- stack_start = stack_end & ~(IRQSTACKSIZE-1);
- if (in_range(stack_start, stack, stack_end))
- goto out_restore;
- /*
- * We get here if we are in an IRQ context but we
- * are also in an exception stack.
- */
- }
-
- /*
- * Iterate over all exception stacks, and figure out whether
- * 'stack' is in one of them:
- */
- for (i = 0; i < N_EXCEPTION_STACKS; i++) {
- /*
- * set 'end' to the end of the exception stack.
- */
- stack_end = per_cpu(init_tss, cpu).ist[i];
- stack_start = stack_end - EXCEPTION_STKSZ;
-
- /*
- * Is 'stack' above this exception frame's end?
- * If yes then skip to the next frame.
- */
- if (stack >= stack_end)
- continue;
- /*
- * Is 'stack' above this exception frame's start address?
- * If yes then we found the right frame.
- */
- if (stack >= stack_start)
- goto out_restore;
-
- /*
- * 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 (i == DEBUG_STACK - 1 && stack >= stack_end - DEBUG_STKSZ) {
- /*
- * Black magic. A large debug stack is composed of
- * multiple exception stack entries, which we
- * iterate through now. Dont look:
- */
- do {
- stack_end -= EXCEPTION_STKSZ;
- stack_start -= EXCEPTION_STKSZ;
- } while (stack < stack_start);
-
- goto out_restore;
- }
-#endif
- }
- /*
- * Ok, 'stack' is not pointing to any of the system stacks.
- */
- stack_end = 0;
-
-out_restore:
- raw_local_irq_restore(flags);
-
- return stack_end;
}
-
-/*
- * Save stack-backtrace addresses into a stack_trace buffer:
- */
-static inline unsigned long
-save_context_stack(struct stack_trace *trace,
- unsigned long stack, unsigned long stack_end)
+static int save_stack_stack(void *data, char *name)
{
- int skip = trace->skip;
- unsigned long addr;
-
-#ifdef CONFIG_FRAME_POINTER
- unsigned long prev_stack = 0;
+ struct stack_trace *trace = (struct stack_trace *)data;
+ return trace->all_contexts ? 0 : -1;
+}
- while (in_range(prev_stack, stack, stack_end)) {
- pr_debug("stack: %p\n", (void *)stack);
- addr = (unsigned long)(((unsigned long *)stack)[1]);
- pr_debug("addr: %p\n", (void *)addr);
- if (!skip)
- trace->entries[trace->nr_entries++] = addr-1;
- else
- skip--;
- if (trace->nr_entries >= trace->max_entries)
- break;
- if (!addr)
- return 0;
- /*
- * Stack frames must go forwards (otherwise a loop could
- * happen if the stackframe is corrupted), so we move
- * prev_stack forwards:
- */
- prev_stack = stack;
- stack = (unsigned long)(((unsigned long *)stack)[0]);
- }
- pr_debug("invalid: %p\n", (void *)stack);
-#else
- while (stack < stack_end) {
- addr = ((unsigned long *)stack)[0];
- stack += sizeof(long);
- if (__kernel_text_address(addr)) {
- if (!skip)
- trace->entries[trace->nr_entries++] = addr-1;
- else
- skip--;
- if (trace->nr_entries >= trace->max_entries)
- break;
- }
+static void save_stack_address(void *data, unsigned long addr)
+{
+ struct stack_trace *trace = (struct stack_trace *)data;
+ if (trace->skip > 0) {
+ trace->skip--;
+ return;
}
-#endif
- return stack;
+ if (trace->nr_entries < trace->max_entries - 1)
+ trace->entries[trace->nr_entries++] = addr;
}
-#define MAX_STACKS 10
+static struct stacktrace_ops save_stack_ops = {
+ .warning = save_stack_warning,
+ .warning_symbol = save_stack_warning_symbol,
+ .stack = save_stack_stack,
+ .address = save_stack_address,
+};
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
{
- unsigned long stack = (unsigned long)&stack;
- int i, nr_stacks = 0, stacks_done[MAX_STACKS];
-
- WARN_ON(trace->nr_entries || !trace->max_entries);
-
- if (!task)
- task = current;
-
- pr_debug("task: %p, ti: %p\n", task, task->thread_info);
-
- if (!task || task == current) {
- /* Grab rbp right from our regs: */
- asm ("mov %%rbp, %0" : "=r" (stack));
- pr_debug("rbp: %p\n", (void *)stack);
- } else {
- /* rbp is the last reg pushed by switch_to(): */
- stack = task->thread.rsp;
- pr_debug("other task rsp: %p\n", (void *)stack);
- stack = (unsigned long)(((unsigned long *)stack)[0]);
- pr_debug("other task rbp: %p\n", (void *)stack);
- }
-
- while (1) {
- unsigned long stack_end = get_stack_end(task, stack);
-
- pr_debug("stack: %p\n", (void *)stack);
- pr_debug("stack end: %p\n", (void *)stack_end);
-
- /*
- * Invalid stack addres?
- */
- if (!stack_end)
- return;
- /*
- * Were we in this stack already? (recursion)
- */
- for (i = 0; i < nr_stacks; i++)
- if (stacks_done[i] == stack_end)
- return;
- stacks_done[nr_stacks] = stack_end;
-
- stack = save_context_stack(trace, stack, stack_end);
- if (!stack || trace->nr_entries >= trace->max_entries)
- return;
- trace->entries[trace->nr_entries++] = ULONG_MAX;
- if (trace->nr_entries >= trace->max_entries)
- return;
- if (++nr_stacks >= MAX_STACKS)
- return;
- }
+ dump_trace(task, NULL, NULL, &save_stack_ops, trace);
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
}
+EXPORT_SYMBOL(save_stack_trace);
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 9ec2b1d..4ac18b0 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -45,6 +45,7 @@
#include <asm/pda.h>
#include <asm/proto.h>
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
asmlinkage void divide_error(void);
asmlinkage void debug(void);
@@ -142,7 +143,7 @@ void printk_address(unsigned long address)
#endif
static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
- unsigned *usedp, const char **idp)
+ unsigned *usedp, char **idp)
{
static char ids[][8] = {
[DEBUG_STACK - 1] = "#DB",
@@ -234,13 +235,19 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
return NULL;
}
-static int show_trace_unwind(struct unwind_frame_info *info, void *context)
+struct ops_and_data {
+ struct stacktrace_ops *ops;
+ void *data;
+};
+
+static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
{
+ struct ops_and_data *oad = (struct ops_and_data *)context;
int n = 0;
while (unwind(info) == 0 && UNW_PC(info)) {
n++;
- printk_address(UNW_PC(info));
+ oad->ops->address(oad->data, UNW_PC(info));
if (arch_unw_user_mode(info))
break;
}
@@ -254,45 +261,51 @@ static int show_trace_unwind(struct unwind_frame_info *info, void *context)
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
-void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack)
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
+ struct stacktrace_ops *ops, void *data)
{
const unsigned cpu = safe_smp_processor_id();
unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
unsigned used = 0;
- printk("\nCall Trace:\n");
-
if (!tsk)
tsk = current;
if (call_trace >= 0) {
int unw_ret = 0;
struct unwind_frame_info info;
+ struct ops_and_data oad = { .ops = ops, .data = data };
if (regs) {
if (unwind_init_frame_info(&info, tsk, regs) == 0)
- unw_ret = show_trace_unwind(&info, NULL);
+ unw_ret = dump_trace_unwind(&info, &oad);
} else if (tsk == current)
- unw_ret = unwind_init_running(&info, show_trace_unwind, NULL);
+ unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
else {
if (unwind_init_blocked(&info, tsk) == 0)
- unw_ret = show_trace_unwind(&info, NULL);
+ unw_ret = dump_trace_unwind(&info, &oad);
}
if (unw_ret > 0) {
if (call_trace == 1 && !arch_unw_user_mode(&info)) {
- print_symbol("DWARF2 unwinder stuck at %s\n",
+ ops->warning_symbol(data, "DWARF2 unwinder stuck at %s\n",
UNW_PC(&info));
if ((long)UNW_SP(&info) < 0) {
- printk("Leftover inexact backtrace:\n");
+ ops->warning(data, "Leftover inexact backtrace:\n");
stack = (unsigned long *)UNW_SP(&info);
} else
- printk("Full inexact backtrace again:\n");
+ ops->warning(data, "Full inexact backtrace again:\n");
} else if (call_trace >= 1)
return;
else
- printk("Full inexact backtrace again:\n");
+ ops->warning(data, "Full inexact backtrace again:\n");
} else
- printk("Inexact backtrace:\n");
+ ops->warning(data, "Inexact backtrace:\n");
+ }
+ if (!stack) {
+ unsigned long dummy;
+ stack = &dummy;
+ if (tsk && tsk != current)
+ stack = (unsigned long *)tsk->thread.rsp;
}
/*
@@ -312,7 +325,7 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
* down the cause of the crash will be able to figure \
* out the call path that was taken. \
*/ \
- printk_address(addr); \
+ ops->address(data, addr); \
} \
} while (0)
@@ -321,16 +334,17 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
* current stack address. If the stacks consist of nested
* exceptions
*/
- for ( ; ; ) {
- const char *id;
+ for (;;) {
+ char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
- printk(" <%s>", id);
+ if (ops->stack(data, id) < 0)
+ break;
HANDLE_STACK (stack < estack_end);
- printk(" <EOE>");
+ ops->stack(data, "<EOE>");
/*
* We link to the next stack via the
* second-to-last pointer (index -2 to end) in the
@@ -345,7 +359,8 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (stack >= irqstack && stack < irqstack_end) {
- printk(" <IRQ>");
+ if (ops->stack(data, "IRQ") < 0)
+ break;
HANDLE_STACK (stack < irqstack_end);
/*
* We link to the next stack (which would be
@@ -354,7 +369,7 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
*/
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
- printk(" <EOI>");
+ ops->stack(data, "EOI");
continue;
}
}
@@ -362,15 +377,53 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
}
/*
- * This prints the process stack:
+ * This handles the process stack:
*/
HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
#undef HANDLE_STACK
+}
+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)
+{
+ printk_address(addr);
+}
+
+static 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(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
+{
+ printk("\nCall Trace:\n");
+ dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
printk("\n");
}
-static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long * rsp)
+static void
+_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
{
unsigned long *stack;
int i;
diff --git a/include/asm-x86_64/stacktrace.h b/include/asm-x86_64/stacktrace.h
new file mode 100644
index 0000000..5eb9799
--- /dev/null
+++ b/include/asm-x86_64/stacktrace.h
@@ -0,0 +1,18 @@
+#ifndef _ASM_STACKTRACE_H
+#define _ASM_STACKTRACE_H 1
+
+/* Generic stack tracer with callbacks */
+
+struct stacktrace_ops {
+ void (*warning)(void *data, char *msg);
+ /* msg must contain %s for the symbol */
+ void (*warning_symbol)(void *data, char *msg, unsigned long symbol);
+ void (*address)(void *data, unsigned long address);
+ /* On negative return stop dumping */
+ int (*stack)(void *data, char *name);
+};
+
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
+ struct stacktrace_ops *ops, void *data);
+
+#endif
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