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-rw-r--r--arch/x86/include/asm/stacktrace.h10
-rw-r--r--arch/x86/kernel/dumpstack.c126
-rw-r--r--arch/x86/kernel/dumpstack_32.c9
-rw-r--r--arch/x86/kernel/dumpstack_64.c9
4 files changed, 107 insertions, 47 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index ed2be1b5ada8..c9ccf0676ca6 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -119,13 +119,11 @@ get_stack_pointer(struct task_struct *task, struct pt_regs *regs)
return (unsigned long *)task->thread.sp;
}
-extern void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp, char *log_lvl);
+void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *stack, char *log_lvl);
-extern void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl);
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl);
extern unsigned int code_bytes;
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index e0648f755158..c08f32ab8ace 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -17,7 +17,7 @@
#include <linux/sysfs.h>
#include <asm/stacktrace.h>
-
+#include <asm/unwind.h>
int panic_on_unrecovered_nmi;
int panic_on_io_nmi;
@@ -142,56 +142,120 @@ print_context_stack_bp(struct task_struct *task,
}
EXPORT_SYMBOL_GPL(print_context_stack_bp);
-static int print_trace_stack(void *data, const char *name)
+void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *stack, char *log_lvl)
{
- printk("%s <%s> ", (char *)data, name);
- return 0;
-}
+ struct unwind_state state;
+ struct stack_info stack_info = {0};
+ unsigned long visit_mask = 0;
+ int graph_idx = 0;
-/*
- * Print one address/symbol entries per line.
- */
-static int print_trace_address(void *data, unsigned long addr, int reliable)
-{
- printk_stack_address(addr, reliable, data);
- return 0;
-}
+ printk("%sCall Trace:\n", log_lvl);
-static const struct stacktrace_ops print_trace_ops = {
- .stack = print_trace_stack,
- .address = print_trace_address,
- .walk_stack = print_context_stack,
-};
+ unwind_start(&state, task, regs, stack);
-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);
+ /*
+ * Iterate through the stacks, starting with the current stack pointer.
+ * Each stack has a pointer to the next one.
+ *
+ * x86-64 can have several stacks:
+ * - task stack
+ * - interrupt stack
+ * - HW exception stacks (double fault, nmi, debug, mce)
+ *
+ * x86-32 can have up to three stacks:
+ * - task stack
+ * - softirq stack
+ * - hardirq stack
+ */
+ for (; stack; stack = stack_info.next_sp) {
+ const char *str_begin, *str_end;
+
+ /*
+ * If we overflowed the task stack into a guard page, jump back
+ * to the bottom of the usable stack.
+ */
+ if (task_stack_page(task) - (void *)stack < PAGE_SIZE)
+ stack = task_stack_page(task);
+
+ if (get_stack_info(stack, task, &stack_info, &visit_mask))
+ break;
+
+ stack_type_str(stack_info.type, &str_begin, &str_end);
+ if (str_begin)
+ printk("%s <%s> ", log_lvl, str_begin);
+
+ /*
+ * Scan the stack, printing any text addresses we find. At the
+ * same time, follow proper stack frames with the unwinder.
+ *
+ * Addresses found during the scan which are not reported by
+ * the unwinder are considered to be additional clues which are
+ * sometimes useful for debugging and are prefixed with '?'.
+ * This also serves as a failsafe option in case the unwinder
+ * goes off in the weeds.
+ */
+ for (; stack < stack_info.end; stack++) {
+ unsigned long real_addr;
+ int reliable = 0;
+ unsigned long addr = *stack;
+ unsigned long *ret_addr_p =
+ unwind_get_return_address_ptr(&state);
+
+ if (!__kernel_text_address(addr))
+ continue;
+
+ if (stack == ret_addr_p)
+ reliable = 1;
+
+ /*
+ * When function graph tracing is enabled for a
+ * function, its return address on the stack is
+ * replaced with the address of an ftrace handler
+ * (return_to_handler). In that case, before printing
+ * the "real" address, we want to print the handler
+ * address as an "unreliable" hint that function graph
+ * tracing was involved.
+ */
+ real_addr = ftrace_graph_ret_addr(task, &graph_idx,
+ addr, stack);
+ if (real_addr != addr)
+ printk_stack_address(addr, 0, log_lvl);
+ printk_stack_address(real_addr, reliable, log_lvl);
+
+ if (!reliable)
+ continue;
+
+ /*
+ * Get the next frame from the unwinder. No need to
+ * check for an error: if anything goes wrong, the rest
+ * of the addresses will just be printed as unreliable.
+ */
+ unwind_next_frame(&state);
+ }
+
+ if (str_end)
+ printk("%s <%s> ", log_lvl, str_end);
+ }
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
- unsigned long bp = 0;
-
task = task ? : current;
/*
* Stack frames below this one aren't interesting. Don't show them
* if we're printing for %current.
*/
- if (!sp && task == current) {
+ if (!sp && task == current)
sp = get_stack_pointer(current, NULL);
- bp = (unsigned long)get_frame_pointer(current, NULL);
- }
- show_stack_log_lvl(task, NULL, sp, bp, "");
+ show_stack_log_lvl(current, NULL, sp, "");
}
void show_stack_regs(struct pt_regs *regs)
{
- show_stack_log_lvl(current, regs, NULL, 0, "");
+ show_stack_log_lvl(current, regs, NULL, "");
}
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 4ff000811e03..e476eb774278 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -156,9 +156,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
}
EXPORT_SYMBOL(dump_trace);
-void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl)
{
unsigned long *stack;
int i;
@@ -181,7 +180,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
touch_nmi_watchdog();
}
pr_cont("\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
put_task_stack(task);
}
@@ -205,7 +204,7 @@ void show_regs(struct pt_regs *regs)
u8 *ip;
pr_emerg("Stack:\n");
- show_stack_log_lvl(current, regs, NULL, 0, KERN_EMERG);
+ show_stack_log_lvl(current, regs, NULL, KERN_EMERG);
pr_emerg("Code:");
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 008a29837cab..4e9f2cf64ac8 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -209,9 +209,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
}
EXPORT_SYMBOL(dump_trace);
-void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl)
{
unsigned long *irq_stack_end;
unsigned long *irq_stack;
@@ -255,7 +254,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
}
pr_cont("\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
put_task_stack(task);
}
@@ -278,7 +277,7 @@ void show_regs(struct pt_regs *regs)
u8 *ip;
printk(KERN_DEFAULT "Stack:\n");
- show_stack_log_lvl(current, regs, NULL, 0, KERN_DEFAULT);
+ show_stack_log_lvl(current, regs, NULL, KERN_DEFAULT);
printk(KERN_DEFAULT "Code: ");
generated by cgit (git 2.34.1) at 2024-07-08 03:03:48 +0000