linux/arch/x86/include/asm/stacktrace.h
Andy Lutomirski 33a2f1a6c4 x86/dumpstack: Add get_stack_info() support for the SYSENTER stack
get_stack_info() doesn't currently know about the SYSENTER stack, so
unwinding will fail if we entered the kernel on the SYSENTER stack
and haven't fully switched off.  Teach get_stack_info() about the
SYSENTER stack.

With future patches applied that run part of the entry code on the
SYSENTER stack and introduce an intentional BUG(), I would get:

  PANIC: double fault, error_code: 0x0
  ...
  RIP: 0010:do_error_trap+0x33/0x1c0
  ...
  Call Trace:
  Code: ...

With this patch, I get:

  PANIC: double fault, error_code: 0x0
  ...
  Call Trace:
   <SYSENTER>
   ? async_page_fault+0x36/0x60
   ? invalid_op+0x22/0x40
   ? async_page_fault+0x36/0x60
   ? sync_regs+0x3c/0x40
   ? sync_regs+0x2e/0x40
   ? error_entry+0x6c/0xd0
   ? async_page_fault+0x36/0x60
   </SYSENTER>
  Code: ...

which is a lot more informative.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.392711508@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17 13:59:54 +01:00

117 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
*/
#ifndef _ASM_X86_STACKTRACE_H
#define _ASM_X86_STACKTRACE_H
#include <linux/uaccess.h>
#include <linux/ptrace.h>
#include <asm/switch_to.h>
enum stack_type {
STACK_TYPE_UNKNOWN,
STACK_TYPE_TASK,
STACK_TYPE_IRQ,
STACK_TYPE_SOFTIRQ,
STACK_TYPE_SYSENTER,
STACK_TYPE_EXCEPTION,
STACK_TYPE_EXCEPTION_LAST = STACK_TYPE_EXCEPTION + N_EXCEPTION_STACKS-1,
};
struct stack_info {
enum stack_type type;
unsigned long *begin, *end, *next_sp;
};
bool in_task_stack(unsigned long *stack, struct task_struct *task,
struct stack_info *info);
bool in_sysenter_stack(unsigned long *stack, struct stack_info *info);
int get_stack_info(unsigned long *stack, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask);
const char *stack_type_name(enum stack_type type);
static inline bool on_stack(struct stack_info *info, void *addr, size_t len)
{
void *begin = info->begin;
void *end = info->end;
return (info->type != STACK_TYPE_UNKNOWN &&
addr >= begin && addr < end &&
addr + len > begin && addr + len <= end);
}
#ifdef CONFIG_X86_32
#define STACKSLOTS_PER_LINE 8
#else
#define STACKSLOTS_PER_LINE 4
#endif
#ifdef CONFIG_FRAME_POINTER
static inline unsigned long *
get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
{
if (regs)
return (unsigned long *)regs->bp;
if (task == current)
return __builtin_frame_address(0);
return &((struct inactive_task_frame *)task->thread.sp)->bp;
}
#else
static inline unsigned long *
get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
{
return NULL;
}
#endif /* CONFIG_FRAME_POINTER */
static inline unsigned long *
get_stack_pointer(struct task_struct *task, struct pt_regs *regs)
{
if (regs)
return (unsigned long *)kernel_stack_pointer(regs);
if (task == current)
return __builtin_frame_address(0);
return (unsigned long *)task->thread.sp;
}
void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, char *log_lvl);
extern unsigned int code_bytes;
/* The form of the top of the frame on the stack */
struct stack_frame {
struct stack_frame *next_frame;
unsigned long return_address;
};
struct stack_frame_ia32 {
u32 next_frame;
u32 return_address;
};
static inline unsigned long caller_frame_pointer(void)
{
struct stack_frame *frame;
frame = __builtin_frame_address(0);
#ifdef CONFIG_FRAME_POINTER
frame = frame->next_frame;
#endif
return (unsigned long)frame;
}
#endif /* _ASM_X86_STACKTRACE_H */