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linux/include/asm-i386/unwind.h
Jan Beulich ea424055b7 [PATCH] x86: Make backtracer fallback logic more bullet-proof
The unwinder fallback logic still had potential for falling through to
the legacy stack trace code without printing an indication (at once
serving as a separator) of this.

Further, the stack pointer retrieval for the fallback should be as
restrictive as possible (in order to avoid having the legacy stack
tracer try to access invalid memory). The patch tightens that, but
this could certainly be further improved.

Also making the call_trace command line option now conditional upon
CONFIG_STACK_UNWIND (as it's meaningless otherwise).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-30 16:05:15 -07:00

100 lines
2.7 KiB
C

#ifndef _ASM_I386_UNWIND_H
#define _ASM_I386_UNWIND_H
/*
* Copyright (C) 2002-2006 Novell, Inc.
* Jan Beulich <jbeulich@novell.com>
* This code is released under version 2 of the GNU GPL.
*/
#ifdef CONFIG_STACK_UNWIND
#include <linux/sched.h>
#include <asm/fixmap.h>
#include <asm/ptrace.h>
#include <asm/uaccess.h>
struct unwind_frame_info
{
struct pt_regs regs;
struct task_struct *task;
};
#define UNW_PC(frame) (frame)->regs.eip
#define UNW_SP(frame) (frame)->regs.esp
#ifdef CONFIG_FRAME_POINTER
#define UNW_FP(frame) (frame)->regs.ebp
#define FRAME_RETADDR_OFFSET 4
#define FRAME_LINK_OFFSET 0
#define STACK_BOTTOM(tsk) STACK_LIMIT((tsk)->thread.esp0)
#define STACK_TOP(tsk) ((tsk)->thread.esp0)
#endif
#define STACK_LIMIT(ptr) (((ptr) - 1) & ~(THREAD_SIZE - 1))
#define UNW_REGISTER_INFO \
PTREGS_INFO(eax), \
PTREGS_INFO(ecx), \
PTREGS_INFO(edx), \
PTREGS_INFO(ebx), \
PTREGS_INFO(esp), \
PTREGS_INFO(ebp), \
PTREGS_INFO(esi), \
PTREGS_INFO(edi), \
PTREGS_INFO(eip)
static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
/*const*/ struct pt_regs *regs)
{
if (user_mode_vm(regs))
info->regs = *regs;
else {
memcpy(&info->regs, regs, offsetof(struct pt_regs, esp));
info->regs.esp = (unsigned long)&regs->esp;
info->regs.xss = __KERNEL_DS;
}
}
static inline void arch_unw_init_blocked(struct unwind_frame_info *info)
{
memset(&info->regs, 0, sizeof(info->regs));
info->regs.eip = info->task->thread.eip;
info->regs.xcs = __KERNEL_CS;
__get_user(info->regs.ebp, (long *)info->task->thread.esp);
info->regs.esp = info->task->thread.esp;
info->regs.xss = __KERNEL_DS;
info->regs.xds = __USER_DS;
info->regs.xes = __USER_DS;
}
extern asmlinkage int arch_unwind_init_running(struct unwind_frame_info *,
asmlinkage int (*callback)(struct unwind_frame_info *,
void *arg),
void *arg);
static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
{
#if 0 /* This can only work when selector register and EFLAGS saves/restores
are properly annotated (and tracked in UNW_REGISTER_INFO). */
return user_mode_vm(&info->regs);
#else
return info->regs.eip < PAGE_OFFSET
|| (info->regs.eip >= __fix_to_virt(FIX_VDSO)
&& info->regs.eip < __fix_to_virt(FIX_VDSO) + PAGE_SIZE)
|| info->regs.esp < PAGE_OFFSET;
#endif
}
#else
#define UNW_PC(frame) ((void)(frame), 0)
#define UNW_SP(frame) ((void)(frame), 0)
static inline int arch_unw_user_mode(const void *info)
{
return 0;
}
#endif
#endif /* _ASM_I386_UNWIND_H */