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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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44b979fa30
Current code has an explicit check for hitting the task stack guard; but overflowing any of the other stacks will get you a non-descript general #DF warning. Improve matters by using get_stack_info_noinstr() to detetrmine if and which stack guard page got hit, enabling a better stack warning. In specific, Michael Wang reported what turned out to be an NMI exception stack overflow, which is now clearly reported as such: [] BUG: NMI stack guard page was hit at 0000000085fd977b (stack is 000000003a55b09e..00000000d8cce1a5) Reported-by: Michael Wang <yun.wang@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Wang <yun.wang@linux.alibaba.com> Link: https://lkml.kernel.org/r/YUTE/NuqnaWbST8n@hirez.programming.kicks-ass.net
114 lines
2.8 KiB
C
114 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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*/
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#ifndef _ASM_X86_STACKTRACE_H
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#define _ASM_X86_STACKTRACE_H
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#include <linux/uaccess.h>
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#include <linux/ptrace.h>
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#include <asm/cpu_entry_area.h>
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#include <asm/switch_to.h>
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enum stack_type {
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STACK_TYPE_UNKNOWN,
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STACK_TYPE_TASK,
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STACK_TYPE_IRQ,
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STACK_TYPE_SOFTIRQ,
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STACK_TYPE_ENTRY,
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STACK_TYPE_EXCEPTION,
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STACK_TYPE_EXCEPTION_LAST = STACK_TYPE_EXCEPTION + N_EXCEPTION_STACKS-1,
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};
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struct stack_info {
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enum stack_type type;
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unsigned long *begin, *end, *next_sp;
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};
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bool in_task_stack(unsigned long *stack, struct task_struct *task,
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struct stack_info *info);
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bool in_entry_stack(unsigned long *stack, struct stack_info *info);
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int get_stack_info(unsigned long *stack, struct task_struct *task,
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struct stack_info *info, unsigned long *visit_mask);
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bool get_stack_info_noinstr(unsigned long *stack, struct task_struct *task,
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struct stack_info *info);
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static __always_inline
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bool get_stack_guard_info(unsigned long *stack, struct stack_info *info)
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{
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/* make sure it's not in the stack proper */
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if (get_stack_info_noinstr(stack, current, info))
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return false;
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/* but if it is in the page below it, we hit a guard */
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return get_stack_info_noinstr((void *)stack + PAGE_SIZE, current, info);
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}
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const char *stack_type_name(enum stack_type type);
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static inline bool on_stack(struct stack_info *info, void *addr, size_t len)
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{
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void *begin = info->begin;
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void *end = info->end;
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return (info->type != STACK_TYPE_UNKNOWN &&
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addr >= begin && addr < end &&
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addr + len > begin && addr + len <= end);
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}
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#ifdef CONFIG_X86_32
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#define STACKSLOTS_PER_LINE 8
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#else
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#define STACKSLOTS_PER_LINE 4
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#endif
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#ifdef CONFIG_FRAME_POINTER
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static inline unsigned long *
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get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
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{
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if (regs)
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return (unsigned long *)regs->bp;
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if (task == current)
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return __builtin_frame_address(0);
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return &((struct inactive_task_frame *)task->thread.sp)->bp;
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}
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#else
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static inline unsigned long *
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get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
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{
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return NULL;
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}
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#endif /* CONFIG_FRAME_POINTER */
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static inline unsigned long *
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get_stack_pointer(struct task_struct *task, struct pt_regs *regs)
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{
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if (regs)
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return (unsigned long *)regs->sp;
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if (task == current)
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return __builtin_frame_address(0);
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return (unsigned long *)task->thread.sp;
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}
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/* The form of the top of the frame on the stack */
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struct stack_frame {
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struct stack_frame *next_frame;
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unsigned long return_address;
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};
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struct stack_frame_ia32 {
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u32 next_frame;
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u32 return_address;
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};
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void show_opcodes(struct pt_regs *regs, const char *loglvl);
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void show_ip(struct pt_regs *regs, const char *loglvl);
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#endif /* _ASM_X86_STACKTRACE_H */
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