76734d26b5
unwind_frame() was previously implicitly checking that the frame record is in bounds of the stack by enforcing that FP is both aligned to 16 and in bounds of the stack. Once the FP alignment requirement is relaxed to 8 this will not be sufficient because it does not account for the case where FP points to 8 bytes before the end of the stack. Make the check explicit by changing the on_*stack functions to take a size argument and adjusting the callers to pass the appropriate sizes. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/Ib7a3eb3eea41b0687ffaba045ceb2012d077d8b4 Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210526174927.2477847-1-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>
155 lines
4.2 KiB
C
155 lines
4.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2012 ARM Ltd.
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*/
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#ifndef __ASM_STACKTRACE_H
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#define __ASM_STACKTRACE_H
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#include <linux/percpu.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/types.h>
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#include <asm/memory.h>
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#include <asm/ptrace.h>
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#include <asm/sdei.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_OVERFLOW,
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STACK_TYPE_SDEI_NORMAL,
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STACK_TYPE_SDEI_CRITICAL,
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__NR_STACK_TYPES
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};
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struct stack_info {
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unsigned long low;
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unsigned long high;
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enum stack_type type;
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};
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/*
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* A snapshot of a frame record or fp/lr register values, along with some
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* accounting information necessary for robust unwinding.
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*
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* @fp: The fp value in the frame record (or the real fp)
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* @pc: The fp value in the frame record (or the real lr)
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*
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* @stacks_done: Stacks which have been entirely unwound, for which it is no
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* longer valid to unwind to.
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*
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* @prev_fp: The fp that pointed to this frame record, or a synthetic value
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* of 0. This is used to ensure that within a stack, each
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* subsequent frame record is at an increasing address.
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* @prev_type: The type of stack this frame record was on, or a synthetic
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* value of STACK_TYPE_UNKNOWN. This is used to detect a
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* transition from one stack to another.
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*
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* @graph: When FUNCTION_GRAPH_TRACER is selected, holds the index of a
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* replacement lr value in the ftrace graph stack.
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*/
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struct stackframe {
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unsigned long fp;
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unsigned long pc;
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DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
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unsigned long prev_fp;
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enum stack_type prev_type;
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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int graph;
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#endif
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};
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extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
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extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
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bool (*fn)(void *, unsigned long), void *data);
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extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
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const char *loglvl);
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DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
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static inline bool on_stack(unsigned long sp, unsigned long size,
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unsigned long low, unsigned long high,
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enum stack_type type, struct stack_info *info)
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{
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if (!low)
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return false;
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if (sp < low || sp + size < sp || sp + size > high)
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return false;
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if (info) {
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info->low = low;
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info->high = high;
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info->type = type;
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}
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return true;
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}
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static inline bool on_irq_stack(unsigned long sp, unsigned long size,
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struct stack_info *info)
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{
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unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
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unsigned long high = low + IRQ_STACK_SIZE;
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return on_stack(sp, size, low, high, STACK_TYPE_IRQ, info);
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}
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static inline bool on_task_stack(const struct task_struct *tsk,
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unsigned long sp, unsigned long size,
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struct stack_info *info)
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{
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unsigned long low = (unsigned long)task_stack_page(tsk);
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unsigned long high = low + THREAD_SIZE;
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return on_stack(sp, size, low, high, STACK_TYPE_TASK, info);
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}
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#ifdef CONFIG_VMAP_STACK
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DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
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static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
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struct stack_info *info)
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{
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unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
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unsigned long high = low + OVERFLOW_STACK_SIZE;
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return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
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}
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#else
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static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
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struct stack_info *info) { return false; }
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#endif
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/*
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* We can only safely access per-cpu stacks from current in a non-preemptible
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* context.
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*/
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static inline bool on_accessible_stack(const struct task_struct *tsk,
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unsigned long sp, unsigned long size,
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struct stack_info *info)
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{
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if (info)
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info->type = STACK_TYPE_UNKNOWN;
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if (on_task_stack(tsk, sp, size, info))
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return true;
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if (tsk != current || preemptible())
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return false;
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if (on_irq_stack(sp, size, info))
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return true;
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if (on_overflow_stack(sp, size, info))
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return true;
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if (on_sdei_stack(sp, size, info))
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return true;
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return false;
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}
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void start_backtrace(struct stackframe *frame, unsigned long fp,
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unsigned long pc);
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#endif /* __ASM_STACKTRACE_H */
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