152 lines
3.5 KiB
C
152 lines
3.5 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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#include <linux/sched/debug.h>
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#include <linux/kallsyms.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/export.h>
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#include <linux/ptrace.h>
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#include <linux/kexec.h>
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#include <linux/sysfs.h>
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#include <linux/bug.h>
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#include <linux/nmi.h>
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#include <asm/stacktrace.h>
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static char *exception_stack_names[N_EXCEPTION_STACKS] = {
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[ DOUBLEFAULT_STACK-1 ] = "#DF",
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[ NMI_STACK-1 ] = "NMI",
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[ DEBUG_STACK-1 ] = "#DB",
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[ MCE_STACK-1 ] = "#MC",
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};
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static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
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[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
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[DEBUG_STACK - 1] = DEBUG_STKSZ
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};
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const char *stack_type_name(enum stack_type type)
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{
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BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
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if (type == STACK_TYPE_IRQ)
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return "IRQ";
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if (type == STACK_TYPE_ENTRY) {
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/*
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* On 64-bit, we have a generic entry stack that we
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* use for all the kernel entry points, including
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* SYSENTER.
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*/
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return "ENTRY_TRAMPOLINE";
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}
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if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST)
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return exception_stack_names[type - STACK_TYPE_EXCEPTION];
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return NULL;
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}
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static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
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{
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unsigned long *begin, *end;
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struct pt_regs *regs;
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unsigned k;
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BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
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for (k = 0; k < N_EXCEPTION_STACKS; k++) {
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end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];
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begin = end - (exception_stack_sizes[k] / sizeof(long));
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regs = (struct pt_regs *)end - 1;
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if (stack <= begin || stack >= end)
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continue;
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info->type = STACK_TYPE_EXCEPTION + k;
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info->begin = begin;
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info->end = end;
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info->next_sp = (unsigned long *)regs->sp;
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return true;
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}
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return false;
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}
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static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
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{
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unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr);
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unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
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/*
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* This is a software stack, so 'end' can be a valid stack pointer.
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* It just means the stack is empty.
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*/
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if (stack <= begin || stack > end)
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return false;
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info->type = STACK_TYPE_IRQ;
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info->begin = begin;
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info->end = end;
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/*
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* The next stack pointer is the first thing pushed by the entry code
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* after switching to the irq stack.
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*/
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info->next_sp = (unsigned long *)*(end - 1);
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return true;
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}
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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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{
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if (!stack)
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goto unknown;
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task = task ? : current;
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if (in_task_stack(stack, task, info))
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goto recursion_check;
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if (task != current)
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goto unknown;
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if (in_exception_stack(stack, info))
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goto recursion_check;
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if (in_irq_stack(stack, info))
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goto recursion_check;
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if (in_entry_stack(stack, info))
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goto recursion_check;
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goto unknown;
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recursion_check:
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/*
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* Make sure we don't iterate through any given stack more than once.
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* If it comes up a second time then there's something wrong going on:
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* just break out and report an unknown stack type.
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*/
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if (visit_mask) {
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if (*visit_mask & (1UL << info->type)) {
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printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
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goto unknown;
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}
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*visit_mask |= 1UL << info->type;
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}
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return 0;
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unknown:
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info->type = STACK_TYPE_UNKNOWN;
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return -EINVAL;
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}
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