linux/mm/kfence/report.c

// SPDX-License-Identifier: GPL-2.0
/*
 * KFENCE reporting.
 *
 * Copyright (C) 2020, Google LLC.
 */

#include <linux/stdarg.h>

#include <linux/kernel.h>
#include <linux/lockdep.h>
#include <linux/math.h>
#include <linux/printk.h>
#include <linux/sched/debug.h>
#include <linux/seq_file.h>
#include <linux/sprintf.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/sched/clock.h>
#include <trace/events/error_report.h>

#include <asm/kfence.h>

#include "kfence.h"

/* May be overridden by <asm/kfence.h>. */
#ifndef ARCH_FUNC_PREFIX
#define ARCH_FUNC_PREFIX …
#endif

/* Helper function to either print to a seq_file or to console. */
__printf(2, 3)
static void seq_con_printf(struct seq_file *seq, const char *fmt, ...)
{ … }

/*
 * Get the number of stack entries to skip to get out of MM internals. @type is
 * optional, and if set to NULL, assumes an allocation or free stack.
 */
static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries,
			    const enum kfence_error_type *type)
{ … }

static void kfence_print_stack(struct seq_file *seq, const struct kfence_metadata *meta,
			       bool show_alloc)
{ … }

void kfence_print_object(struct seq_file *seq, const struct kfence_metadata *meta)
{ … }

/*
 * Show bytes at @addr that are different from the expected canary values, up to
 * @max_bytes.
 */
static void print_diff_canary(unsigned long address, size_t bytes_to_show,
			      const struct kfence_metadata *meta)
{ … }

static const char *get_access_type(bool is_write)
{ … }

void kfence_report_error(unsigned long address, bool is_write, struct pt_regs *regs,
			 const struct kfence_metadata *meta, enum kfence_error_type type)
{ … }

#ifdef CONFIG_PRINTK
static void kfence_to_kp_stack(const struct kfence_track *track, void **kp_stack)
{ … }

bool __kfence_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
{ … }
#endif