// SPDX-License-Identifier: GPL-2.0
-#include <linux/interrupt.h>
-#include <linux/kdebug.h>
-#include <linux/kmemcheck.h>
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/ptrace.h>
-#include <linux/stacktrace.h>
-#include <linux/string.h>
-
-#include "error.h"
-#include "shadow.h"
-
-enum kmemcheck_error_type {
- KMEMCHECK_ERROR_INVALID_ACCESS,
- KMEMCHECK_ERROR_BUG,
-};
-
-#define SHADOW_COPY_SIZE (1 << CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT)
-
-struct kmemcheck_error {
- enum kmemcheck_error_type type;
-
- union {
- /* KMEMCHECK_ERROR_INVALID_ACCESS */
- struct {
- /* Kind of access that caused the error */
- enum kmemcheck_shadow state;
- /* Address and size of the erroneous read */
- unsigned long address;
- unsigned int size;
- };
- };
-
- struct pt_regs regs;
- struct stack_trace trace;
- unsigned long trace_entries[32];
-
- /* We compress it to a char. */
- unsigned char shadow_copy[SHADOW_COPY_SIZE];
- unsigned char memory_copy[SHADOW_COPY_SIZE];
-};
-
-/*
- * Create a ring queue of errors to output. We can't call printk() directly
- * from the kmemcheck traps, since this may call the console drivers and
- * result in a recursive fault.
- */
-static struct kmemcheck_error error_fifo[CONFIG_KMEMCHECK_QUEUE_SIZE];
-static unsigned int error_count;
-static unsigned int error_rd;
-static unsigned int error_wr;
-static unsigned int error_missed_count;
-
-static struct kmemcheck_error *error_next_wr(void)
-{
- struct kmemcheck_error *e;
-
- if (error_count == ARRAY_SIZE(error_fifo)) {
- ++error_missed_count;
- return NULL;
- }
-
- e = &error_fifo[error_wr];
- if (++error_wr == ARRAY_SIZE(error_fifo))
- error_wr = 0;
- ++error_count;
- return e;
-}
-
-static struct kmemcheck_error *error_next_rd(void)
-{
- struct kmemcheck_error *e;
-
- if (error_count == 0)
- return NULL;
-
- e = &error_fifo[error_rd];
- if (++error_rd == ARRAY_SIZE(error_fifo))
- error_rd = 0;
- --error_count;
- return e;
-}
-
-void kmemcheck_error_recall(void)
-{
- static const char *desc[] = {
- [KMEMCHECK_SHADOW_UNALLOCATED] = "unallocated",
- [KMEMCHECK_SHADOW_UNINITIALIZED] = "uninitialized",
- [KMEMCHECK_SHADOW_INITIALIZED] = "initialized",
- [KMEMCHECK_SHADOW_FREED] = "freed",
- };
-
- static const char short_desc[] = {
- [KMEMCHECK_SHADOW_UNALLOCATED] = 'a',
- [KMEMCHECK_SHADOW_UNINITIALIZED] = 'u',
- [KMEMCHECK_SHADOW_INITIALIZED] = 'i',
- [KMEMCHECK_SHADOW_FREED] = 'f',
- };
-
- struct kmemcheck_error *e;
- unsigned int i;
-
- e = error_next_rd();
- if (!e)
- return;
-
- switch (e->type) {
- case KMEMCHECK_ERROR_INVALID_ACCESS:
- printk(KERN_WARNING "WARNING: kmemcheck: Caught %d-bit read from %s memory (%p)\n",
- 8 * e->size, e->state < ARRAY_SIZE(desc) ?
- desc[e->state] : "(invalid shadow state)",
- (void *) e->address);
-
- printk(KERN_WARNING);
- for (i = 0; i < SHADOW_COPY_SIZE; ++i)
- printk(KERN_CONT "%02x", e->memory_copy[i]);
- printk(KERN_CONT "\n");
-
- printk(KERN_WARNING);
- for (i = 0; i < SHADOW_COPY_SIZE; ++i) {
- if (e->shadow_copy[i] < ARRAY_SIZE(short_desc))
- printk(KERN_CONT " %c", short_desc[e->shadow_copy[i]]);
- else
- printk(KERN_CONT " ?");
- }
- printk(KERN_CONT "\n");
- printk(KERN_WARNING "%*c\n", 2 + 2
- * (int) (e->address & (SHADOW_COPY_SIZE - 1)), '^');
- break;
- case KMEMCHECK_ERROR_BUG:
- printk(KERN_EMERG "ERROR: kmemcheck: Fatal error\n");
- break;
- }
-
- __show_regs(&e->regs, 1);
- print_stack_trace(&e->trace, 0);
-}
-
-static void do_wakeup(unsigned long data)
-{
- while (error_count > 0)
- kmemcheck_error_recall();
-
- if (error_missed_count > 0) {
- printk(KERN_WARNING "kmemcheck: Lost %d error reports because "
- "the queue was too small\n", error_missed_count);
- error_missed_count = 0;
- }
-}
-
-static DECLARE_TASKLET(kmemcheck_tasklet, &do_wakeup, 0);
-
-/*
- * Save the context of an error report.
- */
-void kmemcheck_error_save(enum kmemcheck_shadow state,
- unsigned long address, unsigned int size, struct pt_regs *regs)
-{
- static unsigned long prev_ip;
-
- struct kmemcheck_error *e;
- void *shadow_copy;
- void *memory_copy;
-
- /* Don't report several adjacent errors from the same EIP. */
- if (regs->ip == prev_ip)
- return;
- prev_ip = regs->ip;
-
- e = error_next_wr();
- if (!e)
- return;
-
- e->type = KMEMCHECK_ERROR_INVALID_ACCESS;
-
- e->state = state;
- e->address = address;
- e->size = size;
-
- /* Save regs */
- memcpy(&e->regs, regs, sizeof(*regs));
-
- /* Save stack trace */
- e->trace.nr_entries = 0;
- e->trace.entries = e->trace_entries;
- e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
- e->trace.skip = 0;
- save_stack_trace_regs(regs, &e->trace);
-
- /* Round address down to nearest 16 bytes */
- shadow_copy = kmemcheck_shadow_lookup(address
- & ~(SHADOW_COPY_SIZE - 1));
- BUG_ON(!shadow_copy);
-
- memcpy(e->shadow_copy, shadow_copy, SHADOW_COPY_SIZE);
-
- kmemcheck_show_addr(address);
- memory_copy = (void *) (address & ~(SHADOW_COPY_SIZE - 1));
- memcpy(e->memory_copy, memory_copy, SHADOW_COPY_SIZE);
- kmemcheck_hide_addr(address);
-
- tasklet_hi_schedule_first(&kmemcheck_tasklet);
-}
-
-/*
- * Save the context of a kmemcheck bug.
- */
-void kmemcheck_error_save_bug(struct pt_regs *regs)
-{
- struct kmemcheck_error *e;
-
- e = error_next_wr();
- if (!e)
- return;
-
- e->type = KMEMCHECK_ERROR_BUG;
-
- memcpy(&e->regs, regs, sizeof(*regs));
-
- e->trace.nr_entries = 0;
- e->trace.entries = e->trace_entries;
- e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
- e->trace.skip = 1;
- save_stack_trace(&e->trace);
-
- tasklet_hi_schedule_first(&kmemcheck_tasklet);
-}
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