These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 72 insertions, 43 deletions

diff --git a/kernel/mm/kasan/report.c b/kernel/mm/kasan/report.c
index 680ceedf8..12f222d02 100644
--- a/kernel/mm/kasan/report.c
+++ b/kernel/mm/kasan/report.c
@@ -2,9 +2,9 @@
  * This file contains error reporting code.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
- * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
  *
- * Some of code borrowed from https://github.com/xairy/linux by
+ * Some code borrowed from https://github.com/xairy/kasan-prototype by
  *        Andrey Konovalov <adech.fo@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -22,6 +22,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/kasan.h>
+#include <linux/module.h>
 
 #include <asm/sections.h>
 
@@ -48,34 +49,49 @@ static const void *find_first_bad_addr(const void *addr, size_t size)
 
 static void print_error_description(struct kasan_access_info *info)
 {
-	const char *bug_type = "unknown crash";
-	u8 shadow_val;
+	const char *bug_type = "unknown-crash";
+	u8 *shadow_addr;
 
 	info->first_bad_addr = find_first_bad_addr(info->access_addr,
 						info->access_size);
 
-	shadow_val = *(u8 *)kasan_mem_to_shadow(info->first_bad_addr);
+	shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
 
-	switch (shadow_val) {
-	case KASAN_FREE_PAGE:
-	case KASAN_KMALLOC_FREE:
-		bug_type = "use after free";
+	/*
+	 * If shadow byte value is in [0, KASAN_SHADOW_SCALE_SIZE) we can look
+	 * at the next shadow byte to determine the type of the bad access.
+	 */
+	if (*shadow_addr > 0 && *shadow_addr <= KASAN_SHADOW_SCALE_SIZE - 1)
+		shadow_addr++;
+
+	switch (*shadow_addr) {
+	case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
+		/*
+		 * In theory it's still possible to see these shadow values
+		 * due to a data race in the kernel code.
+		 */
+		bug_type = "out-of-bounds";
 		break;
 	case KASAN_PAGE_REDZONE:
 	case KASAN_KMALLOC_REDZONE:
+		bug_type = "slab-out-of-bounds";
+		break;
 	case KASAN_GLOBAL_REDZONE:
-	case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
-		bug_type = "out of bounds access";
+		bug_type = "global-out-of-bounds";
 		break;
 	case KASAN_STACK_LEFT:
 	case KASAN_STACK_MID:
 	case KASAN_STACK_RIGHT:
 	case KASAN_STACK_PARTIAL:
-		bug_type = "out of bounds on stack";
+		bug_type = "stack-out-of-bounds";
+		break;
+	case KASAN_FREE_PAGE:
+	case KASAN_KMALLOC_FREE:
+		bug_type = "use-after-free";
 		break;
 	}
 
-	pr_err("BUG: KASan: %s in %pS at addr %p\n",
+	pr_err("BUG: KASAN: %s in %pS at addr %p\n",
 		bug_type, (void *)info->ip,
 		info->access_addr);
 	pr_err("%s of size %zu by task %s/%d\n",
@@ -85,9 +101,11 @@ static void print_error_description(struct kasan_access_info *info)
 
 static inline bool kernel_or_module_addr(const void *addr)
 {
-	return (addr >= (void *)_stext && addr < (void *)_end)
-		|| (addr >= (void *)MODULES_VADDR
-			&& addr < (void *)MODULES_END);
+	if (addr >= (void *)_stext && addr < (void *)_end)
+		return true;
+	if (is_module_address((unsigned long)addr))
+		return true;
+	return false;
 }
 
 static inline bool init_task_stack_addr(const void *addr)
@@ -161,15 +179,19 @@ static void print_shadow_for_address(const void *addr)
 	for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) {
 		const void *kaddr = kasan_shadow_to_mem(shadow_row);
 		char buffer[4 + (BITS_PER_LONG/8)*2];
+		char shadow_buf[SHADOW_BYTES_PER_ROW];
 
 		snprintf(buffer, sizeof(buffer),
 			(i == 0) ? ">%p: " : " %p: ", kaddr);
-
-		kasan_disable_current();
+		/*
+		 * We should not pass a shadow pointer to generic
+		 * function, because generic functions may try to
+		 * access kasan mapping for the passed address.
+		 */
+		memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW);
 		print_hex_dump(KERN_ERR, buffer,
 			DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1,
-			shadow_row, SHADOW_BYTES_PER_ROW, 0);
-		kasan_enable_current();
+			shadow_buf, SHADOW_BYTES_PER_ROW, 0);
 
 		if (row_is_guilty(shadow_row, shadow))
 			pr_err("%*c\n",
@@ -182,37 +204,43 @@ static void print_shadow_for_address(const void *addr)
 
 static DEFINE_SPINLOCK(report_lock);
 
-void kasan_report_error(struct kasan_access_info *info)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&report_lock, flags);
-	pr_err("================================="
-		"=================================\n");
-	print_error_description(info);
-	print_address_description(info);
-	print_shadow_for_address(info->first_bad_addr);
-	pr_err("================================="
-		"=================================\n");
-	spin_unlock_irqrestore(&report_lock, flags);
-}
-
-void kasan_report_user_access(struct kasan_access_info *info)
+static void kasan_report_error(struct kasan_access_info *info)
 {
 	unsigned long flags;
+	const char *bug_type;
 
+	/*
+	 * Make sure we don't end up in loop.
+	 */
+	kasan_disable_current();
 	spin_lock_irqsave(&report_lock, flags);
 	pr_err("================================="
 		"=================================\n");
-	pr_err("BUG: KASan: user-memory-access on address %p\n",
-		info->access_addr);
-	pr_err("%s of size %zu by task %s/%d\n",
-		info->is_write ? "Write" : "Read",
-		info->access_size, current->comm, task_pid_nr(current));
-	dump_stack();
+	if (info->access_addr <
+			kasan_shadow_to_mem((void *)KASAN_SHADOW_START)) {
+		if ((unsigned long)info->access_addr < PAGE_SIZE)
+			bug_type = "null-ptr-deref";
+		else if ((unsigned long)info->access_addr < TASK_SIZE)
+			bug_type = "user-memory-access";
+		else
+			bug_type = "wild-memory-access";
+		pr_err("BUG: KASAN: %s on address %p\n",
+			bug_type, info->access_addr);
+		pr_err("%s of size %zu by task %s/%d\n",
+			info->is_write ? "Write" : "Read",
+			info->access_size, current->comm,
+			task_pid_nr(current));
+		dump_stack();
+	} else {
+		print_error_description(info);
+		print_address_description(info);
+		print_shadow_for_address(info->first_bad_addr);
+	}
 	pr_err("================================="
 		"=================================\n");
+	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 	spin_unlock_irqrestore(&report_lock, flags);
+	kasan_enable_current();
 }
 
 void kasan_report(unsigned long addr, size_t size,
@@ -220,13 +248,14 @@ void kasan_report(unsigned long addr, size_t size,
 {
 	struct kasan_access_info info;
 
-	if (likely(!kasan_enabled()))
+	if (likely(!kasan_report_enabled()))
 		return;
 
 	info.access_addr = (void *)addr;
 	info.access_size = size;
 	info.is_write = is_write;
 	info.ip = ip;
+
 	kasan_report_error(&info);
 }