kasan: split out generic_report.c from report.c
authorAndrey Konovalov <andreyknvl@google.com>
Fri, 28 Dec 2018 08:30:38 +0000 (00:30 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Dec 2018 20:11:43 +0000 (12:11 -0800)
Move generic KASAN specific error reporting routines to generic_report.c
without any functional changes, leaving common error reporting code in
report.c to be later reused by tag-based KASAN.

Link: http://lkml.kernel.org/r/ba48c32f8e5aefedee78998ccff0413bee9e0f5b.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/kasan/Makefile
mm/kasan/generic_report.c [new file with mode: 0644]
mm/kasan/kasan.h
mm/kasan/report.c
mm/kasan/tags_report.c [new file with mode: 0644]

index 68ba182..0a14fcf 100644 (file)
@@ -14,5 +14,5 @@ CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 
 obj-$(CONFIG_KASAN) := common.o init.o report.o
-obj-$(CONFIG_KASAN_GENERIC) += generic.o quarantine.o
-obj-$(CONFIG_KASAN_SW_TAGS) += tags.o
+obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o
+obj-$(CONFIG_KASAN_SW_TAGS) += tags.o tags_report.o
diff --git a/mm/kasan/generic_report.c b/mm/kasan/generic_report.c
new file mode 100644 (file)
index 0000000..5201d17
--- /dev/null
@@ -0,0 +1,158 @@
+/*
+ * This file contains generic KASAN specific error reporting code.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * Some code borrowed from https://github.com/xairy/kasan-prototype by
+ *        Andrey Konovalov <andreyknvl@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/stackdepot.h>
+#include <linux/stacktrace.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/kasan.h>
+#include <linux/module.h>
+
+#include <asm/sections.h>
+
+#include "kasan.h"
+#include "../slab.h"
+
+static const void *find_first_bad_addr(const void *addr, size_t size)
+{
+       u8 shadow_val = *(u8 *)kasan_mem_to_shadow(addr);
+       const void *first_bad_addr = addr;
+
+       while (!shadow_val && first_bad_addr < addr + size) {
+               first_bad_addr += KASAN_SHADOW_SCALE_SIZE;
+               shadow_val = *(u8 *)kasan_mem_to_shadow(first_bad_addr);
+       }
+       return first_bad_addr;
+}
+
+static const char *get_shadow_bug_type(struct kasan_access_info *info)
+{
+       const char *bug_type = "unknown-crash";
+       u8 *shadow_addr;
+
+       info->first_bad_addr = find_first_bad_addr(info->access_addr,
+                                               info->access_size);
+
+       shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
+
+       /*
+        * 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:
+               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 = "stack-out-of-bounds";
+               break;
+       case KASAN_FREE_PAGE:
+       case KASAN_KMALLOC_FREE:
+               bug_type = "use-after-free";
+               break;
+       case KASAN_USE_AFTER_SCOPE:
+               bug_type = "use-after-scope";
+               break;
+       case KASAN_ALLOCA_LEFT:
+       case KASAN_ALLOCA_RIGHT:
+               bug_type = "alloca-out-of-bounds";
+               break;
+       }
+
+       return bug_type;
+}
+
+static const char *get_wild_bug_type(struct kasan_access_info *info)
+{
+       const char *bug_type = "unknown-crash";
+
+       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";
+
+       return bug_type;
+}
+
+const char *get_bug_type(struct kasan_access_info *info)
+{
+       if (addr_has_shadow(info->access_addr))
+               return get_shadow_bug_type(info);
+       return get_wild_bug_type(info);
+}
+
+#define DEFINE_ASAN_REPORT_LOAD(size)                     \
+void __asan_report_load##size##_noabort(unsigned long addr) \
+{                                                         \
+       kasan_report(addr, size, false, _RET_IP_);        \
+}                                                         \
+EXPORT_SYMBOL(__asan_report_load##size##_noabort)
+
+#define DEFINE_ASAN_REPORT_STORE(size)                     \
+void __asan_report_store##size##_noabort(unsigned long addr) \
+{                                                          \
+       kasan_report(addr, size, true, _RET_IP_);          \
+}                                                          \
+EXPORT_SYMBOL(__asan_report_store##size##_noabort)
+
+DEFINE_ASAN_REPORT_LOAD(1);
+DEFINE_ASAN_REPORT_LOAD(2);
+DEFINE_ASAN_REPORT_LOAD(4);
+DEFINE_ASAN_REPORT_LOAD(8);
+DEFINE_ASAN_REPORT_LOAD(16);
+DEFINE_ASAN_REPORT_STORE(1);
+DEFINE_ASAN_REPORT_STORE(2);
+DEFINE_ASAN_REPORT_STORE(4);
+DEFINE_ASAN_REPORT_STORE(8);
+DEFINE_ASAN_REPORT_STORE(16);
+
+void __asan_report_load_n_noabort(unsigned long addr, size_t size)
+{
+       kasan_report(addr, size, false, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_report_load_n_noabort);
+
+void __asan_report_store_n_noabort(unsigned long addr, size_t size)
+{
+       kasan_report(addr, size, true, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_report_store_n_noabort);
index b080b8d..33cc3b0 100644 (file)
@@ -109,11 +109,18 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
                << KASAN_SHADOW_SCALE_SHIFT);
 }
 
+static inline bool addr_has_shadow(const void *addr)
+{
+       return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+}
+
 void kasan_poison_shadow(const void *address, size_t size, u8 value);
 
 void check_memory_region(unsigned long addr, size_t size, bool write,
                                unsigned long ret_ip);
 
+const char *get_bug_type(struct kasan_access_info *info);
+
 void kasan_report(unsigned long addr, size_t size,
                bool is_write, unsigned long ip);
 void kasan_report_invalid_free(void *object, unsigned long ip);
index 5c169aa..64a74f3 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * This file contains error reporting code.
+ * This file contains common generic and tag-based KASAN error reporting code.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
 #define SHADOW_BYTES_PER_ROW (SHADOW_BLOCKS_PER_ROW * SHADOW_BYTES_PER_BLOCK)
 #define SHADOW_ROWS_AROUND_ADDR 2
 
-static const void *find_first_bad_addr(const void *addr, size_t size)
-{
-       u8 shadow_val = *(u8 *)kasan_mem_to_shadow(addr);
-       const void *first_bad_addr = addr;
-
-       while (!shadow_val && first_bad_addr < addr + size) {
-               first_bad_addr += KASAN_SHADOW_SCALE_SIZE;
-               shadow_val = *(u8 *)kasan_mem_to_shadow(first_bad_addr);
-       }
-       return first_bad_addr;
-}
+static unsigned long kasan_flags;
 
-static bool addr_has_shadow(struct kasan_access_info *info)
-{
-       return (info->access_addr >=
-               kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
-}
+#define KASAN_BIT_REPORTED     0
+#define KASAN_BIT_MULTI_SHOT   1
 
-static const char *get_shadow_bug_type(struct kasan_access_info *info)
+bool kasan_save_enable_multi_shot(void)
 {
-       const char *bug_type = "unknown-crash";
-       u8 *shadow_addr;
-
-       info->first_bad_addr = find_first_bad_addr(info->access_addr,
-                                               info->access_size);
-
-       shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
-
-       /*
-        * 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:
-               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 = "stack-out-of-bounds";
-               break;
-       case KASAN_FREE_PAGE:
-       case KASAN_KMALLOC_FREE:
-               bug_type = "use-after-free";
-               break;
-       case KASAN_USE_AFTER_SCOPE:
-               bug_type = "use-after-scope";
-               break;
-       case KASAN_ALLOCA_LEFT:
-       case KASAN_ALLOCA_RIGHT:
-               bug_type = "alloca-out-of-bounds";
-               break;
-       }
-
-       return bug_type;
+       return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
 }
+EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
 
-static const char *get_wild_bug_type(struct kasan_access_info *info)
+void kasan_restore_multi_shot(bool enabled)
 {
-       const char *bug_type = "unknown-crash";
-
-       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";
-
-       return bug_type;
+       if (!enabled)
+               clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
 }
+EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
 
-static const char *get_bug_type(struct kasan_access_info *info)
+static int __init kasan_set_multi_shot(char *str)
 {
-       if (addr_has_shadow(info))
-               return get_shadow_bug_type(info);
-       return get_wild_bug_type(info);
+       set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
+       return 1;
 }
+__setup("kasan_multi_shot", kasan_set_multi_shot);
 
-static void print_error_description(struct kasan_access_info *info)
+static void print_error_description(struct kasan_access_info *info,
+                                       const char *bug_type)
 {
-       const char *bug_type = get_bug_type(info);
-
        pr_err("BUG: KASAN: %s in %pS\n",
                bug_type, (void *)info->ip);
        pr_err("%s of size %zu at addr %px by task %s/%d\n",
@@ -143,25 +74,9 @@ static void print_error_description(struct kasan_access_info *info)
                info->access_addr, current->comm, task_pid_nr(current));
 }
 
-static inline bool kernel_or_module_addr(const void *addr)
-{
-       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)
-{
-       return addr >= (void *)&init_thread_union.stack &&
-               (addr <= (void *)&init_thread_union.stack +
-                       sizeof(init_thread_union.stack));
-}
-
 static DEFINE_SPINLOCK(report_lock);
 
-static void kasan_start_report(unsigned long *flags)
+static void start_report(unsigned long *flags)
 {
        /*
         * Make sure we don't end up in loop.
@@ -171,7 +86,7 @@ static void kasan_start_report(unsigned long *flags)
        pr_err("==================================================================\n");
 }
 
-static void kasan_end_report(unsigned long *flags)
+static void end_report(unsigned long *flags)
 {
        pr_err("==================================================================\n");
        add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
@@ -249,6 +164,22 @@ static void describe_object(struct kmem_cache *cache, void *object,
        describe_object_addr(cache, object, addr);
 }
 
+static inline bool kernel_or_module_addr(const void *addr)
+{
+       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)
+{
+       return addr >= (void *)&init_thread_union.stack &&
+               (addr <= (void *)&init_thread_union.stack +
+                       sizeof(init_thread_union.stack));
+}
+
 static void print_address_description(void *addr)
 {
        struct page *page = addr_to_page(addr);
@@ -326,29 +257,38 @@ static void print_shadow_for_address(const void *addr)
        }
 }
 
+static bool report_enabled(void)
+{
+       if (current->kasan_depth)
+               return false;
+       if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
+               return true;
+       return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
+}
+
 void kasan_report_invalid_free(void *object, unsigned long ip)
 {
        unsigned long flags;
 
-       kasan_start_report(&flags);
+       start_report(&flags);
        pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
        pr_err("\n");
        print_address_description(object);
        pr_err("\n");
        print_shadow_for_address(object);
-       kasan_end_report(&flags);
+       end_report(&flags);
 }
 
 static void kasan_report_error(struct kasan_access_info *info)
 {
        unsigned long flags;
 
-       kasan_start_report(&flags);
+       start_report(&flags);
 
-       print_error_description(info);
+       print_error_description(info, get_bug_type(info));
        pr_err("\n");
 
-       if (!addr_has_shadow(info)) {
+       if (!addr_has_shadow(info->access_addr)) {
                dump_stack();
        } else {
                print_address_description((void *)info->access_addr);
@@ -356,41 +296,7 @@ static void kasan_report_error(struct kasan_access_info *info)
                print_shadow_for_address(info->first_bad_addr);
        }
 
-       kasan_end_report(&flags);
-}
-
-static unsigned long kasan_flags;
-
-#define KASAN_BIT_REPORTED     0
-#define KASAN_BIT_MULTI_SHOT   1
-
-bool kasan_save_enable_multi_shot(void)
-{
-       return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
-}
-EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
-
-void kasan_restore_multi_shot(bool enabled)
-{
-       if (!enabled)
-               clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
-}
-EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
-
-static int __init kasan_set_multi_shot(char *str)
-{
-       set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
-       return 1;
-}
-__setup("kasan_multi_shot", kasan_set_multi_shot);
-
-static inline bool kasan_report_enabled(void)
-{
-       if (current->kasan_depth)
-               return false;
-       if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
-               return true;
-       return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
+       end_report(&flags);
 }
 
 void kasan_report(unsigned long addr, size_t size,
@@ -398,7 +304,7 @@ void kasan_report(unsigned long addr, size_t size,
 {
        struct kasan_access_info info;
 
-       if (likely(!kasan_report_enabled()))
+       if (likely(!report_enabled()))
                return;
 
        disable_trace_on_warning();
@@ -411,41 +317,3 @@ void kasan_report(unsigned long addr, size_t size,
 
        kasan_report_error(&info);
 }
-
-
-#define DEFINE_ASAN_REPORT_LOAD(size)                     \
-void __asan_report_load##size##_noabort(unsigned long addr) \
-{                                                         \
-       kasan_report(addr, size, false, _RET_IP_);        \
-}                                                         \
-EXPORT_SYMBOL(__asan_report_load##size##_noabort)
-
-#define DEFINE_ASAN_REPORT_STORE(size)                     \
-void __asan_report_store##size##_noabort(unsigned long addr) \
-{                                                          \
-       kasan_report(addr, size, true, _RET_IP_);          \
-}                                                          \
-EXPORT_SYMBOL(__asan_report_store##size##_noabort)
-
-DEFINE_ASAN_REPORT_LOAD(1);
-DEFINE_ASAN_REPORT_LOAD(2);
-DEFINE_ASAN_REPORT_LOAD(4);
-DEFINE_ASAN_REPORT_LOAD(8);
-DEFINE_ASAN_REPORT_LOAD(16);
-DEFINE_ASAN_REPORT_STORE(1);
-DEFINE_ASAN_REPORT_STORE(2);
-DEFINE_ASAN_REPORT_STORE(4);
-DEFINE_ASAN_REPORT_STORE(8);
-DEFINE_ASAN_REPORT_STORE(16);
-
-void __asan_report_load_n_noabort(unsigned long addr, size_t size)
-{
-       kasan_report(addr, size, false, _RET_IP_);
-}
-EXPORT_SYMBOL(__asan_report_load_n_noabort);
-
-void __asan_report_store_n_noabort(unsigned long addr, size_t size)
-{
-       kasan_report(addr, size, true, _RET_IP_);
-}
-EXPORT_SYMBOL(__asan_report_store_n_noabort);
diff --git a/mm/kasan/tags_report.c b/mm/kasan/tags_report.c
new file mode 100644 (file)
index 0000000..8af15e8
--- /dev/null
@@ -0,0 +1,39 @@
+/*
+ * This file contains tag-based KASAN specific error reporting code.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * Some code borrowed from https://github.com/xairy/kasan-prototype by
+ *        Andrey Konovalov <andreyknvl@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/stackdepot.h>
+#include <linux/stacktrace.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/kasan.h>
+#include <linux/module.h>
+
+#include <asm/sections.h>
+
+#include "kasan.h"
+#include "../slab.h"
+
+const char *get_bug_type(struct kasan_access_info *info)
+{
+       return "invalid-access";
+}