Re: [PATCH v3 02/17] khwasan: move common kasan and khwasan code to common.c

From: Andrey Konovalov
Date: Thu Jun 21 2018 - 08:40:56 EST


On Wed, Jun 20, 2018 at 10:36 PM, kbuild test robot <lkp@xxxxxxxxx> wrote:
> Hi Andrey,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on mmotm/master]
> [also build test ERROR on v4.18-rc1 next-20180620]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url: https://github.com/0day-ci/linux/commits/Andrey-Konovalov/khwasan-kernel-hardware-assisted-address-sanitizer/20180621-035912
> base: git://git.cmpxchg.org/linux-mmotm.git master
> config: x86_64-randconfig-x011-201824 (attached as .config)
> compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
> reproduce:
> # save the attached .config to linux build tree
> make ARCH=x86_64
>
> Note: the linux-review/Andrey-Konovalov/khwasan-kernel-hardware-assisted-address-sanitizer/20180621-035912 HEAD 0e30ed7118e854b38bb6ab96365e7c74a2518290 builds fine.
> It only hurts bisectibility.

Will fix in v4, thanks!

>
> All errors (new ones prefixed by >>):
>
>>> mm//kasan/report.c:42:20: error: conflicting types for 'find_first_bad_addr'
> static const void *find_first_bad_addr(const void *addr, size_t size)
> ^~~~~~~~~~~~~~~~~~~
> In file included from mm//kasan/report.c:33:0:
> mm//kasan/kasan.h:130:7: note: previous declaration of 'find_first_bad_addr' was here
> void *find_first_bad_addr(void *addr, size_t size);
> ^~~~~~~~~~~~~~~~~~~
>>> mm//kasan/report.c:54:13: error: conflicting types for 'addr_has_shadow'
> static bool addr_has_shadow(struct kasan_access_info *info)
> ^~~~~~~~~~~~~~~
> In file included from mm//kasan/report.c:33:0:
> mm//kasan/kasan.h:120:20: note: previous definition of 'addr_has_shadow' was here
> static inline bool addr_has_shadow(const void *addr)
> ^~~~~~~~~~~~~~~
> mm//kasan/report.c: In function 'get_shadow_bug_type':
> mm//kasan/report.c:86:2: error: duplicate case value
> case KASAN_KMALLOC_REDZONE:
> ^~~~
> mm//kasan/report.c:85:2: note: previously used here
> case KASAN_PAGE_REDZONE:
> ^~~~
> mm//kasan/report.c:98:2: error: duplicate case value
> case KASAN_FREE_PAGE:
> ^~~~
> mm//kasan/report.c:85:2: note: previously used here
> case KASAN_PAGE_REDZONE:
> ^~~~
> mm//kasan/report.c:99:2: error: duplicate case value
> case KASAN_KMALLOC_FREE:
> ^~~~
> mm//kasan/report.c:85:2: note: previously used here
> case KASAN_PAGE_REDZONE:
> ^~~~
> mm//kasan/report.c: At top level:
>>> mm//kasan/report.c:128:20: error: static declaration of 'get_bug_type' follows non-static declaration
> static const char *get_bug_type(struct kasan_access_info *info)
> ^~~~~~~~~~~~
> In file included from mm//kasan/report.c:33:0:
> mm//kasan/kasan.h:131:13: note: previous declaration of 'get_bug_type' was here
> const char *get_bug_type(struct kasan_access_info *info);
> ^~~~~~~~~~~~
>
> vim +/find_first_bad_addr +42 mm//kasan/report.c
>
> 0b24becc Andrey Ryabinin 2015-02-13 41
> 0b24becc Andrey Ryabinin 2015-02-13 @42 static const void *find_first_bad_addr(const void *addr, size_t size)
> 0b24becc Andrey Ryabinin 2015-02-13 43 {
> 0b24becc Andrey Ryabinin 2015-02-13 44 u8 shadow_val = *(u8 *)kasan_mem_to_shadow(addr);
> 0b24becc Andrey Ryabinin 2015-02-13 45 const void *first_bad_addr = addr;
> 0b24becc Andrey Ryabinin 2015-02-13 46
> 0b24becc Andrey Ryabinin 2015-02-13 47 while (!shadow_val && first_bad_addr < addr + size) {
> 0b24becc Andrey Ryabinin 2015-02-13 48 first_bad_addr += KASAN_SHADOW_SCALE_SIZE;
> 0b24becc Andrey Ryabinin 2015-02-13 49 shadow_val = *(u8 *)kasan_mem_to_shadow(first_bad_addr);
> 0b24becc Andrey Ryabinin 2015-02-13 50 }
> 0b24becc Andrey Ryabinin 2015-02-13 51 return first_bad_addr;
> 0b24becc Andrey Ryabinin 2015-02-13 52 }
> 0b24becc Andrey Ryabinin 2015-02-13 53
> 5e82cd12 Andrey Konovalov 2017-05-03 @54 static bool addr_has_shadow(struct kasan_access_info *info)
> 5e82cd12 Andrey Konovalov 2017-05-03 55 {
> 5e82cd12 Andrey Konovalov 2017-05-03 56 return (info->access_addr >=
> 5e82cd12 Andrey Konovalov 2017-05-03 57 kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
> 5e82cd12 Andrey Konovalov 2017-05-03 58 }
> 5e82cd12 Andrey Konovalov 2017-05-03 59
> 5e82cd12 Andrey Konovalov 2017-05-03 60 static const char *get_shadow_bug_type(struct kasan_access_info *info)
> 0b24becc Andrey Ryabinin 2015-02-13 61 {
> 0952d87f Andrey Konovalov 2015-11-05 62 const char *bug_type = "unknown-crash";
> cdf6a273 Andrey Konovalov 2015-11-05 63 u8 *shadow_addr;
> 0b24becc Andrey Ryabinin 2015-02-13 64
> 0b24becc Andrey Ryabinin 2015-02-13 65 info->first_bad_addr = find_first_bad_addr(info->access_addr,
> 0b24becc Andrey Ryabinin 2015-02-13 66 info->access_size);
> 0b24becc Andrey Ryabinin 2015-02-13 67
> cdf6a273 Andrey Konovalov 2015-11-05 68 shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
> 0b24becc Andrey Ryabinin 2015-02-13 69
> cdf6a273 Andrey Konovalov 2015-11-05 70 /*
> cdf6a273 Andrey Konovalov 2015-11-05 71 * If shadow byte value is in [0, KASAN_SHADOW_SCALE_SIZE) we can look
> cdf6a273 Andrey Konovalov 2015-11-05 72 * at the next shadow byte to determine the type of the bad access.
> cdf6a273 Andrey Konovalov 2015-11-05 73 */
> cdf6a273 Andrey Konovalov 2015-11-05 74 if (*shadow_addr > 0 && *shadow_addr <= KASAN_SHADOW_SCALE_SIZE - 1)
> cdf6a273 Andrey Konovalov 2015-11-05 75 shadow_addr++;
> cdf6a273 Andrey Konovalov 2015-11-05 76
> cdf6a273 Andrey Konovalov 2015-11-05 77 switch (*shadow_addr) {
> 0952d87f Andrey Konovalov 2015-11-05 78 case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
> cdf6a273 Andrey Konovalov 2015-11-05 79 /*
> cdf6a273 Andrey Konovalov 2015-11-05 80 * In theory it's still possible to see these shadow values
> cdf6a273 Andrey Konovalov 2015-11-05 81 * due to a data race in the kernel code.
> cdf6a273 Andrey Konovalov 2015-11-05 82 */
> 0952d87f Andrey Konovalov 2015-11-05 83 bug_type = "out-of-bounds";
> b8c73fc2 Andrey Ryabinin 2015-02-13 84 break;
> 0316bec2 Andrey Ryabinin 2015-02-13 85 case KASAN_PAGE_REDZONE:
> 0316bec2 Andrey Ryabinin 2015-02-13 86 case KASAN_KMALLOC_REDZONE:
> 0952d87f Andrey Konovalov 2015-11-05 87 bug_type = "slab-out-of-bounds";
> 0952d87f Andrey Konovalov 2015-11-05 88 break;
> bebf56a1 Andrey Ryabinin 2015-02-13 89 case KASAN_GLOBAL_REDZONE:
> 0952d87f Andrey Konovalov 2015-11-05 90 bug_type = "global-out-of-bounds";
> 0b24becc Andrey Ryabinin 2015-02-13 91 break;
> c420f167 Andrey Ryabinin 2015-02-13 92 case KASAN_STACK_LEFT:
> c420f167 Andrey Ryabinin 2015-02-13 93 case KASAN_STACK_MID:
> c420f167 Andrey Ryabinin 2015-02-13 94 case KASAN_STACK_RIGHT:
> c420f167 Andrey Ryabinin 2015-02-13 95 case KASAN_STACK_PARTIAL:
> 0952d87f Andrey Konovalov 2015-11-05 96 bug_type = "stack-out-of-bounds";
> 0952d87f Andrey Konovalov 2015-11-05 97 break;
> 0952d87f Andrey Konovalov 2015-11-05 98 case KASAN_FREE_PAGE:
> 0952d87f Andrey Konovalov 2015-11-05 @99 case KASAN_KMALLOC_FREE:
> 0952d87f Andrey Konovalov 2015-11-05 100 bug_type = "use-after-free";
> c420f167 Andrey Ryabinin 2015-02-13 101 break;
> 828347f8 Dmitry Vyukov 2016-11-30 102 case KASAN_USE_AFTER_SCOPE:
> 828347f8 Dmitry Vyukov 2016-11-30 103 bug_type = "use-after-scope";
> 828347f8 Dmitry Vyukov 2016-11-30 104 break;
> 342061ee Paul Lawrence 2018-02-06 105 case KASAN_ALLOCA_LEFT:
> 342061ee Paul Lawrence 2018-02-06 106 case KASAN_ALLOCA_RIGHT:
> 342061ee Paul Lawrence 2018-02-06 107 bug_type = "alloca-out-of-bounds";
> 342061ee Paul Lawrence 2018-02-06 108 break;
> 0b24becc Andrey Ryabinin 2015-02-13 109 }
> 0b24becc Andrey Ryabinin 2015-02-13 110
> 5e82cd12 Andrey Konovalov 2017-05-03 111 return bug_type;
> 5e82cd12 Andrey Konovalov 2017-05-03 112 }
> 5e82cd12 Andrey Konovalov 2017-05-03 113
> 822d5ec2 Colin Ian King 2017-07-10 114 static const char *get_wild_bug_type(struct kasan_access_info *info)
> 5e82cd12 Andrey Konovalov 2017-05-03 115 {
> 5e82cd12 Andrey Konovalov 2017-05-03 116 const char *bug_type = "unknown-crash";
> 5e82cd12 Andrey Konovalov 2017-05-03 117
> 5e82cd12 Andrey Konovalov 2017-05-03 118 if ((unsigned long)info->access_addr < PAGE_SIZE)
> 5e82cd12 Andrey Konovalov 2017-05-03 119 bug_type = "null-ptr-deref";
> 5e82cd12 Andrey Konovalov 2017-05-03 120 else if ((unsigned long)info->access_addr < TASK_SIZE)
> 5e82cd12 Andrey Konovalov 2017-05-03 121 bug_type = "user-memory-access";
> 5e82cd12 Andrey Konovalov 2017-05-03 122 else
> 5e82cd12 Andrey Konovalov 2017-05-03 123 bug_type = "wild-memory-access";
> 5e82cd12 Andrey Konovalov 2017-05-03 124
> 5e82cd12 Andrey Konovalov 2017-05-03 125 return bug_type;
> 5e82cd12 Andrey Konovalov 2017-05-03 126 }
> 5e82cd12 Andrey Konovalov 2017-05-03 127
> 7d418f7b Andrey Konovalov 2017-05-03 @128 static const char *get_bug_type(struct kasan_access_info *info)
> 7d418f7b Andrey Konovalov 2017-05-03 129 {
> 7d418f7b Andrey Konovalov 2017-05-03 130 if (addr_has_shadow(info))
> 7d418f7b Andrey Konovalov 2017-05-03 131 return get_shadow_bug_type(info);
> 7d418f7b Andrey Konovalov 2017-05-03 132 return get_wild_bug_type(info);
> 7d418f7b Andrey Konovalov 2017-05-03 133 }
> 7d418f7b Andrey Konovalov 2017-05-03 134
>
> :::::: The code at line 42 was first introduced by commit
> :::::: 0b24becc810dc3be6e3f94103a866f214c282394 kasan: add kernel address sanitizer infrastructure
>
> :::::: TO: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> :::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
>
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