[compiler-rt] r286708 - [asan] Fix strncmp and strncasecmp interceptors
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 14 12:36:57 PST 2016
maybe better just redefine strncasecmp to strncmp for Windows inside of the
test to avoid code duplication?
On Mon, Nov 14, 2016 at 9:47 AM Reid Kleckner <rnk at google.com> wrote:
> Windows doesn't have strncasecmp. I have a hack to make the test pass, but
> maybe it would be better to split the test into strncmp and strncasecmp and
> XFAIL the strncasecmp one.
>
> On Fri, Nov 11, 2016 at 8:32 PM, Vitaly Buka via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
> Author: vitalybuka
> Date: Fri Nov 11 22:32:31 2016
> New Revision: 286708
>
> URL: http://llvm.org/viewvc/llvm-project?rev=286708&view=rev
> Log:
> [asan] Fix strncmp and strncasecmp interceptors
>
> Summary:
> In non-strict mode we will check memory access for both strings from
> beginning
> to either:
> 1. 0-char
> 2. size
> 3. different chars
>
> In strict mode we will check from beginning to either:
> 1. 0-char
> 2. size
>
> Previously in strict mode we always checked up to the 0-char.
>
> Reviewers: kcc, eugenis
>
> Subscribers: llvm-commits, kubabrecka
>
> Differential Revision: https://reviews.llvm.org/D26574
>
> Modified:
>
> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
> compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c
>
> Modified:
> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
> URL:
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=286708&r1=286707&r2=286708&view=diff
>
> ==============================================================================
> ---
> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
> (original)
> +++
> compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
> Fri Nov 11 22:32:31 2016
> @@ -304,8 +304,14 @@ INTERCEPTOR(int, strncmp, const char *s1
> c2 = (unsigned char)s2[i];
> if (c1 != c2 || c1 == '\0') break;
> }
> - COMMON_INTERCEPTOR_READ_STRING(ctx, s1, Min(i + 1, size));
> - COMMON_INTERCEPTOR_READ_STRING(ctx, s2, Min(i + 1, size));
> + uptr i1 = i;
> + uptr i2 = i;
> + if (common_flags()->strict_string_checks) {
> + for (; i1 < size && s1[i1]; i1++) {}
> + for (; i2 < size && s2[i2]; i2++) {}
> + }
> + COMMON_INTERCEPTOR_READ_RANGE((ctx), (s1), Min(i1 + 1, size));
> + COMMON_INTERCEPTOR_READ_RANGE((ctx), (s2), Min(i2 + 1, size));
> int result = CharCmpX(c1, c2);
> CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncmp,
> GET_CALLER_PC(), s1,
> s2, size, result);
> @@ -348,24 +354,30 @@ INTERCEPTOR(int, strcasecmp, const char
> }
>
> DECLARE_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncasecmp, uptr
> called_pc,
> - const char *s1, const char *s2, uptr n,
> + const char *s1, const char *s2, uptr size,
> int result)
>
> -INTERCEPTOR(int, strncasecmp, const char *s1, const char *s2, SIZE_T n) {
> +INTERCEPTOR(int, strncasecmp, const char *s1, const char *s2, SIZE_T
> size) {
> void *ctx;
> - COMMON_INTERCEPTOR_ENTER(ctx, strncasecmp, s1, s2, n);
> + COMMON_INTERCEPTOR_ENTER(ctx, strncasecmp, s1, s2, size);
> unsigned char c1 = 0, c2 = 0;
> uptr i;
> - for (i = 0; i < n; i++) {
> + for (i = 0; i < size; i++) {
> c1 = (unsigned char)s1[i];
> c2 = (unsigned char)s2[i];
> if (CharCaseCmp(c1, c2) != 0 || c1 == '\0') break;
> }
> - COMMON_INTERCEPTOR_READ_RANGE(ctx, s1, Min(i + 1, n));
> - COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, Min(i + 1, n));
> + uptr i1 = i;
> + uptr i2 = i;
> + if (common_flags()->strict_string_checks) {
> + for (; i1 < size && s1[i1]; i1++) {}
> + for (; i2 < size && s2[i2]; i2++) {}
> + }
> + COMMON_INTERCEPTOR_READ_RANGE((ctx), (s1), Min(i1 + 1, size));
> + COMMON_INTERCEPTOR_READ_RANGE((ctx), (s2), Min(i2 + 1, size));
> int result = CharCaseCmp(c1, c2);
> CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncasecmp,
> GET_CALLER_PC(),
> - s1, s2, n, result);
> + s1, s2, size, result);
> return result;
> }
>
>
> Modified: compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c
> URL:
> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c?rev=286708&r1=286707&r2=286708&view=diff
>
> ==============================================================================
> --- compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c (original)
> +++ compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c Fri Nov 11
> 22:32:31 2016
> @@ -1,26 +1,81 @@
> // Test strict_string_checks option in strncmp function
> -// RUN: %clang_asan %s -o %t && %run %t 2>&1
> -// RUN: %env_asan_opts=strict_string_checks=false %run %t 2>&1
> -// RUN: %env_asan_opts=strict_string_checks=true not %run %t 2>&1 |
> FileCheck %s
> +// RUN: %clang_asan %s -o %t
> +
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t a 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true %run %t a 2>&1
> +// RUN: not %run %t b 2>&1 | FileCheck %s
> +// RUN: not %run %t c 2>&1 | FileCheck %s
> +// RUN: not %run %t d 2>&1 | FileCheck %s
> +// RUN: not %run %t e 2>&1 | FileCheck %s
> +// RUN: not %run %t f 2>&1 | FileCheck %s
> +// RUN: not %run %t g 2>&1 | FileCheck %s
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t h 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true not %run %t h 2>&1 |
> FileCheck %s
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t i 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true not %run %t i 2>&1 |
> FileCheck %s
> +
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t A 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true %run %t A 2>&1
> +// RUN: not %run %t B 2>&1 | FileCheck %s
> +// RUN: not %run %t C 2>&1 | FileCheck %s
> +// RUN: not %run %t D 2>&1 | FileCheck %s
> +// RUN: not %run %t E 2>&1 | FileCheck %s
> +// RUN: not %run %t F 2>&1 | FileCheck %s
> +// RUN: not %run %t G 2>&1 | FileCheck %s
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t H 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true not %run %t H 2>&1 |
> FileCheck %s
> +// RUN: %env_asan_opts=strict_string_checks=false %run %t I 2>&1
> +// RUN: %env_asan_opts=strict_string_checks=true not %run %t I 2>&1 |
> FileCheck %s
>
> #include <assert.h>
> #include <stdlib.h>
> +#include <stdio.h>
> #include <string.h>
> +#include <ctype.h>
>
> int main(int argc, char **argv) {
> - size_t size = 100;
> + assert(argc >= 2);
> + const size_t size = 100;
> char fill = 'o';
> - char *s1 = (char*)malloc(size);
> + char s1[size];
> + char s2[size];
> memset(s1, fill, size);
> - char *s2 = (char*)malloc(size);
> memset(s2, fill, size);
> - s1[size - 1] = 'z';
> - s2[size - 1] = 'x';
> - int r = strncmp(s1, s2, size + 1);
> - // CHECK: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
> - // CHECK: READ of size 101
> - assert(r == 1);
> - free(s1);
> - free(s2);
> +
> + int (*cmp_fn)(const char *, const char *, size_t);
> + cmp_fn = islower(argv[1][0]) ? &strncmp : &strncasecmp;
> +
> + switch(tolower(argv[1][0])) {
> + case 'a':
> + s1[size - 1] = 'z';
> + s2[size - 1] = 'x';
> + for (int i = 0; i <= size; ++i)
> + assert((cmp_fn(s1, s2, i) == 0) == (i < size));
> + s1[size - 1] = '\0';
> + s2[size - 1] = '\0';
> + assert(cmp_fn(s1, s2, 2*size) == 0);
> + break;
> + case 'b':
> + return cmp_fn(s1-1, s2, 1);
> + case 'c':
> + return cmp_fn(s1, s2-1, 1);
> + case 'd':
> + return cmp_fn(s1+size, s2, 1);
> + case 'e':
> + return cmp_fn(s1, s2+size, 1);
> + case 'f':
> + return cmp_fn(s1+1, s2, size);
> + case 'g':
> + return cmp_fn(s1, s2+1, size);
> + case 'h':
> + s1[size - 1] = '\0';
> + assert(cmp_fn(s1, s2, 2*size) != 0);
> + break;
> + case 'i':
> + s2[size - 1] = '\0';
> + assert(cmp_fn(s1, s2, 2*size) != 0);
> + break;
> + // CHECK: {{.*}}ERROR: AddressSanitizer:
> stack-buffer-{{ov|und}}erflow on address
> + }
> return 0;
> }
>
>
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