stdlib: Avoid undefined behavior in stdlib/tst-labs
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Description |
dj/TryBot-apply_patch |
success
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Patch applied to master at the time it was sent
|
dj/TryBot-32bit |
success
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Build for i686
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Commit Message
The last loop could attempt to overflow beyond INT_MAX on 32-bit
architectures.
Also switch to GNU style.
---
stdlib/tst-labs.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
base-commit: 641c4c2b7eb80e2cb2121b1c31096158091a6419
Comments
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
On 2023-05-16 17:35, Florian Weimer via Libc-alpha wrote:
> The last loop could attempt to overflow beyond INT_MAX on 32-bit
> architectures.
>
> Also switch to GNU style.
>
> ---
> stdlib/tst-labs.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/stdlib/tst-labs.c b/stdlib/tst-labs.c
> index 92b456745a..a8d2381f87 100644
> --- a/stdlib/tst-labs.c
> +++ b/stdlib/tst-labs.c
> @@ -25,25 +25,26 @@
>
> static int do_test (void)
> {
> - long i;
> + long int i;
>
> - TEST_COMPARE(labs(LONG_MAX), LONG_MAX);
> - TEST_COMPARE(labs(LONG_MIN + 1), LONG_MAX);
> - TEST_COMPARE(labs(-1), 1);
> - TEST_COMPARE(labs(0), 0);
> - TEST_COMPARE(labs(1), 1);
> + TEST_COMPARE (labs (LONG_MAX), LONG_MAX);
> + TEST_COMPARE (labs (LONG_MIN + 1), LONG_MAX);
> + TEST_COMPARE (labs (-1), 1);
> + TEST_COMPARE (labs (0), 0);
> + TEST_COMPARE (labs (1), 1);
>
> for (i = LONG_MIN + 1; i < LONG_MIN + INT_MAX; i += LARGE_PRIME)
> - TEST_COMPARE(labs(i), -i);
> + TEST_COMPARE (labs (i), -i);
>
> - for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME; i += LARGE_PRIME)
> - TEST_COMPARE(labs(i), i);
> + for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME;
> + i += LARGE_PRIME)
> + TEST_COMPARE (labs (i), i);
>
> for (i = INT_MIN + 1; i < 0; i += LARGE_PRIME)
> - TEST_COMPARE(labs(i), -i);
> + TEST_COMPARE (labs (i), -i);
>
> - for (i = 0; i < INT_MAX; i += LARGE_PRIME)
> - TEST_COMPARE(labs(i), i);
> + for (i = 0; i <= INT_MAX - LARGE_PRIME; i += LARGE_PRIME)
> + TEST_COMPARE (labs (i), i);
>
> return EXIT_SUCCESS;
> }
>
> base-commit: 641c4c2b7eb80e2cb2121b1c31096158091a6419
>
@@ -25,25 +25,26 @@
static int do_test (void)
{
- long i;
+ long int i;
- TEST_COMPARE(labs(LONG_MAX), LONG_MAX);
- TEST_COMPARE(labs(LONG_MIN + 1), LONG_MAX);
- TEST_COMPARE(labs(-1), 1);
- TEST_COMPARE(labs(0), 0);
- TEST_COMPARE(labs(1), 1);
+ TEST_COMPARE (labs (LONG_MAX), LONG_MAX);
+ TEST_COMPARE (labs (LONG_MIN + 1), LONG_MAX);
+ TEST_COMPARE (labs (-1), 1);
+ TEST_COMPARE (labs (0), 0);
+ TEST_COMPARE (labs (1), 1);
for (i = LONG_MIN + 1; i < LONG_MIN + INT_MAX; i += LARGE_PRIME)
- TEST_COMPARE(labs(i), -i);
+ TEST_COMPARE (labs (i), -i);
- for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME; i += LARGE_PRIME)
- TEST_COMPARE(labs(i), i);
+ for (i = LONG_MAX - INT_MAX; i < LONG_MAX - LARGE_PRIME;
+ i += LARGE_PRIME)
+ TEST_COMPARE (labs (i), i);
for (i = INT_MIN + 1; i < 0; i += LARGE_PRIME)
- TEST_COMPARE(labs(i), -i);
+ TEST_COMPARE (labs (i), -i);
- for (i = 0; i < INT_MAX; i += LARGE_PRIME)
- TEST_COMPARE(labs(i), i);
+ for (i = 0; i <= INT_MAX - LARGE_PRIME; i += LARGE_PRIME)
+ TEST_COMPARE (labs (i), i);
return EXIT_SUCCESS;
}