[PATCH] Fix i386 memmove issue [BZ #22644]

[H.J. Lu]

On Mon, Mar 19, 2018 at 12:29 PM, Andrew Senkevich
<andrew.n.senkevich@gmail.com> wrote:
> 2018-03-19 18:57 GMT+01:00 H.J. Lu <hjl.tools@gmail.com>:
>> On Mon, Mar 19, 2018 at 10:52 AM, Andrew Senkevich
>> <andrew.n.senkevich@gmail.com> wrote:
>>> 2018-03-19 16:33 GMT+01:00 Florian Weimer <fweimer@redhat.com>:
>>>> On 03/19/2018 03:25 PM, Szabolcs Nagy wrote:
>>>>>
>>>>> i thought not using MAP_FIXED is the 'non-overriding MAP_FIXED variant'
>>>
>>> Hmm, I tried so and had got much bigger address. But now I see it
>>> works (with size just 0x20000000 and 0x70000000 as a hint) in both 64
>>> and 32 bit cases, so proposing the following:
>>>
>>> diff --git a/string/test-memmove.c b/string/test-memmove.c
>>> index edc7a4c..fa4037d 100644
>>> --- a/string/test-memmove.c
>>> +++ b/string/test-memmove.c
>>> @@ -24,6 +24,7 @@
>>>  # define TEST_NAME "memmove"
>>>  #endif
>>>  #include "test-string.h"
>>> +#include <support/test-driver.h>
>>>
>>>  char *simple_memmove (char *, const char *, size_t);
>>>
>>> @@ -245,6 +246,59 @@ do_random_tests (void)
>>>      }
>>>  }
>>>
>>> +static void
>>> +do_test2 (void)
>>> +{
>>> +  size_t size = 0x20000000;
>>> +  uint32_t * large_buf;
>>> +
>>> +  large_buf = mmap ((void*)0x70000000, size, PROT_READ | PROT_WRITE,
>>> +     MAP_PRIVATE | MAP_ANON, -1, 0);
>>> +
>>> +  if (large_buf == MAP_FAILED)
>>> +    error (EXIT_UNSUPPORTED, errno, "Large mmap failed");
>>> +
>>> +  if ((uintptr_t)large_buf > 0x80000000 - 128)
>>
>> Don't you need to test if address is too low such that
>> 0x80000000 - (uintptr_t)large_buf > 0x20000000?
>
> Indeed, thanks. Updated below.
>
> diff --git a/string/test-memmove.c b/string/test-memmove.c
> index edc7a4c..9f1437d 100644
> --- a/string/test-memmove.c
> +++ b/string/test-memmove.c
> @@ -24,6 +24,7 @@
>  # define TEST_NAME "memmove"
>  #endif
>  #include "test-string.h"
> +#include <support/test-driver.h>
>
>  char *simple_memmove (char *, const char *, size_t);
>
> @@ -245,6 +246,60 @@ do_random_tests (void)
>      }
>  }
>
> +static void
> +do_test2 (void)
> +{
> +  size_t size = 0x20000000;
> +  uint32_t * large_buf;
> +
> +  large_buf = mmap ((void*)0x70000000, size, PROT_READ | PROT_WRITE,
> +     MAP_PRIVATE | MAP_ANON, -1, 0);
> +
> +  if (large_buf == MAP_FAILED)
> +    error (EXIT_UNSUPPORTED, errno, "Large mmap failed");
> +
> +  if ((uintptr_t)large_buf > 0x80000000 - 128
> +      || 0x80000000 - (uintptr_t)large_buf > 0x20000000)
> +    {
> +      error (0, 0,"Large mmap allocated improperly");
> +      ret = EXIT_UNSUPPORTED;
> +      munmap((void *)large_buf, size);
> +      return;
> +    }
> +
> +  size_t bytes_move = 0x80000000 - (uintptr_t)large_buf;
> +  size_t arr_size = bytes_move / sizeof(uint32_t);
> +  size_t i;
> +
> +  FOR_EACH_IMPL (impl, 0)
> +    {
> +      for (i = 0; i < arr_size; i++)
> +        large_buf[i] = i;
> +
> +      uint32_t * dst = &large_buf[33];
> +
> +#ifdef TEST_BCOPY
> +      CALL (impl, (char *)large_buf, (char *)dst, bytes_move);
> +#else
> +      CALL (impl, (char *)dst, (char *)large_buf, bytes_move);
> +#endif
> +
> +      for (i = 0; i < arr_size; i++)
> +        {
> +          if (dst[i] != i)
> +     {
> +       error (0, 0,
> +      "Wrong result in function %s dst \"%p\" src \"%p\" offset \"%d\"",
> +      impl->name, dst, large_buf, i);
> +       ret = 1;
> +       break;
> +     }
> + }
> +    }
> +
> +  munmap((void *)large_buf, size);
> +}
> +
>  int
>  test_main (void)
>  {
> @@ -284,6 +339,9 @@ test_main (void)
>      }
>
>    do_random_tests ();
> +
> +  do_test2 ();
> +
>    return ret;
>  }
>
>

Look good.

Please submit the updated patch with the proper commit message.

-- 
H.J.