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

[Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>]

2018-03-14 15:59 GMT+01:00 H.J. Lu <hjl.tools@gmail.com>:
> On Wed, Mar 14, 2018 at 7:43 AM, Andrew Senkevich
> <andrew.n.senkevich@gmail.com> wrote:
>> 2018-02-19 11:13 GMT+01:00 Andreas Schwab <schwab@suse.de>:
>>> On Feb 19 2018, Andrew Senkevich <andrew.n.senkevich@gmail.com> wrote:
>>>
>>>> diff --git a/string/test-memmove.c b/string/test-memmove.c
>>>> index edc7a4c..8dc152b
>>>> --- a/string/test-memmove.c
>>>> +++ b/string/test-memmove.c
>>>> @@ -245,6 +245,49 @@ do_random_tests (void)
>>>>      }
>>>>  }
>>>>
>>>> +#if __SIZEOF_POINTER__ == 4
>>>> +static void
>>>> +do_test2 (void)
>>>> +{
>>>> +  uint32_t i;
>>>> +  uint32_t num = 0x20000000;
>>>> +  uint32_t * large_buf = mmap (0, sizeof(uint32_t) * num, PROT_READ |
>>>> PROT_WRITE,
>>>> +        MAP_PRIVATE | MAP_ANON, -1, 0);
>>>> +  if (large_buf == MAP_FAILED)
>>>> +    error (EXIT_FAILURE, errno, "large mmap failed");
>>>> +
>>>> +  if (!((uint32_t)(large_buf) < (0x80000000 - 128) && (0x80000000 +
>>>> 128) < (uint32_t)(&large_buf[num])))
>>>> +    {
>>>> +      error (0, 0,"allocated large memory doesn't cross 0x80000000 boundary");
>>>> +      ret = 1;
>>>> +      return;
>>>
>>> Please properly fold long lines, and remove the redundant parens.  Also,
>>> there is no guarantee that the address range is unallocated.
>>
>> Thanks, updated patch below.  Any comment or it is Ok for trunk?
>
> Please also test crossing 0x80000000 boundary on 64-bit systems.

Hi,

I extended test for 64-bit using MAP_FIXED which lets to hardcode
allocated address.  Manual says it is less portable, but without
MAP_FIXED I was unable to get proper address for 64bits.
I checked what test fails without fix of memcpy-sse2-unaligned
implementation.  Is it Ok for trunk?

diff --git a/string/test-memmove.c b/string/test-memmove.c
index edc7a4c..5920652 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 +246,57 @@ do_random_tests (void)
     }
 }

+#if __SIZEOF_POINTER__ == 4
+# define ptr_type uint32_t
+#else
+# define ptr_type uint64_t
+#endif
+
+static void
+do_test2 (void)
+{
+  uint32_t num = 0x20000000;
+  uint32_t * large_buf;
+
+  large_buf = mmap ((void*)0x70000000, num, PROT_READ | PROT_WRITE,
+     MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
+
+  if (large_buf == MAP_FAILED)
+    error (EXIT_FAILURE, errno, "Large mmap failed");
+
+  uint32_t bytes_move = 0x80000000 - (ptr_type)large_buf;
+  uint32_t arr_size = bytes_move / sizeof(uint32_t);
+  uint32_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, sizeof(uint32_t) * num);
+}
+
 int
 test_main (void)
 {
@@ -284,6 +336,9 @@ test_main (void)
     }

   do_random_tests ();
+
+  do_test2 ();
+
   return ret;
 }

diff --git a/sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S
b/sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S
index 9c3bbe7..9aa17de 100644
--- a/sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S
+++ b/sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S
@@ -72,7 +72,7 @@ ENTRY (MEMCPY)
  cmp %edx, %eax

 # ifdef USE_AS_MEMMOVE
- jg L(check_forward)
+ ja L(check_forward)

 L(mm_len_0_or_more_backward):
 /* Now do checks for lengths. We do [0..16], [16..32], [32..64], [64..128]
@@ -81,7 +81,7 @@ L(mm_len_0_or_more_backward):
  jbe L(mm_len_0_16_bytes_backward)

  cmpl $32, %ecx
- jg L(mm_len_32_or_more_backward)
+ ja L(mm_len_32_or_more_backward)

 /* Copy [0..32] and return.  */
  movdqu (%eax), %xmm0
@@ -92,7 +92,7 @@ L(mm_len_0_or_more_backward):

 L(mm_len_32_or_more_backward):
  cmpl $64, %ecx
- jg L(mm_len_64_or_more_backward)
+ ja L(mm_len_64_or_more_backward)

 /* Copy [0..64] and return.  */
  movdqu (%eax), %xmm0
@@ -107,7 +107,7 @@ L(mm_len_32_or_more_backward):

 L(mm_len_64_or_more_backward):
  cmpl $128, %ecx
- jg L(mm_len_128_or_more_backward)
+ ja L(mm_len_128_or_more_backward)

 /* Copy [0..128] and return.  */
  movdqu (%eax), %xmm0
@@ -132,7 +132,7 @@ L(mm_len_128_or_more_backward):
  add %ecx, %eax
  cmp %edx, %eax
  movl SRC(%esp), %eax
- jle L(forward)
+ jbe L(forward)
  PUSH (%esi)
  PUSH (%edi)
  PUSH (%ebx)
@@ -269,7 +269,7 @@ L(check_forward):
  add %edx, %ecx
  cmp %eax, %ecx
  movl LEN(%esp), %ecx
- jle L(forward)
+ jbe L(forward)

 /* Now do checks for lengths. We do [0..16], [0..32], [0..64], [0..128]
  separately.  */


--
WBR,
Andrew