Re: [PATCH] Use size_t for mallinfo fields.

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 31/08/2020 11:00, H.J. Lu wrote:
> On Mon, Aug 31, 2020 at 6:57 AM Adhemerval Zanella via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
>>
>>
>>
>> On 31/08/2020 10:35, H.J. Lu via Libc-alpha wrote:
>>> On Fri, Aug 28, 2020 at 12:06 PM DJ Delorie via Libc-alpha
>>> <libc-alpha@sourceware.org> wrote:
>>>>
>>>> Martin Li¡ka <mliska@suse.cz> writes:
>>>>
>>>>> PING^1
>>>>
>>>> LGTM
>>>>
>>>> Reviewed-by: DJ Delorie <dj@redhat.com>
>>>>
>>>>> On 8/12/20 2:29 PM, Martin Liška wrote:
>>>>>> On 8/11/20 7:08 PM, DJ Delorie wrote:
>>>>>>> Florian Weimer <fw@deneb.enyo.de> writes:
>>>>>>>> DJ, what do you think about this patch?
>>>>>>>
>>>>>>> I have no real problems with the patch, but two minor things that could
>>>>>>> be handled in a follow-up patch...
>>>>>>
>>>>>> Thank you for the review.
>>>>>> Can I read it as ready to go into master?
>>>>>>
>>>>>>>
>>>>>>> 1. The copy code for the old function doesn't handle overflow.  We've
>>>>>>> Â Â Â  seen bug reports for this before so should consider the edge cases.
>>>>>>> Â Â Â  IMHO if a size_t value is larger than MAXINT, then MAXINT (or -1)
>>>>>>> Â Â Â  should be stored instead of a randomly truncated value.
>>>>>>>
>>>>>>> 2. The new documentation makes no mention of the older "compatible"
>>>>>>> Â Â Â  interface.
>>>>>>>
>>>>>>
>>>>>> Both comments are valid to me and I can address them in a follow-up patch.
>>>>>>
>>>>>> Martin
>>>>
>>>
>>> $ gcc ../sysdeps/x86_64/multiarch/test-multiarch.c -c -std=gnu11
>>> -fgnu89-inline  -O2 -g -Wall -Wwrite-strings -Wundef -Werror
>>> -fmerge-all-constants -frounding-math -fno-stack-protector
>>> -Wstrict-prototypes -Wold-style-definition -fmath-errno
>>> -fno-stack-protector -DSTACK_PROTECTOR_LEVEL=0         -I../include
>>> -I/export/build/gnu/tools-build/glibc/build-x86_64-linux/csu
>>> -I/export/build/gnu/tools-build/glibc/build-x86_64-linux
>>> -I../sysdeps/unix/sysv/linux/x86_64/64
>>> -I../sysdeps/unix/sysv/linux/x86_64
>>> -I../sysdeps/unix/sysv/linux/x86/include
>>> -I../sysdeps/unix/sysv/linux/x86  -I../sysdeps/x86/nptl
>>> -I../sysdeps/unix/sysv/linux/wordsize-64  -I../sysdeps/x86_64/nptl
>>> -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux
>>> -I../sysdeps/nptl  -I../sysdeps/pthread  -I../sysdeps/gnu
>>> -I../sysdeps/unix/inet  -I../sysdeps/unix/sysv
>>> -I../sysdeps/unix/x86_64  -I../sysdeps/unix  -I../sysdeps/posix
>>> -I../sysdeps/x86_64/64  -I../sysdeps/x86_64/fpu/multiarch
>>> -I../sysdeps/x86_64/fpu  -I../sysdeps/x86/fpu
>>> -I../sysdeps/x86_64/multiarch  -I../sysdeps/x86_64  -I../sysdeps/x86
>>> -I../sysdeps/ieee754/float128  -I../sysdeps/ieee754/ldbl-96/include
>>> -I../sysdeps/ieee754/ldbl-96  -I../sysdeps/ieee754/dbl-64/wordsize-64
>>> -I../sysdeps/ieee754/dbl-64  -I../sysdeps/ieee754/flt-32
>>> -I../sysdeps/wordsize-64  -I../sysdeps/ieee754  -I../sysdeps/generic
>>> -I.. -I../libio -I.   -D_LIBC_REENTRANT -include
>>> /export/build/gnu/tools-build/glibc/build-x86_64-linux/libc-modules.h
>>> -DMODULE_NAME=testsuite -include ../include/libc-symbols.h
>>> -DTOP_NAMESPACE=glibc -o
>>> /export/build/gnu/tools-build/glibc/build-x86_64-linux/csu/test-multiarch.o
>>> -MD -MP -MF /export/build/gnu/tools-build/glibc/build-x86_64-linux/csu/test-multiarch.o.dt
>>> -MT /export/build/gnu/tools-build/glibc/build-x86_64-linux/csu/test-multiarch.o
>>>
>>> In file included from ../include/malloc.h:3,
>>>                  from ../sysdeps/x86_64/multiarch/../../../test-skeleton.c:31,
>>>                  from ../sysdeps/x86_64/multiarch/test-multiarch.c:96:
>>> ../malloc/malloc.h:118:1: error: empty declaration [-Werror]
>>>   118 | __MALLOC_DEPRECATED;
>>>       | ^~~~~~~~~~~~~~~~~~~
>>> cc1: all warnings being treated as errors
>>>
>>
>> I hit this today as well, I think the straightforward fix is:
>>
>> diff --git a/malloc/malloc.h b/malloc/malloc.h
>> index e25b33462a..b2371f7704 100644
>> --- a/malloc/malloc.h
>> +++ b/malloc/malloc.h
>> @@ -115,8 +115,7 @@ struct mallinfo2
>>  };
>>
>>  /* Returns a copy of the updated current mallinfo. */
>> -__MALLOC_DEPRECATED;
>> -extern struct mallinfo mallinfo (void) __THROW;
>> +extern struct mallinfo mallinfo (void) __THROW __MALLOC_DEPRECATED;
>>
>>  /* Returns a copy of the updated current mallinfo. */
>>  extern struct mallinfo2 mallinfo2 (void) __THROW;
> 
> LGTM.

In fact we need to additionally handle on the tests to avoid the warning
errors.  The full patch is:

---

diff --git a/malloc/malloc.h b/malloc/malloc.h
index e25b33462a..b2371f7704 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -115,8 +115,7 @@ struct mallinfo2
 };
 
 /* Returns a copy of the updated current mallinfo. */
-__MALLOC_DEPRECATED;
-extern struct mallinfo mallinfo (void) __THROW;
+extern struct mallinfo mallinfo (void) __THROW __MALLOC_DEPRECATED;
 
 /* Returns a copy of the updated current mallinfo. */
 extern struct mallinfo2 mallinfo2 (void) __THROW;
diff --git a/malloc/tst-malloc-tcache-leak.c b/malloc/tst-malloc-tcache-leak.c
index f6f6023b5a..2a7a0646c5 100644
--- a/malloc/tst-malloc-tcache-leak.c
+++ b/malloc/tst-malloc-tcache-leak.c
@@ -29,6 +29,7 @@
 #include <malloc.h>
 #include <pthread.h>
 #include <assert.h>
+#include <libc-diag.h>
 
 #include <support/check.h>
 #include <support/support.h>
@@ -72,6 +73,10 @@ do_test (void)
      pthread_t required to run the test.  */
   thread = (pthread_t *) xcalloc (1, sizeof (pthread_t));
 
+  /* The test below covers the deprecated mallinfo function.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
   info_before = mallinfo ();
 
   assert (info_before.uordblks != 0);
@@ -104,6 +109,8 @@ do_test (void)
   if (info_after.uordblks > (info_before.uordblks + threads))
     FAIL_EXIT1 ("Memory usage after threads is too high.\n");
 
+  DIAG_POP_NEEDS_COMMENT;
+
   /* Did not detect excessive memory usage.  */
   free (thread);
   exit (0);
diff --git a/malloc/tst-mxfast.c b/malloc/tst-mxfast.c
index 57b4a0a8dc..8afee0f9d5 100644
--- a/malloc/tst-mxfast.c
+++ b/malloc/tst-mxfast.c
@@ -21,6 +21,7 @@
    the fast bins.  */
 
 #include <malloc.h>
+#include <libc-diag.h>
 #include <support/check.h>
 
 int
@@ -36,8 +37,14 @@ do_test (void)
   p2 = malloc (512);
   free (p1);
 
+  /* The test below covers the deprecated mallinfo function.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
   m = mallinfo ();
 
+  DIAG_POP_NEEDS_COMMENT;
+
   /* This will fail if there are any blocks in the fastbins.  */
   TEST_COMPARE (m.smblks, 0);