[Pvfs2-developers] double memory free problem

[Sam Lang]

Hagai,

This looks like a bug when using the system interfaces directly.  Can  
you try the attached patch?

Thanks,

-sam

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On Oct 22, 2007, at 4:29 AM, Hagai Avrahami wrote:

>
>
> Hi
>
> Maybe someone can help me with the following problem
>
> I have met double free problem described in valgrind log
>
> 1.
> ==18442== Invalid free() / delete / delete[]
> ==18442== at 0x401CFCF: free (vg_replace_malloc.c:235)
> ==18442== by 0x81E983A: PINT_copy_object_attr (pint-util.c:208)
> ==18442== by 0x81B26E5: getattr_object_getattr_comp_fn (sys- 
> etattr.sm:535)
> ==18442== by 0x81E8B56: msgpairarray_completion_fn (msgpairarray.sm: 
> 554)
> ==18442== by 0x81B032B: PINT_state_machine_next (state-machine- 
> fns.h:158)
> ==18442== by 0x81B1196: PINT_client_state_machine_testsome
> (client-state-machine.c:744)
> ==18442== by 0x81B154C: PVFS_sys_testsome (client-state-machine.c:934)
>
> 2.
> ==18442==  Address 0x47421C0 is 0 bytes inside a block of size 32  
> free'd
> ==18442==    at 0x401CFCF: free (vg_replace_malloc.c:235)
> ==18442==    by 0x81E9A33: PINT_free_object_attr (pint-util.c:283)
> ==18442==    by 0x81B234B: getattr_acache_lookup (sys-getattr.sm:447)
> ==18442==    by 0x81B032B: PINT_state_machine_next (state-machine- 
> fns.h:158)
> ==18442==    by 0x81B0052: PINT_client_state_machine_post
> (client-state-machine.c:369)
> ==18442==    by 0x81BA519: PVFS_isys_io (sys-io.sm:329)
>
>
> ///////////////////////////////////////////////
> I got this double free case after using:
>  PVFS_isys_getattr with mask =(PVFS_ATTR_SYS_ALL_NOHINT &
> (~PVFS_ATTR_SYS_SIZE))
>
> And after that, trying to read data using
> PVFS_isys_io
>
> ///////////////////////////////////////////////
>
> After some debugging I can see that after calling free(X) there are  
> places
> There is assignment of X to NULL and in some cases not
>
> After Adding this lines to pvfs2-types.h
>
> #define free(x) free(x); \
>                 x = NULL
> The problem solved
>
> Do you think it's OK to Add this lines?
>
> Thanx for your help
> Hagai
>
>
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