[petsc-users] valgrind error messages with PETSc V3.5.1

[Barry Smith]

   Randall,

    If you replace the PetscStrncpy(b,a,n+1);  with PetscStrncpy(b,a,n); 

#define FIXCHAR(a,n,b) \
{\
  if (a == PETSC_NULL_CHARACTER_Fortran) { \
    b = a = 0; \
  } else { \
    while((n > 0) && (a[n-1] == ' ')) n--; \
    *ierr = PetscMalloc((n+1)*sizeof(char),&b); \
    if (*ierr) return; \
    *ierr = PetscStrncpy(b,a,n+1); \
    if (*ierr) return; \
    b[n] = 0; \
  } \
}

in include/petsc-private/fortranimpl.h and recompile the PETSc libraries does the problem go away?  

Let me know and I’ll fix the code.

   Thanks

   Barry



On Aug 2, 2014, at 2:20 PM, Randall Mackie <rlmackie862 at gmail.com> wrote:

> The attached small program, basically a call to PetscPrintf, gives the following valgrind errors:
> 
> [rmackie ~/tst_petsc_problem] ./cmd_test
> ==24812== Invalid read of size 1
> ==24812==    at 0x4C2E500: __GI_strncpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==24812==    by 0x4EF5B4D: PetscStrncpy (str.c:335)
> ==24812==    by 0x4F334E0: petscprintf_ (zmprintf.c:54)
> ==24812==    by 0x400F28: MAIN__ (test.F90:11)
> ==24812==    by 0x400F9A: main (test.F90:16)
> ==24812==  Address 0x8cef9bb is 0 bytes after a block of size 11 alloc'd
> ==24812==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==24812==    by 0x6828BB4: ??? (in /usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
> ==24812==    by 0x68FBC97: _gfortran_string_trim (in /usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
> ==24812==    by 0x400EFD: MAIN__ (test.F90:11)
> ==24812==    by 0x400F9A: main (test.F90:16)
> ==24812== 
> 
> 
> The program was compiled with PETSc V3.5.1 and --download-mpich.
> 
> The same program compiled with V3.4.4 and --download-mpich does not give these errors.
> 
> It seems like an innocuous error, and I can certainly create a suppression file for it, but I thought I'd report it anyway.
> I get the same error on 2 different systems and I've tried 3 different gfortran versions, all with the same result.
> 
> Program, configure commands, etc, attached.
> 
> Randy M.
> 
> 
> <makefile><test.F90><valgrind_out.txt><cmd_configure><cmd_test>