Bug 101837

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Description of problem:
When lstat is called from a routine in a shared library, the following error is
generated when a binary linked against the shared library is executed:

<binary>: relocation error: <shared library>: undefined symbol: lstat

This also holds true for lstat64, fstat, and fstat64.

This appears to be a problem with the glibc headers, because in sys/stat.h,
lstat is #defined to translate to __lxstat.  lstat is not a symbol in libc,
where __lxstat is.  For some reason, the define is not being applied properly
and lstat remains unresolved.

As a work-around, the #define from sys/stat.h can be removed and inserted at the
top of the shared library source file which calls lstat, and everything works
correctly (see below).

Version-Release number of selected component (if applicable):
glibc-2.3.2-4.80.6

How reproducible:
Always

Steps to Reproduce:
Can be reproduced by building the following source code:

==== main.c ====

#include <stdio.h>

int size(char *);

int main(int argc, char **argv)
{
    int s;

    s = size(argv[1]);
    fprintf(stdout, "Size of %s is %d\n", argv[1], s);

    return 0;
}

==== size.c ====

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int size(char *file)
{
    struct stat sbuf;

    if (lstat(file, &sbuf) < 0)
    {
        perror("lstat");
        return 0;
    }

    fprintf(stdout, "File size: %d\n",sbuf.st_size);
    return sbuf.st_size;
}

Then:

% gcc -c -o size.o size.c
% ld -G -o libsize.so size.o
% gcc -L. -lsize -o main main.c
% export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:.
% ./main main.c

Actual Results:  Received the relocation error:

./main: relocation error: ./libsize.so: undefined symbol: lstat


Expected Results:  The binary should have executed without the relocation error.

Additional info:

There is a work-around for this, though it is somewhat awkward.  Modifying the
size.c file to include the #define from sys/stat.h corrects the problem:

==== size.c ====
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

static __inline__ int lstat (__const char *__path,
                                     struct stat *__statbuf) __THROW
{
      return __lxstat (_STAT_VER, __path, __statbuf);
}

int size(char *file)
{
    struct stat sbuf;

    if (lstat(file, &sbuf) < 0)
    {
        perror("lstat");
        return 0;
    }

    fprintf(stdout, "File size: %d\n",sbuf.st_size);
    return sbuf.st_size;
}

Rebuild using the steps above, and everything works correctly.