[Bug gold/22844] New: Handling of R_X86_64_PC32 in a PIE against a function in a shared library could be better

[rafael.espindola at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=22844

            Bug ID: 22844
           Summary: Handling of R_X86_64_PC32 in a PIE against a function
                    in a shared library could be better
           Product: binutils
           Version: unspecified
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: gold
          Assignee: ccoutant at gmail dot com
          Reporter: rafael.espindola at gmail dot com
                CC: ian at airs dot com
  Target Milestone: ---

Created attachment 10817
  --> https://sourceware.org/bugzilla/attachment.cgi?id=10817&action=edit
testcase

The attached testcase has a shared library that defines a function foo with
default visibility. The function just prints its own address and argument:

void foo(void *bar) {
  printf("%p %p\n", bar, foo);
}

There is also a position independent executable that uses a R_X86_64_PC32 to
find the address of foo and call it with that value.

The expected result is to see the same value printed twice.

If we try to use gold it errors out when linking the executable:

error: test.o: requires dynamic R_X86_64_PC32 reloc against 'foo' which may
overflow at runtime; recompile with -fPIC

With ld.bfd after 1031c264fd23641111df1e12a35d0a8f7e82fb80 or ld.lld it works
since a canonical plt entry for foo is created in the main executable:

 6: 00000000000011f0     0 FUNC    GLOBAL DEFAULT  UND foo

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