From 32ae0d80cd430150ad9536aa160f34f504e129bc Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Fri, 11 Apr 2014 16:02:52 +0100 Subject: [PATCH] PE32+ binaries that use addresses > 1^32 have a problem in that the linker converts some address expressions into absolute values, but the PE format only stores absolutes as 32-bits. This is a partial solution which attempts to convert such absolute values back to section relative ones instead. It fails for symbols like __image_base and ImageBase__, but it is unclear as to whether these values are ever actually used by applications. PR ld/16821 * peXXigen.c (abs_finder): New function. (_bfd_XXi_swap_sym_out): For absolute symbols with values larger than 1^32 try to convert them into section relative values instead. --- bfd/ChangeLog | 8 ++++++++ bfd/peXXigen.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 79d32c7..7621c6f 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,13 @@ 2014-04-11 Nick Clifton + PR ld/16821 + * peXXigen.c (abs_finder): New function. + (_bfd_XXi_swap_sym_out): For absolute symbols with values larger + than 1^32 try to convert them into section relative values + instead. + +2014-04-11 Nick Clifton + * bfd-in2.h: Regenerate. * libbfd.h: Regenerate. diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c index ea7846f..36d90cc 100644 --- a/bfd/peXXigen.c +++ b/bfd/peXXigen.c @@ -207,6 +207,14 @@ _bfd_XXi_swap_sym_in (bfd * abfd, void * ext1, void * in1) #endif } +static bfd_boolean +abs_finder (bfd * abfd ATTRIBUTE_UNUSED, asection * sec, void * data) +{ + bfd_vma abs_val = * (bfd_vma *) data; + + return (sec->vma <= abs_val) && ((sec->vma + (1L << 32)) > abs_val); +} + unsigned int _bfd_XXi_swap_sym_out (bfd * abfd, void * inp, void * extp) { @@ -221,6 +229,29 @@ _bfd_XXi_swap_sym_out (bfd * abfd, void * inp, void * extp) else memcpy (ext->e.e_name, in->_n._n_name, SYMNMLEN); + /* The PE32 and PE32+ formats only use 4 bytes to hold the value of a + symbol. This is a problem on 64-bit targets where we can generate + absolute symbols with values >= 1^32. We try to work around this + problem by finding a section whose base address is sufficient to + reduce the absolute value to < 1^32, and then transforming the + symbol into a section relative symbol. This of course is a hack. */ + if (sizeof (in->n_value) > 4 + && in->n_value > ((1L << 32) - 1) + && in->n_scnum == -1) + { + asection * sec; + + sec = bfd_sections_find_if (abfd, abs_finder, & in->n_value); + if (sec) + { + in->n_value -= sec->vma; + in->n_scnum = sec->target_index; + } + /* else: FIXME: The value is outside the range of any section. This + happens for __image_base__ and __ImageBase__ and maybe some other + symbols as well. We should find a way to handle these values. */ + } + H_PUT_32 (abfd, in->n_value, ext->e_value); H_PUT_16 (abfd, in->n_scnum, ext->e_scnum); -- 2.7.4