| From 735321812435ae278d3766a3371f55937dc776d6 Mon Sep 17 00:00:00 2001 |
| From: Max Filippov <jcmvbkbc@gmail.com> |
| Date: Sat, 25 Apr 2020 00:40:25 -0700 |
| Subject: [PATCH] xtensa: fix XTENSA_NDIFF handling for PR ld/25861 |
| |
| Fields marked with XTENSA_NDIFF relocations are not negated, they only |
| have sign bits removed. Don't negate their values when relaxation is |
| performed. Don't add sign bits when the value is zero. Report overflow |
| when the result has negative sign but all significant bits are zero. |
| |
| 2020-04-29 Max Filippov <jcmvbkbc@gmail.com> |
| bfd/ |
| * elf32-xtensa.c (relax_section): Don't negate diff_value for |
| XTENSA_NDIFF relocations. Don't add sign bits whe diff_value |
| equals 0. Report overflow when the result has negative sign but |
| all significant bits are zero. |
| |
| Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> |
| Backported from: d548f47df4d2e3d117d504a4c9977982c78a0556 |
| --- |
| |
| bfd/elf32-xtensa.c | 26 +++++++++++++++----------- |
| 1 file changed, 15 insertions(+), 11 deletions(-) |
| |
| diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c |
| index fded42d52a9a..4327b027911f 100644 |
| --- a/bfd/elf32-xtensa.c |
| +++ b/bfd/elf32-xtensa.c |
| @@ -9670,37 +9670,44 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info) |
| switch (r_type) |
| { |
| case R_XTENSA_DIFF8: |
| + diff_mask = 0x7f; |
| diff_value = |
| bfd_get_signed_8 (abfd, &contents[old_source_offset]); |
| break; |
| case R_XTENSA_DIFF16: |
| + diff_mask = 0x7fff; |
| diff_value = |
| bfd_get_signed_16 (abfd, &contents[old_source_offset]); |
| break; |
| case R_XTENSA_DIFF32: |
| + diff_mask = 0x7fffffff; |
| diff_value = |
| bfd_get_signed_32 (abfd, &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF8: |
| case R_XTENSA_NDIFF8: |
| + diff_mask = 0xff; |
| diff_value = |
| bfd_get_8 (abfd, &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF16: |
| case R_XTENSA_NDIFF16: |
| + diff_mask = 0xffff; |
| diff_value = |
| bfd_get_16 (abfd, &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF32: |
| case R_XTENSA_NDIFF32: |
| + diff_mask = 0xffffffff; |
| diff_value = |
| bfd_get_32 (abfd, &contents[old_source_offset]); |
| break; |
| } |
| |
| if (r_type >= R_XTENSA_NDIFF8 |
| - && r_type <= R_XTENSA_NDIFF32) |
| - diff_value = -diff_value; |
| + && r_type <= R_XTENSA_NDIFF32 |
| + && diff_value) |
| + diff_value |= ~diff_mask; |
| |
| new_end_offset = offset_with_removed_text_map |
| (&target_relax_info->action_list, |
| @@ -9710,43 +9717,40 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info) |
| switch (r_type) |
| { |
| case R_XTENSA_DIFF8: |
| - diff_mask = 0x7f; |
| bfd_put_signed_8 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| case R_XTENSA_DIFF16: |
| - diff_mask = 0x7fff; |
| bfd_put_signed_16 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| case R_XTENSA_DIFF32: |
| - diff_mask = 0x7fffffff; |
| bfd_put_signed_32 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF8: |
| case R_XTENSA_NDIFF8: |
| - diff_mask = 0xff; |
| bfd_put_8 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF16: |
| case R_XTENSA_NDIFF16: |
| - diff_mask = 0xffff; |
| bfd_put_16 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| case R_XTENSA_PDIFF32: |
| case R_XTENSA_NDIFF32: |
| - diff_mask = 0xffffffff; |
| bfd_put_32 (abfd, diff_value, |
| &contents[old_source_offset]); |
| break; |
| } |
| |
| - /* Check for overflow. Sign bits must be all zeroes or all ones */ |
| - if ((diff_value & ~diff_mask) != 0 && |
| - (diff_value & ~diff_mask) != (-1 & ~diff_mask)) |
| + /* Check for overflow. Sign bits must be all zeroes or |
| + all ones. When sign bits are all ones diff_value |
| + may not be zero. */ |
| + if (((diff_value & ~diff_mask) != 0 |
| + && (diff_value & ~diff_mask) != ~diff_mask) |
| + || (diff_value && (bfd_vma) diff_value == ~diff_mask)) |
| { |
| (*link_info->callbacks->reloc_dangerous) |
| (link_info, _("overflow after relaxation"), |
| -- |
| 2.20.1 |
| |
