[PATCH] xtensa: fix XTENSA_NDIFF handling for PR ld/25861
Max Filippov
jcmvbkbc@gmail.com
Sat Apr 25 19:40:11 GMT 2020
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.
2020-04-25 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.
ld/
* testsuite/ld-xtensa/relax-diff1.d: New test definition.
* testsuite/ld-xtensa/relax-diff1.s: New test source.
* testsuite/ld-xtensa/relax-ndiff.d: New test definition.
* testsuite/ld-xtensa/relax-ndiff.s: New test source.
* testsuite/ld-xtensa/xtensa.exp: (relax-diff1)
(relax-ndiff): New tests.
---
bfd/elf32-xtensa.c | 26 +++++++++++++++-----------
ld/testsuite/ld-xtensa/relax-diff1.d | 6 ++++++
ld/testsuite/ld-xtensa/relax-diff1.s | 18 ++++++++++++++++++
ld/testsuite/ld-xtensa/relax-ndiff.d | 6 ++++++
ld/testsuite/ld-xtensa/relax-ndiff.s | 20 ++++++++++++++++++++
ld/testsuite/ld-xtensa/xtensa.exp | 2 ++
6 files changed, 67 insertions(+), 11 deletions(-)
create mode 100644 ld/testsuite/ld-xtensa/relax-diff1.d
create mode 100644 ld/testsuite/ld-xtensa/relax-diff1.s
create mode 100644 ld/testsuite/ld-xtensa/relax-ndiff.d
create mode 100644 ld/testsuite/ld-xtensa/relax-ndiff.s
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"),
diff --git a/ld/testsuite/ld-xtensa/relax-diff1.d b/ld/testsuite/ld-xtensa/relax-diff1.d
new file mode 100644
index 000000000000..900b55bb9c8e
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/relax-diff1.d
@@ -0,0 +1,6 @@
+#as: --text-section-literals
+#ld:
+#objdump: -s
+#...
+ 410154 06fa0006 fffa.*
+#...
diff --git a/ld/testsuite/ld-xtensa/relax-diff1.s b/ld/testsuite/ld-xtensa/relax-diff1.s
new file mode 100644
index 000000000000..6cc8e2b9cef0
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/relax-diff1.s
@@ -0,0 +1,18 @@
+ .globl _start
+ .globl _ResetVector
+ .text
+_ResetVector:
+_start:
+ .literal_position
+ movi a2, 0x12345678
+ movi a2, 0x12345678
+1:
+ .space 250
+2:
+ .space 65530
+3:
+ .align 4
+ .byte 1b - 2b
+ .byte 2b - 1b
+ .short 2b - 3b
+ .short 3b - 2b
diff --git a/ld/testsuite/ld-xtensa/relax-ndiff.d b/ld/testsuite/ld-xtensa/relax-ndiff.d
new file mode 100644
index 000000000000..2a1cfd3fff3d
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/relax-ndiff.d
@@ -0,0 +1,6 @@
+#as: --text-section-literals
+#ld:
+#objdump: -s
+#...
+ 400074 fffffff6 0000000a fff6000a f60a.*
+#...
diff --git a/ld/testsuite/ld-xtensa/relax-ndiff.s b/ld/testsuite/ld-xtensa/relax-ndiff.s
new file mode 100644
index 000000000000..4e4176b129c2
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/relax-ndiff.s
@@ -0,0 +1,20 @@
+ .globl _start
+ .globl _ResetVector
+ .text
+_ResetVector:
+_start:
+ .literal_position
+ movi a2, 0x12345678
+ movi a2, 0x12345678
+1:
+ .space 10
+2:
+ .space 10
+3:
+ .align 4
+ .word 1b - 2b
+ .word 3b - 2b
+ .short 1b - 2b
+ .short 3b - 2b
+ .byte 1b - 2b
+ .byte 3b - 2b
diff --git a/ld/testsuite/ld-xtensa/xtensa.exp b/ld/testsuite/ld-xtensa/xtensa.exp
index de39887936ad..5334bc60df34 100644
--- a/ld/testsuite/ld-xtensa/xtensa.exp
+++ b/ld/testsuite/ld-xtensa/xtensa.exp
@@ -27,7 +27,9 @@ run_dump_test "call_overflow"
run_dump_test "coalesce"
run_dump_test "diff_overflow"
run_dump_test "lcall"
+run_dump_test "relax-diff1"
run_dump_test "relax-loc"
+run_dump_test "relax-ndiff"
run_dump_test "relax-static-pie"
run_dump_test "relax-static-local-pie"
--
2.20.1
More information about the Binutils
mailing list