[binutils-gdb] Fix PR 13402

[Senthil Kumar Selvaraj <saaadhu at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6806377956c76c23ae96a3844e29412ae117e07a

commit 6806377956c76c23ae96a3844e29412ae117e07a
Author: Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com>
Date:   Tue Jun 27 14:46:08 2017 +0530

    Fix PR 13402
    
    Fix incorrect adjustment of diff relocs when relaxing, and thus the
    resulting source line to address mismatch.
    
    Fix two issues when adjusting diff relocs to account for
    deleted bytes.
    
    1. Don't adjust the difference if the end address is the shrinked
    insn's address i.e. use < instead of <=. The relaxation code deletes
    count bytes from or after shrinked_insn_address, so the difference
    between start_address and end_address should remain unchanged in this
    case.
    
    2. Adjust the reloc addend if the difference is to be adjusted and
    symval + reloc addend is past the shrinked insn address. This is
    because for a typical sym1 - sym2 diff reloc, sym1 is .text +
    irel->r_addend, and the addend should be reduced to account for the
    shrinked insn.
    
    For example, assume the reloc value is .text + 0x8 with .text = 0, the
    diff value in the object file = 0x4, and shrinked_insn_address = 0x4
    with count = 0x2. Then the existing code writes 0x2 into the object
    file to account for the deleted bytes, as shrinked_insn_address lies
    between 0x8 and 0x8 - 0x4 = 0x4, but leaves the addend as is. The next
    time the reloc is looked at, the code sees if a shrinked_insn_address
    lies between 0x8 and 0x8 - 0x2 = 0x6, instead of 0x6 and 0x4. If there
    happens to be one, then the diff value in the object file ends up
    getting reduced again.
    
    bfd/
    
    2017-06-27  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
    
    	PR ld/13402
    	* elf32-avr.c (elf32_avr_adjust_diff_reloc_value): Adjust
    	reloc addend if necessary. Adjust diff only if
    	shrinked_insn_address < end_address.
    
    ld/
    
    2017-06-27  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
    
    	PR ld/13402
    	* testsuite/ld-avr/pr13402.d: New test.
    	* testsuite/ld-avr/pr13402.s: New test.

Diff:
---
 bfd/ChangeLog                 |  7 +++++++
 bfd/elf32-avr.c               |  5 ++++-
 ld/ChangeLog                  |  6 ++++++
 ld/testsuite/ld-avr/pr13402.d | 16 ++++++++++++++++
 ld/testsuite/ld-avr/pr13402.s |  9 +++++++++
 5 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 5f840a1..272da0c 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2017-06-27  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
+
+	PR ld/13402
+	* elf32-avr.c (elf32_avr_adjust_diff_reloc_value): Adjust
+	reloc addend if necessary. Adjust diff only if
+	shrinked_insn_address < end_address.
+
 2017-06-27  Alan Modra  <amodra@gmail.com>
 
 	PR binutils/21665
diff --git a/bfd/elf32-avr.c b/bfd/elf32-avr.c
index f140aa7..830da28 100644
--- a/bfd/elf32-avr.c
+++ b/bfd/elf32-avr.c
@@ -1785,12 +1785,15 @@ elf32_avr_adjust_diff_reloc_value (bfd *abfd,
 
 
   if (shrinked_insn_address >= start_address
-      && shrinked_insn_address <= end_address)
+      && shrinked_insn_address < end_address)
   {
     /* Reduce the diff value by count bytes and write it back into section
        contents. */
     bfd_signed_vma new_diff = x < 0 ? x + count : x - count;
 
+    if (sym2_address > shrinked_insn_address)
+      irel->r_addend -= count;
+
     switch (ELF32_R_TYPE (irel->r_info))
     {
     case R_AVR_DIFF8:
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 92d0003..fec44c9 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-27  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
+
+	PR ld/13402
+	* testsuite/ld-avr/pr13402.d: New test.
+	* testsuite/ld-avr/pr13402.s: New test.
+
 2017-06-27  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* testsuite/ld-mips-elf/mips-elf-flags.exp (good_combination):
diff --git a/ld/testsuite/ld-avr/pr13402.d b/ld/testsuite/ld-avr/pr13402.d
new file mode 100644
index 0000000..6663950
--- /dev/null
+++ b/ld/testsuite/ld-avr/pr13402.d
@@ -0,0 +1,16 @@
+#name: AVR fix broken sync between debug_line and code addresses
+#as: -mmcu=avrxmega2 -mlink-relax -gdwarf-2
+#ld:  -mavrxmega2 --relax
+#source: pr13402.s
+#objdump: -S
+#target: avr-*-*
+
+#...
+main:
+call a
+   0:	02 d0       	rcall	.+4      	; 0x6 <_etext>
+call b
+   2:	01 d0       	rcall	.+2      	; 0x6 <_etext>
+call c
+   4:	00 d0       	rcall	.+0      	; 0x6 <_etext>
+#...
diff --git a/ld/testsuite/ld-avr/pr13402.s b/ld/testsuite/ld-avr/pr13402.s
new file mode 100644
index 0000000..9539829
--- /dev/null
+++ b/ld/testsuite/ld-avr/pr13402.s
@@ -0,0 +1,9 @@
+.global main
+main:
+call a
+call b
+call c
+
+a:
+b:
+c: