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[COMMITTED][AArch64] Fix off by one error in instruction relaxation mask.
- From: Marcus Shawcroft <marcus dot shawcroft at arm dot com>
- To: "binutils at sourceware dot org" <binutils at sourceware dot org>
- Date: Tue, 15 Apr 2014 17:52:34 +0100
- Subject: [COMMITTED][AArch64] Fix off by one error in instruction relaxation mask.
- Authentication-results: sourceware.org; auth=none
Hi,
The AArch64 TLSDESC to IE relaxation code uses a bit mask intended to
ensure that destination register in a relaxed ldr instruction is
always X0. The mask has an off by one error resulting in the most
significant bit of the destination register being retained in the
relaxed instruction. The issue generally appears when the compiler
emits TLS accesses code under high register pressure resulting in a
broken code sequence.
Tested on aarch64-none-linux-gnu. Committed.
I'll back port to 2.24 shortly.
/Marcus
ld
2014-04-15 Marcus Shawcroft <marcus.shawcroft@arm.com>
* (elfNN_aarch64_tls_relax): Fix instruction mask.
ld/testsuite
2014-04-15 Marcus Shawcroft <marcus.shawcroft@arm.com>
* ld-aarch64/tls-relax-gdesc-ie.s (var): Adjust test case
to include all 5 bits of LDR destination register.diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 638938d..a251698 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -3957,7 +3957,7 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
ldr xd, [x0, #:tlsdesc_lo12:var] => ldr x0, [x0, #:gottprel_lo12:var]
*/
insn = bfd_getl32 (contents + rel->r_offset);
- insn &= 0xfffffff0;
+ insn &= 0xffffffe0;
bfd_putl32 (insn, contents + rel->r_offset);
return bfd_reloc_continue;
}
diff --git a/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s b/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
index c20690c..38b3721 100644
--- a/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
+++ b/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
@@ -4,7 +4,7 @@ var:
.word 2
.text
adrp x0, :tlsdesc:var
- ldr x1, [x0, #:tlsdesc_lo12:var]
+ ldr x17, [x0, #:tlsdesc_lo12:var]
add x0, x0, :tlsdesc_lo12:var
.tlsdesccall var
blr x1