[PATCH 3/4] s390: Do not emit orphaned GOT entry for TLS IE to LE transition
Jens Remus
jremus@linux.ibm.com
Thu Nov 13 13:21:11 GMT 2025
Commit 69fc87f180bf introduced TLS support for s390 32-bit and 64-bit.
It defined GOT_TLS_IE_NLT in both elf32-s390.c and elf64-s390.c, but
erroneously assigned it the same value as GOT_TLS_IE in elf64-s390.c.
As a consequence the linker for s390 64-bit erroneously emitted an
orphaned GOT entry when performing TLS Initial Exec (IE) to Local
Exec (LE) transition optimization.
Correct the value of GOT_TLS_IE_NLT in elf64-s390.c. This causes the
liker to actually optimize away the GOT entry when performing IE to LE
transition. While at it add a comment that the suffix NLT denotes
"no literal (pool entry)".
Found while inspecting and cleaning up differences between elf32-s390.c
and elf64-s390.c.
bfd/
* elf32-s390.c (GOT_TLS_IE_NLT): Add comment that NLT denotes
no literal pool entry.
* elf64-s390.c (GOT_TLS_IE_NLT): Likewise. Correct value.
ld/testsuite/
* ld-s390/tlsbin_64.dd: Adjust expected test results.
* ld-s390/tlsbin_64.sd: Likewise.
Fixes: 69fc87f180bf
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
bfd/elf32-s390.c | 2 +-
bfd/elf64-s390.c | 2 +-
ld/testsuite/ld-s390/tlsbin_64.dd | 16 ++++++++--------
ld/testsuite/ld-s390/tlsbin_64.sd | 4 +---
4 files changed, 11 insertions(+), 13 deletions(-)
diff --git a/bfd/elf32-s390.c b/bfd/elf32-s390.c
index 52aad070d441..ea5368ea9ddb 100644
--- a/bfd/elf32-s390.c
+++ b/bfd/elf32-s390.c
@@ -661,7 +661,7 @@ struct elf_s390_link_hash_entry
#define GOT_NORMAL 1
#define GOT_TLS_GD 2
#define GOT_TLS_IE 3
-#define GOT_TLS_IE_NLT 4
+#define GOT_TLS_IE_NLT 4 /* Initial Exec, no literal pool entry. */
unsigned char tls_type;
/* For pointer equality reasons we might need to change the symbol
diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c
index f5a80e73f113..9242407b1b5d 100644
--- a/bfd/elf64-s390.c
+++ b/bfd/elf64-s390.c
@@ -653,7 +653,7 @@ struct elf_s390_link_hash_entry
#define GOT_NORMAL 1
#define GOT_TLS_GD 2
#define GOT_TLS_IE 3
-#define GOT_TLS_IE_NLT 3
+#define GOT_TLS_IE_NLT 4 /* Initial Exec, no literal pool entry. */
unsigned char tls_type;
/* For pointer equality reasons we might need to change the symbol
diff --git a/ld/testsuite/ld-s390/tlsbin_64.dd b/ld/testsuite/ld-s390/tlsbin_64.dd
index d2aa851af46a..124c268b5646 100644
--- a/ld/testsuite/ld-s390/tlsbin_64.dd
+++ b/ld/testsuite/ld-s390/tlsbin_64.dd
@@ -24,10 +24,10 @@ Disassembly of section .text:
+[0-9a-f]+: a7 d5 00 3e bras %r13,[0-9a-f]+ <fn2\+0x82>
# sG1@tlsgd
+[0-9a-f]+: 00 00 00 00 .long 0x00000000
- +[0-9a-f]+: 00 00 00 60 .long 0x00000060
+ +[0-9a-f]+: 00 00 00 50 .long 0x00000050
# sG2@tlsgd
+[0-9a-f]+: 00 00 00 00 .long 0x00000000
- +[0-9a-f]+: 00 00 00 48 .long 0x00000048
+ +[0-9a-f]+: 00 00 00 40 .long 0x00000040
# sg1@tlsgd
+[0-9a-f]+: ff ff ff ff .long 0xffffffff
+[0-9a-f]+: ff ff ff 60 .long 0xffffff60
@@ -57,7 +57,7 @@ Disassembly of section .text:
+[0-9a-f]+: ff ff ff a4 .long 0xffffffa4
# sG2@gotntpoff
+[0-9a-f]+: 00 00 00 00 .long 0x00000000
- +[0-9a-f]+: 00 00 00 48 .long 0x00000048
+ +[0-9a-f]+: 00 00 00 40 .long 0x00000040
# sg1@gotntpoff
+[0-9a-f]+: ff ff ff ff .long 0xffffffff
+[0-9a-f]+: ff ff ff 60 .long 0xffffff60
@@ -133,7 +133,7 @@ Disassembly of section .text:
+[0-9a-f]+: e3 33 c0 00 00 04 lg %r3,0\(%r3,%r12\)
+[0-9a-f]+: 41 33 90 00 la %r3,0\(%r3,%r9\)
# IE against global var defined in exec with larl got access
- +[0-9a-f]+: c0 30 [0-9a-f ]+ larl %r3,[0-9a-f]+ <_GLOBAL_OFFSET_TABLE_\+0x38>
+ +[0-9a-f]+: c0 30 [0-9a-f ]+ larl %r3,[0-9a-f]+ <_GLOBAL_OFFSET_TABLE_\+0x30>
+[0-9a-f]+: eb 43 00 00 00 0d sllg %r4,%r3,0
+[0-9a-f]+: 41 54 90 00 la %r5,0\(%r4,%r9\)
# IE against local var with larl got access
@@ -141,7 +141,7 @@ Disassembly of section .text:
+[0-9a-f]+: eb 43 00 00 00 0d sllg %r4,%r3,0
+[0-9a-f]+: 41 54 90 00 la %r5,0\(%r4,%r9\)
# IE against hidden var with larl got access
- +[0-9a-f]+: c0 30 [0-9a-f ]+ larl %r3,[0-9a-f]+ <_GLOBAL_OFFSET_TABLE_\+0x40>
+ +[0-9a-f]+: c0 30 [0-9a-f ]+ larl %r3,[0-9a-f]+ <_GLOBAL_OFFSET_TABLE_\+0x38>
+[0-9a-f]+: eb 43 00 00 00 0d sllg %r4,%r3,0
+[0-9a-f]+: 41 54 90 00 la %r5,0\(%r4,%r9\)
# IE against global var with small got access (no optimization)
@@ -149,13 +149,13 @@ Disassembly of section .text:
+[0-9a-f]+: 41 33 90 00 la %r3,0\(%r3,%r9\)
# IE against global var defined in exec with small got access
# (no optimization)
- +[0-9a-f]+: e3 30 c0 38 00 04 lg %r3,56\(%r12\)
+ +[0-9a-f]+: e3 30 c0 30 00 04 lg %r3,48\(%r12\)
+[0-9a-f]+: 41 33 90 00 la %r3,0\(%r3,%r9\)
# IE against local var with small got access (no optimization)
+[0-9a-f]+: e3 30 c0 20 00 04 lg %r3,32\(%r12\)
+[0-9a-f]+: 41 33 90 00 la %r3,0\(%r3,%r9\)
# IE against hidden var with small got access (no optimization)
- +[0-9a-f]+: e3 30 c0 40 00 04 lg %r3,64\(%r12\)
+ +[0-9a-f]+: e3 30 c0 38 00 04 lg %r3,56\(%r12\)
+[0-9a-f]+: 41 33 90 00 la %r3,0\(%r3,%r9\)
# function epilog
+[0-9a-f]+: eb 6e f0 d0 00 04 lmg %r6,%r14,208\(%r15\)
@@ -177,7 +177,7 @@ Disassembly of section .text:
+[0-9a-f]+: a7 d5 00 16 bras %r13,[0-9a-f]+ <_start\+0x30>
# sG6@indntpoff
+[0-9a-f]+: 00 00 00 00 .long 0x00000000
- +[0-9a-f]+: 01 00 18 18 .long 0x01001818
+ +[0-9a-f]+: 01 00 18 08 .long 0x01001808
# bg6@indntpoff
+[0-9a-f]+: ff ff ff ff .long 0xffffffff
+[0-9a-f]+: ff ff ff d4 .long 0xffffffd4
diff --git a/ld/testsuite/ld-s390/tlsbin_64.sd b/ld/testsuite/ld-s390/tlsbin_64.sd
index 6618e455d731..d4309231557a 100644
--- a/ld/testsuite/ld-s390/tlsbin_64.sd
+++ b/ld/testsuite/ld-s390/tlsbin_64.sd
@@ -11,8 +11,6 @@ Contents of section .got:
[0-9a-f]+ [0-9a-f]+ [0-9a-f]+ 00000000 00000000 .*
[0-9a-f]+ 00000000 00000000 [0-9a-f]+ [0-9a-f]+ .*
[0-9a-f]+ ffffffff ffffff88 00000000 00000000 .*
- [0-9a-f]+ 00000000 00000000 ffffffff ffffff68 .*
- [0-9a-f]+ ffffffff ffffffa8 00000000 00000000 .*
- [0-9a-f]+ 00000000 00000000 00000000 00000000 .*
+ [0-9a-f]+ ffffffff ffffff68 ffffffff ffffffa8 .*
[0-9a-f]+ 00000000 00000000 00000000 00000000 .*
[0-9a-f]+ 00000000 00000000 .*
--
2.48.1
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