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[committed 1/2] PR ld/22570: MIPS/BFD: Fix TLS relocation resolution for PIE executables
- From: "Maciej W. Rozycki" <macro at mips dot com>
- To: Nick Clifton <nickc at redhat dot com>, Rich Felker <bugdal at aerifal dot cx>
- Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, <binutils at sourceware dot org>
- Date: Wed, 11 Jul 2018 17:48:21 +0100
- Subject: [committed 1/2] PR ld/22570: MIPS/BFD: Fix TLS relocation resolution for PIE executables
- References: <alpine.DEB.2.00.1807111604390.30992@tp.orcam.me.uk>
Correct a commit 0e1862bb401f ("Add output_type to bfd_link_info") issue
and use `bfd_link_dll' rather than `bfd_link_pic' in determining whether
to fully resolve GD, LD and IE TLS relocations referring to symbols
locally defined rather than deferring them to the load time by means of
dynamic relocations.
Such symbols cannot be preempted in PIE executables, which are
necessarily PIC, and therefore their values (thread pointer offsets) are
fixed at the static link time as is the associated module ID of the main
executable.
Given the `tlsbin-o32.s' and `tlsdyn-o32.s' sources from our test suite
this removes the absolute TLS relocations from the static:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
1000002c R_MIPS_TLS_TPREL32 *ABS*
10000030 R_MIPS_TLS_DTPMOD32 *ABS*
10000038 R_MIPS_TLS_DTPMOD32 *ABS*
and the dynamic:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
1000002c R_MIPS_TLS_TPREL32 *ABS*
10000038 R_MIPS_TLS_DTPMOD32 *ABS*
10000044 R_MIPS_TLS_DTPMOD32 *ABS*
10000030 R_MIPS_TLS_DTPMOD32 tlsvar_gd
10000034 R_MIPS_TLS_DTPREL32 tlsvar_gd
10000040 R_MIPS_TLS_TPREL32 tlsvar_ie
PIE executable respectively, as reported by `objdump -R', and fills the
corresponding GOT slots with the values expected, as recorded with the
test cases added. The new output from `objdump -R' is:
DYNAMIC RELOCATION RECORDS (none)
and:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
10000030 R_MIPS_TLS_DTPMOD32 tlsvar_gd
10000034 R_MIPS_TLS_DTPREL32 tlsvar_gd
10000040 R_MIPS_TLS_TPREL32 tlsvar_ie
for the static and the dynamic executable respectively.
2018-07-11 Maciej W. Rozycki <macro@mips.com>
Rich Felker <bugdal@aerifal.cx>
bfd/
PR ld/22570
* elfxx-mips.c (mips_tls_got_relocs): Use `bfd_link_dll' rather
than `bfd_link_pic' to determine whether dynamic relocations are
to be produced.
(mips_elf_initialize_tls_slots): Likewise.
ld/
PR ld/22570
* testsuite/ld-mips-elf/tlsbin-pie-o32.d: New test.
* testsuite/ld-mips-elf/tlsbin-pie-o32.got: New test.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.d: New test.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.got: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
---
bfd/elfxx-mips.c | 8 ++--
ld/testsuite/ld-mips-elf/mips-elf.exp | 12 ++++++
ld/testsuite/ld-mips-elf/tlsbin-pie-o32.d | 43 ++++++++++++++++++++++
ld/testsuite/ld-mips-elf/tlsbin-pie-o32.got | 7 +++
ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.d | 53 ++++++++++++++++++++++++++++
ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.got | 13 ++++++
6 files changed, 132 insertions(+), 4 deletions(-)
binutils-mips-bfd-tls-pie.diff
Index: binutils/bfd/elfxx-mips.c
===================================================================
--- binutils.orig/bfd/elfxx-mips.c 2018-07-10 23:25:24.732506008 +0100
+++ binutils/bfd/elfxx-mips.c 2018-07-11 15:44:53.362014462 +0100
@@ -3255,7 +3255,7 @@ mips_tls_got_relocs (struct bfd_link_inf
&& (!bfd_link_pic (info) || !SYMBOL_REFERENCES_LOCAL (info, h)))
indx = h->dynindx;
- if ((bfd_link_pic (info) || indx != 0)
+ if ((bfd_link_dll (info) || indx != 0)
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak))
@@ -3273,7 +3273,7 @@ mips_tls_got_relocs (struct bfd_link_inf
return 1;
case GOT_TLS_LDM:
- return bfd_link_pic (info) ? 1 : 0;
+ return bfd_link_dll (info) ? 1 : 0;
default:
return 0;
@@ -3367,7 +3367,7 @@ mips_elf_initialize_tls_slots (bfd *abfd
if (entry->tls_initialized)
return;
- if ((bfd_link_pic (info) || indx != 0)
+ if ((bfd_link_dll (info) || indx != 0)
&& (h == NULL
|| ELF_ST_VISIBILITY (h->root.other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak))
@@ -3442,7 +3442,7 @@ mips_elf_initialize_tls_slots (bfd *abfd
sgot->contents + got_offset
+ MIPS_ELF_GOT_SIZE (abfd));
- if (!bfd_link_pic (info))
+ if (!bfd_link_dll (info))
MIPS_ELF_PUT_WORD (abfd, 1,
sgot->contents + got_offset);
else
Index: binutils/ld/testsuite/ld-mips-elf/mips-elf.exp
===================================================================
--- binutils.orig/ld/testsuite/ld-mips-elf/mips-elf.exp 2018-07-11 15:44:12.652237783 +0100
+++ binutils/ld/testsuite/ld-mips-elf/mips-elf.exp 2018-07-11 15:45:07.470738328 +0100
@@ -863,6 +863,12 @@ set mips_tls_tests {
"-EB -march=mips1 -32 -KPIC" {tlsbin-o32.s}
{{objdump {-dr -m mips:isa32r2} tlsbin-o32.d} {objdump -srj.got tlsbin-o32.got}}
"tls-static-o32"}
+ {"Static PIE executable with TLS"
+ "-static -pie -melf32btsmip -T mips-dyn.ld" ""
+ "-EB -march=mips1 -32 -KPIC" {tlsbin-o32.s}
+ {{objdump {-dr -m mips:isa32r2} tlsbin-pie-o32.d}
+ {objdump -Rsj.got tlsbin-pie-o32.got}}
+ "tls-static-pie-o32"}
{"Shared library with TLS" "-shared -melf32btsmip -T mips-lib.ld" ""
"-EB -march=mips1 -32 -KPIC" {tlslib-o32.s}
{{objdump {-dr -m mips:isa32r2} tlslib-o32.d} {objdump -Rsj.got tlslib-o32.got}}
@@ -872,6 +878,12 @@ set mips_tls_tests {
"-EB -march=mips1 -32 -KPIC" {tlsdyn-o32.s}
{{objdump {-dr -m mips:isa32r2} tlsdyn-o32.d} {objdump -Rsj.got tlsdyn-o32.got}}
"tls-dynamic-o32"}
+ {"Dynamic PIE executable with TLS"
+ "-pie -melf32btsmip -T mips-dyn.ld tmpdir/tlslib-o32.so" ""
+ "-EB -march=mips1 -32 -KPIC" {tlsdyn-o32.s}
+ {{objdump {-dr -m mips:isa32r2} tlsdyn-pie-o32.d}
+ {objdump -Rsj.got tlsdyn-pie-o32.got}}
+ "tls-dynamic-pie-o32"}
{"Shared library with multiple GOTs and TLS"
"-shared -melf32btsmip -T mips-lib.ld" ""
"-EB -march=mips1 -32 -KPIC" {tls-multi-got-1-1.s tls-multi-got-1-2.s}
Index: binutils/ld/testsuite/ld-mips-elf/tlsbin-pie-o32.d
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/tlsbin-pie-o32.d 2018-07-11 15:45:07.487580566 +0100
@@ -0,0 +1,43 @@
+.*: file format elf32-tradbigmips
+
+Disassembly of section \.text:
+
+.* <__start>:
+ .*: 3c1c0fc0 lui gp,0xfc0
+ .*: 279c7d20 addiu gp,gp,32032
+ .*: 0399e021 addu gp,gp,t9
+ .*: 27bdfff0 addiu sp,sp,-16
+ .*: afbe0008 sw s8,8\(sp\)
+ .*: 03a0f025 move s8,sp
+ .*: afbc0000 sw gp,0\(sp\)
+ .*: 8f998018 lw t9,-32744\(gp\)
+ .*: 27848020 addiu a0,gp,-32736
+ .*: 0320f809 jalr t9
+ .*: 00000000 nop
+ .*: 8fdc0000 lw gp,0\(s8\)
+ .*: 00000000 nop
+ .*: 8f998018 lw t9,-32744\(gp\)
+ .*: 27848028 addiu a0,gp,-32728
+ .*: 0320f809 jalr t9
+ .*: 00000000 nop
+ .*: 8fdc0000 lw gp,0\(s8\)
+ .*: 00401025 move v0,v0
+ .*: 3c030000 lui v1,0x0
+ .*: 24638000 addiu v1,v1,-32768
+ .*: 00621821 addu v1,v1,v0
+ .*: 7c02283b rdhwr v0,\$5
+ .*: 8f83801c lw v1,-32740\(gp\)
+ .*: 00000000 nop
+ .*: 00621821 addu v1,v1,v0
+ .*: 7c02283b rdhwr v0,\$5
+ .*: 3c030000 lui v1,0x0
+ .*: 24639004 addiu v1,v1,-28668
+ .*: 00621821 addu v1,v1,v0
+ .*: 03c0e825 move sp,s8
+ .*: 8fbe0008 lw s8,8\(sp\)
+ .*: 03e00008 jr ra
+ .*: 27bd0010 addiu sp,sp,16
+
+.* <__tls_get_addr>:
+ .*: 03e00008 jr ra
+ .*: 00000000 nop
Index: binutils/ld/testsuite/ld-mips-elf/tlsbin-pie-o32.got
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/tlsbin-pie-o32.got 2018-07-11 15:45:07.501216486 +0100
@@ -0,0 +1,7 @@
+.*: file format elf32-tradbigmips
+
+DYNAMIC RELOCATION RECORDS \(none\)
+
+Contents of section \.got:
+ 10000020 00000000 80000000 00400378 ffff900c .*
+ 10000030 00000001 ffff8008 00000001 00000000 .*
Index: binutils/ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.d
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.d 2018-07-11 15:45:07.562969452 +0100
@@ -0,0 +1,53 @@
+.*: file format elf32-tradbigmips
+
+Disassembly of section \.text:
+
+.* <__start>:
+ .*: 3c1c0fc0 lui gp,0xfc0
+ .*: 279c7bd0 addiu gp,gp,31696
+ .*: 0399e021 addu gp,gp,t9
+ .*: 27bdfff0 addiu sp,sp,-16
+ .*: afbe0008 sw s8,8\(sp\)
+ .*: 03a0f025 move s8,sp
+ .*: afbc0000 sw gp,0\(sp\)
+ .*: 8f998018 lw t9,-32744\(gp\)
+ .*: 27848034 addiu a0,gp,-32716
+ .*: 0320f809 jalr t9
+ .*: 00000000 nop
+ .*: 8fdc0000 lw gp,0\(s8\)
+ .*: 00000000 nop
+ .*: 8f998018 lw t9,-32744\(gp\)
+ .*: 27848020 addiu a0,gp,-32736
+ .*: 0320f809 jalr t9
+ .*: 00000000 nop
+ .*: 8fdc0000 lw gp,0\(s8\)
+ .*: 00000000 nop
+ .*: 8f998018 lw t9,-32744\(gp\)
+ .*: 27848028 addiu a0,gp,-32728
+ .*: 0320f809 jalr t9
+ .*: 00000000 nop
+ .*: 8fdc0000 lw gp,0\(s8\)
+ .*: 00401025 move v0,v0
+ .*: 3c030000 lui v1,0x0
+ .*: 24638000 addiu v1,v1,-32768
+ .*: 00621821 addu v1,v1,v0
+ .*: 7c02283b rdhwr v0,\$5
+ .*: 8f83801c lw v1,-32740\(gp\)
+ .*: 00000000 nop
+ .*: 00621821 addu v1,v1,v0
+ .*: 8f838030 lw v1,-32720\(gp\)
+ .*: 00000000 nop
+ .*: 00621821 addu v1,v1,v0
+ .*: 7c02283b rdhwr v0,\$5
+ .*: 3c030000 lui v1,0x0
+ .*: 24639004 addiu v1,v1,-28668
+ .*: 00621821 addu v1,v1,v0
+ .*: 03c0e825 move sp,s8
+ .*: 8fbe0008 lw s8,8\(sp\)
+ .*: 03e00008 jr ra
+ .*: 27bd0010 addiu sp,sp,16
+
+.* <__tls_get_addr>:
+ .*: 03e00008 jr ra
+ .*: 00000000 nop
+ \.\.\.
Index: binutils/ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.got
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/tlsdyn-pie-o32.got 2018-07-11 15:45:07.624948877 +0100
@@ -0,0 +1,13 @@
+.*: file format elf32-tradbigmips
+
+DYNAMIC RELOCATION RECORDS
+OFFSET TYPE VALUE
+00000000 R_MIPS_NONE \*ABS\*
+10000030 R_MIPS_TLS_DTPMOD32 tlsvar_gd
+10000034 R_MIPS_TLS_DTPREL32 tlsvar_gd
+10000040 R_MIPS_TLS_TPREL32 tlsvar_ie
+
+Contents of section .got:
+ 10000020 00000000 80000000 004004ec ffff900c .*
+ 10000030 00000000 00000000 00000001 00000000 .*
+ 10000040 00000000 00000001 ffff8008 .*