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authorAlan Modra <amodra@gmail.com>2015-03-25 15:53:47 +1030
committerAlan Modra <amodra@gmail.com>2015-03-25 15:53:47 +1030
commitafcd9480feca651eef436d8438b783dde5c3bbb2 (patch)
tree97bd1be08268c51e674154d3bf98af3a2256c6f8 /sysdeps
parentda9f3334106ee0f98c499c54bdfe3c4fcbb348f4 (diff)
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powerpc __tls_get_addr call optimization
This patch is glibc support for a PowerPC TLS optimization, inspired by Alexandre Oliva's TLS optimization for other processors, http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt In essence, this optimization uses a zero module id in the tls_index GOT entry to indicate that a TLS variable is allocated space in the static TLS area. A special plt call linker stub for __tls_get_addr checks for such a tls_index and if found, returns the offset immediately. The linker communicates the fact that the special __tls_get_addr stub is used by setting a bit in the dynamic tag DT_PPC64_OPT/DT_PPC_OPT. glibc communicates to the linker that this optimization is available by the presence of __tls_get_addr_opt. tst-tlsmod2.so is built with -Wl,--no-tls-get-addr-optimize for tst-tls-dlinfo, which otherwise would fail since it tests that no static tls is allocated. The ld option --no-tls-get-addr-optimize has been available since binutils-2.20 so doesn't need a configure test. * NEWS: Advertise TLS optimization. * elf/elf.h (R_PPC_TLSGD, R_PPC_TLSLD, DT_PPC_OPT, PPC_OPT_TLS): Define. (DT_PPC_NUM): Increment. * elf/dynamic-link.h (HAVE_STATIC_TLS): Define. (CHECK_STATIC_TLS): Use here. * sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela): Optimize TLS descriptors. * sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela): Likewise. * sysdeps/powerpc/dl-tls.c: New file. * sysdeps/powerpc/Versions: Add __tls_get_addr_opt. * sysdeps/powerpc/tst-tlsopt-powerpc.c: New tls test. * sysdeps/unix/sysv/linux/powerpc/Makefile: Add new test. Build tst-tlsmod2.so with --no-tls-get-addr-optimize. * sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist: Update. * sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist: Likewise.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/powerpc/Makefile3
-rw-r--r--sysdeps/powerpc/Versions6
-rw-r--r--sysdeps/powerpc/dl-tls.c24
-rw-r--r--sysdeps/powerpc/powerpc32/dl-machine.h48
-rw-r--r--sysdeps/powerpc/powerpc64/dl-machine.h48
-rw-r--r--sysdeps/powerpc/tst-tlsopt-powerpc.c52
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/Makefile2
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist3
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist3
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist3
10 files changed, 192 insertions, 0 deletions
diff --git a/sysdeps/powerpc/Makefile b/sysdeps/powerpc/Makefile
index b11edd7..533d763 100644
--- a/sysdeps/powerpc/Makefile
+++ b/sysdeps/powerpc/Makefile
@@ -8,6 +8,9 @@ sysdep-dl-routines += dl-machine
sysdep_routines += dl-machine
# extra shared linker files to link only into dl-allobjs.so
sysdep-rtld-routines += dl-machine
+# Don't optimize GD tls sequence to LE.
+LDFLAGS-tst-tlsopt-powerpc += -Wl,--no-tls-optimize
+tests += tst-tlsopt-powerpc
endif
ifeq ($(subdir),setjmp)
diff --git a/sysdeps/powerpc/Versions b/sysdeps/powerpc/Versions
index 47c2c3e..2aebf7c 100644
--- a/sysdeps/powerpc/Versions
+++ b/sysdeps/powerpc/Versions
@@ -15,3 +15,9 @@ libc {
__vmx__libc_longjmp; __vmx__libc_siglongjmp;
}
}
+
+ld {
+ GLIBC_2.22 {
+ __tls_get_addr_opt;
+ }
+}
diff --git a/sysdeps/powerpc/dl-tls.c b/sysdeps/powerpc/dl-tls.c
new file mode 100644
index 0000000..a18b23e
--- /dev/null
+++ b/sysdeps/powerpc/dl-tls.c
@@ -0,0 +1,24 @@
+/* Thread-local storage handling in the ELF dynamic linker. PowerPC version.
+ Copyright (C) 2009-2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include "elf/dl-tls.c"
+
+#ifdef SHARED
+strong_alias(__tls_get_addr, __tls_get_addr_opt)
+#endif
diff --git a/sysdeps/powerpc/powerpc32/dl-machine.h b/sysdeps/powerpc/powerpc32/dl-machine.h
index c94674f..8b0c067 100644
--- a/sysdeps/powerpc/powerpc32/dl-machine.h
+++ b/sysdeps/powerpc/powerpc32/dl-machine.h
@@ -333,6 +333,32 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
# endif
case R_PPC_DTPMOD32:
+ if (map->l_info[DT_PPC(OPT)]
+ && (map->l_info[DT_PPC(OPT)]->d_un.d_val & PPC_OPT_TLS))
+ {
+ if (!NOT_BOOTSTRAP)
+ {
+ reloc_addr[0] = 0;
+ reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
+ + TLS_DTV_OFFSET);
+ break;
+ }
+ else if (sym_map != NULL)
+ {
+# ifndef SHARED
+ CHECK_STATIC_TLS (map, sym_map);
+# else
+ if (TRY_STATIC_TLS (map, sym_map))
+# endif
+ {
+ reloc_addr[0] = 0;
+ /* Set up for local dynamic. */
+ reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
+ + TLS_DTV_OFFSET);
+ break;
+ }
+ }
+ }
if (!NOT_BOOTSTRAP)
/* During startup the dynamic linker is always index 1. */
*reloc_addr = 1;
@@ -342,6 +368,28 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
*reloc_addr = sym_map->l_tls_modid;
break;
case R_PPC_DTPREL32:
+ if (map->l_info[DT_PPC(OPT)]
+ && (map->l_info[DT_PPC(OPT)]->d_un.d_val & PPC_OPT_TLS))
+ {
+ if (!NOT_BOOTSTRAP)
+ {
+ *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
+ break;
+ }
+ else if (sym_map != NULL)
+ {
+ /* This reloc is always preceded by R_PPC_DTPMOD32. */
+# ifndef SHARED
+ assert (HAVE_STATIC_TLS (map, sym_map));
+# else
+ if (HAVE_STATIC_TLS (map, sym_map))
+# endif
+ {
+ *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
+ break;
+ }
+ }
+ }
/* During relocation all TLS symbols are defined and used.
Therefore the offset is already correct. */
if (NOT_BOOTSTRAP && sym_map != NULL)
diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h
index 5cb0087..55ac736 100644
--- a/sysdeps/powerpc/powerpc64/dl-machine.h
+++ b/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -701,6 +701,32 @@ elf_machine_rela (struct link_map *map,
return;
case R_PPC64_DTPMOD64:
+ if (map->l_info[DT_PPC64(OPT)]
+ && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_TLS))
+ {
+#ifdef RTLD_BOOTSTRAP
+ reloc_addr[0] = 0;
+ reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
+ + TLS_DTV_OFFSET);
+ return;
+#else
+ if (sym_map != NULL)
+ {
+# ifndef SHARED
+ CHECK_STATIC_TLS (map, sym_map);
+# else
+ if (TRY_STATIC_TLS (map, sym_map))
+# endif
+ {
+ reloc_addr[0] = 0;
+ /* Set up for local dynamic. */
+ reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
+ + TLS_DTV_OFFSET);
+ return;
+ }
+ }
+#endif
+ }
#ifdef RTLD_BOOTSTRAP
/* During startup the dynamic linker is always index 1. */
*reloc_addr = 1;
@@ -713,6 +739,28 @@ elf_machine_rela (struct link_map *map,
return;
case R_PPC64_DTPREL64:
+ if (map->l_info[DT_PPC64(OPT)]
+ && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_TLS))
+ {
+#ifdef RTLD_BOOTSTRAP
+ *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
+ return;
+#else
+ if (sym_map != NULL)
+ {
+ /* This reloc is always preceded by R_PPC64_DTPMOD64. */
+# ifndef SHARED
+ assert (HAVE_STATIC_TLS (map, sym_map));
+# else
+ if (HAVE_STATIC_TLS (map, sym_map))
+# endif
+ {
+ *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
+ return;
+ }
+ }
+#endif
+ }
/* During relocation all TLS symbols are defined and used.
Therefore the offset is already correct. */
#ifndef RTLD_BOOTSTRAP
diff --git a/sysdeps/powerpc/tst-tlsopt-powerpc.c b/sysdeps/powerpc/tst-tlsopt-powerpc.c
new file mode 100644
index 0000000..c9a14cb
--- /dev/null
+++ b/sysdeps/powerpc/tst-tlsopt-powerpc.c
@@ -0,0 +1,52 @@
+/* glibc test for __tls_get_addr optimization. */
+#include <stdio.h>
+
+#include "../../elf/tls-macros.h"
+#include "dl-tls.h"
+
+/* common 'int' variable in TLS. */
+COMMON_INT_DEF(foo);
+
+
+#define TEST_FUNCTION do_test ()
+static int
+do_test (void)
+{
+ int result = 0;
+
+ /* Get variable using general dynamic model. */
+ int *ap = TLS_GD (foo);
+ if (*ap != 0)
+ {
+ printf ("foo = %d\n", *ap);
+ result = 1;
+ }
+
+ tls_index *tls_arg;
+#ifdef __powerpc64__
+ register unsigned long thread_pointer __asm__ ("r13");
+ asm ("addi %0,2,foo@got@tlsgd" : "=r" (tls_arg));
+#else
+ register unsigned long thread_pointer __asm__ ("r2");
+ asm ("bcl 20,31,1f\n1:\t"
+ "mflr %0\n\t"
+ "addis %0,%0,_GLOBAL_OFFSET_TABLE_-1b@ha\n\t"
+ "addi %0,%0,_GLOBAL_OFFSET_TABLE_-1b@l\n\t"
+ "addi %0,%0,foo@got@tlsgd" : "=b" (tls_arg));
+#endif
+
+ if (tls_arg->ti_module != 0)
+ {
+ printf ("tls_index not optimized, binutils too old?\n");
+ result = 1;
+ }
+ else if (tls_arg->ti_offset + thread_pointer != (unsigned long) ap)
+ {
+ printf ("tls_index->ti_offset wrong value\n");
+ result = 1;
+ }
+
+ return result;
+}
+
+#include "../../test-skeleton.c"
diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
index fcf3bb5..c89ed9e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/Makefile
+++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
@@ -20,6 +20,8 @@ ifeq ($(build-shared),yes)
# This is needed for DSO loading from static binaries.
sysdep-dl-routines += dl-static
endif
+# Otherwise tst-tls-dlinfo fails due to tst-tlsmod2.so using static tls.
+LDFLAGS-tst-tlsmod2.so += -Wl,--no-tls-get-addr-optimize
endif
ifeq ($(subdir),misc)
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
index d71611f..7d24961 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
@@ -10,6 +10,9 @@ GLIBC_2.1
GLIBC_2.1 A
__libc_stack_end D 0x4
_dl_mcount F
+GLIBC_2.22
+ GLIBC_2.22 A
+ __tls_get_addr_opt F
GLIBC_2.3
GLIBC_2.3 A
__tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist
index 3530fb4..3174e21 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist
@@ -9,3 +9,6 @@ GLIBC_2.17
free F
malloc F
realloc F
+GLIBC_2.22
+ GLIBC_2.22 A
+ __tls_get_addr_opt F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist
index 899360e..d8c4201 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist
@@ -1,3 +1,6 @@
+GLIBC_2.22
+ GLIBC_2.22 A
+ __tls_get_addr_opt F
GLIBC_2.3
GLIBC_2.3 A
__libc_memalign F