You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
226 lines
7.6 KiB
226 lines
7.6 KiB
Backport of this upstream patch: |
|
|
|
commit 031e519c95c069abe4e4c7c59e2b4b67efccdee5 |
|
Author: H.J. Lu <hjl.tools@gmail.com> |
|
Date: Thu Jul 6 04:43:06 2017 -0700 |
|
|
|
x86-64: Align the stack in __tls_get_addr [BZ #21609] |
|
|
|
This change forces realignment of the stack pointer in __tls_get_addr, so |
|
that binaries compiled by GCCs older than GCC 4.9: |
|
|
|
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 |
|
|
|
continue to work even if vector instructions are used in glibc which |
|
require the ABI stack realignment. |
|
|
|
__tls_get_addr_slow is added to handle the slow paths in the default |
|
implementation of__tls_get_addr in elf/dl-tls.c. The new __tls_get_addr |
|
calls __tls_get_addr_slow after realigning the stack. Internal calls |
|
within ld.so go directly to the default implementation of __tls_get_addr |
|
because they do not need stack realignment. |
|
|
|
[BZ #21609] |
|
* sysdeps/x86_64/Makefile (sysdep-dl-routines): Add tls_get_addr. |
|
(gen-as-const-headers): Add rtld-offsets.sym. |
|
* sysdeps/x86_64/dl-tls.c: New file. |
|
* sysdeps/x86_64/rtld-offsets.sym: Likwise. |
|
* sysdeps/x86_64/tls_get_addr.S: Likewise. |
|
* sysdeps/x86_64/dl-tls.h: Add multiple inclusion guards. |
|
* sysdeps/x86_64/tlsdesc.sym (TI_MODULE_OFFSET): New. |
|
(TI_OFFSET_OFFSET): Likwise. |
|
|
|
Adjusted for drift in sysdeps/x86_64/Makefile and lack of |
|
TLS_DTV_UNALLOCATED consolidation (upstream commit |
|
aca1daef298b43bd7b1987b31f5aabcf6c2f6021). |
|
|
|
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile |
|
index 6c03a89fb3ea3063..c6766bb2b443a28a 100644 |
|
--- a/sysdeps/x86_64/Makefile |
|
+++ b/sysdeps/x86_64/Makefile |
|
@@ -19,7 +19,7 @@ gen-as-const-headers += locale-defines.sym |
|
endif |
|
|
|
ifeq ($(subdir),elf) |
|
-sysdep-dl-routines += tlsdesc dl-tlsdesc |
|
+sysdep-dl-routines += tlsdesc dl-tlsdesc tls_get_addr |
|
|
|
tests += ifuncmain8 |
|
modules-names += ifuncmod8 |
|
@@ -69,5 +69,5 @@ endif |
|
endif |
|
|
|
ifeq ($(subdir),csu) |
|
-gen-as-const-headers += tlsdesc.sym |
|
+gen-as-const-headers += tlsdesc.sym rtld-offsets.sym |
|
endif |
|
diff --git a/sysdeps/x86_64/dl-tls.c b/sysdeps/x86_64/dl-tls.c |
|
new file mode 100644 |
|
index 0000000000000000..3584805c8ecca59a |
|
--- /dev/null |
|
+++ b/sysdeps/x86_64/dl-tls.c |
|
@@ -0,0 +1,53 @@ |
|
+/* Thread-local storage handling in the ELF dynamic linker. x86-64 version. |
|
+ Copyright (C) 2017 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, see |
|
+ <http://www.gnu.org/licenses/>. */ |
|
+ |
|
+#ifdef SHARED |
|
+/* Work around GCC PR58066, due to which __tls_get_addr may be called |
|
+ with an unaligned stack. The compat implementation is in |
|
+ tls_get_addr-compat.S. */ |
|
+ |
|
+# include <dl-tls.h> |
|
+ |
|
+/* Define __tls_get_addr within elf/dl-tls.c under a different |
|
+ name. */ |
|
+extern __typeof__ (__tls_get_addr) ___tls_get_addr; |
|
+ |
|
+# define __tls_get_addr ___tls_get_addr |
|
+# include <elf/dl-tls.c> |
|
+# undef __tls_get_addr |
|
+ |
|
+hidden_ver (___tls_get_addr, __tls_get_addr) |
|
+ |
|
+/* Only handle slow paths for __tls_get_addr. */ |
|
+attribute_hidden |
|
+void * |
|
+__tls_get_addr_slow (GET_ADDR_ARGS) |
|
+{ |
|
+ dtv_t *dtv = THREAD_DTV (); |
|
+ |
|
+ if (__glibc_unlikely (dtv[0].counter != GL(dl_tls_generation))) |
|
+ return update_get_addr (GET_ADDR_PARAM); |
|
+ |
|
+ return tls_get_addr_tail (GET_ADDR_PARAM, dtv, NULL); |
|
+} |
|
+#else |
|
+ |
|
+/* No compatibility symbol needed. */ |
|
+# include <elf/dl-tls.c> |
|
+ |
|
+#endif |
|
diff --git a/sysdeps/x86_64/dl-tls.h b/sysdeps/x86_64/dl-tls.h |
|
index 56162ee64a4aae7d..0b4a6b3b634a83f4 100644 |
|
--- a/sysdeps/x86_64/dl-tls.h |
|
+++ b/sysdeps/x86_64/dl-tls.h |
|
@@ -16,6 +16,10 @@ |
|
License along with the GNU C Library; if not, see |
|
<http://www.gnu.org/licenses/>. */ |
|
|
|
+#ifndef _X86_64_DL_TLS_H |
|
+#define _X86_64_DL_TLS_H |
|
+ |
|
+#include <stdint.h> |
|
|
|
/* Type used for the representation of TLS information in the GOT. */ |
|
typedef struct dl_tls_index |
|
@@ -29,3 +33,5 @@ extern void *__tls_get_addr (tls_index *ti); |
|
|
|
/* Value used for dtv entries for which the allocation is delayed. */ |
|
#define TLS_DTV_UNALLOCATED ((void *) -1l) |
|
+ |
|
+#endif /* _X86_64_DL_TLS_H */ |
|
diff --git a/sysdeps/x86_64/rtld-offsets.sym b/sysdeps/x86_64/rtld-offsets.sym |
|
new file mode 100644 |
|
index 0000000000000000..fd41b51521ac80bd |
|
--- /dev/null |
|
+++ b/sysdeps/x86_64/rtld-offsets.sym |
|
@@ -0,0 +1,6 @@ |
|
+#define SHARED |
|
+#include <ldsodefs.h> |
|
+ |
|
+-- |
|
+ |
|
+GL_TLS_GENERATION_OFFSET offsetof (struct rtld_global, _dl_tls_generation) |
|
diff --git a/sysdeps/x86_64/tls_get_addr.S b/sysdeps/x86_64/tls_get_addr.S |
|
new file mode 100644 |
|
index 0000000000000000..9d38fb3be54fbcb5 |
|
--- /dev/null |
|
+++ b/sysdeps/x86_64/tls_get_addr.S |
|
@@ -0,0 +1,61 @@ |
|
+/* Stack-aligning implementation of __tls_get_addr. x86-64 version. |
|
+ Copyright (C) 2017 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, see |
|
+ <http://www.gnu.org/licenses/>. */ |
|
+ |
|
+#ifdef SHARED |
|
+ |
|
+# include <sysdep.h> |
|
+# include "tlsdesc.h" |
|
+# include "rtld-offsets.h" |
|
+ |
|
+/* See __tls_get_addr and __tls_get_addr_slow in dl-tls.c. This function |
|
+ call __tls_get_addr_slow on both slow paths. It realigns the stack |
|
+ before the call to work around GCC PR58066. */ |
|
+ |
|
+ENTRY (__tls_get_addr) |
|
+ mov %fs:DTV_OFFSET, %RDX_LP |
|
+ mov GL_TLS_GENERATION_OFFSET+_rtld_local(%rip), %RAX_LP |
|
+ /* GL(dl_tls_generation) == dtv[0].counter */ |
|
+ cmp %RAX_LP, (%rdx) |
|
+ jne 1f |
|
+ mov TI_MODULE_OFFSET(%rdi), %RAX_LP |
|
+ /* dtv[ti->ti_module] */ |
|
+# ifdef __LP64__ |
|
+ salq $4, %rax |
|
+ movq (%rdx,%rax), %rax |
|
+# else |
|
+ movl (%rdx,%rax, 8), %eax |
|
+# endif |
|
+ cmp $-1, %RAX_LP |
|
+ je 1f |
|
+ add TI_OFFSET_OFFSET(%rdi), %RAX_LP |
|
+ ret |
|
+1: |
|
+ /* On the slow path, align the stack. */ |
|
+ pushq %rbp |
|
+ cfi_def_cfa_offset (16) |
|
+ cfi_offset (%rbp, -16) |
|
+ mov %RSP_LP, %RBP_LP |
|
+ cfi_def_cfa_register (%rbp) |
|
+ and $-16, %RSP_LP |
|
+ call __tls_get_addr_slow |
|
+ mov %RBP_LP, %RSP_LP |
|
+ popq %rbp |
|
+ cfi_def_cfa (%rsp, 8) |
|
+ ret |
|
+END (__tls_get_addr) |
|
+#endif /* SHARED */ |
|
diff --git a/sysdeps/x86_64/tlsdesc.sym b/sysdeps/x86_64/tlsdesc.sym |
|
index 33854975d04184b2..fc897ab4b522b1a9 100644 |
|
--- a/sysdeps/x86_64/tlsdesc.sym |
|
+++ b/sysdeps/x86_64/tlsdesc.sym |
|
@@ -15,3 +15,6 @@ TLSDESC_ARG offsetof(struct tlsdesc, arg) |
|
TLSDESC_GEN_COUNT offsetof(struct tlsdesc_dynamic_arg, gen_count) |
|
TLSDESC_MODID offsetof(struct tlsdesc_dynamic_arg, tlsinfo.ti_module) |
|
TLSDESC_MODOFF offsetof(struct tlsdesc_dynamic_arg, tlsinfo.ti_offset) |
|
+ |
|
+TI_MODULE_OFFSET offsetof(tls_index, ti_module) |
|
+TI_OFFSET_OFFSET offsetof(tls_index, ti_offset)
|
|
|