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authorH.J. Lu <hjl.tools@gmail.com>2017-07-06 04:43:06 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-07-06 04:43:20 -0700
commit031e519c95c069abe4e4c7c59e2b4b67efccdee5 (patch)
tree9d30174961011616431c092d2ba827ce5555944d /sysdeps/x86_64/tlsdesc.sym
parent0cae0b1a281be45280e12e668434ef2f183edfda (diff)
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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.
Diffstat (limited to 'sysdeps/x86_64/tlsdesc.sym')
-rw-r--r--sysdeps/x86_64/tlsdesc.sym3
1 files changed, 3 insertions, 0 deletions
diff --git a/sysdeps/x86_64/tlsdesc.sym b/sysdeps/x86_64/tlsdesc.sym
index 33854975d0..fc897ab4b5 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)