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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/rtld-offsets.sym
parent0cae0b1a281be45280e12e668434ef2f183edfda (diff)
downloadglibc-031e519c95c069abe4e4c7c59e2b4b67efccdee5.tar.gz
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/rtld-offsets.sym')
-rw-r--r--sysdeps/x86_64/rtld-offsets.sym6
1 files changed, 6 insertions, 0 deletions
diff --git a/sysdeps/x86_64/rtld-offsets.sym b/sysdeps/x86_64/rtld-offsets.sym
new file mode 100644
index 0000000000..fd41b51521
--- /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)