@@ -5,7 +5,7 @@ CFLAGS-backtrace.c += -funwind-tables
endif
ifeq ($(subdir),elf)
-sysdep-dl-routines += tlsdesc dl-tlsdesc
+sysdep-dl-routines += tlsdesc dl-tlsdesc tcb-version
gen-as-const-headers += dl-link.sym
endif
@@ -3,3 +3,11 @@ libc {
_mcount;
}
}
+
+ld {
+ GLIBC_2.27 {
+ # Symbol used to version control the private GLIBC TCB split-stack
+ # field.
+ __libc_tcb_private_ss;
+ }
+}
@@ -3,4 +3,4 @@
PTHREAD_MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads)
PTHREAD_TID_OFFSET offsetof (struct pthread, tid)
-PTHREAD_SIZEOF sizeof (struct pthread)
+PTHREAD_PRE_TCB_SIZE TLS_PRE_TCB_SIZE
@@ -26,6 +26,7 @@
# include <stddef.h>
# include <stdint.h>
# include <dl-dtv.h>
+# include <libc-pointer-arith.h>
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
@@ -49,6 +50,12 @@ typedef struct
void *private;
} tcbhead_t;
+typedef struct
+{
+ /* GCC split stack support. */
+ void *__private_ss;
+} tcbprehead_t;
+
/* This is the size of the initial TCB. */
# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
@@ -58,8 +65,14 @@ typedef struct
/* This is the size of the TCB. */
# define TLS_TCB_SIZE sizeof (tcbhead_t)
-/* This is the size we need before TCB. */
-# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
+/* This is the size we need before TCB. Check if there is room for
+ tcbprehead_t in struct pthread's final padding and if not add it on
+ required pre-tcb size. */
+# define TLS_PRE_TCB_SIZE \
+ (sizeof (struct pthread) \
+ + (PTHREAD_STRUCT_END_PADDING < sizeof (tcbprehead_t) \
+ ? ALIGN_UP (sizeof (tcbprehead_t), __alignof__ (struct pthread)) \
+ : 0))
/* Alignment requirements for the TCB. */
# define TLS_TCB_ALIGN __alignof__ (struct pthread)
@@ -84,7 +97,8 @@ typedef struct
({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
/* Value passed to 'clone' for initialization of the thread register. */
-# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
+# define TLS_DEFINE_INIT_TP(tp, pd) \
+ void *tp = (void*)((uintptr_t) (pd) + TLS_PRE_TCB_SIZE)
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
@@ -92,11 +106,12 @@ typedef struct
/* Return the thread descriptor for the current thread. */
# define THREAD_SELF \
- ((struct pthread *)__builtin_thread_pointer () - 1)
+ ((struct pthread *)((uintptr_t) __builtin_thread_pointer () \
+ - TLS_PRE_TCB_SIZE))
/* Magic for libthread_db to know how to do THREAD_SELF. */
# define DB_THREAD_SELF \
- CONST_THREAD_AREA (64, sizeof (struct pthread))
+ CONST_THREAD_AREA (64, TLS_PRE_TCB_SIZE)
/* Access to data in the thread descriptor is easy. */
# define THREAD_GETMEM(descr, member) \
new file mode 100644
@@ -0,0 +1,23 @@
+/* TCB field abi advertise symbols.
+ 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/>. */
+
+#include <libc-internal.h>
+
+/* Symbol used to version control the private GLIBC TCB split-stack
+ field. */
+long int attribute_relro __libc_tcb_private_ss;
@@ -8,3 +8,5 @@ GLIBC_2.17 calloc F
GLIBC_2.17 free F
GLIBC_2.17 malloc F
GLIBC_2.17 realloc F
+GLIBC_2.27 GLIBC_2.27 A
+GLIBC_2.27 __libc_tcb_private_ss D 0x8
@@ -114,7 +114,7 @@ extern int __local_multiple_threads attribute_hidden;
# else
# define SINGLE_THREAD_P(R) \
mrs x##R, tpidr_el0; \
- sub x##R, x##R, PTHREAD_SIZEOF; \
+ sub x##R, x##R, PTHREAD_PRE_TCB_SIZE; \
ldr w##R, [x##R, PTHREAD_MULTIPLE_THREADS_OFFSET]
# endif
# endif