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[PATCH] [AArch64] Provide symbol versions for mcount and _mcount.


Hi,

This patch fixes the symbol versions associated with mcount and _mcount in the AArch64 port.
The initial AArch64 port in 2.17 omitted this interface.  A patch earlier this year here
http://sourceware.org/ml/libc-ports/2013-05/msg00087.html introduced
the symbols but introduced them with default 2_17 versions instead of 2_18.

This patch versions them correctly.

I'd appreciate a review of this patch.

Cheers
/Marcus

 
2013-07-25  Marcus Shawcroft  <marcus.shawcroft@linaro.org>

        * sysdeps/aarch64/Versions: New file.
        * sysdeps/aarch64/machine-gmon.h: New file.
        * sysdeps/aarch64/mcount.c: New file.
        * sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist (mcount): Add.
        (_mcount): Likewise.

---
 ports/ChangeLog.aarch64                            |  8 ++++
 ports/sysdeps/aarch64/Versions                     |  5 +++
 ports/sysdeps/aarch64/machine-gmon.h               | 43 ++++++++++++++++++++++
 ports/sysdeps/aarch64/mcount.c                     | 39 ++++++++++++++++++++
 .../unix/sysv/linux/aarch64/nptl/libc.abilist      |  2 +
 5 files changed, 97 insertions(+)
 create mode 100644 ports/sysdeps/aarch64/Versions
 create mode 100644 ports/sysdeps/aarch64/machine-gmon.h
 create mode 100644 ports/sysdeps/aarch64/mcount.c

diff --git a/ports/ChangeLog.aarch64 b/ports/ChangeLog.aarch64
index 3f26cb7..ee7f831 100644
--- a/ports/ChangeLog.aarch64
+++ b/ports/ChangeLog.aarch64
@@ -1,3 +1,11 @@
+2013-07-25  Marcus Shawcroft  <marcus.shawcroft@linaro.org>
+
+        * sysdeps/aarch64/Versions: New file.
+        * sysdeps/aarch64/machine-gmon.h: New file.
+        * sysdeps/aarch64/mcount.c: New file.
+        * sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist (mcount): Add.
+        (_mcount): Likewise.
+
 2013-07-12  Marcus Shawcroft  <marcus.shawcroft@linaro.org>
 
 	* sysdeps/aarch64/Makefile (CFLAGS-backtrace.c): Define.
diff --git a/ports/sysdeps/aarch64/Versions b/ports/sysdeps/aarch64/Versions
new file mode 100644
index 0000000..29bbc86
--- /dev/null
+++ b/ports/sysdeps/aarch64/Versions
@@ -0,0 +1,5 @@
+libc {
+  GLIBC_2.18 {
+    mcount; _mcount;
+  }
+}
diff --git a/ports/sysdeps/aarch64/machine-gmon.h b/ports/sysdeps/aarch64/machine-gmon.h
new file mode 100644
index 0000000..815f7bb
--- /dev/null
+++ b/ports/sysdeps/aarch64/machine-gmon.h
@@ -0,0 +1,43 @@
+/* Machine-dependent definitions for profiling support.  Generic GCC 2 version.
+   Copyright (C) 1996-2013 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/>.  */
+
+/* GCC version 2 gives us a perfect magical function to get
+   just the information we need:
+     void *__builtin_return_address (unsigned int N)
+   returns the return address of the frame N frames up.  */
+
+/* Be warned that GCC cannot usefully compile __builtin_return_address(N)
+   for N != 0 on all machines.  In this case, you may have to write
+   your own version of _mcount().  */
+
+#if __GNUC__ < 2
+ #error "This file uses __builtin_return_address, a GCC 2 extension."
+#endif
+
+#include <sysdep.h>
+
+static void mcount_internal (u_long frompc, u_long selfpc);
+
+#define _MCOUNT_DECL(frompc, selfpc) \
+static inline void mcount_internal (u_long frompc, u_long selfpc)
+
+#define MCOUNT \
+void __mcount (void)							      \
+{									      \
+  mcount_internal ((u_long) RETURN_ADDRESS (1), (u_long) RETURN_ADDRESS (0)); \
+}
diff --git a/ports/sysdeps/aarch64/mcount.c b/ports/sysdeps/aarch64/mcount.c
new file mode 100644
index 0000000..8871a4f
--- /dev/null
+++ b/ports/sysdeps/aarch64/mcount.c
@@ -0,0 +1,39 @@
+/* Copyright (C) 2013 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 <shlib-compat.h>
+
+#include <gmon/mcount.c>
+
+/* We forgot to add _mcount and mcount in glibc 2.17.  We added them in 2.18
+   therefore we want them to be added with version GLIBC_2_18.  However, setting
+   then version is not straight forward because generic Version files include
+   an earlier 2.xx version for each of these symbols and the linker uses the
+   first version it sees.  */
+
+#if SHLIB_COMPAT (libc, GLIBC_2_17, GLIBC_2_18)
+/* The canonical name for the function is `_mcount' in both C and asm,
+   but some old asm code might assume it's `mcount'.  */
+weak_alias (__mcount, __weak_mcount)
+versioned_symbol (libc, __weak_mcount,  mcount, GLIBC_2_18);
+
+versioned_symbol (libc, __mcount, _mcount, GLIBC_2_18);
+#else
+strong_alias (__mcount, _mcount);
+weak_alias (__mcount, mcount)
+#endif
diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
index b04a761..b99dc36 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
@@ -2080,3 +2080,5 @@ GLIBC_2.17
 GLIBC_2.18
  GLIBC_2.18 A
  __cxa_thread_atexit_impl F
+ _mcount F
+ mcount F
-- 
1.8.1.2


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