Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/backends/ppc64_unwind.c b/backends/ppc64_unwind.c
new file mode 100644
index 0000000..4fa0b5a
--- /dev/null
+++ b/backends/ppc64_unwind.c
@@ -0,0 +1,76 @@
+/* Get previous frame state for an existing frame state.
+ Copyright (C) 2017 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ elfutils 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
+ General Public License for more details.
+
+ You should have received copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#define BACKEND ppc64_
+
+#define LR_REG 65 /* Not 108, see ppc_dwarf_to_regno. */
+#define SP_REG 1
+
+#define LR_OFFSET 16
+
+#include "libebl_CPU.h"
+
+/* Simplistic fallback frame unwinder. SP points to the backchain (contains
+ address of previous stack pointer). At SP offset 16 is the LR save area
+ (contains the value of the previous LR). */
+
+bool
+EBLHOOK(unwind) (Ebl *ebl __attribute__ ((unused)),
+ Dwarf_Addr pc __attribute__ ((unused)),
+ ebl_tid_registers_t *setfunc, ebl_tid_registers_get_t *getfunc,
+ ebl_pid_memory_read_t *readfunc, void *arg,
+ bool *signal_framep __attribute__ ((unused)))
+{
+ Dwarf_Word sp, newSp, lr, newLr;
+
+ /* Stack pointer points to the backchain which contains the previous sp. */
+ if (! getfunc (SP_REG, 1, &sp, arg))
+ sp = 0;
+
+ /* Link register contains previous program counter. */
+ if (! getfunc (LR_REG, 1, &lr, arg)
+ || lr == 0
+ || ! setfunc (-1, 1, &lr, arg))
+ return false;
+
+ if (! readfunc(sp, &newSp, arg))
+ newSp = 0;
+
+ if (! readfunc(newSp + LR_OFFSET, &newLr, arg))
+ newLr = 0;
+
+ setfunc(SP_REG, 1, &newSp, arg);
+ setfunc(LR_REG, 1, &newLr, arg);
+
+ /* Sanity check the stack grows down. */
+ return newSp > sp;
+}