Merge commit 'origin/unwind'

* commit 'origin/unwind':
  Fixes for 2.6.25 pt_regs changes.
  Include string.h
  Change stap to get kernel symbols from debuginfo and
  reincarnate vim/ directory in this branch to match master
  Add new define STP_USE_DWARF_UNWINDER which is set based on which archs
  Remove misleading error message.
  Support for kernels built with CONFIG_FRAME_POINTER
  Fix regression.
  dded _stp_read_address() and changed code to use it.
  kretprobe trampoline fixes
  i386 fixes.
  control.c (_stp_ctl_write_dbug): Insert missing break.
  32-bit fixes
  Cleanup.
  2008-03-23  Frank Ch. Eigler  <fche@elastic.org>
  2008-03-23  Frank Ch. Eigler  <fche@elastic.org>
  2008-03-21  Eugene Teo  <eugeneteo@kernel.sg>
  add (back) runtime/unwind files
  * clarify utility of epilogue-type probe aliases in documentation
  rebased unwind_branch on top of current master

1 files changed, 97 insertions, 0 deletions

diff --git a/runtime/staprun/unwind_data.c b/runtime/staprun/unwind_data.c
new file mode 100644
index 00000000..ed27cc20
--- /dev/null
+++ b/runtime/staprun/unwind_data.c
@@ -0,0 +1,97 @@
+/* -*- linux-c -*-
+ * Unwind data functions for staprun.
+ *
+ * Copyright (C) 2008 Red Hat Inc.
+ *
+ * This file is part of systemtap, and is free software.  You can
+ * redistribute it and/or modify it under the terms of the GNU General
+ * Public License (GPL); either version 2, or (at your option) any
+ * later version.
+ */
+
+#include "staprun.h"
+#include <elfutils/libdwfl.h>
+#include <dwarf.h>
+
+static char debuginfo_path_arr[] = "-:.debug:/usr/lib/debug";
+static char *debuginfo_path = debuginfo_path_arr;
+static const Dwfl_Callbacks kernel_callbacks = {
+	.find_debuginfo = dwfl_standard_find_debuginfo,
+	.debuginfo_path = &debuginfo_path,
+	.find_elf = dwfl_linux_kernel_find_elf,
+	.section_address = dwfl_linux_kernel_module_section_address,
+};
+
+void *get_module_unwind_data(Dwfl * dwfl, const char *name, int *len)
+{
+	Dwarf_Addr bias = 0;
+	Dwarf *dw;
+	GElf_Ehdr *ehdr, ehdr_mem;
+	GElf_Shdr *shdr, shdr_mem;
+	Elf_Scn *scn = NULL;
+	Elf_Data *data = NULL;
+
+	Dwfl_Module *mod = dwfl_report_module(dwfl, name, 0, 0);
+	dwfl_report_end(dwfl, NULL, NULL);
+	dw = dwfl_module_getdwarf(mod, &bias);
+	Elf *elf = dwarf_getelf(dw);
+	ehdr = gelf_getehdr(elf, &ehdr_mem);
+	while ((scn = elf_nextscn(elf, scn))) {
+		shdr = gelf_getshdr(scn, &shdr_mem);
+		if (strcmp(elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name), ".debug_frame") == 0) {
+			data = elf_rawdata(scn, NULL);
+			break;
+		}
+	}
+
+	if (data == NULL) {
+		*len = 0;
+		dbug(2, "module %s returns NULL\n", name);
+		return NULL;
+	}
+	dbug(2, "module %s returns %d\n", name, (int)data->d_size);
+	*len = data->d_size;
+	return data->d_buf;
+}
+
+void send_unwind_data(const char *name)
+{
+	struct _stp_msg_unwind *un;
+	int unwind_data_len = 0;
+	void *unwind_data = NULL;
+	char *buf;
+
+	dbug(2, "module %s\n", name);
+	if (strcmp(name, "*")) {
+		Dwfl *dwfl = dwfl_begin(&kernel_callbacks);
+
+		if (name[0] == 0)
+			unwind_data = get_module_unwind_data(dwfl, "kernel", &unwind_data_len);
+		else
+			unwind_data = get_module_unwind_data(dwfl, name, &unwind_data_len);
+
+		/* yuck */
+		buf = (char *)malloc(unwind_data_len + sizeof(*un) + sizeof(uint32_t));
+		if (!buf) {
+			err("malloc failed\n");
+			return;
+		}
+		memcpy(buf + sizeof(*un) + sizeof(uint32_t), unwind_data, unwind_data_len);
+		dwfl_end(dwfl);
+	} else {
+		buf = (char *)malloc(sizeof(*un) + sizeof(uint32_t));
+		if (!buf) {
+			err("malloc failed\n");
+			return;
+		}
+	}
+		
+	un = (struct _stp_msg_unwind *)(buf + sizeof(uint32_t));
+	strncpy(un->name, name, sizeof(un->name));
+	un->unwind_len = unwind_data_len;
+	*(uint32_t *) buf = STP_UNWIND;
+
+	/* send unwind data */
+	if (write(control_channel, buf, unwind_data_len + sizeof(*un) + sizeof(uint32_t)) <= 0)
+		err("write failed\n");
+}