Fetch and store both debug_frame and eh_frame tables.

* runtime/sym.h (_stp_module): Remove unwind_data, unwind_data_len and
  unwind_is_ehframe fields. Add debug_frame, eh_frame, debug_frame_len,
  eh_frame_len and eh_frame_addr fields.
* runtime/unwind.c: Use debug_frame and debug_frame_len instead of
  unwind_data and unwind_data_len throughout.
  (cie_for_fde): Take unwind_data and is_ehframe as direct arguments.
* runtime/unwind/unwind.h (cie_for_fde): New function declaration.
* translate.cxx (get_unwind_data): Fetch and return both debug_frame
  and eh_frame tables.
  (dump_unwindsyms): Dump both debug_frame and eh_frame tables.

4 files changed, 113 insertions, 58 deletions

diff --git a/runtime/sym.h b/runtime/sym.h
index 80c334fb..7e28ebe6 100644
--- a/runtime/sym.h
+++ b/runtime/sym.h
@@ -42,11 +42,13 @@ struct _stp_module {
   	unsigned long dwarf_module_base;
 
 	/* the stack unwind data for this module */
-	void *unwind_data;
+	void *debug_frame;
+	void *eh_frame;
 	void *unwind_hdr;	
-	uint32_t unwind_data_len;
+	uint32_t debug_frame_len;
+	uint32_t eh_frame_len;
 	uint32_t unwind_hdr_len;
-	uint32_t unwind_is_ehframe; /* unwind data comes from .eh_frame */
+	unsigned long eh_frame_addr; /* Orig load address (offset) .eh_frame */
 	/* build-id information */
 	unsigned char *build_id_bits;
 	unsigned long  build_id_offset;
diff --git a/runtime/unwind.c b/runtime/unwind.c
index f03534bd..8ba3cf76 100644
--- a/runtime/unwind.c
+++ b/runtime/unwind.c
@@ -87,7 +87,8 @@ static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
 }
 
 /* given an FDE, find its CIE */
-static const u32 *cie_for_fde(const u32 *fde, const struct _stp_module *m)
+static const u32 *cie_for_fde(const u32 *fde, void *unwind_data,
+			      int is_ehframe)
 {
 	const u32 *cie;
 
@@ -96,7 +97,7 @@ static const u32 *cie_for_fde(const u32 *fde, const struct _stp_module *m)
 		return &bad_cie;
 
 	/* CIE id for eh_frame is 0, otherwise 0xffffffff */
-	if (m->unwind_is_ehframe && fde[1] == 0)
+	if (is_ehframe && fde[1] == 0)
 		return &not_fde;
 	else if (fde[1] == 0xffffffff)
 		return &not_fde;
@@ -104,18 +105,18 @@ static const u32 *cie_for_fde(const u32 *fde, const struct _stp_module *m)
 	/* OK, must be an FDE.  Now find its CIE. */
 
 	/* CIE_pointer must be a proper offset */
-	if ((fde[1] & (sizeof(*fde) - 1)) || fde[1] > (unsigned long)(fde + 1) - (unsigned long)m->unwind_data) {
+	if ((fde[1] & (sizeof(*fde) - 1)) || fde[1] > (unsigned long)(fde + 1) - (unsigned long)unwind_data) {
 		dbug_unwind(1, "fde[1]=%lx fde+1=%lx, unwind_data=%lx  %lx\n",
 			    (unsigned long)fde[1], (unsigned long)(fde + 1),
-			    (unsigned long)m->unwind_data, (unsigned long)(fde + 1) - (unsigned long)m->unwind_data);
+			    (unsigned long)unwind_data, (unsigned long)(fde + 1) - (unsigned long)unwind_data);
 		return NULL;	/* this is not a valid FDE */
 	}
 
 	/* cie pointer field is different in eh_frame vs debug_frame */
-	if (m->unwind_is_ehframe)
+	if (is_ehframe)
 		cie = fde + 1 - fde[1] / sizeof(*fde);
 	else
-		cie = m->unwind_data + fde[1];
+		cie = unwind_data + fde[1];
 
 	if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
 	    || (*cie & (sizeof(*cie) - 1))
@@ -488,7 +489,7 @@ static u32 *_stp_search_unwind_hdr(unsigned long pc,
 	ptr = hdr + 4;
 	end = hdr + m->unwind_hdr_len;
 
-	if (read_pointer(&ptr, end, hdr[1]) != (unsigned long)m->unwind_data) {
+	if (read_pointer(&ptr, end, hdr[1]) != (unsigned long)m->debug_frame) {
 		dbug_unwind(1, "eh_frame_ptr not valid");
 		return NULL;
 	}
@@ -592,8 +593,8 @@ static int unwind(struct unwind_frame_info *frame, struct task_struct *tsk)
 		return -EINVAL;
 	}
 
-	if (unlikely(m->unwind_data_len == 0 || m->unwind_data_len & (sizeof(*fde) - 1))) {
-		dbug_unwind(1, "Module %s: unwind_data_len=%d", m->name, m->unwind_data_len);
+	if (unlikely(m->debug_frame_len == 0 || m->debug_frame_len & (sizeof(*fde) - 1))) {
+		dbug_unwind(1, "Module %s: unwind_data_len=%d", m->name, m->debug_fram_len);
 		goto err;
 	}
 
@@ -602,7 +603,7 @@ static int unwind(struct unwind_frame_info *frame, struct task_struct *tsk)
 
 	/* found the fde, now set startLoc and endLoc */
 	if (fde != NULL) {
-		cie = cie_for_fde(fde, m);
+		cie = cie_for_fde(fde, m->debug_frame, false);
 		if (likely(cie != NULL && cie != &bad_cie && cie != &not_fde)) {
 			ptr = (const u8 *)(fde + 2);
 			ptrType = fde_pointer_type(cie);
@@ -625,10 +626,10 @@ static int unwind(struct unwind_frame_info *frame, struct task_struct *tsk)
 
 	/* did not a good fde find with binary search, so do slow linear search */
 	if (fde == NULL) {
-		for (fde = m->unwind_data, tableSize = m->unwind_data_len; cie = NULL, tableSize > sizeof(*fde)
-		     && tableSize - sizeof(*fde) >= *fde; tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
+	    for (fde = m->debug_frame, tableSize = m->debug_frame_len; cie = NULL, tableSize > sizeof(*fde)
+		 && tableSize - sizeof(*fde) >= *fde; tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
 			dbug_unwind(3, "fde=%lx tableSize=%d\n", (long)*fde, (int)tableSize);
-			cie = cie_for_fde(fde, m);
+			cie = cie_for_fde(fde, m->debug_frame, false);
 			if (cie == &bad_cie) {
 				cie = NULL;
 				break;
@@ -651,7 +652,7 @@ static int unwind(struct unwind_frame_info *frame, struct task_struct *tsk)
 		}
 	}
 
-	dbug_unwind(1, "cie=%lx fde=%lx startLoc=%lx endLoc=%lx\n", cie, fde, startLoc, endLoc);
+	dbug_unwind(1, "cie=%lx fde=%lx startLoc=%lx endLoc=%lx, pc=%lx\n", cie, fde, startLoc, endLoc, pc);
 	if (cie == NULL || fde == NULL)
 		goto err;
 
diff --git a/runtime/unwind/unwind.h b/runtime/unwind/unwind.h
index 3b6d0de0..285a3a34 100644
--- a/runtime/unwind/unwind.h
+++ b/runtime/unwind/unwind.h
@@ -1,7 +1,7 @@
 /* -*- linux-c -*-
  *
  * dwarf unwinder header file
- * Copyright (C) 2008 Red Hat Inc.
+ * Copyright (C) 2008, 2009 Red Hat Inc.
  * Copyright (C) 2002-2006 Novell, Inc.
  * 
  * This file is part of systemtap, and is free software.  You can
@@ -143,7 +143,7 @@ static unsigned long read_pointer(const u8 **pLoc,
                                   const void *end,
                                   signed ptrType);
 static const u32 bad_cie, not_fde;
-static const u32 *cie_for_fde(const u32 *fde, const struct _stp_module *);
+static const u32 *cie_for_fde(const u32 *fde, void *table, int is_ehframe);
 static signed fde_pointer_type(const u32 *cie);
 
 
diff --git a/translate.cxx b/translate.cxx
index 87811e9f..eaa2e942 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -4413,41 +4413,56 @@ struct unwindsym_dump_context
 };
 
 
-// Get the .debug_frame section for the given module.
-// l will be set to the length of the size of the unwind data if found.
-static void *get_unwind_data (Dwfl_Module *m, size_t *l)
+// Get the .debug_frame end .eh_frame sections for the given module.
+// Also returns the lenght of both sections when found, plus the section
+// address of the eh_frame data.
+static void get_unwind_data (Dwfl_Module *m,
+			     void **debug_frame, void **eh_frame,
+			     size_t *debug_len, size_t *eh_len,
+			     Dwarf_Addr *eh_addr)
 {
   Dwarf_Addr bias = 0;
-  Dwarf *dw;
   GElf_Ehdr *ehdr, ehdr_mem;
   GElf_Shdr *shdr, shdr_mem;
-  Elf_Scn *scn = NULL;
-  Elf_Data *data = NULL;
-
-  dw = dwfl_module_getdwarf(m, &bias);
-  if (dw != NULL)
+  Elf_Scn *scn;
+  Elf_Data *data;
+  Elf *elf;
+
+  // fetch .eh_frame info preferably from main elf file.
+  elf = dwfl_module_getelf(m, &bias);
+  ehdr = gelf_getehdr(elf, &ehdr_mem);
+  scn = NULL;
+  while ((scn = elf_nextscn(elf, scn)))
     {
-      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),
+		 ".eh_frame") == 0)
 	{
-	  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;
-	    }
+	  data = elf_rawdata(scn, NULL);
+	  *eh_frame = data->d_buf;
+	  *eh_len = data->d_size;
+	  *eh_addr = shdr->sh_addr;
+	  break;
 	}
     }
 
-  if (data != NULL)
+  // fetch .debug_frame info preferably from dwarf debuginfo file.
+  elf = (dwarf_getelf (dwfl_module_getdwarf (m, &bias))
+	 ?: dwfl_module_getelf (m, &bias));
+  ehdr = gelf_getehdr(elf, &ehdr_mem);
+  scn = NULL;
+  while ((scn = elf_nextscn(elf, scn)))
     {
-      *l = data->d_size;
-      return data->d_buf;
+      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);
+	  *debug_frame = data->d_buf;
+	  *debug_len = data->d_size;
+	  break;
+	}
     }
-
-  return NULL;
 }
 
 static int
@@ -4680,17 +4695,21 @@ dump_unwindsyms (Dwfl_Module *m,
     }
 
   // Add unwind data to be included if it exists for this module.
-  size_t len = 0;
-  void *unwind = get_unwind_data (m, &len);
-  if (unwind != NULL)
+  void *debug_frame = NULL;
+  size_t debug_len = 0;
+  void *eh_frame = NULL;
+  size_t eh_len = 0;
+  Dwarf_Addr eh_addr = NULL;
+  get_unwind_data (m, &debug_frame, &eh_frame, &debug_len, &eh_len, &eh_addr);
+  if (debug_frame != NULL && debug_len > 0)
     {
       c->output << "#if defined(STP_USE_DWARF_UNWINDER) && defined(STP_NEED_UNWIND_DATA)\n";
       c->output << "static uint8_t _stp_module_" << stpmod_idx
-		<< "_unwind_data[] = \n";
+		<< "_debug_frame[] = \n";
       c->output << "  {";
-      for (size_t i = 0; i < len; i++)
+      for (size_t i = 0; i < debug_len; i++)
 	{
-	  int h = ((uint8_t *)unwind)[i];
+	  int h = ((uint8_t *)debug_frame)[i];
 	  c->output << "0x" << hex << h << dec << ",";
 	  if ((i + 1) % 16 == 0)
 	    c->output << "\n" << "   ";
@@ -4698,7 +4717,25 @@ dump_unwindsyms (Dwfl_Module *m,
       c->output << "};\n";
       c->output << "#endif /* STP_USE_DWARF_UNWINDER && STP_NEED_UNWIND_DATA */\n";
     }
-  else
+
+  if (eh_frame != NULL && eh_len > 0)
+    {
+      c->output << "#if defined(STP_USE_DWARF_UNWINDER) && defined(STP_NEED_UNWIND_DATA)\n";
+      c->output << "static uint8_t _stp_module_" << stpmod_idx
+		<< "_eh_frame[] = \n";
+      c->output << "  {";
+      for (size_t i = 0; i < debug_len; i++)
+	{
+	  int h = ((uint8_t *)debug_frame)[i];
+	  c->output << "0x" << hex << h << dec << ",";
+	  if ((i + 1) % 16 == 0)
+	    c->output << "\n" << "   ";
+	}
+      c->output << "};\n";
+      c->output << "#endif /* STP_USE_DWARF_UNWINDER && STP_NEED_UNWIND_DATA */\n";
+    }
+
+  if (debug_frame == NULL && eh_frame == NULL)
     {
       // There would be only a small benefit to warning.  A user
       // likely can't do anything about this; backtraces for the
@@ -4755,25 +4792,40 @@ dump_unwindsyms (Dwfl_Module *m,
   c->output << ".path = " << lex_cast_qstring (mainfile) << ",\n";
 
   c->output << ".dwarf_module_base = 0x" << hex << base << dec << ", \n";
+  c->output << ".eh_frame_addr = 0x" << hex << eh_addr << dec << ", \n";
+
+  if (debug_frame != NULL)
+    {
+      c->output << "#if defined(STP_USE_DWARF_UNWINDER) && defined(STP_NEED_UNWIND_DATA)\n";
+      c->output << ".debug_frame = "
+		<< "_stp_module_" << stpmod_idx << "_debug_frame, \n";
+      c->output << ".debug_frame_len = " << debug_len << ", \n";
+      c->output << "#else\n";
+    }
+
+  c->output << ".debug_frame = NULL,\n";
+  c->output << ".debug_frame_len = 0,\n";
+
+  if (debug_frame != NULL)
+    c->output << "#endif /* STP_USE_DWARF_UNWINDER && STP_NEED_UNWIND_DATA*/\n";
 
-  if (unwind != NULL)
+  if (eh_frame != NULL)
     {
       c->output << "#if defined(STP_USE_DWARF_UNWINDER) && defined(STP_NEED_UNWIND_DATA)\n";
-      c->output << ".unwind_data = "
-		<< "_stp_module_" << stpmod_idx << "_unwind_data, \n";
-      c->output << ".unwind_data_len = " << len << ", \n";
+      c->output << ".eh_frame = "
+		<< "_stp_module_" << stpmod_idx << "_eh_frame, \n";
+      c->output << ".eh_frame_len = " << eh_len << ", \n";
       c->output << "#else\n";
     }
 
-  c->output << ".unwind_data = NULL,\n";
-  c->output << ".unwind_data_len = 0,\n";
+  c->output << ".eh_frame = NULL,\n";
+  c->output << ".eh_frame_len = 0,\n";
 
-  if (unwind != NULL)
+  if (eh_frame != NULL)
     c->output << "#endif /* STP_USE_DWARF_UNWINDER && STP_NEED_UNWIND_DATA*/\n";
 
   c->output << ".unwind_hdr = NULL,\n";
   c->output << ".unwind_hdr_len = 0,\n";
-  c->output << ".unwind_is_ehframe = 0,\n";
 
   c->output << ".sections = _stp_module_" << stpmod_idx << "_sections" << ",\n";
   c->output << ".num_sections = sizeof(_stp_module_" << stpmod_idx << "_sections)/"