Merge branch 'master' of ssh://sources.redhat.com/git/systemtap

7 files changed, 115 insertions, 33 deletions

diff --git a/runtime/ChangeLog b/runtime/ChangeLog
index f7a844d8..97b1a0c0 100644
--- a/runtime/ChangeLog
+++ b/runtime/ChangeLog
@@ -1,3 +1,36 @@
+2008-09-10  Frank Ch. Eigler  <fche@elastic.org>
+
+	* runtime.h (STP_USE_FRAME_POINTER): Remove architecture #if's.
+	All will activate it if CONFIG_FRAME_POINTER unless
+	STP_USE_DWARF_UNWINDER.
+	* stack-i386.c: (__stp_stack_print): Handle !DWARF and !FRAME
+	configuration.
+
+2008-09-10  Mark Wielaard  <mjw@redhat.com>
+
+	* sym.h (_stp_module): Rename module_base to dwarf_module_base.
+	* unwind.c (adjustStartLoc): Document and use dwarf_module_base.
+
+2008-09-10  Mark Wielaard  <mjw@redhat.com>
+
+	* runtime.h (CONFIG_FRAME_POINTER): Don't enable when
+	STP_USE_DWARF_UNWINDER is already defined.
+
+2008-09-10  Mark Wielaard  <mjw@redhat.com>
+
+	* sym.h (_stp_module): Add module_base field.
+	* unwind.c (adjustStartLoc): New function.
+	(_stp_search_unwind_hdr): Use adjustStartLoc.
+	(unwind): Likewise.
+
+2008-09-10  Mark Wielaard  <mjw@redhat.com>
+
+	* unwind.c (unwind): Use _stp_mod_sec_lookup to get module and
+	unwind tables.
+	* runtime.h (STP_USE_FRAME_BUFFER): Disable by default for now.
+	* stack-x86_64.c (__stp_stack_print): Add levels to
+	_stp_stack_print_fallback call.
+
 2008-09-09  Masami Hiramatsu  <mhiramat@redhat.com>
 
 	* regs-ia64.c (__ia64_fetch_register): Return the address of the
@@ -15,6 +48,11 @@
 
 2008-09-09  Mark Wielaard  <mwielaard@redhat.com>
 
+	* sym.c (_stp_mod_sec_lookup): New function, extracted from
+	_stp_kallsyms_lookup.
+
+2008-09-09  Mark Wielaard  <mwielaard@redhat.com>
+
 	* sym.c (_stp_kallsyms_lookup): Correct this_section_offset
 	calculation.
 
diff --git a/runtime/runtime.h b/runtime/runtime.h
index fd0cac9e..cd3d0b11 100644
--- a/runtime/runtime.h
+++ b/runtime/runtime.h
@@ -68,13 +68,15 @@ static struct
 
 #ifdef CONFIG_FRAME_POINTER
 /* Just because frame pointers are available does not mean we can trust them. */
-#if defined (__i386__) || defined (__arm__)
+#ifndef STP_USE_DWARF_UNWINDER
 #define STP_USE_FRAME_POINTER
 #endif
 #endif
 
-/* dwarf unwinder only tested so far on i386 and x86_64 */
-#if !defined(STP_USE_FRAME_BUFFER) && (defined(__i386__) || defined(__x86_64__))
+/* dwarf unwinder only tested so far on i386 and x86_64,
+   but globally disabled for now */
+#if 0
+// !defined(STP_USE_FRAME_BUFFER) && (defined(__i386__) || defined(__x86_64__))
 #define STP_USE_DWARF_UNWINDER
 #endif
 
diff --git a/runtime/stack-i386.c b/runtime/stack-i386.c
index ad101889..ed7e2ce1 100644
--- a/runtime/stack-i386.c
+++ b/runtime/stack-i386.c
@@ -54,9 +54,10 @@ static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
 		fp = next_fp;
 	}
 #else
+#ifdef STP_USE_DWARF_UNWINDER
 	struct unwind_frame_info info;
 	arch_unw_init_frame_info(&info, regs);
-	
+
 	while (levels && !arch_unw_user_mode(&info)) {
 		int ret = unwind(&info);
 		dbug_unwind(1, "ret=%d PC=%lx SP=%lx\n", ret, UNW_PC(&info), UNW_SP(&info));
@@ -71,5 +72,8 @@ static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
 			_stp_stack_print_fallback(context, UNW_SP(&info), verbose, levels);
 		break;
 	}
+#else /* ! STP_USE_DWARF_UNWINDER */
+	_stp_stack_print_fallback(context, (unsigned long)&REG_SP(regs), verbose, levels);
 #endif /* STP_USE_FRAME_POINTER */
+#endif
 }
diff --git a/runtime/stack-x86_64.c b/runtime/stack-x86_64.c
index 783e72bd..d3ec91cf 100644
--- a/runtime/stack-x86_64.c
+++ b/runtime/stack-x86_64.c
@@ -45,6 +45,6 @@ static void __stp_stack_print(struct pt_regs *regs, int verbose, int levels)
 		break;
 	}
 #else /* ! STP_USE_DWARF_UNWINDER */
-	_stp_stack_print_fallback(REG_SP(regs), verbose);
+	_stp_stack_print_fallback(REG_SP(regs), verbose, levels);
 #endif
 }
diff --git a/runtime/sym.c b/runtime/sym.c
index b594d9c2..1a9e26b2 100644
--- a/runtime/sym.c
+++ b/runtime/sym.c
@@ -73,6 +73,37 @@ unsigned long _stp_module_relocate(const char *module, const char *section, unsi
 }
 
 
+/* Return module owner and fills in closest section of the address
+   if found, return NULL otherwise.
+   XXX: needs to be address-space-specific. */
+static struct _stp_module *_stp_mod_sec_lookup(unsigned long addr,
+					       struct _stp_section **sec)
+{
+  struct _stp_module *m = NULL;
+  unsigned midx = 0;
+  unsigned long closest_section_offset = ~0;
+  for (midx = 0; midx < _stp_num_modules; midx++)
+    {
+      unsigned secidx;
+      for (secidx = 0; secidx < _stp_modules[midx]->num_sections; secidx++)
+	{
+	  unsigned long this_section_addr;
+	  unsigned long this_section_offset;
+	  this_section_addr = _stp_modules[midx]->sections[secidx].addr;
+	  if (addr < this_section_addr) continue;
+	  this_section_offset = addr - this_section_addr;
+	  if (this_section_offset < closest_section_offset)
+	    {
+	      closest_section_offset = this_section_offset;
+	      m = _stp_modules[midx];
+	      *sec = & m->sections[secidx];
+	    }
+	}
+      }
+  return m;
+}
+
+
 /* XXX: needs to be address-space-specific. */
 static const char *_stp_kallsyms_lookup(unsigned long addr, unsigned long *symbolsize,
                                         unsigned long *offset, 
@@ -86,29 +117,7 @@ static const char *_stp_kallsyms_lookup(unsigned long addr, unsigned long *symbo
 	unsigned long flags;
 	unsigned end, begin = 0;
 
-        /* Find the closest section (and its owner module); fill in m & sec. */
-        {
-          unsigned midx = 0;
-          unsigned long closest_section_offset = ~0;
-          for (midx = 0; midx < _stp_num_modules; midx++)
-            {
-              unsigned secidx;
-              for (secidx = 0; secidx < _stp_modules[midx]->num_sections; secidx++)
-                {
-                  unsigned long this_section_addr = _stp_modules[midx]->sections[secidx].addr;
-                  unsigned long this_section_offset;
-                  if (addr < this_section_addr) continue;
-                  this_section_offset = addr - this_section_addr;
-                  if (this_section_offset < closest_section_offset)
-                    {
-                      closest_section_offset = this_section_offset;
-                      m = _stp_modules[midx];
-                      sec = & m->sections[secidx];
-                    }
-                }
-            }
-        }
-        
+	m = _stp_mod_sec_lookup(addr, &sec);
         if (unlikely (m == NULL || sec == NULL))
           return NULL;
         
diff --git a/runtime/sym.h b/runtime/sym.h
index b2fb8ee9..5888d2c7 100644
--- a/runtime/sym.h
+++ b/runtime/sym.h
@@ -33,7 +33,12 @@ struct _stp_module {
 	/* any notifier hooks that will tell us when a module */
 	/* is unloading. */
   	unsigned long module; /* XXX: why not struct module * ? */
-	
+
+	 /* This is to undo .debug_frame relocation performed by elfutils, */
+	 /* which is done during the translate phase when we encode the    */
+	 /* unwind data into the module. See adjustStartLoc() in unwind.c. */
+  	unsigned long dwarf_module_base;
+
 	/* the stack unwind data for this module */
 	void *unwind_data;
 	void *unwind_hdr;	
diff --git a/runtime/unwind.c b/runtime/unwind.c
index 21ea4559..bc8a93dc 100644
--- a/runtime/unwind.c
+++ b/runtime/unwind.c
@@ -550,10 +550,29 @@ static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc, s
 	return result && ptr.p8 == end && (targetLoc == 0 || state->label == NULL);
 }
 
+// If this is an address inside a module, adjust for section relocation
+// and the elfutils base relocation done during loading of the .dwarf_frame
+// in translate.cxx.
+static unsigned long
+adjustStartLoc (unsigned long startLoc,
+		struct _stp_module *m,
+		struct _stp_section *s)
+{
+  if (startLoc && (strcmp (m->name, "kernel") != 0))
+    {
+      startLoc = _stp_module_relocate (m->name, s->name,
+				       startLoc);
+      startLoc -= m->dwarf_module_base;
+    }
+  return startLoc;
+}
+
 /* If we previously created an unwind header, then use it now to binary search */
 /* for the FDE corresponding to pc. */
 
-static u32 *_stp_search_unwind_hdr(unsigned long pc, struct _stp_module *m)
+static u32 *_stp_search_unwind_hdr(unsigned long pc,
+				   struct _stp_module *m,
+				   struct _stp_section *s)
 {
 	const u8 *ptr, *end, *hdr = m->unwind_hdr;
 	unsigned long startLoc;
@@ -600,6 +619,7 @@ static u32 *_stp_search_unwind_hdr(unsigned long pc, struct _stp_module *m)
 	do {
 		const u8 *cur = ptr + (num / 2) * (2 * tableSize);
 		startLoc = read_pointer(&cur, cur + tableSize, hdr[3]);
+		startLoc = adjustStartLoc(startLoc, m, s);
 		if (pc < startLoc)
 			num /= 2;
 		else {
@@ -608,7 +628,7 @@ static u32 *_stp_search_unwind_hdr(unsigned long pc, struct _stp_module *m)
 		}
 	} while (startLoc && num > 1);
 
-	if (num == 1 && (startLoc = read_pointer(&ptr, ptr + tableSize, hdr[3])) != 0 && pc >= startLoc)
+	if (num == 1 && (startLoc = adjustStartLoc(read_pointer(&ptr, ptr + tableSize, hdr[3]), m, s)) != 0 && pc >= startLoc)
 		fde = (void *)read_pointer(&ptr, ptr + tableSize, hdr[3]);
 
 	dbug_unwind(1, "returning fde=%lx startLoc=%lx", fde, startLoc);
@@ -676,6 +696,7 @@ int unwind(struct unwind_frame_info *frame)
 	signed ptrType = -1;
 	uleb128_t retAddrReg = 0;
 	struct _stp_module *m;
+	struct _stp_section *s = NULL;
 	struct unwind_state state;
 
 	dbug_unwind(1, "pc=%lx, %lx", pc, UNW_PC(frame));
@@ -683,7 +704,7 @@ int unwind(struct unwind_frame_info *frame)
 	if (UNW_PC(frame) == 0)
 		return -EINVAL;
 
-	m = NULL /*_stp_get_unwind_info(pc) */;
+	m = _stp_mod_sec_lookup (pc, &s);
 	if (unlikely(m == NULL)) {
 		dbug_unwind(1, "No module found for pc=%lx", pc);
 		return -EINVAL;
@@ -694,7 +715,7 @@ int unwind(struct unwind_frame_info *frame)
 		goto err;
 	}
 
-	fde = _stp_search_unwind_hdr(pc, m);
+	fde = _stp_search_unwind_hdr(pc, m, s);
 	dbug_unwind(1, "%s: fde=%lx\n", m->name, fde);
 
 	/* found the fde, now set startLoc and endLoc */
@@ -704,6 +725,8 @@ int unwind(struct unwind_frame_info *frame)
 			ptr = (const u8 *)(fde + 2);
 			ptrType = fde_pointer_type(cie);
 			startLoc = read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType);
+			startLoc = adjustStartLoc(startLoc, m, s);
+
 			dbug_unwind(2, "startLoc=%lx, ptrType=%s", startLoc, _stp_eh_enc_name(ptrType));
 			if (!(ptrType & DW_EH_PE_indirect))
 				ptrType &= DW_EH_PE_FORM | DW_EH_PE_signed;
@@ -733,6 +756,7 @@ int unwind(struct unwind_frame_info *frame)
 
 			ptr = (const u8 *)(fde + 2);
 			startLoc = read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType);
+			startLoc = adjustStartLoc(startLoc, m, s);
 			dbug_unwind(2, "startLoc=%lx, ptrType=%s", startLoc, _stp_eh_enc_name(ptrType));
 			if (!startLoc)
 				continue;