Merge branch 'jankratochvil/forunwind-baseaddr-hookvars-corereport-unwindx86-nonx86-fddebuginfo' into jankratochvil/forunwind-baseaddr-hookvars-corereport-unwindx86-nonx86-fddebuginfo-ports

3 files changed, 45 insertions, 69 deletions

diff --git a/backends/ppc64_init.c b/backends/ppc64_init.c
index 32ca876e..8b3c9462 100644
--- a/backends/ppc64_init.c
+++ b/backends/ppc64_init.c
@@ -71,8 +71,6 @@ ppc64_init (elf, machine, eh, ehlen)
   HOOK (eh, frame_state);
   HOOK (eh, abi_cfi);
   HOOK (eh, frame_dwarf_to_regno);
-  HOOK (eh, get_func_pc);
-  HOOK (eh, destr);
 
   return MODVERSION;
 }
diff --git a/libdwfl/dwfl_frame_unwind.c b/libdwfl/dwfl_frame_unwind.c
index e35ccb5d..c1a81b15 100644
--- a/libdwfl/dwfl_frame_unwind.c
+++ b/libdwfl/dwfl_frame_unwind.c
@@ -312,46 +312,6 @@ have_unwound (Dwfl_Frame_State **statep)
   abort ();
 }
 
-/* Check if PC is in the "_start" function which may have no FDE.
-   It corresponds to the GDB get_prev_frame logic "inside entry func".
-   Return TRUE if PC is in an outer frame.  Return FALSE (and call
-   __libdwfl_seterrno) otherwise.  */
-
-static bool
-no_fde (Dwarf_Addr pc, Dwfl_Module *mod, Dwarf_Addr bias)
-{
-  GElf_Sym sym;
-  const char *symname = INTUSE(dwfl_module_addrsym) (mod, pc, &sym, NULL);
-  if (symname == NULL)
-    {
-      __libdwfl_seterrno (DWFL_E_NO_DWARF);
-      return false;
-    }
-  /* It has no FDE on PPC64; it can be still unwound via the stack frame.  */
-  if (strcmp (symname, ".generic_start_main") == 0)
-    return true;
-  GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (mod->main.elf, &ehdr_mem);
-  if (ehdr == NULL)
-    {
-      __libdwfl_seterrno (DWFL_E_LIBELF);
-      return false;
-    }
-  if (pc < ehdr->e_entry + bias)
-    {
-      __libdwfl_seterrno (DWFL_E_NO_DWARF);
-      return false;
-    }
-  /* "_start" is size-less.  Search for PC, if the closest symbol is the one
-     for E_ENTRY it belongs into the function starting at E_ENTRY.  */
-  if (sym.st_value != ehdr->e_entry + bias
-      || (sym.st_size != 0 && pc >= sym.st_value + sym.st_size))
-    {
-      __libdwfl_seterrno (DWFL_E_NO_DWARF);
-      return false;
-    }
-  return true;
-}
-
 /* The logic is to call __libdwfl_seterrno for any CFI bytecode interpretation
    error so one can easily catch the problem with a debugger.  Still there are
    archs with invalid CFI for some registers where the registers are never used
@@ -362,22 +322,12 @@ no_fde (Dwarf_Addr pc, Dwfl_Module *mod, Dwarf_Addr bias)
    an undefined PC register (due to an error unwinding it).  */
 
 static bool
-handle_cfi (Dwfl_Frame_State **statep, Dwarf_Addr pc, Dwfl_Module *mod,
-	    Dwarf_CFI *cfi, Dwarf_Addr bias)
+handle_cfi (Dwfl_Frame_State **statep, Dwarf_Addr pc, Dwarf_CFI *cfi)
 {
   Dwfl_Frame_State *state = *statep;
   Dwarf_Frame *frame;
-  if (INTUSE(dwarf_cfi_addrframe) (cfi, pc - bias, &frame) != 0)
+  if (INTUSE(dwarf_cfi_addrframe) (cfi, pc, &frame) != 0)
     {
-      int dw_errno = dwarf_errno ();
-      if (dw_errno == DWARF_E_NO_MATCH)
-	{
-	  if (! no_fde (pc, mod, bias))
-	    return false;
-	  *statep = NULL;
-	  return true;
-	}
-      __libdw_seterrno (dw_errno);
       __libdwfl_seterrno (DWFL_E_LIBDW);
       return false;
     }
@@ -474,7 +424,7 @@ dwfl_frame_unwind (Dwfl_Frame_State **statep)
       Dwarf_CFI *cfi_eh = INTUSE(dwfl_module_eh_cfi) (mod, &bias);
       if (cfi_eh)
 	{
-	  if (handle_cfi (statep, pc, mod, cfi_eh, bias))
+	  if (handle_cfi (statep, pc - bias, cfi_eh))
 	    return true;
 	  if (state->unwound)
 	    {
@@ -485,7 +435,7 @@ dwfl_frame_unwind (Dwfl_Frame_State **statep)
       Dwarf_CFI *cfi_dwarf = INTUSE(dwfl_module_dwarf_cfi) (mod, &bias);
       if (cfi_dwarf)
 	{
-	  if (handle_cfi (statep, pc, mod, cfi_dwarf, bias) && state->unwound)
+	  if (handle_cfi (statep, pc - bias, cfi_dwarf) && state->unwound)
 	    return true;
 	  if (state->unwound)
 	    {
diff --git a/tests/run-backtrace.sh b/tests/run-backtrace.sh
index a57d4744..0d1e7370 100755
--- a/tests/run-backtrace.sh
+++ b/tests/run-backtrace.sh
@@ -27,41 +27,69 @@ mytestrun()
   testrun "$@"
 }
 
+check_main()
+{
+  if grep -w main $1; then
+    return
+  fi
+  cat >&2 $1
+  echo >&2 $2: no main
+  false
+}
+
 check_gsignal()
 {
   # Without proper ELF symbols resolution we could get inappropriate weak
   # symbol "gsignal" with the same address as the correct symbol "raise".
-  if grep -w gsignal $1; then
-    false
+  if ! grep -w gsignal $1; then
+    return
   fi
+  cat >&2 $1
+  echo >&2 $2: found gsignal
+  false
 }
 
-check_empty()
+check_err()
 {
-  if test -s $1; then
-    false
+  if test ! -s $1; then
+    return
+  fi
+  # In some cases we cannot reliably find out we got behind _start.
+  if echo "No DWARF information found" | cmp -s - $1; then
+    return
   fi
+  cat >&2 $1
+  echo >&2 $2: neither empty nor just out of DWARF
 }
 
 for child in backtrace-child{,-biarch}; do
-  mytestrun ./backtrace ./$child
+  tempfiles $child{.bt,err}
+  ./backtrace ./$child 1>$child.bt 2>$child.err \
+    || true
+  check_main $child.bt $child
+  check_gsignal $child.bt $child
+  check_err $child.err $child
   core="core.`ulimit -c unlimited; set +e; ./$child --gencore --run; true`"
   tempfiles $core{,.bt,.err}
-  mytestrun ./backtrace ./$child ./$core 1>$core.bt 2>$core.err
+  ./backtrace ./$child ./$core 1>$core.bt 2>$core.err \
+    || true
   cat $core.{bt,err}
-  check_gsignal $core.bt
-  check_empty $core.err
+  check_main $core.bt $child-$core
+  check_gsignal $core.bt $child-$core
+  check_err $core.err $child-$core
 done
 
 for arch in ppc ppc64 s390 s390x; do
   testfiles backtrace.$arch.{exec,core}
   tempfiles backtrace.$arch.{bt,err}
   echo ./backtrace ./backtrace.$arch.{exec,core}
-  mytestrun ./backtrace ./backtrace.$arch.{exec,core} 1>backtrace.$arch.bt \
-						      2>backtrace.$arch.err
+  ./backtrace ./backtrace.$arch.{exec,core} 1>backtrace.$arch.bt  \
+					    2>backtrace.$arch.err \
+    || true
   cat backtrace.$arch.{bt,err}
-  check_gsignal backtrace.$arch.bt
-  check_empty backtrace.$arch.err
+  check_main backtrace.$arch.bt $arch
+  check_gsignal backtrace.$arch.bt $arch
+  check_err backtrace.$arch.err $arch
 done
 
 exit 0