Backport "fix logic of find_comp_unit and set_comp_unit"

_gdb.spec.Patch.include

@@ -459,3 +459,7 @@ Patch110: gdb-rhbz2012819-ibmz-update-5of5.patch
 # (Carl Love, RHBZ 1870017)
 Patch111: gdb-rhbz1870017-p10-plt-prologue-skipping.patch
 
+# Backport "fix logic of find_comp_unit and set_comp_unit"
+# (Simon Marchi, RHBZ 2086761)
+Patch112: gdb-rhbz2086761-unknown-cfa-rule.patch
+

_gdb.spec.patch.include

@@ -109,3 +109,4 @@
 %patch109 -p1
 %patch110 -p1
 %patch111 -p1
+%patch112 -p1

_patch_order

@@ -109,3 +109,4 @@ gdb-rhbz2012819-ibmz-update-3of5.patch
 gdb-rhbz2012819-ibmz-update-4of5.patch
 gdb-rhbz2012819-ibmz-update-5of5.patch
 gdb-rhbz1870017-p10-plt-prologue-skipping.patch
+gdb-rhbz2086761-unknown-cfa-rule.patch

gdb-rhbz2086761-unknown-cfa-rule.patch

@@ -0,0 +1,54 @@
+From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
+From: Keith Seitz <keiths@redhat.com>
+Date: Tue, 24 May 2022 07:39:17 -0700
+Subject: gdb-rhbz2086761-unknown-cfa-rule.patch
+
+;; Backport "fix logic of find_comp_unit and set_comp_unit"
+;; (Simon Marchi, RHBZ 2086761)
+
+The logic in find_comp_unit and set_comp_unit is reversed.  When the BFD
+requires relocation, we want to put the comp_unit structure in the
+map where the comp_unit objects are not shared, that is the one indexed
+by objfile.  If the BFD does not require relocation, then, we can share
+a single comp_unit structure for all users of that BFD, so we want to
+put it in the BFD-indexed map.  The comments on top of
+dwarf2_frame_bfd_data and dwarf2_frame_objfile_data make that clear.
+
+Fix it by swapping the two in find_comp_unit and set_comp_unit.
+
+I don't have a test for this, because I don't see how to write one in a
+reasonable amount of time.
+
+gdb/ChangeLog:
+
+        PR gdb/26876
+        * dwarf2/frame.c (find_comp_unit, set_comp_unit): Reverse use of
+        dwarf2_frame_bfd_data and dwarf2_frame_objfile_data.
+
+diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
+--- a/gdb/dwarf2/frame.c
++++ b/gdb/dwarf2/frame.c
+@@ -1640,8 +1640,9 @@ find_comp_unit (struct objfile *objfile)
+ {
+   bfd *abfd = objfile->obfd;
+   if (gdb_bfd_requires_relocations (abfd))
+-    return dwarf2_frame_bfd_data.get (abfd);
+-  return dwarf2_frame_objfile_data.get (objfile);
++    return dwarf2_frame_objfile_data.get (objfile);
++
++  return dwarf2_frame_bfd_data.get (abfd);
+ }
+ 
+ /* Store the comp_unit on OBJFILE, or the corresponding BFD, as
+@@ -1652,8 +1653,9 @@ set_comp_unit (struct objfile *objfile, struct comp_unit *unit)
+ {
+   bfd *abfd = objfile->obfd;
+   if (gdb_bfd_requires_relocations (abfd))
+-    return dwarf2_frame_bfd_data.set (abfd, unit);
+-  return dwarf2_frame_objfile_data.set (objfile, unit);
++    return dwarf2_frame_objfile_data.set (objfile, unit);
++
++  return dwarf2_frame_bfd_data.set (abfd, unit);
+ }
+ 
+ /* Find the FDE for *PC.  Return a pointer to the FDE, and store the

gdb.spec

@@ -1158,7 +1158,11 @@ fi
 %endif
 
 %changelog
-* Mon Apr 11 2022 Bruno Larsen <blarsen@redhat.com> - 10.2-10.el9
+* Tue May 24 2022 Keith Seitz <keiths@redhat.com> - 10.2-10.el9
+- Backport "fix logic of find_comp_unit and set_comp_unit"
+  (Simon Marchi, RHBZ 2086761)
+
+* Mon Apr 11 2022 Bruno Larsen <blarsen@redhat.com>
 - Backport Add Power 10 PLT instruction patterns
   (Carl Love, RHBZ 1870017)