[rpms/gdb] gdb-17.2-rebase-f44: Suppress repeated warnings when loading a core file

[rpms/gdb] gdb-17.2-rebase-f44: Suppress repeated warnings when loading a core file

[Kevin Buettner]

            A new commit has been pushed.

            Repo   : rpms/gdb
            Branch : gdb-17.2-rebase-f44
            Commit : d5dc87ea90091b6e3664fe94da0c8ece672fb320
            Author : Kevin Buettner <kevinb@redhat.com>
            Date   : 2023-06-30T15:20:10-07:00
            Stats  : +122/-3 in 5 file(s)
            URL    : https://src.fedoraproject.org/rpms/gdb/c/d5dc87ea90091b6e3664fe94da0c8ece672fb320?branch=gdb-17.2-rebase-f44

            Log:
            Suppress repeated warnings when loading a core file

Backport upstream changes which prevent repeated warnings from being
printed when loading a core file  (RHBZ 2160211, Lancelot SIX).

---
diff --git a/_gdb.spec.Patch.include b/_gdb.spec.Patch.include
index 1befb33..eeed776 100644
--- a/_gdb.spec.Patch.include
+++ b/_gdb.spec.Patch.include
@@ -206,3 +206,8 @@ Patch046: gdb-binutils29988-read_indexed_address.patch
 # first seen when building with GCC 13.1.1 20230426 (Red Hat ;; 13.1.1-1).
 Patch047: gdb-rhbz2192105-ftbs-dangling-pointer
 
+# Backport two commits, 0ad504dd464 and ea70f941f9b, from Lancelot SIX
+# which prevent repeated warnings from being printed while loading a
+# core file. (RH BZ 2160211)
+Patch048: gdb-rhbz2160211-excessive-core-file-warnings.patch
+

diff --git a/_gdb.spec.patch.include b/_gdb.spec.patch.include
index 8258dc9..ef55dd0 100644
--- a/_gdb.spec.patch.include
+++ b/_gdb.spec.patch.include
@@ -45,3 +45,4 @@
 %patch -p1 -P045
 %patch -p1 -P046
 %patch -p1 -P047
+%patch -p1 -P048

diff --git a/_patch_order b/_patch_order
index 6c3981d..cddc2ce 100644
--- a/_patch_order
+++ b/_patch_order
@@ -45,3 +45,4 @@ gdb-add-index.patch
 gdb-rhbz1553104-s390x-arch12-test.patch
 gdb-binutils29988-read_indexed_address.patch
 gdb-rhbz2192105-ftbs-dangling-pointer
+gdb-rhbz2160211-excessive-core-file-warnings.patch

diff --git a/gdb-rhbz2160211-excessive-core-file-warnings.patch b/gdb-rhbz2160211-excessive-core-file-warnings.patch
new file mode 100644
index 0000000..a790054
--- /dev/null
+++ b/gdb-rhbz2160211-excessive-core-file-warnings.patch
@@ -0,0 +1,108 @@
+From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
+From: Kevin Buettner <kevinb@redhat.com>
+Date: Thu, 29 Jun 2023 18:20:30 -0700
+Subject: gdb-rhbz2160211-excessive-core-file-warnings.patch
+
+;; Backport two commits, 0ad504dd464 and ea70f941f9b, from Lancelot SIX
+;; which prevent repeated warnings from being printed while loading a
+;; core file. (RH BZ 2160211)
+
+gdb/corelow.c: avoid repeated warnings in build_file_mappings
+
+When GDB opens a coredump it tries to locate and then open all files
+which were mapped in the process.
+
+If a file is found but cannot be opened with BFD (bfd_open /
+bfd_check_format fails), then a warning is printed to the user.  If the
+same file was mapped multiple times in the process's address space, the
+warning is printed once for each time the file was mapped.  I find this
+un-necessarily noisy.
+
+This patch makes it so the warning message is printed only once per
+file.
+
+There was a comment in the code assuming that if the file was found on
+the system, opening it (bfd_open + bfd_check_format) should always
+succeed.  A recent change in BFD (014a602b86f "Don't optimise bfd_seek
+to same position") showed that this assumption is not valid.  For
+example, it is possible to have a core dump of a process which had
+mmaped an IO page from a DRI render node (/dev/dri/runderD$NUM).  In
+such case the core dump does contain the information that portions of
+this special file were mapped in the host process, but trying to seek to
+position 0 will fail, making bfd_check_format fail.  This patch removes
+this comment.
+
+Reviewed-By: John Baldwin <jhb@FreeBSD.org>
+Approved-By: Andrew Burgess <aburgess@redhat.com>
+
+gdb/corelow.c: do not try to reopen a file if open failed once
+
+In the current implementation, core_target::build_file_mappings will try
+to locate and open files which were mapped in the process for which the
+core dump was produced.  If the file cannot be found or cannot be
+opened, GDB will re-try to open it once for each time it was mapped in
+the process's address space.
+
+This patch makes it so GDB recognizes that it has already failed to open
+a given file once and does not re-try the process for each mapping.
+
+Reviewed-By: John Baldwin <jhb@FreeBSD.org>
+Approved-By: Andrew Burgess <aburgess@redhat.com>
+
+diff --git a/gdb/corelow.c b/gdb/corelow.c
+--- a/gdb/corelow.c
++++ b/gdb/corelow.c
+@@ -237,6 +237,16 @@ core_target::build_file_mappings ()
+ 	   weed out non-file-backed mappings.  */
+ 	gdb_assert (filename != nullptr);
+ 
++	if (unavailable_paths.find (filename) != unavailable_paths.end ())
++	  {
++	    /* We have already seen some mapping for FILENAME but failed to
++	       find/open the file.  There is no point in trying the same
++	       thing again so just record that the range [start, end) is
++	       unavailable.  */
++	    m_core_unavailable_mappings.emplace_back (start, end - start);
++	    return;
++	  }
++
+ 	struct bfd *bfd = bfd_map[filename];
+ 	if (bfd == nullptr)
+ 	  {
+@@ -254,11 +264,10 @@ core_target::build_file_mappings ()
+ 	    if (expanded_fname == nullptr)
+ 	      {
+ 		m_core_unavailable_mappings.emplace_back (start, end - start);
+-		/* Print just one warning per path.  */
+-		if (unavailable_paths.insert (filename).second)
+-		  warning (_("Can't open file %s during file-backed mapping "
+-			     "note processing"),
+-			   filename);
++		unavailable_paths.insert (filename);
++		warning (_("Can't open file %s during file-backed mapping "
++			   "note processing"),
++			 filename);
+ 		return;
+ 	      }
+ 
+@@ -268,18 +277,11 @@ core_target::build_file_mappings ()
+ 	    if (bfd == nullptr || !bfd_check_format (bfd, bfd_object))
+ 	      {
+ 		m_core_unavailable_mappings.emplace_back (start, end - start);
+-		/* If we get here, there's a good chance that it's due to
+-		   an internal error.  We issue a warning instead of an
+-		   internal error because of the possibility that the
+-		   file was removed in between checking for its
+-		   existence during the expansion in exec_file_find()
+-		   and the calls to bfd_openr() / bfd_check_format(). 
+-		   Output both the path from the core file note along
+-		   with its expansion to make debugging this problem
+-		   easier.  */
++		unavailable_paths.insert (filename);
+ 		warning (_("Can't open file %s which was expanded to %s "
+ 			   "during file-backed mapping note processing"),
+ 			 filename, expanded_fname.get ());
++
+ 		if (bfd != nullptr)
+ 		  bfd_close (bfd);
+ 		return;

diff --git a/gdb.spec b/gdb.spec
index ba0ab43..13e4f89 100644
--- a/gdb.spec
+++ b/gdb.spec
@@ -57,7 +57,7 @@ Version: 13.2
 
 # The release always contains a leading reserved number, start it at 1.
 # `upstream' is not a part of `name' to stay fully rpm dependencies compatible for the testing.
-Release: 2%{?dist}
+Release: 3%{?dist}
 
 License: GPLv3+ and GPLv3+ with exceptions and GPLv2+ and GPLv2+ with exceptions and GPL+ and LGPLv2+ and LGPLv3+ and BSD and Public Domain and GFDL
 # Do not provide URL for snapshots as the file lasts there only for 2 days.
@@ -1252,10 +1252,14 @@ fi
 %endif
 
 %changelog
-* Wed Jun 28 2023 Python Maint <python-maint@redhat.com>
+* Fri Jun 30 2023 Kevin Buettner <kevinb@redhat.com> - 13.2-3
+- Backport upstream changes which prevent repeated warnings from being
+  printed when loading a core file  (RHBZ 2160211, Lancelot SIX).
+
+* Wed Jun 28 2023 Python Maint <python-maint@redhat.com> - 13.2-2
 - Rebuilt for Python 3.12
 
-* Sun Jun 25 2023 Alexandra Hájková <ahajkova@redhat.com> - 13.2
+* Sun Jun 25 2023 Alexandra Hájková <ahajkova@redhat.com> - 13.2-1
 - Rebase to FSF GDB 13.22.
 - Remove gdb-rhbz2177655-aarch64-pauth-valid-regcache.patch.
 - Remove gdb-rhbz2183595-rustc-inside_main.patch.