libdrgn: orc_info: work around ORC backports in RHEL 9.6

Resolves: RHEL-136527
Upstream: https://github.com/osandov/drgn

This problem is fixed in the kernel with b9f174c811e3 ("x86/unwind/orc:
Add ELF section with ORC version identifier"). But the fix won't work as
expected due to missing commit 321648455061 ("kbuild: use obj-y instead
extra-y for objects placed at the head"). The second commit however is
very invasive and shouldn't be backported this late in the RHEL9 cycle
(see RHEL-27234 for details). So backport the workaround in drgn
instead.

commit 8660ee186377aabf28cd54d76beb942b9a06d09a
Author: Stephen Brennan <stephen.s.brennan@oracle.com>
Date:   Fri Dec 5 10:43:44 2025 -0800

    libdrgn: orc_info: work around ORC backports in RHEL 9.6

    Add a special case to detect RHEL 9 kernel versions since release
    5.14.0-517.el9, and use ORC "v3" for these kernels.

    Fixes #578.

    Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>

Signed-off-by: Philipp Rudo <prudo@redhat.com>

0001-libdrgn-orc_info-work-around-ORC-backports-in-RHEL-9.patch

@@ -0,0 +1,44 @@
+From 8660ee186377aabf28cd54d76beb942b9a06d09a Mon Sep 17 00:00:00 2001
+From: Stephen Brennan <stephen.s.brennan@oracle.com>
+Date: Fri, 5 Dec 2025 10:43:44 -0800
+Subject: [PATCH] libdrgn: orc_info: work around ORC backports in RHEL 9.6
+
+Add a special case to detect RHEL 9 kernel versions since release
+5.14.0-517.el9, and use ORC "v3" for these kernels.
+
+Fixes #578.
+
+Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
+---
+ libdrgn/orc_info.c | 15 +++++++++++++++
+ 1 file changed, 15 insertions(+)
+
+diff --git a/libdrgn/orc_info.c b/libdrgn/orc_info.c
+index 7015d096..83ea3f4e 100644
+--- a/libdrgn/orc_info.c
++++ b/libdrgn/orc_info.c
+@@ -254,6 +254,21 @@ static int orc_version_from_osrelease(struct drgn_program *prog)
+ 	long minor = 0;
+ 	if (*p == '.')
+ 		minor = strtol(p + 1, NULL, 10);
++
++	// RHEL & derivatives started shipping backported ORC patches without
++	// the ".orc_header" section in 9.6. According to git history this was
++	// introduced in kernel version 5.14.0-517.el9. With those changes, the
++	// kernel's ORC "format" is indeed v3, but we cannot detect that without
++	// the ORC header hash. Add special-case detection for this situation.
++	// If it is fixed by including the ".orc_header" section, this fix will
++	// not be active, but will still be necessary for the already released
++	// kernels.
++	char *rhrelease = NULL;
++	if (major == 5 && minor == 14 && strstr(p, ".el9")
++	    && (rhrelease = strchr(p, '-'))
++	    && strtol(rhrelease + 1, NULL, 10) >= 517)
++		return 3;
++
+ 	if (major > 6 || (major == 6 && minor >= 4))
+ 		return 3;
+ 	else if (major == 6 && minor == 3)
+-- 
+2.52.0
+

python-drgn.spec

@@ -15,7 +15,7 @@ scripting in Python.}
 
 Name:           python-%{pypi_name}
 Version:        0.0.33
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        Programmable debugger
 
 License:        LGPL-2.1-or-later
@@ -46,6 +46,8 @@ BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  libtool
 
+Patch001: 0001-libdrgn-orc_info-work-around-ORC-backports-in-RHEL-9.patch
+
 %description %{_description}
 
 %package -n     %{pypi_name}
@@ -125,6 +127,10 @@ cp -PR man/drgn.1* %{buildroot}%{_mandir}/man1
 %endif
 
 %changelog
+* Wed Dec 17 2025 Philipp Rudo <prudo@redhat.com> - 0.0.33-2
+- Work around ORC backports in RHEL 9.6
+  Resolves: RHEL-136527
+
 * Thu Nov 13 2025 Philipp Rudo <prudo@redhat.com> - 0.0.33-1
 - Rebase to upstream v0.0.33
   Resolves: RHEL-114118