After switching to the kernel's default package scripts for our local
kernel RPM builds, we noticed that module BTF entries were missing:
$ ls /sys/kernel/btf/
vmlinux <<<< only vmlinux, no module BTF
Root cause: find-debuginfo.sh (from the debugedit package) prefers
eu-strip over strip when elfutils is installed, which is the common
case on RHEL 9. eu-strip removes non-allocated ELF sections, including
the .BTF section that contains BPF Type Format information for kernel
modules. Without .BTF, BPF tools (bpftool, bcc, bpftrace) cannot resolve
kernel types at runtime, and /sys/kernel/btf/<module> entries are not
created when modules are loaded.
Additionally, since commit 8646db238997 ("libbpf,bpf: Share BTF
relocate-related code with kernel"), modules contain a .BTF.base section
that maps distilled type IDs to vmlinux types. If .BTF.base is stripped,
btf_parse_module() falls back to vmlinux BTF directly, causing type ID
mismatches and rejecting the module's BTF entirely.
Fix by passing --keep-section .BTF and --keep-section .BTF.base via
_find_debuginfo_opts, which adds -K .BTF and -K .BTF.base to the
eu-strip/strip command, preserving both sections while allowing normal
debuginfo extraction to proceed.
After this change, all module BTF files are properly generated:
$ ls /sys/kernel/btf/
aesni_intel drm i2c_i801 mfd_core
ahci drm_client_lib i2c_mux net_failover
backlight drm_kms_helper i2c_smbus pcspkr
ccp drm_shmem_helper input_leds qemu_fw_cfg
dm_log failover intel_rapl_common sch_fq_codel
dm_mirror fat intel_rapl_msr serio_raw
dm_mod fuse irqbypass sunrpc
dm_region_hash gf128mul iTCO_wdt vfat
virtio_balloon virtio_console virtio_dma_buf virtio_gpu
virtio_net virtio_rng virtio_blk vmlinux
xfs
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Link: https://patch.msgid.link/20260728024950.44946-1-laoar.shao@gmail.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Add support for the %{?dist} macro in the kernel.spec file. This enables
building and releasing kernel RPMs with a custom distribution suffix
(e.g., via rpmbuild's --define option) to better match production
environment tracking.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://patch.msgid.link/20260526062732.84006-1-laoar.shao@gmail.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Stefano reports that after commit 62089b804895 ("kbuild: rpm-pkg:
Generate debuginfo package manually"), building with an rpm package
using rpm 4.20.0 fails with:
RPM build errors:
Dependency tokens must begin with alpha-numeric, '_' or '/': #�) = 0x0d000002
Dependency tokens must begin with alpha-numeric, '_' or '/': �) = 0x0d000000
Dependency tokens must begin with alpha-numeric, '_' or '/': ) = 0x7c0e000000
Unknown rich dependency op 'Hat': (Red Hat 15.2.1-7)) = 0x3130363230322000
Unknown rich dependency op 'Hat': (Red Hat 15.2.1-7)) = 0x4728203a43434800
Unknown rich dependency op 'Hat': (Red Hat 15.2.1-7)) = 0x3130363230322000
Unknown rich dependency op 'Hat': (Red Hat 15.2.1-7)) = 0x4728203a43434800
This error comes from the automatic requirements feature of rpm. The
-debuginfo subpackage has no dependencies, so disable this feature with
'AutoReq: 0' for this subpackage, avoiding the error. This matches the
official %_debug_template macro that rpm provides. While automatic
provides should be default enabled, be explicit like %_debug_template
does.
Additionally, while in the area, add the manual debug information
package to the Development/Debug group, further aligning with
%_debug_template.
Cc: stable@vger.kernel.org
Fixes: 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package manually")
Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Closes: https://lore.kernel.org/CAGxU2F7FFNgb781_A7a1oL63n9Oy8wsyWceKhUpeZ6mLk=focw@mail.gmail.com/
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260216-improve-manual-debuginfo-template-v1-1-e584b3f8d3be@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Commit 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package
manually") added uses of OBJCOPY and READELF, variables from Kbuild.
These variables are defined and work properly when using the binrpm-pkg
target because rpmbuild is run within Kbuild. However, these variables
are not defined when building from a source RPM package generated with
the srcrpm-pkg target, breaking the build when generating the debug info
subpackage.
Define a default value for these variables so that these commands
respect the value from Kbuild but continue to work when built from a
source RPM package.
Cc: stable@vger.kernel.org
Fixes: 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package manually")
Reported-by: Lukas Herbolt <lukas@herbolt.com>
Closes: https://lore.kernel.org/20260212135855.147906-2-lukas@herbolt.com/
Tested-by: Lukas Herbolt <lukas@herbolt.com>
Link: https://patch.msgid.link/20260213-fix-debuginfo-srcrpm-pkg-v1-1-45cd0c0501b9@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Commit 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package
manually") effectively reverted commit a7c699d090a1 ("kbuild: rpm-pkg:
build a debuginfo RPM") but the approach it took is not safe for older
RPM releases. Restore commit a7c699d090a1 ("kbuild: rpm-pkg: build a
debuginfo RPM") for the !CONFIG_MODULE_SIG case to allow more
environments and configurations to take advantage of the separate debug
information package process.
Cc: stable@vger.kernel.org
Fixes: 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package manually")
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Tested-by: Steve French <stfrench@microsoft.com>
Tested-by: Juergen Gross <jgross@suse.com>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260210-kbuild-fix-debuginfo-rpm-v1-2-0730b92b14bc@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Commit 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package
manually") moved away from the built-in RPM machinery for generating
-debuginfo packages to a more manual way to be compatible with module
signing, as the built-in machinery strips the modules after the
installation process, breaking the signatures.
Unfortunately, prior to rpm 4.20.0, there is a bug where a custom %files
directive is ignored for a -debuginfo subpackage [1], meaning builds
using older versions of RPM (such as on RHEL9 or RHEL10) fail with:
Checking for unpackaged file(s): /usr/lib/rpm/check-files .../rpmbuild/BUILDROOT/kernel-6.19.0_dirty-1.x86_64
error: Installed (but unpackaged) file(s) found:
/debuginfo.list
/usr/lib/debug/.build-id/09/748c214974bfba1522d434a7e0a02e2fd7f29b.debug
/usr/lib/debug/.build-id/0b/b96dd9c7d3689d82e56d2e73b46f53103cc6c7.debug
/usr/lib/debug/.build-id/0e/979a2f34967c7437fd30aabb41de1f0c8b6a66.debug
...
To workaround this, restrict the manual debug info package creation
process to when it is necessary (CONFIG_MODULE_SIG=y) and possible (when
using RPM >= 4.20.0). A follow up change will restore the RPM debuginfo
creation process using a separate internal flag to allow the package to
be built in more situations, as RPM 4.20.0 is a fairly recent version
and the built-in -debuginfo generation works fine when module signing is
disabled.
Cc: stable@vger.kernel.org
Fixes: 62089b804895 ("kbuild: rpm-pkg: Generate debuginfo package manually")
Link: https://github.com/rpm-software-management/rpm/commit/49f906998f3cf1f4152162ca61ac0869251c380f [1]
Reported-by: Steve French <smfrench@gmail.com>
Closes: https://lore.kernel.org/CAH2r5mugbrHTwnaQwQiYEUVwbtqmvFYf0WZiLrrJWpgT8iwftw@mail.gmail.com/
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Tested-by: Steve French <stfrench@microsoft.com>
Tested-by: Juergen Gross <jgross@suse.com>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260210-kbuild-fix-debuginfo-rpm-v1-1-0730b92b14bc@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Commit a7c699d090a1 ("kbuild: rpm-pkg: build a debuginfo RPM") adjusted
the __spec_install_post macro to include __os_install_post, which runs
brp-strip. This ends up stripping module signatures, breaking loading
modules with lockdown enabled.
Undo most of the changes of the aforementioned debuginfo patch and
mirror commit 16c36f8864e3 ("kbuild: deb-pkg: use build ID instead of
debug link for dbg package") in kernel.spec to generate a functionally
equivalent debuginfo package while avoiding touching the modules after
they have already been signed during modules_install.
Fixes: a7c699d090a1 ("kbuild: rpm-pkg: build a debuginfo RPM")
Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de>
Closes: https://lore.kernel.org/68c375f6-e07e-fec-434d-6a45a4f1390@praktifix.dwd.de/
Tested-by: Holger Kiehl <Holger.Kiehl@dwd.de>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260121-fix-module-signing-binrpm-pkg-v1-1-8fc5832b6cbc@kernel.org
Signed-off-by: Nicolas Schier <nsc@kernel.org>
The dwarf.h header, which is included by
scripts/gendwarfksyms/gendwarfksyms.h, resides within elfutils-devel
or libdw-devel package.
This portion of the code is compiled under the condition that
CONFIG_GENDWARFKSYMS is enabled.
Consequently, add (elfutils-devel or libdw-devel) to BuildRequires to
prevent unforeseen compilation failures.
Fix follow possible error:
In file included from scripts/gendwarfksyms/cache.c:6:
scripts/gendwarfksyms/gendwarfksyms.h:6:10: fatal error: 'dwarf.h' file not found
6 | #include <dwarf.h>
| ^~~~~~~~~
Link: https://lore.kernel.org/all/3e52d80d-0c60-4df5-8cb5-21d4b1fce7b7@suse.com/
Fixes: f28568841ae0 ("tools: Add gendwarfksyms")
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The rpm-pkg make target currently suffers from a few issues related to
debuginfo:
1. debuginfo for things built into the kernel (vmlinux) is not available
in any RPM produced by make rpm-pkg. This makes using tools like
systemtap against a make rpm-pkg kernel impossible.
2. debug source for the kernel is not available. This means that
commands like 'disas /s' in gdb, which display source intermixed with
assembly, can only print file names/line numbers which then must be
painstakingly resolved to actual source in a separate editor.
3. debuginfo for modules is available, but it remains bundled with the
.ko files that contain module code, in the main kernel RPM. This is a
waste of space for users who do not need to debug the kernel (i.e.
most users).
Address all of these issues by additionally building a debuginfo RPM
when the kernel configuration allows for it, in line with standard
patterns followed by RPM distributors. With these changes:
1. systemtap now works (when these changes are backported to 6.11, since
systemtap lags a bit behind in compatibility), as verified by the
following simple test script:
# stap -e 'probe kernel.function("do_sys_open").call { printf("%s\n", $$parms); }'
dfd=0xffffffffffffff9c filename=0x7fe18800b160 flags=0x88800 mode=0x0
...
2. disas /s works correctly in gdb, with source and disassembly
interspersed:
# gdb vmlinux --batch -ex 'disas /s blk_op_str'
Dump of assembler code for function blk_op_str:
block/blk-core.c:
125 {
0xffffffff814c8740 <+0>: endbr64
127
128 if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op])
0xffffffff814c8744 <+4>: mov $0xffffffff824a7378,%rax
0xffffffff814c874b <+11>: cmp $0x23,%edi
0xffffffff814c874e <+14>: ja 0xffffffff814c8768 <blk_op_str+40>
0xffffffff814c8750 <+16>: mov %edi,%edi
126 const char *op_str = "UNKNOWN";
0xffffffff814c8752 <+18>: mov $0xffffffff824a7378,%rdx
127
128 if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op])
0xffffffff814c8759 <+25>: mov -0x7dfa0160(,%rdi,8),%rax
126 const char *op_str = "UNKNOWN";
0xffffffff814c8761 <+33>: test %rax,%rax
0xffffffff814c8764 <+36>: cmove %rdx,%rax
129 op_str = blk_op_name[op];
130
131 return op_str;
132 }
0xffffffff814c8768 <+40>: jmp 0xffffffff81d01360 <__x86_return_thunk>
End of assembler dump.
3. The size of the main kernel package goes down substantially,
especially if many modules are built (quite typical). Here is a
comparison of installed size of the kernel package (configured with
allmodconfig, dwarf4 debuginfo, and module compression turned off)
before and after this patch:
# rpm -qi kernel-6.13* | grep -E '^(Version|Size)'
Version : 6.13.0postpatch+
Size : 1382874089
Version : 6.13.0prepatch+
Size : 17870795887
This is a ~92% size reduction.
Note that a debuginfo package can only be produced if the following
configs are set:
- CONFIG_DEBUG_INFO=y
- CONFIG_MODULE_COMPRESS=n
- CONFIG_DEBUG_INFO_SPLIT=n
The first of these is obvious - we can't produce debuginfo if the build
does not generate it. The second two requirements can in principle be
removed, but doing so is difficult with the current approach, which uses
a generic rpmbuild script find-debuginfo.sh that processes all packaged
executables. If we want to remove those requirements the best path
forward is likely to add some debuginfo extraction/installation logic to
the modules_install target (controllable by flags). That way, it's
easier to operate on modules before they're compressed, and the logic
can be reused by all packaging targets.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
In the same way as for other similar files, mark as ghost the new file generated by depmod for configured weak dependencies for modules, modules.weakdep, so that although it is not included in the package, claim the ownership on it. Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>