On Thu, Dec 08, 2022 at 05:31:06PM -0600, Tom Saeger wrote: > On Thu, Dec 08, 2022 at 09:34:40PM +0100, Greg Kroah-Hartman wrote: > > On Tue, Dec 06, 2022 at 01:43:08PM -0700, Tom Saeger wrote: > > > Backport of: 0d362be5b142 ("Makefile: link with -z noexecstack --no-warn-rwx-segments") > > > breaks arm64 Build ID when CONFIG_MODVERSIONS=y. > > > > > > CONFIG_MODVERSIONS adds extra tooling to calculate symbol versions. > > > This kernel's KBUILD tooling uses both > > > relocatable (-r) and (-z noexecstack) to link head.o > > > which results in ld adding a .note.GNU-stack section. > > > Final linking of vmlinux should add a .NOTES segment containing the > > > Build ID, but does NOT if head.o has a .note.GNU-stack section. > > > > > > Selectively remove -z noexecstack from head.o's KBUILD_LDFLAGS to > > > prevent .note.GNU-stack from being added to head.o. Final link of > > > vmlinux then properly adds .NOTES segment containing Build ID that can > > > be read using tools like 'readelf -n'. > > > > > > Cc: <stable@xxxxxxxxxxxxxxx> # 5.15, 5.10, 5.4 > > > Signed-off-by: Tom Saeger <tom.saeger@xxxxxxxxxx> > > > --- > > > arch/arm64/kernel/Makefile | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > Why isn't this needed in Linus's tree? > > 0d362be5b142 ("Makefile: link with -z noexecstack --no-warn-rwx-segments") > > was merged after > 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") > > Linus's tree never had -z noexecstack with these same KBUILD rules. Then it needs to say that, in detail, in this changelog please. > > And why not cc: everyone involved in this, I would need acks from > > maintainers to be able to accept this... > > Fair request. > > Between ~5.3 and 5.19-rc1 cherry-picking > 0d362be5b142 ("Makefile: link with -z noexecstack --no-warn-rwx-segments") > and building arm64 with CONFIG_MODVERSIONS=y > results in vmlinux missing Build ID > > head.S is compiled to head.o > head.o is linked (ld) with -r and -z noexecstack which adds .note.GNU-stack section in head.o > head.o is then linked again with vmlinux (resulting vmlinux is missing .NOTE segment) > > > Can folks confirm/deny ld behavior is expected (arm64)? > And whether the above patch would be an acceptable fix for these kernel > versions? > > repro test in cover letter: https://lore.kernel.org/all/cover.1670358255.git.tom.saeger@xxxxxxxxxx/#r Please resend, no need for a cover letter for just one patch, and include all of the needed info in the changelog itself. thanks, greg k-h