* [PATCH 0/2] objtool: xxhash dependency improvements @ 2025-11-12 23:32 Josh Poimboeuf 2025-11-12 23:32 ` [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 Josh Poimboeuf 2025-11-12 23:32 ` [PATCH 2/2] objtool/klp: Only enable --checksum when needed Josh Poimboeuf 0 siblings, 2 replies; 5+ messages in thread From: Josh Poimboeuf @ 2025-11-12 23:32 UTC (permalink / raw) To: x86; +Cc: linux-kernel, Peter Zijlstra, Michael Kelley, live-patching Set the minimum xxhash version to 0.8, and soften the xxhash dependency a bit so that it's only needed when running klp-build rather than doing a normal kernel build. For tip/objtool/core. Josh Poimboeuf (2): objtool: Set minimum xxhash version to 0.8 objtool/klp: Only enable --checksum when needed arch/x86/boot/startup/Makefile | 2 +- scripts/Makefile.lib | 1 - scripts/livepatch/klp-build | 4 ++++ tools/objtool/Makefile | 2 +- tools/objtool/builtin-check.c | 2 +- 5 files changed, 7 insertions(+), 4 deletions(-) -- 2.51.1 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 2025-11-12 23:32 [PATCH 0/2] objtool: xxhash dependency improvements Josh Poimboeuf @ 2025-11-12 23:32 ` Josh Poimboeuf 2025-11-13 2:25 ` Michael Kelley 2025-11-12 23:32 ` [PATCH 2/2] objtool/klp: Only enable --checksum when needed Josh Poimboeuf 1 sibling, 1 reply; 5+ messages in thread From: Josh Poimboeuf @ 2025-11-12 23:32 UTC (permalink / raw) To: x86; +Cc: linux-kernel, Peter Zijlstra, Michael Kelley, live-patching XXH3 is only supported starting with xxhash 0.8. Enforce that. Fixes: 0d83da43b1e1 ("objtool/klp: Add --checksum option to generate per-function checksums") Reported-by: Michael Kelley <mhklinux@outlook.com> Closes: https://lore.kernel.org/SN6PR02MB41579B83CD295C9FEE40EED6D4FCA@SN6PR02MB4157.namprd02.prod.outlook.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- tools/objtool/Makefile | 2 +- tools/objtool/builtin-check.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index 48928c9bebef..021f55b7bd87 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -12,7 +12,7 @@ ifeq ($(SRCARCH),loongarch) endif ifeq ($(ARCH_HAS_KLP),y) - HAVE_XXHASH = $(shell echo "int main() {}" | \ + HAVE_XXHASH = $(shell printf "$(pound)include <xxhash.h>\nXXH3_state_t *state;int main() {}" | \ $(HOSTCC) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n) ifeq ($(HAVE_XXHASH),y) BUILD_KLP := y diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 1e1ea8396eb3..aab7fa9c7e00 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -164,7 +164,7 @@ static bool opts_valid(void) #ifndef BUILD_KLP if (opts.checksum) { - ERROR("--checksum not supported; install xxhash-devel/libxxhash-dev and recompile"); + ERROR("--checksum not supported; install xxhash-devel/libxxhash-dev (version >= 0.8) and recompile"); return false; } #endif -- 2.51.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* RE: [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 2025-11-12 23:32 ` [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 Josh Poimboeuf @ 2025-11-13 2:25 ` Michael Kelley 0 siblings, 0 replies; 5+ messages in thread From: Michael Kelley @ 2025-11-13 2:25 UTC (permalink / raw) To: Josh Poimboeuf, x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra, live-patching@vger.kernel.org From: Josh Poimboeuf <jpoimboe@kernel.org> Sent: Wednesday, November 12, 2025 3:33 PM > > XXH3 is only supported starting with xxhash 0.8. Enforce that. > > Fixes: 0d83da43b1e1 ("objtool/klp: Add --checksum option to generate per-function checksums") > Reported-by: Michael Kelley <mhklinux@outlook.com> > Closes: https://lore.kernel.org/all/SN6PR02MB41579B83CD295C9FEE40EED6D4FCA@SN6PR02MB4157.namprd02.prod.outlook.com > Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> > --- > tools/objtool/Makefile | 2 +- > tools/objtool/builtin-check.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile > index 48928c9bebef..021f55b7bd87 100644 > --- a/tools/objtool/Makefile > +++ b/tools/objtool/Makefile > @@ -12,7 +12,7 @@ ifeq ($(SRCARCH),loongarch) > endif > > ifeq ($(ARCH_HAS_KLP),y) > - HAVE_XXHASH = $(shell echo "int main() {}" | \ > + HAVE_XXHASH = $(shell printf "$(pound)include <xxhash.h>\nXXH3_state_t *state;int main() {}" | \ > $(HOSTCC) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n) > ifeq ($(HAVE_XXHASH),y) > BUILD_KLP := y > diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c > index 1e1ea8396eb3..aab7fa9c7e00 100644 > --- a/tools/objtool/builtin-check.c > +++ b/tools/objtool/builtin-check.c > @@ -164,7 +164,7 @@ static bool opts_valid(void) > > #ifndef BUILD_KLP > if (opts.checksum) { > - ERROR("--checksum not supported; install xxhash-devel/libxxhash-dev and recompile"); > + ERROR("--checksum not supported; install xxhash-devel/libxxhash-dev (version >= 0.8) and recompile"); > return false; > } > #endif > -- > 2.51.1 Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 2/2] objtool/klp: Only enable --checksum when needed 2025-11-12 23:32 [PATCH 0/2] objtool: xxhash dependency improvements Josh Poimboeuf 2025-11-12 23:32 ` [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 Josh Poimboeuf @ 2025-11-12 23:32 ` Josh Poimboeuf 2025-11-13 2:29 ` Michael Kelley 1 sibling, 1 reply; 5+ messages in thread From: Josh Poimboeuf @ 2025-11-12 23:32 UTC (permalink / raw) To: x86; +Cc: linux-kernel, Peter Zijlstra, Michael Kelley, live-patching With CONFIG_KLP_BUILD enabled, checksums are only needed during a klp-build run. There's no need to enable them for normal kernel builds. This also has the benefit of softening the xxhash dependency. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- arch/x86/boot/startup/Makefile | 2 +- scripts/Makefile.lib | 1 - scripts/livepatch/klp-build | 4 ++++ 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile index e8fdf020b422..5e499cfb29b5 100644 --- a/arch/x86/boot/startup/Makefile +++ b/arch/x86/boot/startup/Makefile @@ -36,7 +36,7 @@ $(patsubst %.o,$(obj)/%.o,$(lib-y)): OBJECT_FILES_NON_STANDARD := y # relocations, even if other objtool actions are being deferred. # $(pi-objs): objtool-enabled = 1 -$(pi-objs): objtool-args = $(if $(delay-objtool),,$(objtool-args-y)) --noabs +$(pi-objs): objtool-args = $(if $(delay-objtool),--dry-run,$(objtool-args-y)) --noabs # # Confine the startup code by prefixing all symbols with __pi_ (for position diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f4b33919ec37..28a1c08e3b22 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -173,7 +173,6 @@ ifdef CONFIG_OBJTOOL objtool := $(objtree)/tools/objtool/objtool -objtool-args-$(CONFIG_KLP_BUILD) += --checksum objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake diff --git a/scripts/livepatch/klp-build b/scripts/livepatch/klp-build index 881e052e7fae..882272120c9e 100755 --- a/scripts/livepatch/klp-build +++ b/scripts/livepatch/klp-build @@ -489,8 +489,11 @@ clean_kernel() { build_kernel() { local log="$TMP_DIR/build.log" + local objtool_args=() local cmd=() + objtool_args=("--checksum") + cmd=("make") # When a patch to a kernel module references a newly created unexported @@ -513,6 +516,7 @@ build_kernel() { cmd+=("$VERBOSE") cmd+=("-j$JOBS") cmd+=("KCFLAGS=-ffunction-sections -fdata-sections") + cmd+=("OBJTOOL_ARGS=${objtool_args[*]}") cmd+=("vmlinux") cmd+=("modules") -- 2.51.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* RE: [PATCH 2/2] objtool/klp: Only enable --checksum when needed 2025-11-12 23:32 ` [PATCH 2/2] objtool/klp: Only enable --checksum when needed Josh Poimboeuf @ 2025-11-13 2:29 ` Michael Kelley 0 siblings, 0 replies; 5+ messages in thread From: Michael Kelley @ 2025-11-13 2:29 UTC (permalink / raw) To: Josh Poimboeuf, x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra, live-patching@vger.kernel.org From: Josh Poimboeuf <jpoimboe@kernel.org> Sent: Wednesday, November 12, 2025 3:33 PM > > With CONFIG_KLP_BUILD enabled, checksums are only needed during a > klp-build run. There's no need to enable them for normal kernel builds. > > This also has the benefit of softening the xxhash dependency. > > Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> > --- > arch/x86/boot/startup/Makefile | 2 +- > scripts/Makefile.lib | 1 - > scripts/livepatch/klp-build | 4 ++++ > 3 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile > index e8fdf020b422..5e499cfb29b5 100644 > --- a/arch/x86/boot/startup/Makefile > +++ b/arch/x86/boot/startup/Makefile > @@ -36,7 +36,7 @@ $(patsubst %.o,$(obj)/%.o,$(lib-y)): > OBJECT_FILES_NON_STANDARD := y > # relocations, even if other objtool actions are being deferred. > # > $(pi-objs): objtool-enabled = 1 > -$(pi-objs): objtool-args = $(if $(delay-objtool),,$(objtool-args-y)) --noabs > +$(pi-objs): objtool-args = $(if $(delay-objtool),--dry-run,$(objtool-args-y)) --noabs > > # > # Confine the startup code by prefixing all symbols with __pi_ (for position > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib > index f4b33919ec37..28a1c08e3b22 100644 > --- a/scripts/Makefile.lib > +++ b/scripts/Makefile.lib > @@ -173,7 +173,6 @@ ifdef CONFIG_OBJTOOL > > objtool := $(objtree)/tools/objtool/objtool > > -objtool-args-$(CONFIG_KLP_BUILD) += --checksum > objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label > objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr > objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake > diff --git a/scripts/livepatch/klp-build b/scripts/livepatch/klp-build > index 881e052e7fae..882272120c9e 100755 > --- a/scripts/livepatch/klp-build > +++ b/scripts/livepatch/klp-build > @@ -489,8 +489,11 @@ clean_kernel() { > > build_kernel() { > local log="$TMP_DIR/build.log" > + local objtool_args=() > local cmd=() > > + objtool_args=("--checksum") > + > cmd=("make") > > # When a patch to a kernel module references a newly created unexported > @@ -513,6 +516,7 @@ build_kernel() { > cmd+=("$VERBOSE") > cmd+=("-j$JOBS") > cmd+=("KCFLAGS=-ffunction-sections -fdata-sections") > + cmd+=("OBJTOOL_ARGS=${objtool_args[*]}") > cmd+=("vmlinux") > cmd+=("modules") > > -- > 2.51.1 Did a normal linux-next kernel build on an Ubuntu 20.04 system, which by default does not have xxhash installed. Previous error about needing to install libxxhash-dev is no longer generated. Have not tested a klp-build. Tested-by: Michael Kelley <mhklinux@outlook.com> ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2025-11-13 2:29 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2025-11-12 23:32 [PATCH 0/2] objtool: xxhash dependency improvements Josh Poimboeuf 2025-11-12 23:32 ` [PATCH 1/2] objtool: Set minimum xxhash version to 0.8 Josh Poimboeuf 2025-11-13 2:25 ` Michael Kelley 2025-11-12 23:32 ` [PATCH 2/2] objtool/klp: Only enable --checksum when needed Josh Poimboeuf 2025-11-13 2:29 ` Michael Kelley
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