| Message ID | 20241007-powerpc-fix-stackprotector-test-clang-v1-2-08c15b2694e4@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | powerpc: Prepare for clang's per-task stack protector support | expand |
Le 08/10/2024 à 06:22, Nathan Chancellor a écrit : > After fixing the HAVE_STACKPROTECTER checks for clang's in-progress > per-task stack protector support [1], the build fails during prepare0 > because '-mstack-protector-guard-offset' has not been added to > KBUILD_CFLAGS yet but the other '-mstack-protector-guard' flags have. > > clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default > clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default > make[4]: *** [scripts/Makefile.build:229: scripts/mod/empty.o] Error 1 > make[4]: *** [scripts/Makefile.build:102: scripts/mod/devicetable-offsets.s] Error 1 > > Mirror other architectures and add all '-mstack-protector-guard' flags > to KBUILD_CFLAGS atomically during stack_protector_prepare, which > resolves the issue and allows clang's implementation to fully work with > the kernel. > > Link: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fllvm%2Fllvm-project%2Fpull%2F110928&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7Cc099707fa5464808c49108dce750d65e%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638639581583232977%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=b%2BcqodA6k739DD%2F74EJMXUtIHAZDt1DGcyd7mzzhbd8%3D&reserved=0 [1] > Signed-off-by: Nathan Chancellor <nathan@kernel.org> Is it worth a Fixes: tag so that it gets applied on stable, or wont CLANG 20 be used with kernels older than 6.13 ? > --- > arch/powerpc/Makefile | 15 ++++++--------- > 1 file changed, 6 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > index bbfe4a1f06ef9db9b2f2e48e02096b1e0500a14b..8f9e387c4c7dd06d8756dca3eac808cc344a937d 100644 > --- a/arch/powerpc/Makefile > +++ b/arch/powerpc/Makefile > @@ -100,13 +100,6 @@ KBUILD_AFLAGS += -m$(BITS) > KBUILD_LDFLAGS += -m elf$(BITS)$(LDEMULATION) > endif > > -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard=tls > -ifdef CONFIG_PPC64 > -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r13 > -else > -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r2 > -endif > - > LDFLAGS_vmlinux-y := -Bstatic > LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie > LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) += -z notext > @@ -402,9 +395,13 @@ prepare: stack_protector_prepare > PHONY += stack_protector_prepare > stack_protector_prepare: prepare0 > ifdef CONFIG_PPC64 > - $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) > + $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls \ > + -mstack-protector-guard-reg=r13 \ Can you put both above lines on a single line to avoid having too many lines at the end: + $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls -mstack-protector-guard-reg=r13 \ > + -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) > else > - $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) > + $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls \ > + -mstack-protector-guard-reg=r2 \ Same > + -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) > endif > endif > >
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index bbfe4a1f06ef9db9b2f2e48e02096b1e0500a14b..8f9e387c4c7dd06d8756dca3eac808cc344a937d 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -100,13 +100,6 @@ KBUILD_AFLAGS += -m$(BITS) KBUILD_LDFLAGS += -m elf$(BITS)$(LDEMULATION) endif -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard=tls -ifdef CONFIG_PPC64 -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r13 -else -cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r2 -endif - LDFLAGS_vmlinux-y := -Bstatic LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) += -z notext @@ -402,9 +395,13 @@ prepare: stack_protector_prepare PHONY += stack_protector_prepare stack_protector_prepare: prepare0 ifdef CONFIG_PPC64 - $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) + $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls \ + -mstack-protector-guard-reg=r13 \ + -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h)) else - $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) + $(eval KBUILD_CFLAGS += -mstack-protector-guard=tls \ + -mstack-protector-guard-reg=r2 \ + -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h)) endif endif
After fixing the HAVE_STACKPROTECTER checks for clang's in-progress per-task stack protector support [1], the build fails during prepare0 because '-mstack-protector-guard-offset' has not been added to KBUILD_CFLAGS yet but the other '-mstack-protector-guard' flags have. clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default make[4]: *** [scripts/Makefile.build:229: scripts/mod/empty.o] Error 1 make[4]: *** [scripts/Makefile.build:102: scripts/mod/devicetable-offsets.s] Error 1 Mirror other architectures and add all '-mstack-protector-guard' flags to KBUILD_CFLAGS atomically during stack_protector_prepare, which resolves the issue and allows clang's implementation to fully work with the kernel. Link: https://github.com/llvm/llvm-project/pull/110928 [1] Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- arch/powerpc/Makefile | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)