| Message ID | 20241007-powerpc-fix-stackprotector-test-clang-v1-3-08c15b2694e4@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | powerpc: Prepare for clang's per-task stack protector support | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 5 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 21 jobs. |
Le 08/10/2024 à 06:22, Nathan Chancellor a écrit : > Kbuild uses the powerpc64le-linux-gnu target for clang, which causes the > Kconfig check for 32-bit powerpc stack protector support to fail because > nothing flips the target to 32-bit: > > $ clang --target=powerpc64le-linux-gnu \ > -mstack-protector-guard=tls > -mstack-protector-guard-reg=r2 \ > -mstack-protector-guard-offset=0 \ > -x c -c -o /dev/null /dev/null > clang: error: invalid value 'r2' in 'mstack-protector-guard-reg=', expected one of: r13 Why is there any restriction at all on which register can be used ? I can't see such restriction in GCC documentation : https://gcc.gnu.org/onlinedocs/gcc/RS_002f6000-and-PowerPC-Options.html > > Use the Kconfig macro '$(m32-flag)', which expands to '-m32' when > supported, in the stack protector support cc-option call to properly > switch the target to a 32-bit one, which matches what happens in Kbuild. > While the 64-bit macro does not strictly need it, add the equivalent > 64-bit option for symmetry. > > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- > arch/powerpc/Kconfig | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index eb98050b8c016bb23887a9d669d29e69d933c9c8..6aaca48955a34b2a38af1415bfa36f74f35c3f3e 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -275,8 +275,8 @@ config PPC > select HAVE_RSEQ > select HAVE_SETUP_PER_CPU_AREA if PPC64 > select HAVE_SOFTIRQ_ON_OWN_STACK > - select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=0) > - select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=0) > + select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,$(m32-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=0) > + select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,$(m64-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=0) You modify the exact same line than Patch 1, if this patch is really required it should be squashed into patch 1 I think. > select HAVE_STATIC_CALL if PPC32 > select HAVE_SYSCALL_TRACEPOINTS > select HAVE_VIRT_CPU_ACCOUNTING >
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index eb98050b8c016bb23887a9d669d29e69d933c9c8..6aaca48955a34b2a38af1415bfa36f74f35c3f3e 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -275,8 +275,8 @@ config PPC select HAVE_RSEQ select HAVE_SETUP_PER_CPU_AREA if PPC64 select HAVE_SOFTIRQ_ON_OWN_STACK - select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=0) - select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=0) + select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,$(m32-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=0) + select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,$(m64-flag) -mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=0) select HAVE_STATIC_CALL if PPC32 select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING
Kbuild uses the powerpc64le-linux-gnu target for clang, which causes the Kconfig check for 32-bit powerpc stack protector support to fail because nothing flips the target to 32-bit: $ clang --target=powerpc64le-linux-gnu \ -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 \ -mstack-protector-guard-offset=0 \ -x c -c -o /dev/null /dev/null clang: error: invalid value 'r2' in 'mstack-protector-guard-reg=', expected one of: r13 Use the Kconfig macro '$(m32-flag)', which expands to '-m32' when supported, in the stack protector support cc-option call to properly switch the target to a 32-bit one, which matches what happens in Kbuild. While the 64-bit macro does not strictly need it, add the equivalent 64-bit option for symmetry. Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- arch/powerpc/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)