On Thu, 9 Mar 2023 at 01:29, Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > Building sigaltstack with clang via: > $ ARCH=x86 make LLVM=1 -C tools/testing/selftests/sigaltstack/ > > produces the following warning: > warning: variable 'sp' is uninitialized when used here [-Wuninitialized] > if (sp < (unsigned long)sstack || > ^~ > > Clang expects these to be declared at global scope; we've fixed this in > the kernel proper by using the macro `current_stack_pointer`. This is > defined in different headers for different target architectures, so just > create a new header that defines the arch-specific register names for > the stack pointer register, and define it for more targets (at least the > ones that support current_stack_pointer/ARCH_HAS_CURRENT_STACK_POINTER). > > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> > Link: https://lore.kernel.org/lkml/CA+G9fYsi3OOu7yCsMutpzKDnBMAzJBCPimBp86LhGBa0eCnEpA@xxxxxxxxxxxxxx/ > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Build and boot tested with clang-16 and tested sigaltstack on arm64, armv7, FVP, x86_64 and i386 [1] & [2]. These tests were performed at Linaro test farm by Anders with the help of tuxplan / tuxmake and tuxrun. Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx> Build log: ------- clang --target=aarch64-linux-gnu -fintegrated-as -Werror=unknown-warning-option -Werror=ignored-optimization-argument -Werror=option-ignored -Werror=unused-command-line-argument --target=aarch64-linux-gnu -fintegrated-as -Wall sas.c -o /home/tuxbuild/.cache/tuxmake/builds/1/build/kselftest/sigaltstack/sas Test log: ---------- Linux version 6.3.0-rc1-next-20230310 (tuxmake@tuxmake) (Debian clang version 16.0.0 (++20230228093516+60692a66ced6-1~exp1~20230228093525.41), Debian LLD 16.0.0) #1 SMP PREEMPT @1678519789 ... [ 56.327569] kselftest: Running tests in sigaltstack TAP version 13 1..1 # selftests: sigaltstack: sas # # [NOTE] the stack size is 26400 # TAP version 13 # 1..3 # ok 1 Initial sigaltstack state was SS_DISABLE # # [RUN] signal USR1 # ok 2 sigaltstack is disabled in sighandler # # [RUN] switched to user ctx # # [RUN] signal USR2 # # [OK] Stack preserved # ok 3 sigaltstack is still SS_AUTODISARM after signal # # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 ok 1 selftests: sigaltstack: sas Details of test log links provided [3]. > --- > Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > Cc: KERNEL SELFTEST FRAMEWORK <linux-kselftest@xxxxxxxxxxxxxxx> > Cc: linux-api@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: lkft-triage@xxxxxxxxxxxxxxxx > Cc: Shuah Khan <shuah@xxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: "Chang S. Bae" <chang.seok.bae@xxxxxxxxx> > Cc: Len Brown <len.brown@xxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: Stas Sergeev <stsp@xxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Anders Roxell <anders.roxell@xxxxxxxxxx> > Cc: Andy Lutomirski <luto@xxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Nathan Chancellor <nathan@xxxxxxxxxx> > Cc: llvm@xxxxxxxxxxxxxxx > --- > .../sigaltstack/current_stack_pointer.h | 23 +++++++++++++++++++ > tools/testing/selftests/sigaltstack/sas.c | 7 +----- > 2 files changed, 24 insertions(+), 6 deletions(-) > create mode 100644 tools/testing/selftests/sigaltstack/current_stack_pointer.h > > diff --git a/tools/testing/selftests/sigaltstack/current_stack_pointer.h b/tools/testing/selftests/sigaltstack/current_stack_pointer.h > new file mode 100644 > index 000000000000..ea9bdf3a90b1 > --- /dev/null > +++ b/tools/testing/selftests/sigaltstack/current_stack_pointer.h > @@ -0,0 +1,23 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#if __alpha__ > +register unsigned long sp asm("$30"); > +#elif __arm__ || __aarch64__ || __csky__ || __m68k__ || __mips__ || __riscv > +register unsigned long sp asm("sp"); > +#elif __i386__ > +register unsigned long sp asm("esp"); > +#elif __loongarch64 > +register unsigned long sp asm("$sp"); > +#elif __ppc__ > +register unsigned long sp asm("r1"); > +#elif __s390x__ > +register unsigned long sp asm("%15"); > +#elif __sh__ > +register unsigned long sp asm("r15"); > +#elif __x86_64__ > +register unsigned long sp asm("rsp"); > +#elif __XTENSA__ > +register unsigned long sp asm("a1"); > +#else > +#error "implement current_stack_pointer equivalent" > +#endif > diff --git a/tools/testing/selftests/sigaltstack/sas.c b/tools/testing/selftests/sigaltstack/sas.c > index c53b070755b6..98d37cb744fb 100644 > --- a/tools/testing/selftests/sigaltstack/sas.c > +++ b/tools/testing/selftests/sigaltstack/sas.c > @@ -20,6 +20,7 @@ > #include <sys/auxv.h> > > #include "../kselftest.h" > +#include "current_stack_pointer.h" > > #ifndef SS_AUTODISARM > #define SS_AUTODISARM (1U << 31) > @@ -46,12 +47,6 @@ void my_usr1(int sig, siginfo_t *si, void *u) > stack_t stk; > struct stk_data *p; > > -#if __s390x__ > - register unsigned long sp asm("%15"); > -#else > - register unsigned long sp asm("sp"); > -#endif > - > if (sp < (unsigned long)sstack || > sp >= (unsigned long)sstack + stack_size) { > ksft_exit_fail_msg("SP is not on sigaltstack\n"); > -- > 2.40.0.rc0.216.gc4246ad0f0-goog log link: ----- [1] https://qa-reports.linaro.org/~anders.roxell/linux-mainline-patches/build/lore_kernel_org_linux-kselftest_20230308195933_806917-1-ndesaulniers_google_com/?failures_only=false#!?filter-tests=kselftest-sigaltstack&details=#test-results [2] https://qa-reports.linaro.org/~anders.roxell/linux-mainline-patches/build/lore_kernel_org_linux-kselftest_20230308195933_806917-1-ndesaulniers_google_com/testrun/15468761/suite/kselftest-sigaltstack/test/sigaltstack_sas/log [3] https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/anders/tests/2MrJ2e4bDCC4iZjIrnRqmnE7KfC -- Linaro LKFT https://lkft.linaro.org
