From 05107edc910135d27fe557267dc45be9630bf3dd Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Wed, 8 Mar 2023 11:59:33 -0800 Subject: [PATCH] selftests: sigaltstack: fix -Wuninitialized 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 Link: https://lore.kernel.org/lkml/CA+G9fYsi3OOu7yCsMutpzKDnBMAzJBCPimBp86LhGBa0eCnEpA@mail.gmail.com/ Signed-off-by: Nick Desaulniers Reviewed-by: Kees Cook Tested-by: Linux Kernel Functional Testing Tested-by: Anders Roxell Signed-off-by: Shuah Khan --- .../selftests/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 0000000..ea9bdf3 --- /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 c53b070..98d37cb 100644 --- a/tools/testing/selftests/sigaltstack/sas.c +++ b/tools/testing/selftests/sigaltstack/sas.c @@ -20,6 +20,7 @@ #include #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"); -- 2.7.4