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authorKees Cook <keescook@chromium.org>2022-03-10 01:09:39 +0300
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2022-03-14 17:02:53 +0300
commitb847bd64ea9f484510e27065cb2bccc58d9b829b (patch)
tree6ee0d94d6ce3516b2047ecf0bfcab2148afcc273 /arch/mips
parent4d409ca3e5107a1b300d0f36550d61c5da4fd8a7 (diff)
downloadlinux-b847bd64ea9f484510e27065cb2bccc58d9b829b.tar.xz
MIPS: Only use current_stack_pointer on GCC
Unfortunately, Clang did not have support for "sp" as a global register definition, and was crashing after the addition of current_stack_pointer. This has been fixed in Clang 14, but earlier Clang versions need to avoid this code, so add a versioned test and revert back to the open-coded asm instances. Fixes Clang build error: fatal error: error in backend: Invalid register name global variable Fixes: 200ed341b864 ("mips: Implement "current_stack_pointer"") Reported-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/lkml/YikTQRql+il3HbrK@dev-arch.thelio-3990X Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Marc Zyngier <maz@kernel.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Yanteng Si <siyanteng01@gmail.com> Cc: linux-mips@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/Kconfig2
-rw-r--r--arch/mips/include/asm/thread_info.h2
-rw-r--r--arch/mips/kernel/irq.c3
-rw-r--r--arch/mips/lib/uncached.c4
4 files changed, 8 insertions, 3 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3f58b45fc953..0dae5f1e61cc 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,7 +4,7 @@ config MIPS
default y
select ARCH_32BIT_OFF_T if !64BIT
select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
- select ARCH_HAS_CURRENT_STACK_POINTER
+ select ARCH_HAS_CURRENT_STACK_POINTER if !CC_IS_CLANG || CLANG_VERSION >= 140000
select ARCH_HAS_DEBUG_VIRTUAL if !64BIT
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KCOV
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 4463348d2372..ecae7470faa4 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -69,7 +69,9 @@ static inline struct thread_info *current_thread_info(void)
return __current_thread_info;
}
+#ifdef CONFIG_ARCH_HAS_CURRENT_STACK_POINTER
register unsigned long current_stack_pointer __asm__("sp");
+#endif
#endif /* !__ASSEMBLY__ */
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index fc313c49a417..5e11582fe308 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -75,8 +75,9 @@ void __init init_IRQ(void)
#ifdef CONFIG_DEBUG_STACKOVERFLOW
static inline void check_stack_overflow(void)
{
- unsigned long sp = current_stack_pointer;
+ unsigned long sp;
+ __asm__ __volatile__("move %0, $sp" : "=r" (sp));
sp &= THREAD_MASK;
/*
diff --git a/arch/mips/lib/uncached.c b/arch/mips/lib/uncached.c
index f8d4ca046c3e..f80a67c092b6 100644
--- a/arch/mips/lib/uncached.c
+++ b/arch/mips/lib/uncached.c
@@ -40,7 +40,9 @@ unsigned long run_uncached(void *func)
register long ret __asm__("$2");
long lfunc = (long)func, ufunc;
long usp;
- long sp = current_stack_pointer;
+ long sp;
+
+ __asm__("move %0, $sp" : "=r" (sp));
if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
usp = CKSEG1ADDR(sp);