From: Kees Cook <keescook@chromium.org>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Kees Cook <keescook@chromium.org>, Marc Zyngier <maz@kernel.org>,
Guenter Roeck <linux@roeck-us.net>,
Mark Rutland <mark.rutland@arm.com>,
Yanteng Si <siyanteng01@gmail.com>,
linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] mips: Implement "current_stack_pointer"
Date: Wed, 23 Feb 2022 22:04:32 -0800 [thread overview]
Message-ID: <20220224060432.1855897-1-keescook@chromium.org> (raw)
To follow the existing per-arch conventions replace open-coded uses
of asm "sp" as "current_stack_pointer". This will let it be used in
non-arch places (like HARDENED_USERCOPY).
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Yanteng Si <siyanteng01@gmail.com>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/thread_info.h | 2 ++
arch/mips/kernel/irq.c | 3 +--
arch/mips/lib/uncached.c | 4 +---
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 058446f01487..6781f87e2218 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,6 +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_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 0b17aaa9e012..4463348d2372 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -69,6 +69,8 @@ static inline struct thread_info *current_thread_info(void)
return __current_thread_info;
}
+register unsigned long current_stack_pointer __asm__("sp");
+
#endif /* !__ASSEMBLY__ */
/* thread information allocation */
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 5e11582fe308..fc313c49a417 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -75,9 +75,8 @@ void __init init_IRQ(void)
#ifdef CONFIG_DEBUG_STACKOVERFLOW
static inline void check_stack_overflow(void)
{
- unsigned long sp;
+ unsigned long sp = current_stack_pointer;
- __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 f80a67c092b6..f8d4ca046c3e 100644
--- a/arch/mips/lib/uncached.c
+++ b/arch/mips/lib/uncached.c
@@ -40,9 +40,7 @@ unsigned long run_uncached(void *func)
register long ret __asm__("$2");
long lfunc = (long)func, ufunc;
long usp;
- long sp;
-
- __asm__("move %0, $sp" : "=r" (sp));
+ long sp = current_stack_pointer;
if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
usp = CKSEG1ADDR(sp);
--
2.30.2
next reply other threads:[~2022-02-24 6:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-24 6:04 Kees Cook [this message]
2022-03-01 16:30 ` [PATCH] mips: Implement "current_stack_pointer" Thomas Bogendoerfer
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