From bd1912de892ce30e1e2242e67716d25188fbfa44 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Wed, 23 Feb 2022 22:05:58 -0800
Subject: [PATCH] alpha: Implement "current_stack_pointer"
To follow the existing per-arch conventions replace open-coded use
of asm "$30" as "current_stack_pointer". This will let it be used in
non-arch places (like HARDENED_USERCOPY).
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Alexander A. Klimov" <grandmaster@al2klimov.de>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
---
arch/alpha/Kconfig | 1 +
arch/alpha/include/asm/thread_info.h | 2 ++
arch/alpha/lib/stacktrace.c | 2 +-
3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 97fce7386b00..780d4673c3ca 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -3,6 +3,7 @@ config ALPHA
bool
default y
select ARCH_32BIT_USTAT_F_TINODE
+ select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_NO_PREEMPT
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 082631465074..354247dca161 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -41,6 +41,8 @@ struct thread_info {
register struct thread_info *__current_thread_info __asm__("$8");
#define current_thread_info() __current_thread_info
+register unsigned long *current_stack_pointer __asm__ ("$30");
+
#endif /* __ASSEMBLY__ */
/* Thread information allocation. */
diff --git a/arch/alpha/lib/stacktrace.c b/arch/alpha/lib/stacktrace.c
index 62454a7810e2..2b1176dd5174 100644
--- a/arch/alpha/lib/stacktrace.c
+++ b/arch/alpha/lib/stacktrace.c
@@ -92,7 +92,7 @@ stacktrace(void)
{
instr * ret_pc;
instr * prologue = (instr *)stacktrace;
- register unsigned char * sp __asm__ ("$30");
+ unsigned char *sp = (unsigned char *)current_stack_pointer;
printk("\tstack trace:\n");
do {