Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Kees Cook <keescook@chromium.org>
To:     Paul Walmsley <paul.walmsley@sifive.com>
Cc:     Kees Cook <keescook@chromium.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Peter Zijlstra <peterz@infradead.org>,
        Jisheng Zhang <jszhang@kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Chen Huang <chenhuang5@huawei.com>,
        linux-riscv@lists.infradead.org,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] riscv: Rename "sp_in_global" to "current_stack_pointer"
Date:   Wed, 23 Feb 2022 22:04:11 -0800
Message-Id: <20220224060411.1855683-1-keescook@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

To follow the existing per-arch conventions, rename "sp_in_global" to
"current_stack_pointer". This will let it be used in non-arch places
(like HARDENED_USERCOPY).

Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jisheng Zhang <jszhang@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/riscv/Kconfig               | 1 +
 arch/riscv/include/asm/current.h | 2 ++
 arch/riscv/kernel/stacktrace.c   | 4 +---
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5adcbd9b5e88..b120c32697af 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -16,6 +16,7 @@ config RISCV
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_HAS_BINFMT_FLAT
+	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEBUG_WX
diff --git a/arch/riscv/include/asm/current.h b/arch/riscv/include/asm/current.h
index 1de233d8e8de..21774d868c65 100644
--- a/arch/riscv/include/asm/current.h
+++ b/arch/riscv/include/asm/current.h
@@ -33,6 +33,8 @@ static __always_inline struct task_struct *get_current(void)
 
 #define current get_current()
 
+register unsigned long current_stack_pointer __asm__("sp");
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_CURRENT_H */
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 201ee206fb57..278380e2e956 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -14,8 +14,6 @@
 
 #include <asm/stacktrace.h>
 
-register unsigned long sp_in_global __asm__("sp");
-
 #ifdef CONFIG_FRAME_POINTER
 
 void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
@@ -77,7 +75,7 @@ void notrace walk_stackframe(struct task_struct *task,
 		sp = user_stack_pointer(regs);
 		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
-		sp = sp_in_global;
+		sp = current_stack_pointer;
 		pc = (unsigned long)walk_stackframe;
 	} else {
 		/* task blocked in __switch_to */
-- 
2.30.2