Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Mark Rutland <mark.rutland@arm.com>
To:     linux-arm-kernel@lists.infradead.org
Cc:     akpm@linux-foundation.org, alex.popov@linux.com,
        catalin.marinas@arm.com, keescook@chromium.org,
        linux-kernel@vger.kernel.org, luto@kernel.org,
        mark.rutland@arm.com, will@kernel.org
Subject: [PATCH v2 13/13] arm64: entry: use stackleak_erase_on_task_stack()
Date:   Wed, 27 Apr 2022 18:31:28 +0100
Message-Id: <20220427173128.2603085-14-mark.rutland@arm.com>
In-Reply-To: <20220427173128.2603085-1-mark.rutland@arm.com>
References: <20220427173128.2603085-1-mark.rutland@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

On arm64 we always call stackleak_erase() on a task stack, and never
call it on another stack. We can avoid some redundant work by using
stackleak_erase_on_task_stack(), telling the stackleak code that it's
being called on a task stack.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/entry.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index ede028dee81b0..5b82b92924005 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -596,7 +596,7 @@ SYM_CODE_START_LOCAL(ret_to_user)
 	ldr	x19, [tsk, #TSK_TI_FLAGS]	// re-check for single-step
 	enable_step_tsk x19, x2
 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
-	bl	stackleak_erase
+	bl	stackleak_erase_on_task_stack
 #endif
 	kernel_exit 0
 SYM_CODE_END(ret_to_user)
-- 
2.30.2