From: Vasily Gorbik <gor@linux.ibm.com>
Date: Thu, 20 Jun 2019 10:18:35 +0200
Subject: s390/unwind: cleanup unused READ_ONCE_TASK_STACK
Git-commit: da1776733617c4a92319eddb4e765ce60426b20a
Patch-mainline: v5.3-rc1
References: jsc#SLE-11178
Kasan instrumentation of backchain unwinder stack reads is disabled
completely and simply uses READ_ONCE_NOCHECK now.
READ_ONCE_TASK_STACK macro is unused and could be removed.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
arch/s390/include/asm/unwind.h | 19 -------------------
1 file changed, 19 deletions(-)
diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h
index 6eb2ef105d87..d827b5b9a32c 100644
--- a/arch/s390/include/asm/unwind.h
+++ b/arch/s390/include/asm/unwind.h
@@ -79,23 +79,4 @@ static inline void unwind_module_init(struct module *mod, void *orc_ip,
size_t orc_ip_size, void *orc,
size_t orc_size) {}
-#ifdef CONFIG_KASAN
-/*
- * This disables KASAN checking when reading a value from another task's stack,
- * since the other task could be running on another CPU and could have poisoned
- * the stack in the meantime.
- */
-#define READ_ONCE_TASK_STACK(task, x) \
-({ \
- unsigned long val; \
- if (task == current) \
- val = READ_ONCE(x); \
- else \
- val = READ_ONCE_NOCHECK(x); \
- val; \
-})
-#else
-#define READ_ONCE_TASK_STACK(task, x) READ_ONCE(x)
-#endif
-
#endif /* _ASM_S390_UNWIND_H */