diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2020-06-24 17:39:14 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-16 08:13:36 +0200 |
| commit | 8942819f040e5c3e9b903ebca55e95f2b7cbc214 (patch) | |
| tree | 9e4fc60a61634e0268201337e9ae9bbe07e53abe | |
| parent | f5857c6b717ecdcee9bfe3b53e2f3b54120d94a7 (diff) | |
s390/maccess: add no DAT mode to kernel_write
[ Upstream commit d6df52e9996dcc2062c3d9c9123288468bb95b52 ]
To be able to patch kernel code before paging is initialized do plain
memcpy if DAT is off. This is required to enable early jump label
initialization.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/s390/mm/maccess.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 22a0be655f27..1d17413b319a 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -62,11 +62,15 @@ notrace void *s390_kernel_write(void *dst, const void *src, size_t size) long copied; spin_lock_irqsave(&s390_kernel_write_lock, flags); - while (size) { - copied = s390_kernel_write_odd(tmp, src, size); - tmp += copied; - src += copied; - size -= copied; + if (!(flags & PSW_MASK_DAT)) { + memcpy(dst, src, size); + } else { + while (size) { + copied = s390_kernel_write_odd(tmp, src, size); + tmp += copied; + src += copied; + size -= copied; + } } spin_unlock_irqrestore(&s390_kernel_write_lock, flags); |