This is a note to let you know that I've just added the patch titled
s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-setup-preserve-memory-at-oldmem_base-and-oldmem.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ce1ab2ca6f876edd9c3118d16224e046ceb7c313
Author: Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
Date: Wed Feb 9 11:25:09 2022 +0100
s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE
[ Upstream commit 6b4b54c7ca347bcb4aa7a3cc01aa16e84ac7fbe4 ]
We need to preserve the values at OLDMEM_BASE and OLDMEM_SIZE which are
used by zgetdump in case when kdump crashes. In that case zgetdump will
attempt to read OLDMEM_BASE and OLDMEM_SIZE in order to find out where
the memory range [0 - OLDMEM_SIZE] belonging to the production kernel is.
Fixes: f1a546947431 ("s390/setup: don't reserve memory that occupied decompressor's head")
Cc: stable@xxxxxxxxxxxxxxx # 5.15+
Signed-off-by: Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
Acked-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2ebde341d057..36c1f31dfd66 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -798,6 +798,8 @@ static void __init check_initrd(void)
static void __init reserve_kernel(void)
{
memblock_reserve(0, STARTUP_NORMAL_OFFSET);
+ memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
+ memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
memblock_reserve(__amode31_base, __eamode31 - __samode31);
memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
memblock_reserve(__pa(_stext), _end - _stext);
