This is a note to let you know that I've just added the patch titled
s390/setup: avoid reserving memory above identity mapping
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-avoid-reserving-memory-above-identity-mapping.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.
>From 420f48f636b98fd685f44a3acc4c0a7c0840910d Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Date: Thu, 14 Oct 2021 13:33:45 +0200
Subject: s390/setup: avoid reserving memory above identity mapping
From: Vasily Gorbik <gor@xxxxxxxxxxxxx>
commit 420f48f636b98fd685f44a3acc4c0a7c0840910d upstream.
Such reserved memory region, if not cleaned up later causes problems when
memblock_free_all() is called to release free pages to the buddy allocator
and those reserved regions are carried over to reserve_bootmem_region()
which marks the pages as PageReserved.
Instead use memblock_set_current_limit() to make sure memblock allocations
do not go over identity mapping (which could happen when "mem=" option
is used or during kdump).
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 73045a08cf55 ("s390: unify identity mapping limits handling")
Reported-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kernel/setup.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -634,14 +634,6 @@ static struct notifier_block kdump_mem_n
#endif
/*
- * Make sure that the area above identity mapping is protected
- */
-static void __init reserve_above_ident_map(void)
-{
- memblock_reserve(ident_map_size, ULONG_MAX);
-}
-
-/*
* Reserve memory for kdump kernel to be loaded with kexec
*/
static void __init reserve_crashkernel(void)
@@ -1005,11 +997,11 @@ void __init setup_arch(char **cmdline_p)
setup_control_program_code();
/* Do some memory reservations *before* memory is added to memblock */
- reserve_above_ident_map();
reserve_kernel();
reserve_initrd();
reserve_certificate_list();
reserve_mem_detect_info();
+ memblock_set_current_limit(ident_map_size);
memblock_allow_resize();
/* Get information about *all* installed memory */
Patches currently in stable-queue which might be from gor@xxxxxxxxxxxxx are
queue-5.15/s390-boot-simplify-and-fix-kernel-memory-layout-setup.patch
queue-5.15/s390-setup-avoid-reserving-memory-above-identity-mapping.patch
