From: Vasily Gorbik Date: Thu, 14 Oct 2021 13:33:45 +0200 Subject: s390/setup: avoid reserving memory above identity mapping Git-commit: 420f48f636b98fd685f44a3acc4c0a7c0840910d Patch-mainline: v5.16-rc2 References: git-fixes 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@vger.kernel.org Fixes: 73045a08cf55 ("s390: unify identity mapping limits handling") Reported-by: Gerald Schaefer Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Acked-by: Petr Tesarik --- 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 @@ -590,14 +590,6 @@ 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) @@ -1064,11 +1056,11 @@ 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 */