diff options
Diffstat (limited to 'arch/x86/kernel/setup.c')
| -rw-r--r-- | arch/x86/kernel/setup.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 905dae880563..bbe35bf879f5 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 1995 Linus Torvalds * @@ -452,15 +453,24 @@ static void __init memblock_x86_reserve_range_setup_data(void) #define CRASH_ALIGN SZ_16M /* - * Keep the crash kernel below this limit. On 32 bits earlier kernels - * would limit the kernel to the low 512 MiB due to mapping restrictions. + * Keep the crash kernel below this limit. + * + * On 32 bits earlier kernels would limit the kernel to the low 512 MiB + * due to mapping restrictions. + * + * On 64bit, kdump kernel need be restricted to be under 64TB, which is + * the upper limit of system RAM in 4-level paing mode. Since the kdump + * jumping could be from 5-level to 4-level, the jumping will fail if + * kernel is put above 64TB, and there's no way to detect the paging mode + * of the kernel which will be loaded for dumping during the 1st kernel + * bootup. */ #ifdef CONFIG_X86_32 # define CRASH_ADDR_LOW_MAX SZ_512M # define CRASH_ADDR_HIGH_MAX SZ_512M #else # define CRASH_ADDR_LOW_MAX SZ_4G -# define CRASH_ADDR_HIGH_MAX MAXMEM +# define CRASH_ADDR_HIGH_MAX SZ_64T #endif static int __init reserve_crashkernel_low(void) @@ -826,8 +836,14 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) void __init setup_arch(char **cmdline_p) { + /* + * Reserve the memory occupied by the kernel between _text and + * __end_of_kernel_reserve symbols. Any kernel sections after the + * __end_of_kernel_reserve symbol must be explicitly reserved with a + * separate memblock_reserve() or they will be discarded. + */ memblock_reserve(__pa_symbol(_text), - (unsigned long)__bss_stop - (unsigned long)_text); + (unsigned long)__end_of_kernel_reserve - (unsigned long)_text); /* * Make sure page 0 is always reserved because on systems with |