diff options
| -rw-r--r-- | arch/x86/kernel/setup.c | 15 | ||||
| -rw-r--r-- | include/linux/sizes.h | 1 |
2 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 08a5f4a131f5..dcbdf54fb5c1 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -453,15 +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) diff --git a/include/linux/sizes.h b/include/linux/sizes.h index fbde0bc7e882..8651269cb46c 100644 --- a/include/linux/sizes.h +++ b/include/linux/sizes.h @@ -47,5 +47,6 @@ #define SZ_2G 0x80000000 #define SZ_4G _AC(0x100000000, ULL) +#define SZ_64T _AC(0x400000000000, ULL) #endif /* __LINUX_SIZES_H__ */ |