On 09/27/18 at 04:31pm, Masayoshi Mizuma wrote:
> From: Masayoshi Mizuma <[email protected]>
>
> Add warning message if the padding size for KASLR,
> rand_mem_physical_padding, is not enough. The message also
> says the suitable padding size.
>
> Signed-off-by: Masayoshi Mizuma <[email protected]>
> ---
> arch/x86/include/asm/setup.h | 2 ++
> drivers/acpi/numa.c | 14 ++++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
> index ae13bc9..65a5bf8 100644
> --- a/arch/x86/include/asm/setup.h
> +++ b/arch/x86/include/asm/setup.h
> @@ -80,6 +80,8 @@ static inline unsigned long kaslr_offset(void)
> return (unsigned long)&_text - __START_KERNEL;
> }
>
> +extern int rand_mem_physical_padding;
> +
> /*
> * Do NOT EVER look at the BIOS memory size location.
> * It does not work on many machines.
> diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
> index 8516760..9c3cc3c 100644
> --- a/drivers/acpi/numa.c
> +++ b/drivers/acpi/numa.c
> @@ -32,6 +32,7 @@
> #include <linux/numa.h>
> #include <linux/nodemask.h>
> #include <linux/topology.h>
> +#include <asm/setup.h>
>
> static nodemask_t nodes_found_map = NODE_MASK_NONE;
>
> @@ -435,6 +436,8 @@ acpi_table_parse_srat(enum acpi_srat_type id,
> int __init acpi_numa_init(void)
> {
> int cnt = 0;
> + u32 max_phys_addr_tb;
> + u64 max_phys_addr;
>
> if (acpi_disabled)
> return -EINVAL;
> @@ -463,6 +466,17 @@ int __init acpi_numa_init(void)
>
> cnt = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
> acpi_parse_memory_affinity, 0);
> +
> + if (parsed_numa_memblks && kaslr_enabled()) {
> + max_phys_addr = PFN_PHYS(max_possible_pfn);
> + max_phys_addr_tb = (roundup(max_phys_addr, 1ULL << 40))
> >> 40;
> +
> + if (max_phys_addr_tb > rand_mem_physical_padding)
Here I assume max_phys_addr_tb is the end of the possible RAM in system.
rand_mem_physical_padding is the preserved space for later memory
extending. Don't we add the actual RAM size to the
rand_mem_physical_padding, then compare with max_phys_addr_tb?
Please correct me if I am wrong.
Thanks
Baoquan
> + pr_warn("Set 'rand_mem_physical_padding=%d' "
> + "as the kernel parameter. "
> + "Otherwise, memory hotadd may be
> failed.\n",
> + max_phys_addr_tb);
> + }
> }
>
> /* SLIT: System Locality Information Table */
> --
> 2.18.0
>
