On Mon, Nov 12, 2018 at 03:52:54PM -0500, Masayoshi Mizuma wrote:
[...]
>
>> +
>> +    ret = cmdline_find_option("acpi", arg, sizeof(arg));
>> +    if (ret == 4 && !strncmp(arg, "rsdt", 4))
>> +            acpi_use_rsdt = true;
>
>All have to do for ret is checking whether it's above 0, right?
>So how about the following?
>
>       if ((cmdline_find_option("acpi", arg, sizeof(arg)) > 0) &&
>               !strncmp(arg, "rsdt", 4))
>               acpi_use_rsdt = true;

Maybe:
>       if ((cmdline_find_option("acpi", arg, sizeof(arg)) == 4) &&
>               !strncmp(arg, "rsdt", 4))
>               acpi_use_rsdt = true;
looks better. Thanks for your suggestion.

>
>> +
>> +    /* Get RSDT or XSDT from RSDP. */
>> +    if (!acpi_use_rsdt &&
>> +        rsdp->xsdt_physical_address && rsdp->revision > 1) {
>> +            root_table = rsdp->xsdt_physical_address;
>> +            size = ACPI_XSDT_ENTRY_SIZE;
>> +    } else {
>> +            root_table = rsdp->rsdt_physical_address;
>> +            size = ACPI_RSDT_ENTRY_SIZE;
>> +    }
>> +
>> +    /* Get ACPI root table from RSDT or XSDT.*/
>> +    header = (struct acpi_table_header *)root_table;
>> +    len = header->length;
>> +    count = (u32)((len - sizeof(struct acpi_table_header)) / size);
>> +    entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
>> +
>> +    for (i = 0; i < count; i++) {
>> +            u64 address64;
>> +
>> +            if (size == ACPI_RSDT_ENTRY_SIZE)
>> +                    acpi_table = ((acpi_physical_address)
>> +                                  (*ACPI_CAST_PTR(u32, entry)));
>> +            else {
>> +                    *(u64 *)(void *)&address64 = *(u64 *)(void *)entry;
>> +                    acpi_table = (acpi_physical_address) address64;
>> +            }
>> +
>> +            if (acpi_table) {
>> +                    header = (struct acpi_table_header *)acpi_table;
>
>> +                    signature = header->signature;
>
>this isn't needed.

Yes, will change it.

>
>> +
>> +                    if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT))
>> +                            return header;
>> +            }
>> +            entry += size;
>> +    }
>> +    return NULL;
>> +}
>> +
>> +/*
>> + * According to ACPI table, filter the immvoable memory regions
>> + * and store them in immovable_mem[].
>> + */
>> +void get_immovable_mem(void)
>> +{
>> +    struct acpi_table_header *table_header;
>> +    struct acpi_subtable_header *table;
>> +    struct acpi_srat_mem_affinity *ma;
>> +    unsigned long table_end;
>> +    char arg[10];
>> +    int i = 0;
>> +    int ret;
>> +
>
>> +    ret = cmdline_find_option("acpi", arg, sizeof(arg));
>> +    if (ret == 3 && !strncmp(arg, "off", 3))
>> +            return;
>
>Same as above.
>
>       if ((cmdline_find_option("acpi", arg, sizeof(arg)) > 0) &&
>               !strncmp(arg, "off", 3))
>               return;
>> +
>> +    if (!cmdline_find_option_bool("movable_node"))
>> +            return;
>
>I think this check isn't needed.
>The SRAT parsing is needed to the kaslr issue which I'm trying
>to fix. The issue may happen even if movable_node isn't set.

Got it.

>
>> +
>> +    table_header = get_acpi_srat_table();
>> +    if (!table_header)
>> +            return;
>> +
>> +    table_end = (unsigned long)table_header + table_header->length;
>> +
>> +    table = (struct acpi_subtable_header *)
>> +            ((unsigned long)table_header + sizeof(struct acpi_table_srat));
>> +
>> +    while (((unsigned long)table) +
>> +                   sizeof(struct acpi_subtable_header) < table_end) {
>> +            if (table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
>> +                    ma = (struct acpi_srat_mem_affinity *)table;
>> +                    if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)) {
>> +                            immovable_mem[i].start = ma->base_address;
>> +                            immovable_mem[i].size = ma->length;
>> +                            i++;
>> +                    }
>> +
>> +                    if (i >= MAX_NUMNODES*2) {
>> +                            debug_putstr("Too many immovable memory 
>> regions, aborted.\n");
>
>I'm not sure this statement gets true actually,
>but if so, should it be set 0 to fallback in process_mem_region()?

That's a good problem.
Well, I don't know what will cause "i >= MAX_NUMNODES*2", maybe some
error in SRAT table or failed to parse table.
Anyway, it's a good idea to set it 0.

Thanks,
Chao Fan

>
>Thanks,
>Masa
>
>> +                            break;
>> +                    }
>> +            }
>> +            table = (struct acpi_subtable_header *)
>> +                    ((unsigned long)table + table->length);
>> +    }
>> +    num_immovable_mem = i;
>> +}
>> diff --git a/arch/x86/boot/compressed/kaslr.c 
>> b/arch/x86/boot/compressed/kaslr.c
>> index 9ed9709d9947..b251572e77af 100644
>> --- a/arch/x86/boot/compressed/kaslr.c
>> +++ b/arch/x86/boot/compressed/kaslr.c
>> @@ -87,10 +87,6 @@ static unsigned long get_boot_seed(void)
>>  #define KASLR_COMPRESSED_BOOT
>>  #include "../../lib/kaslr.c"
>>  
>> -struct mem_vector {
>> -    unsigned long long start;
>> -    unsigned long long size;
>> -};
>>  
>>  /* Only supporting at most 4 unusable memmap regions with kaslr */
>>  #define MAX_MEMMAP_REGIONS  4
>> diff --git a/arch/x86/boot/compressed/misc.h 
>> b/arch/x86/boot/compressed/misc.h
>> index a1d5918765f3..4a3645fda0ed 100644
>> --- a/arch/x86/boot/compressed/misc.h
>> +++ b/arch/x86/boot/compressed/misc.h
>> @@ -77,6 +77,11 @@ void choose_random_location(unsigned long input,
>>                          unsigned long *output,
>>                          unsigned long output_size,
>>                          unsigned long *virt_addr);
>> +struct mem_vector {
>> +    unsigned long long start;
>> +    unsigned long long size;
>> +};
>> +
>>  /* cpuflags.c */
>>  bool has_cpuflag(int flag);
>>  #else
>> @@ -116,3 +121,13 @@ static inline void console_init(void)
>>  void set_sev_encryption_mask(void);
>>  
>>  #endif
>> +
>> +/* acpitb.c */
>> +#ifdef CONFIG_RANDOMIZE_BASE
>> +int num_immovable_mem;
>> +#ifdef CONFIG_MEMORY_HOTREMOVE
>> +/* Store the amount of immovable memory regions */
>> +#define ACPI_MAX_TABLES                128
>> +void get_immovable_mem(void);
>> +#endif
>> +#endif
>> -- 
>> 2.19.1
>> 
>> 
>> 
>
>


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