Messages in this thread | | | Subject | Re: [PATCH 2/4] kaslr: select the memory region in immovable node to process | From | Dou Liyang <> | Date | Fri, 20 Oct 2017 14:05:13 +0800 |
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Hi Chao,
At 10/20/2017 11:41 AM, Chao Fan wrote: > On Fri, Oct 20, 2017 at 11:17:26AM +0800, Dou Liyang wrote: >> Hi Chao >> > Hi Dou-san, > >> At 10/19/2017 06:02 PM, Chao Fan wrote: >>> Since the interrelationship between e820 or efi entries and memory >>> region in immovable_mem is different: >>> One memory region in one node may contain several entries of e820 or >>> efi sometimes, and one entry of e820 or efi may contain the memory in >>> different nodes sometimes. So select the intersection as a region to >>> process_mem_region. It may split one node or one entry to several regions. >>> >>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> >>> --- >>> arch/x86/boot/compressed/kaslr.c | 72 ++++++++++++++++++++++++++++++++-------- >>> 1 file changed, 58 insertions(+), 14 deletions(-) >>> >>> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c >>> index 3c1f5204693b..22330cbe8515 100644 >>> --- a/arch/x86/boot/compressed/kaslr.c >>> +++ b/arch/x86/boot/compressed/kaslr.c >>> @@ -563,6 +563,7 @@ static void process_mem_region(struct mem_vector *entry, >>> end = min(entry->size + entry->start, mem_limit); >>> if (entry->start >= end) >>> return; >>> + >>> cur_entry.start = entry->start; >>> cur_entry.size = end - entry->start; >> >> Above code has nothing to do with this patch. remove it. >> >>> >>> @@ -621,6 +622,52 @@ static void process_mem_region(struct mem_vector *entry, >>> } >>> } >>> >>> +static bool select_immovable_node(unsigned long long start, >>> + unsigned long long size, >>> + unsigned long long minimum, >>> + unsigned long long image_size) >>> +{ >>> + struct mem_vector region; >>> + int i; >>> + >>> + if (num_immovable_region == 0) { >> >> Seems it more better: >> >> #ifdef CONFIG_MEMORY_HOTPLUG >> for (i = 0; i < num_immovable_region; i++) { >> ... >> } >> #else >> ... >> process_mem_region(®ion, minimum, image_size); >> ... >> #endif > > No, if we set CONFIG_MEMORY_HOTPLUG=y(the default is y in fedora), but we do not > use movable_node, we should go to process_mem_region straight, right?
Yes, Indeed, you are right! ;-).
> But in your change, we still go to the for(...), even if > num_immovable_region == 0. > So if num_immovable_region is 0, it includes the situation of > CONFIG_MEMORY_HOTPLUG=n > >> >>> + region.start = start; >>> + region.size = size; >>> + process_mem_region(®ion, minimum, image_size); >>> + >>> + if (slot_area_index == MAX_SLOT_AREA) { >>> + debug_putstr("Aborted memmap scan (slot_areas full)!\n"); >>> + return 1; >>> + } >>> + } else { >>> + for (i = 0; i < num_immovable_region; i++) { >>> + unsigned long long end, select_end; >>> + unsigned long long region_start, region_end; >>> + >>> + end = start + size - 1; >>> + region_start = immovable_mem[i].start; >>> + region_end = region_start + immovable_mem[i].size - 1; >>> + >>> + if (end < region_start || start > region_end) >>> + continue; >>> + >>> + region.start = start > region_start ? >>> + start : region_start; >>> + select_end = end > region_end ? region_end : end; >>> + >>> + region.size = select_end - region.start + 1; >>> + >>> + process_mem_region(®ion, minimum, image_size); >>> + >>> + if (slot_area_index == MAX_SLOT_AREA) { >>> + debug_putstr("Aborted memmap scan (slot_areas full)!\n"); >>> + return 1; >>> + } >>> + } >>> + } >>> + return 0; >>> +} >>> + >>> #ifdef CONFIG_EFI >>> /* >>> * Returns true if mirror region found (and must have been processed >>> @@ -631,7 +678,6 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) >>> { >>> struct efi_info *e = &boot_params->efi_info; >>> bool efi_mirror_found = false; >>> - struct mem_vector region; >>> efi_memory_desc_t *md; >>> unsigned long pmap; >>> char *signature; >>> @@ -664,6 +710,8 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) >>> } >>> >>> for (i = 0; i < nr_desc; i++) { >>> + unsigned long long start, size; >>> + >>> md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); >>> >>> /* >>> @@ -684,13 +732,11 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) >>> !(md->attribute & EFI_MEMORY_MORE_RELIABLE)) >>> continue; >>> >>> - region.start = md->phys_addr; >>> - region.size = md->num_pages << EFI_PAGE_SHIFT; >>> - process_mem_region(®ion, minimum, image_size); >>> - if (slot_area_index == MAX_SLOT_AREA) { >>> - debug_putstr("Aborted EFI scan (slot_areas full)!\n"); >>> + start = md->phys_addr; >>> + size = md->num_pages << EFI_PAGE_SHIFT; >>> + >>> + if (select_immovable_node(start, size, minimum, image_size)) >> >> Why you replace the region with two parameters? Just use region. >> > > You can see the commit message, we may splite one entry to more regions, > so there will be region.start compared with memory region in > immovable_mem and then fill more new regions if we use region here. > The code will look strange. > > Start and size will be more clear.
OK, Understood!
Thanks, dou.
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