Messages in this thread Patch in this message | | | From | Chao Fan <> | Subject | [PATCH v4 2/4] kaslr: calculate the memory region in immovable node | Date | Tue, 12 Dec 2017 20:07:03 +0800 |
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kaslr: calculate the memory region in immovable node
If there is no immovable memory region specified, use region directely. There are several conditons: 1. CONFIG_MEMORY_HOTPLUG is not specified to y. 2. immovable_mem= is not specified.
Otherwise, calculate the intersecting between memmap entry and immovable memory.
Rename process_mem_region to slots_count to match slots_fetch_random, and rename new function sa process_mem_region.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> --- arch/x86/boot/compressed/kaslr.c | 65 +++++++++++++++++++++++++++++++++------- 1 file changed, 54 insertions(+), 11 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 40f299d8cd34..fe49d6e79c50 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -579,9 +579,9 @@ static unsigned long slots_fetch_random(void) return 0; } -static void process_mem_region(struct mem_vector *entry, - unsigned long minimum, - unsigned long image_size) +static void slots_count(struct mem_vector *entry, + unsigned long minimum, + unsigned long image_size) { struct mem_vector region, overlap; struct slot_area slot_area; @@ -658,6 +658,53 @@ static void process_mem_region(struct mem_vector *entry, } } +static bool process_mem_region(struct mem_vector region, + unsigned long long minimum, + unsigned long long image_size) +{ +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * If immovable_mem= specified, walk all immovable regions, and + * filter the intersection to slots_count. + */ + if (num_immovable_region > 0) { + for (int i = 0; i < num_immovable_region; i++) { + struct mem_vector entry; + unsigned long long start, end, entry_end, region_end; + + start = immovable_mem[i].start; + end = start + immovable_mem[i].size; + region_end = region.start + region.size; + + entry.start = clamp(region.start, start, end); + entry_end = clamp(region_end, start, end); + + if (entry.start < entry_end) { + entry.size = entry_end - entry.start; + slots_count(&entry, minimum, image_size); + } + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted memmap scan (slot_areas full)!\n"); + return 1; + } + } + return 0; + } +#endif + + /* + * If no immovable_mem stored, or CONFIG_MEMORY_HOTPLUG not specified, + * use region directly + */ + slots_count(®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 @@ -723,11 +770,9 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) 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"); + + if (process_mem_region(region, minimum, image_size)) break; - } } return true; } @@ -754,11 +799,9 @@ static void process_e820_entries(unsigned long minimum, continue; region.start = entry->addr; region.size = entry->size; - process_mem_region(®ion, minimum, image_size); - if (slot_area_index == MAX_SLOT_AREA) { - debug_putstr("Aborted e820 scan (slot_areas full)!\n"); + + if (process_mem_region(region, minimum, image_size)) break; - } } } -- 2.14.3
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