Messages in this thread Patch in this message |  | | From | Chao Fan <> | Subject | [PATCH v9 2/5] x86/KASLR: Handle the memory regions specified in kaslr_boot_mem | Date | Wed, 28 Feb 2018 18:51:02 +0800 |
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If no 'kaslr_boot_mem=' specified, just handle the e820/efi entries directly as before. Otherwise, limit kernel to memory regions specified in 'kaslr_boot_mem=' commandline.
Rename process_mem_region to slots_count to match slots_fetch_random, and name new function as process_mem_region.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> Tested-by: Luiz Capitulino <lcapitulino@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> --- arch/x86/boot/compressed/kaslr.c | 64 +++++++++++++++++++++++++++++++++------- 1 file changed, 53 insertions(+), 11 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index e33e5cbf7244..eb47502fbe54 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -554,9 +554,9 @@ 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; @@ -633,6 +633,52 @@ 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) +{ + /* + * If 'kaslr_boot_mem=' specified, walk all the regions, and + * filter the intersection to slots_count. + */ + if (num_usable_region > 0) { + int i; + + for (i = 0; i < num_usable_region; i++) { + struct mem_vector entry; + unsigned long long start, end, entry_end, region_end; + + start = mem_usable[i].start; + end = start + mem_usable[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 e820/efi memmap scan (slot_areas full)!\n"); + return 1; + } + } + return 0; + } + + /* + * If no kaslr_boot_mem stored, use region directly + */ + slots_count(®ion, minimum, image_size); + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); + return 1; + } + return 0; +} + #ifdef CONFIG_EFI /* * Returns true if mirror region found (and must have been processed @@ -698,11 +744,9 @@ 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; } @@ -729,11 +773,9 @@ 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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