Messages in this thread Patch in this message | | | Date | Mon, 27 Aug 2018 15:10:32 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v5 4/4] x86/boot/KASLR: Limit kaslr to choosing the immovable memory |
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On 08/27/18 at 01:56pm, Baoquan He wrote: > On 08/07/18 at 02:50pm, Chao Fan wrote: > > If 'CONFIG_MEMORY_HOTREMOVE' specified and the account of immovable > If CONFIG_MEMORY_HOTREMOVE is enabled, > > memory regions is not zero. Calculate the intersection between memory > > regions from e820/efi memory table and immovable memory regions. > > Or go on the old code. > > > > 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> > > --- > > arch/x86/boot/compressed/kaslr.c | 66 ++++++++++++++++++++++++++------ > > 1 file changed, 55 insertions(+), 11 deletions(-) > > > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > > index 720878f967a3..9c6e24a23a2d 100644 > > --- a/arch/x86/boot/compressed/kaslr.c > > +++ b/arch/x86/boot/compressed/kaslr.c > > @@ -635,9 +635,9 @@ 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; > > @@ -714,6 +714,56 @@ 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) > > +{ > > Is it possible to take num_immovable_mem definition out from #ifdef > CONFIG_MEMORY_HOTREMOVE block and check it here like below? This way, > one level of indentation can be reduced in the for loop, and code is > more readable. > > > static bool process_mem_region(struct mem_vector *region, > unsigned long long minimum, > unsigned long long image_size) > { > > /* > * If no immovable memory found, or MEMORY_HOTREMOVE disabled, > * walk all the regions, so use region directely. > */ > if (num_immovable_mem > 0) { Sorry, I meant if (!num_immovable_mem) {
> slots_count(region, 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_MEMORY_HOTREMOVE > for (i = 0; i < num_immovable_mem; i++) { > ... > } > #endif > } > > > +#ifdef CONFIG_MEMORY_HOTREMOVE > > + /* > > + * If immovable memory found, filter the intersection between > > + * immovable memory and region to slots_count. > > + * Otherwise, go on old code. > > + */ > > + if (num_immovable_mem > 0) { > > + int i; > > + > > + for (i = 0; i < num_immovable_mem; 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 + image_size < 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; > > + } > > +#endif > > + /* > > + * If no immovable memory found, or MEMORY_HOTREMOVE disabled, > > + * walk all the regions, so use region directely. > > + */ > > + slots_count(region, 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 > > @@ -779,11 +829,8 @@ 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(®ion, minimum, image_size)) > > break; > > - } > > } > > return true; > > } > > @@ -810,11 +857,8 @@ 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(®ion, minimum, image_size)) > > break; > > - } > > } > > } > > > > -- > > 2.17.1 > > > > > >
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