Messages in this thread | | | Date | Thu, 17 May 2018 07:12:26 +0200 | From | damian <> | Subject | Re: [PATCH 1/2] x86/boot/KASLR: Add two functions for 1GB huge pages handling |
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On Wed, 16. May 18:05, Baoquan He wrote: > Functions parse_gb_huge_pages() and process_gb_huge_page() are introduced to > handle conflict between KASLR and huge pages, will be used in the next patch. > > Function parse_gb_huge_pages() is used to parse kernel command-line to get > how many 1GB huge pages have been specified. A static global variable > 'max_gb_huge_pages' is added to store the number. > > And process_gb_huge_page() is used to skip as many 1GB huge pages as possible > from the passed in memory region according to the specified number. > > Signed-off-by: Baoquan He <bhe@redhat.com> > --- > arch/x86/boot/compressed/kaslr.c | 71 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 71 insertions(+) > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index a0a50b91ecef..13bd879cdc5d 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -215,6 +215,32 @@ static void mem_avoid_memmap(char *str) > memmap_too_large = true; > } > > +/* Store the number of 1GB huge pages which user specified.*/ > +static unsigned long max_gb_huge_pages; > + > +static int parse_gb_huge_pages(char *param, char* val) > +{ > + char *p; > + u64 mem_size; > + static bool gbpage_sz = false; > + > + if (!strcmp(param, "hugepagesz")) { > + p = val; > + mem_size = memparse(p, &p); > + if (mem_size == PUD_SIZE) { > + if (gbpage_sz) > + warn("Repeadly set hugeTLB page size of 1G!\n"); > + gbpage_sz = true; > + } else > + gbpage_sz = false; > + } else if (!strcmp(param, "hugepages") && gbpage_sz) { > + p = val; > + max_gb_huge_pages = simple_strtoull(p, &p, 0); > + debug_putaddr(max_gb_huge_pages); > + } > +} Hello,
the return value is missing for the function or not ?
regards Damian
> + > + > static int handle_mem_memmap(void) > { > char *args = (char *)get_cmd_line_ptr(); > @@ -466,6 +492,51 @@ static void store_slot_info(struct mem_vector *region, unsigned long image_size) > } > } > > +/* Skip as many 1GB huge pages as possible in the passed region. */ > +static void process_gb_huge_page(struct mem_vector *region, unsigned long image_size) > +{ > + int i = 0; > + unsigned long addr, size; > + struct mem_vector tmp; > + > + if (!max_gb_huge_pages) { > + store_slot_info(region, image_size); > + return; > + } > + > + addr = ALIGN(region->start, PUD_SIZE); > + /* If Did we raise the address above the passed in memory entry? */ > + if (addr < region->start + region->size) > + size = region->size - (addr - region->start); > + > + /* Check how many 1GB huge pages can be filtered out*/ > + while (size > PUD_SIZE && max_gb_huge_pages) { > + size -= PUD_SIZE; > + max_gb_huge_pages--; > + i++; > + } > + > + if (!i) { > + store_slot_info(region, image_size); > + return; > + } > + > + /* Process the remaining regions after filtering out. */ > + > + if (addr >= region->start + image_size) { > + tmp.start = region->start; > + tmp.size = addr - region->start; > + store_slot_info(&tmp, image_size); > + } > + > + size = region->size - (addr - region->start) - i * PUD_SIZE; > + if (size >= image_size) { > + tmp.start = addr + i*PUD_SIZE; > + tmp.size = size; > + store_slot_info(&tmp, image_size); > + } > +} > + > static unsigned long slots_fetch_random(void) > { > unsigned long slot; > -- > 2.13.6 >
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