Get rid of unnecessary temporary variables and redundant tests in __process_mem_region.
Fix one minor bug: in case of an overlap, the beginning of the region should be used even if it is exactly image_size, not just strictly larger. Change type of minimum/image_size arguments in process_mem_region to unsigned long. These actually can never be above 4G (even on x86_64), and they're unsigned long in every other function except this one. Signed-off-by: Arvind Sankar <[email protected]> --- arch/x86/boot/compressed/kaslr.c | 50 ++++++++------------------------ 1 file changed, 12 insertions(+), 38 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 758d78433f94..850e131121f7 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -622,42 +622,24 @@ static void __process_mem_region(struct mem_vector *entry, unsigned long image_size) { struct mem_vector region, overlap; - unsigned long start_orig, end; - struct mem_vector cur_entry; + unsigned long region_end; - /* Ignore entries entirely below our minimum. */ - if (entry->start + entry->size < minimum) - return; - - /* Ignore entries above memory limit */ - end = min(entry->size + entry->start, mem_limit); - if (entry->start >= end) - return; - cur_entry.start = entry->start; - cur_entry.size = end - entry->start; - - region.start = cur_entry.start; - region.size = cur_entry.size; + /* Clamp region to minimum and memory limit. */ + region.start = clamp_val(entry->start, minimum, mem_limit); + region_end = clamp_val(entry->start + entry->size, minimum, mem_limit); /* Give up if slot area array is full. */ while (slot_area_index < MAX_SLOT_AREA) { - start_orig = region.start; - - /* Potentially raise address to minimum location. */ - if (region.start < minimum) - region.start = minimum; - /* Potentially raise address to meet alignment needs. */ region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN); /* Did we raise the address above the passed in memory entry? */ - if (region.start > cur_entry.start + cur_entry.size) + if (region.start > region_end) return; - /* Reduce size by any delta from the original address. */ - region.size -= region.start - start_orig; + region.size = region_end - region.start; - /* Return if region can't contain decompressed kernel */ + /* Return if region can't contain decompressed kernel. */ if (region.size < image_size) return; @@ -668,27 +650,19 @@ static void __process_mem_region(struct mem_vector *entry, } /* Store beginning of region if holds at least image_size. */ - if (overlap.start > region.start + image_size) { - struct mem_vector beginning; - - beginning.start = region.start; - beginning.size = overlap.start - region.start; - process_gb_huge_pages(&beginning, image_size); + if (overlap.start - region.start >= image_size) { + region.size = overlap.start - region.start; + process_gb_huge_pages(®ion, image_size); } - /* Return if overlap extends to or past end of region. */ - if (overlap.start + overlap.size >= region.start + region.size) - return; - /* Clip off the overlapping region and start over. */ - region.size -= overlap.start - region.start + overlap.size; region.start = overlap.start + overlap.size; } } static bool process_mem_region(struct mem_vector *region, - unsigned long long minimum, - unsigned long long image_size) + unsigned long minimum, + unsigned long image_size) { int i; /* -- 2.26.2
