This macro adds some debug code to check that vmap allocations are happened in ascending order.
By default this option is set to 0 and not active. It requires recompilation of the kernel to activate it. Set to 1, compile the kernel. Signed-off-by: Uladzislau Rezki (Sony) <[email protected]> Reviewed-by: Roman Gushchin <[email protected]> --- mm/vmalloc.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a74e605e042f..92b784d8088c 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -325,6 +325,7 @@ EXPORT_SYMBOL(vmalloc_to_pfn); /*** Global kva allocator ***/ #define DEBUG_AUGMENT_PROPAGATE_CHECK 0 +#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 #define VM_LAZY_FREE 0x02 #define VM_VM_AREA 0x04 @@ -833,6 +834,44 @@ find_vmap_lowest_match(unsigned long size, return NULL; } +#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK +#include <linux/random.h> + +static struct vmap_area * +find_vmap_lowest_linear_match(unsigned long size, + unsigned long align, unsigned long vstart) +{ + struct vmap_area *va; + + list_for_each_entry(va, &free_vmap_area_list, list) { + if (!is_within_this_va(va, size, align, vstart)) + continue; + + return va; + } + + return NULL; +} + +static void +find_vmap_lowest_match_check(unsigned long size) +{ + struct vmap_area *va_1, *va_2; + unsigned long vstart; + unsigned int rnd; + + get_random_bytes(&rnd, sizeof(rnd)); + vstart = VMALLOC_START + rnd; + + va_1 = find_vmap_lowest_match(size, 1, vstart); + va_2 = find_vmap_lowest_linear_match(size, 1, vstart); + + if (va_1 != va_2) + pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", + va_1, va_2, vstart); +} +#endif + enum fit_type { NOTHING_FIT = 0, FL_FIT_TYPE = 1, /* full fit */ @@ -975,6 +1014,10 @@ __alloc_vmap_area(unsigned long size, unsigned long align, if (ret) return vend; +#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK + find_vmap_lowest_match_check(size); +#endif + return nva_start_addr; } -- 2.11.0
