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) <urezki@xxxxxxxxx>
---
mm/vmalloc.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1449a8c43aa2..dffc45e645e7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -323,6 +323,7 @@ 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
@@ -844,6 +845,44 @@ __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 alloc_fit_type {
NOTHING_FIT = 0,
FL_FIT_TYPE = 1, /* full fit */
@@ -985,6 +1024,10 @@ __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
