fix /proc/*/pagemap

refs #387

arch/x86_64/kernel/memory.c

@@ -493,7 +493,7 @@ uint64_t ihk_mc_pt_virt_to_pagemap(struct page_table *pt, unsigned long virt)
 
 	error = ihk_mc_pt_virt_to_phys(pt, (void *)virt, &phys);
 	if (error) {
-		return 0;
+		return PM_PSHIFT(PAGE_SHIFT);
 	}
 
 	pagemap = PM_PFRAME(phys >> PAGE_SHIFT);

kernel/procfs.c

@@ -422,12 +422,6 @@ void process_procfs_request(struct ikc_scd_packet *rpacket)
 	if (strcmp(p, "pagemap") == 0) {
 		uint64_t *_buf = (uint64_t *)buf;
 		uint64_t start, end;
-		
-		if (offset < PAGE_SIZE) {
-			kprintf("WARNING: /proc/pagemap queried for NULL page\n");
-			ans = 0;
-			goto end;
-		}
 
 		/* Check alignment */
 		if ((offset % sizeof(uint64_t) != 0) ||