ANDROID: 16K: Only check basename of linker context

Depending on the platform binary being executed, the linker
(interpreter) requested can be one of:

    1) /system/bin/bootstrap/linker64
    2) /system/bin/linker64
    3) /apex/com.android.runtime/bin/linker64

Relax the check to the basename (linker64), instead of the path.

Bug: 383389169
Bug: 330767927
Bug: 335584973
Change-Id: I4a1f95b7cecd126f85ad8cefd9ff10d272947f9e
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>

mm/pgsize_migration.c

@@ -18,6 +18,7 @@
 #include <linux/kstrtox.h>
 #include <linux/sched/task_stack.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/sysfs.h>
 
 typedef void (*show_pad_maps_fn)	(struct seq_file *m, struct vm_area_struct *vma);
@@ -196,7 +197,15 @@ static inline bool linker_ctx(void)
 		memset(buf, 0, bufsize);
 		path = d_path(&file->f_path, buf, bufsize);
 
-		if (!strcmp(path, "/system/bin/linker64"))
+		/*
+		 * Depending on interpreter requested, valid paths could be any of:
+		 *   1. /system/bin/bootstrap/linker64
+		 *   2. /system/bin/linker64
+		 *   3. /apex/com.android.runtime/bin/linker64
+		 *
+		 * Check the base name (linker64).
+		 */
+		if (!strcmp(kbasename(path), "linker64"))
 			return true;
 	}