From: Seung-Woo Kim <sw0312.kim@samsung.com>
Date: Mon, 25 Jan 2021 06:44:20 +0000 (+0900)
Subject: kmemleak: Fix bad memory access with scan stack for amlogic vmap
X-Git-Tag: submit/tizen/20210204.012538~15
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F72%2F252172%2F1;p=platform%2Fkernel%2Flinux-amlogic.git

kmemleak: Fix bad memory access with scan stack for amlogic vmap

When AMLOGIC_VMAP is enabled, try_get_task_stack() returns address
of stasck instead of page address. This causes bad memory access
during kmemleak scan stack. Fix the bad memory access by using
aml_task_stack().

Note: Maybe, get_task_stack() needs to call aml_task_stack() is
required, but aml_task_stack() has no consideration for kmalloced
task stack, so just fix from kmemleak.

Change-Id: I58a2e324cb92cd692d2260c675e81d7d0715e96c
Fixes: commit 4d6ae4359385 ("mm: optimize thread stack usage on arm64 [1/1]")
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
---

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index d05133b37b17..7eeb84a73c94 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -112,6 +112,10 @@
 #include <linux/kmemleak.h>
 #include <linux/memory_hotplug.h>
 
+#ifdef CONFIG_AMLOGIC_VMAP
+#include <linux/amlogic/vmap_stack.h>
+#endif
+
 /*
  * Kmemleak configuration and common defines.
  */
@@ -1456,11 +1460,17 @@ static void kmemleak_scan(void)
 
 		read_lock(&tasklist_lock);
 		do_each_thread(g, p) {
+#ifdef CONFIG_AMLOGIC_VMAP
+			void *stack = aml_task_stack(p);
+			if (stack)
+				scan_block(stack, stack + THREAD_SIZE, NULL);
+#else
 			void *stack = try_get_task_stack(p);
 			if (stack) {
 				scan_block(stack, stack + THREAD_SIZE, NULL);
 				put_task_stack(p);
 			}
+#endif
 		} while_each_thread(g, p);
 		read_unlock(&tasklist_lock);
 	}