From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 13 May 2024 10:30:14 +0000
Subject: [PATCH] modify sin led gpio
---
kernel/drivers/misc/lkdtm/heap.c | 81 ++++++++++++++++++++++++++++++++++++++--
1 files changed, 77 insertions(+), 4 deletions(-)
diff --git a/kernel/drivers/misc/lkdtm/heap.c b/kernel/drivers/misc/lkdtm/heap.c
index 65026d7..1323bc1 100644
--- a/kernel/drivers/misc/lkdtm/heap.c
+++ b/kernel/drivers/misc/lkdtm/heap.c
@@ -7,6 +7,10 @@
#include <linux/slab.h>
#include <linux/sched.h>
+static struct kmem_cache *double_free_cache;
+static struct kmem_cache *a_cache;
+static struct kmem_cache *b_cache;
+
/*
* This tries to stay within the next largest power-of-2 kmalloc cache
* to avoid actually overwriting anything important if it's not detected
@@ -54,11 +58,12 @@
int *base, *val, saw;
size_t len = 1024;
/*
- * The slub allocator uses the first word to store the free
- * pointer in some configurations. Use the middle of the
- * allocation to avoid running into the freelist
+ * The slub allocator will use the either the first word or
+ * the middle of the allocation to store the free pointer,
+ * depending on configurations. Store in the second word to
+ * avoid running into the freelist.
*/
- size_t offset = (len / sizeof(*base)) / 2;
+ size_t offset = sizeof(*base);
base = kmalloc(len, GFP_KERNEL);
if (!base) {
@@ -146,3 +151,71 @@
kfree(val);
}
+
+void lkdtm_SLAB_FREE_DOUBLE(void)
+{
+ int *val;
+
+ val = kmem_cache_alloc(double_free_cache, GFP_KERNEL);
+ if (!val) {
+ pr_info("Unable to allocate double_free_cache memory.\n");
+ return;
+ }
+
+ /* Just make sure we got real memory. */
+ *val = 0x12345678;
+ pr_info("Attempting double slab free ...\n");
+ kmem_cache_free(double_free_cache, val);
+ kmem_cache_free(double_free_cache, val);
+}
+
+void lkdtm_SLAB_FREE_CROSS(void)
+{
+ int *val;
+
+ val = kmem_cache_alloc(a_cache, GFP_KERNEL);
+ if (!val) {
+ pr_info("Unable to allocate a_cache memory.\n");
+ return;
+ }
+
+ /* Just make sure we got real memory. */
+ *val = 0x12345679;
+ pr_info("Attempting cross-cache slab free ...\n");
+ kmem_cache_free(b_cache, val);
+}
+
+void lkdtm_SLAB_FREE_PAGE(void)
+{
+ unsigned long p = __get_free_page(GFP_KERNEL);
+
+ pr_info("Attempting non-Slab slab free ...\n");
+ kmem_cache_free(NULL, (void *)p);
+ free_page(p);
+}
+
+/*
+ * We have constructors to keep the caches distinctly separated without
+ * needing to boot with "slab_nomerge".
+ */
+static void ctor_double_free(void *region)
+{ }
+static void ctor_a(void *region)
+{ }
+static void ctor_b(void *region)
+{ }
+
+void __init lkdtm_heap_init(void)
+{
+ double_free_cache = kmem_cache_create("lkdtm-heap-double_free",
+ 64, 0, 0, ctor_double_free);
+ a_cache = kmem_cache_create("lkdtm-heap-a", 64, 0, 0, ctor_a);
+ b_cache = kmem_cache_create("lkdtm-heap-b", 64, 0, 0, ctor_b);
+}
+
+void __exit lkdtm_heap_exit(void)
+{
+ kmem_cache_destroy(double_free_cache);
+ kmem_cache_destroy(a_cache);
+ kmem_cache_destroy(b_cache);
+}
--
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