[PATCH v3 9/9] KVM: arm64: Add UBSan tests for PKVM.
From: Elena Petrova
Date: Fri Jan 15 2021 - 12:20:17 EST
From: George-Aurelian Popescu <georgepope@xxxxxxxxxx>
Test the UBsan functionality inside hyp/nVHE.
Because modules are not supported inside of hyp/nVHE code, the default
testing module for UBSan can not be used.
New functions have to be defined inside of hyp/nVHE.
They are called in kvm_get_mdcr_el2, to test UBSAN whenever a VM starts.
Signed-off-by: Elena Petrova <lenaptr@xxxxxxxxxx>
---
arch/arm64/include/asm/assembler.h | 17 ++-
arch/arm64/include/asm/kvm_debug_buffer.h | 10 +-
arch/arm64/include/asm/kvm_ubsan.h | 2 +-
arch/arm64/kvm/hyp/include/hyp/test_ubsan.h | 112 ++++++++++++++++++++
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 +
arch/arm64/kvm/kvm_ubsan_buffer.c | 1 -
6 files changed, 128 insertions(+), 17 deletions(-)
create mode 100644 arch/arm64/kvm/hyp/include/hyp/test_ubsan.h
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index ebc18a8a0e1f..8422b0d925e8 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -259,16 +259,15 @@ alternative_endif
.endm
/*
- * @sym: The name of the per-cpu variable
- * @reg: value to store
- * @tmp1: scratch register
- * @tmp2: scratch register
- */
- .macro str_this_cpu sym, reg, tmp1, tmp2
- adr_this_cpu \tmp1, \sym, \tmp2
+ * @sym: The name of the per-cpu variable
+ * @reg: value to store
+ * @tmp1: scratch register
+ * @tmp2: scratch register
+ */
+ .macro str_this_cpu sym, reg, tmp1, tmp2
+ adr_this_cpu \tmp1, \sym, \tmp2
str \reg, [\tmp1]
- .endm
-
+ .endm
/*
* vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
*/
diff --git a/arch/arm64/include/asm/kvm_debug_buffer.h b/arch/arm64/include/asm/kvm_debug_buffer.h
index e5375c2cff1a..361b473bb004 100644
--- a/arch/arm64/include/asm/kvm_debug_buffer.h
+++ b/arch/arm64/include/asm/kvm_debug_buffer.h
@@ -3,10 +3,8 @@
* Copyright 2020 Google LLC
* Author: George Popescu <georgepope@xxxxxxxxxx>
*/
-
#include <linux/percpu-defs.h>
-
#define KVM_DEBUG_BUFFER_SIZE 1000
#ifdef __KVM_NVHE_HYPERVISOR__
@@ -20,17 +18,17 @@
#else
#define DECLARE_KVM_DEBUG_BUFFER(type_name, buffer_name, write_ind, size)\
DECLARE_KVM_NVHE_PER_CPU(type_name, buffer_name)[size]; \
- DECLARE_KVM_NVHE_PER_CPU(unsigned long, write_ind);
+ DECLARE_KVM_NVHE_PER_CPU(unsigned long, write_ind);
#endif //__KVM_NVHE_HYPERVISOR__
#ifdef __ASSEMBLY__
#include <asm/assembler.h>
.macro clear_buffer tmp1, tmp2, tmp3
- mov \tmp1, 0
+ mov \tmp1, 0
#ifdef CONFIG_UBSAN
- str_this_cpu kvm_ubsan_buff_wr_ind, \tmp1, \tmp2, \tmp3
+ str_this_cpu kvm_ubsan_buff_wr_ind, \tmp1, \tmp2, \tmp3
#endif //CONFIG_UBSAN
.endm
-#endif
\ No newline at end of file
+#endif
diff --git a/arch/arm64/include/asm/kvm_ubsan.h b/arch/arm64/include/asm/kvm_ubsan.h
index da4a3b4e28e0..0b8bed08d48e 100644
--- a/arch/arm64/include/asm/kvm_ubsan.h
+++ b/arch/arm64/include/asm/kvm_ubsan.h
@@ -9,7 +9,6 @@
#define UBSAN_MAX_TYPE 6
#define KVM_UBSAN_BUFFER_SIZE 1000
-
struct ubsan_values {
void *lval;
void *rval;
@@ -18,6 +17,7 @@ struct ubsan_values {
struct kvm_ubsan_info {
enum {
+ UBSAN_NONE,
UBSAN_OUT_OF_BOUNDS,
UBSAN_UNREACHABLE_DATA,
UBSAN_SHIFT_OUT_OF_BOUNDS,
diff --git a/arch/arm64/kvm/hyp/include/hyp/test_ubsan.h b/arch/arm64/kvm/hyp/include/hyp/test_ubsan.h
new file mode 100644
index 000000000000..07759c0d1e0e
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/hyp/test_ubsan.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <linux/ctype.h>
+
+typedef void(*test_ubsan_fp)(void);
+
+static void test_ubsan_add_overflow(void)
+{
+ volatile int val = INT_MAX;
+
+ val += 2;
+}
+
+static void test_ubsan_sub_overflow(void)
+{
+ volatile int val = INT_MIN;
+ volatile int val2 = 2;
+
+ val -= val2;
+}
+
+static void test_ubsan_mul_overflow(void)
+{
+ volatile int val = INT_MAX / 2;
+
+ val *= 3;
+}
+
+static void test_ubsan_negate_overflow(void)
+{
+ volatile int val = INT_MIN;
+
+ val = -val;
+}
+
+static void test_ubsan_divrem_overflow(void)
+{
+ volatile int val = 16;
+ volatile int val2 = 0;
+
+ val /= val2;
+}
+
+static void test_ubsan_shift_out_of_bounds(void)
+{
+ volatile int val = -1;
+ int val2 = 10;
+
+ val2 <<= val;
+}
+
+static void test_ubsan_out_of_bounds(void)
+{
+ volatile int i = 4, j = 5;
+ volatile int arr[4];
+
+ arr[j] = i;
+}
+
+static void test_ubsan_load_invalid_value(void)
+{
+ volatile char *dst, *src;
+ bool val, val2, *ptr;
+ char c = 4;
+
+ dst = (char *)&val;
+ src = &c;
+ *dst = *src;
+
+ ptr = &val2;
+ val2 = val;
+}
+
+static void test_ubsan_misaligned_access(void)
+{
+ volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
+ volatile int *ptr, val = 6;
+
+ ptr = (int *)(arr + 1);
+ *ptr = val;
+}
+
+static void test_ubsan_object_size_mismatch(void)
+{
+ /* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
+ volatile int val __aligned(8) = 4;
+ volatile long long *ptr, val2;
+
+ ptr = (long long *)&val;
+ val2 = *ptr;
+}
+
+static const test_ubsan_fp test_ubsan_array[] = {
+ test_ubsan_out_of_bounds,
+ test_ubsan_add_overflow,
+ test_ubsan_sub_overflow,
+ test_ubsan_mul_overflow,
+ test_ubsan_negate_overflow,
+ test_ubsan_divrem_overflow,
+ test_ubsan_shift_out_of_bounds,
+ test_ubsan_load_invalid_value,
+ test_ubsan_misaligned_access,
+ test_ubsan_object_size_mismatch,
+};
+
+static void test_ubsan(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
+ test_ubsan_array[i]();
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index a906f9e2ff34..939600e9fdd6 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -13,6 +13,7 @@
#include <asm/kvm_mmu.h>
#include <nvhe/trap_handler.h>
+#include <hyp/test_ubsan.h>
DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
@@ -90,6 +91,8 @@ static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt)
{
cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2();
+ if (IS_ENABLED(CONFIG_TEST_UBSAN))
+ test_ubsan();
}
static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/kvm_ubsan_buffer.c b/arch/arm64/kvm/kvm_ubsan_buffer.c
index 2c7060cbb48b..49bedc9de139 100644
--- a/arch/arm64/kvm/kvm_ubsan_buffer.c
+++ b/arch/arm64/kvm/kvm_ubsan_buffer.c
@@ -11,7 +11,6 @@
#include <asm/kvm_asm.h>
#include <kvm/arm_pmu.h>
-#include <ubsan.h>
#include <asm/kvm_ubsan.h>
DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buffer,
--
2.30.0.296.g2bfb1c46d8-goog