5 files changed, 50 insertions, 5 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 7284a22b1a09..a4fdad04809a 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -12,6 +12,10 @@
 #include <linux/sched/task_stack.h>
 #include <linux/uaccess.h>
 
+#ifdef CONFIG_X86_32
+#include <asm/desc.h>
+#endif
+
 struct lkdtm_list {
 	struct list_head node;
 };
@@ -337,3 +341,38 @@ void lkdtm_UNSET_SMEP(void)
 	pr_err("FAIL: this test is x86_64-only\n");
 #endif
 }
+
+#ifdef CONFIG_X86_32
+void lkdtm_DOUBLE_FAULT(void)
+{
+	/*
+	 * Trigger #DF by setting the stack limit to zero.  This clobbers
+	 * a GDT TLS slot, which is okay because the current task will die
+	 * anyway due to the double fault.
+	 */
+	struct desc_struct d = {
+		.type = 3,	/* expand-up, writable, accessed data */
+		.p = 1,		/* present */
+		.d = 1,		/* 32-bit */
+		.g = 0,		/* limit in bytes */
+		.s = 1,		/* not system */
+	};
+
+	local_irq_disable();
+	write_gdt_entry(get_cpu_gdt_rw(smp_processor_id()),
+			GDT_ENTRY_TLS_MIN, &d, DESCTYPE_S);
+
+	/*
+	 * Put our zero-limit segment in SS and then trigger a fault.  The
+	 * 4-byte access to (%esp) will fault with #SS, and the attempt to
+	 * deliver the fault will recursively cause #SS and result in #DF.
+	 * This whole process happens while NMIs and MCEs are blocked by the
+	 * MOV SS window.  This is nice because an NMI with an invalid SS
+	 * would also double-fault, resulting in the NMI or MCE being lost.
+	 */
+	asm volatile ("movw %0, %%ss; addl $0, (%%esp)" ::
+		      "r" ((unsigned short)(GDT_ENTRY_TLS_MIN << 3)));
+
+	panic("tried to double fault but didn't die\n");
+}
+#endif
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index cbc4c9045a99..ee0d6e721441 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -171,6 +171,9 @@ static const struct crashtype crashtypes[] = {
 	CRASHTYPE(USERCOPY_KERNEL_DS),
 	CRASHTYPE(STACKLEAK_ERASING),
 	CRASHTYPE(CFI_FORWARD_PROTO),
+#ifdef CONFIG_X86_32
+	CRASHTYPE(DOUBLE_FAULT),
+#endif
 };
 
 
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index ab446e0bde97..c56d23e37643 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -28,6 +28,9 @@ void lkdtm_CORRUPT_USER_DS(void);
 void lkdtm_STACK_GUARD_PAGE_LEADING(void);
 void lkdtm_STACK_GUARD_PAGE_TRAILING(void);
 void lkdtm_UNSET_SMEP(void);
+#ifdef CONFIG_X86_32
+void lkdtm_DOUBLE_FAULT(void);
+#endif
 
 /* lkdtm_heap.c */
 void __init lkdtm_heap_init(void);
diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index 6e208a060a58..a5e317073d95 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -94,7 +94,7 @@ enum pci_barno {
 struct pci_endpoint_test {
 	struct pci_dev	*pdev;
 	void __iomem	*base;
-	void __iomem	*bar[6];
+	void __iomem	*bar[PCI_STD_NUM_BARS];
 	struct completion irq_raised;
 	int		last_irq;
 	int		num_irqs;
@@ -687,7 +687,7 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
 	if (!pci_endpoint_test_request_irq(test))
 		goto err_disable_irq;
 
-	for (bar = BAR_0; bar <= BAR_5; bar++) {
+	for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
 		if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) {
 			base = pci_ioremap_bar(pdev, bar);
 			if (!base) {
@@ -740,7 +740,7 @@ err_ida_remove:
 	ida_simple_remove(&pci_endpoint_test_ida, id);
 
 err_iounmap:
-	for (bar = BAR_0; bar <= BAR_5; bar++) {
+	for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
 		if (test->bar[bar])
 			pci_iounmap(pdev, test->bar[bar]);
 	}
@@ -771,7 +771,7 @@ static void pci_endpoint_test_remove(struct pci_dev *pdev)
 	misc_deregister(&test->miscdev);
 	kfree(misc_device->name);
 	ida_simple_remove(&pci_endpoint_test_ida, id);
-	for (bar = BAR_0; bar <= BAR_5; bar++) {
+	for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
 		if (test->bar[bar])
 			pci_iounmap(pdev, test->bar[bar]);
 	}
diff --git a/drivers/misc/sram-exec.c b/drivers/misc/sram-exec.c
index 426ad912b441..d054e2842a5f 100644
--- a/drivers/misc/sram-exec.c
+++ b/drivers/misc/sram-exec.c
@@ -96,7 +96,7 @@ void *sram_exec_copy(struct gen_pool *pool, void *dst, void *src,
 	if (!part)
 		return NULL;
 
-	if (!addr_in_gen_pool(pool, (unsigned long)dst, size))
+	if (!gen_pool_has_addr(pool, (unsigned long)dst, size))
 		return NULL;
 
 	base = (unsigned long)part->base;