6 files changed, 74 insertions, 14 deletions
diff --git a/arch/um/include/shared/as-layout.h b/arch/um/include/shared/as-layout.h
index 5f286ef2721b..9a0bd648d872 100644
--- a/arch/um/include/shared/as-layout.h
+++ b/arch/um/include/shared/as-layout.h
@@ -20,18 +20,10 @@
  * 'UL' and other type specifiers unilaterally.  We
  * use the following macros to deal with this.
  */
-
-#ifdef __ASSEMBLY__
-#define _UML_AC(X, Y)	(Y)
-#else
-#define __UML_AC(X, Y)	(X(Y))
-#define _UML_AC(X, Y)	__UML_AC(X, Y)
-#endif
-
-#define STUB_START _UML_AC(, 0x100000)
-#define STUB_CODE _UML_AC((unsigned long), STUB_START)
-#define STUB_DATA _UML_AC((unsigned long), STUB_CODE + UM_KERN_PAGE_SIZE)
-#define STUB_END _UML_AC((unsigned long), STUB_DATA + UM_KERN_PAGE_SIZE)
+#define STUB_START stub_start
+#define STUB_CODE STUB_START
+#define STUB_DATA (STUB_CODE + UM_KERN_PAGE_SIZE)
+#define STUB_END (STUB_DATA + UM_KERN_PAGE_SIZE)
 
 #ifndef __ASSEMBLY__
 
@@ -54,6 +46,7 @@ extern unsigned long long highmem;
 extern unsigned long brk_start;
 
 extern unsigned long host_task_size;
+extern unsigned long stub_start;
 
 extern int linux_main(int argc, char **argv);
 extern void uml_finishsetup(void);
diff --git a/arch/um/include/shared/common-offsets.h b/arch/um/include/shared/common-offsets.h
index 16a51a8c800f..edc90ab73734 100644
--- a/arch/um/include/shared/common-offsets.h
+++ b/arch/um/include/shared/common-offsets.h
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /* for use by sys-$SUBARCH/kernel-offsets.c */
+#include <stub-data.h>
 
 DEFINE(KERNEL_MADV_REMOVE, MADV_REMOVE);
 
@@ -43,3 +44,8 @@ DEFINE(UML_CONFIG_64BIT, CONFIG_64BIT);
 #ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
 DEFINE(UML_CONFIG_UML_TIME_TRAVEL_SUPPORT, CONFIG_UML_TIME_TRAVEL_SUPPORT);
 #endif
+
+/* for stub */
+DEFINE(UML_STUB_FIELD_OFFSET, offsetof(struct stub_data, offset));
+DEFINE(UML_STUB_FIELD_CHILD_ERR, offsetof(struct stub_data, child_err));
+DEFINE(UML_STUB_FIELD_FD, offsetof(struct stub_data, fd));
diff --git a/arch/um/include/shared/irq_kern.h b/arch/um/include/shared/irq_kern.h
index 7807de593bda..f2dc817abb7c 100644
--- a/arch/um/include/shared/irq_kern.h
+++ b/arch/um/include/shared/irq_kern.h
@@ -7,6 +7,7 @@
 #define __IRQ_KERN_H__
 
 #include <linux/interrupt.h>
+#include <linux/time-internal.h>
 #include <asm/ptrace.h>
 #include "irq_user.h"
 
@@ -15,5 +16,64 @@
 int um_request_irq(int irq, int fd, enum um_irq_type type,
 		   irq_handler_t handler, unsigned long irqflags,
 		   const char *devname, void *dev_id);
+
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+/**
+ * um_request_irq_tt - request an IRQ with timetravel handler
+ *
+ * @irq: the IRQ number, or %UM_IRQ_ALLOC
+ * @fd: The file descriptor to request an IRQ for
+ * @type: read or write
+ * @handler: the (generic style) IRQ handler
+ * @irqflags: Linux IRQ flags
+ * @devname: name for this to show
+ * @dev_id: data pointer to pass to the IRQ handler
+ * @timetravel_handler: the timetravel interrupt handler, invoked with the IRQ
+ *	number, fd, dev_id and time-travel event pointer.
+ *
+ * Returns: The interrupt number assigned or a negative error.
+ *
+ * Note that the timetravel handler is invoked only if the time_travel_mode is
+ * %TT_MODE_EXTERNAL, and then it is invoked even while the system is suspended!
+ * This function must call time_travel_add_irq_event() for the event passed with
+ * an appropriate delay, before sending an ACK on the socket it was invoked for.
+ *
+ * If this was called while the system is suspended, then adding the event will
+ * cause the system to resume.
+ *
+ * Since this function will almost certainly have to handle the FD's condition,
+ * a read will consume the message, and after that it is up to the code using
+ * it to pass such a message to the @handler in whichever way it can.
+ *
+ * If time_travel_mode is not %TT_MODE_EXTERNAL the @timetravel_handler will
+ * not be invoked at all and the @handler must handle the FD becoming
+ * readable (or writable) instead. Use um_irq_timetravel_handler_used() to
+ * distinguish these cases.
+ *
+ * See virtio_uml.c for an example.
+ */
+int um_request_irq_tt(int irq, int fd, enum um_irq_type type,
+		      irq_handler_t handler, unsigned long irqflags,
+		      const char *devname, void *dev_id,
+		      void (*timetravel_handler)(int, int, void *,
+						 struct time_travel_event *));
+#else
+static inline
+int um_request_irq_tt(int irq, int fd, enum um_irq_type type,
+		      irq_handler_t handler, unsigned long irqflags,
+		      const char *devname, void *dev_id,
+		      void (*timetravel_handler)(int, int, void *,
+						 struct time_travel_event *))
+{
+	return um_request_irq(irq, fd, type, handler, irqflags,
+			      devname, dev_id);
+}
+#endif
+
+static inline bool um_irq_timetravel_handler_used(void)
+{
+	return time_travel_mode == TT_MODE_EXTERNAL;
+}
+
 void um_free_irq(int irq, void *dev_id);
 #endif
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index d8c279e3312f..2888ec812f6e 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -19,7 +19,7 @@ extern int kmalloc_ok;
 #define UML_ROUND_UP(addr) \
 	((((unsigned long) addr) + PAGE_SIZE - 1) & PAGE_MASK)
 
-extern unsigned long alloc_stack(int atomic);
+extern unsigned long alloc_stack(int order, int atomic);
 extern void free_stack(unsigned long stack, int order);
 
 struct pt_regs;
diff --git a/arch/um/include/shared/skas/mm_id.h b/arch/um/include/shared/skas/mm_id.h
index 4337b4ced095..e82e203f5f41 100644
--- a/arch/um/include/shared/skas/mm_id.h
+++ b/arch/um/include/shared/skas/mm_id.h
@@ -12,6 +12,7 @@ struct mm_id {
 		int pid;
 	} u;
 	unsigned long stack;
+	int kill;
 };
 
 #endif
diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h
index 6b01d97a9386..5e3ade3fb38b 100644
--- a/arch/um/include/shared/skas/stub-data.h
+++ b/arch/um/include/shared/skas/stub-data.h
@@ -11,7 +11,7 @@
 struct stub_data {
 	unsigned long offset;
 	int fd;
-	long err;
+	long parent_err, child_err;
 };
 
 #endif