Merge tag 's390-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Vasily Gorbik:

 - Get rid of s390 specific use of two PTEs per 4KB page with complex
   half-used pages tracking. Using full 4KB pages for 2KB PTEs increases
   the memory footprint of page tables but drastically simplify mm code,
   removing a common blocker for common code changes and adaptations

 - Simplify and rework "cmma no-dat" handling. This is a follow up for
   recent fixes which prevent potential incorrect guest TLB flushes

 - Add perf user stack unwinding as well as USER_STACKTRACE support for
   user space built with -mbackchain compile option

 - Add few missing conversion from tlb_remove_table to tlb_remove_ptdesc

 - Fix crypto cards vanishing in a secure execution environment due to
   asynchronous errors

 - Avoid reporting crypto cards or queues in check-stop state as online

 - Fix null-ptr deference in AP bus code triggered by early config
   change via SCLP

 - Couple of stability improvements in AP queue interrupt handling

* tag 's390-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: make pte_free_tlb() similar to pXd_free_tlb()
  s390/mm: use compound page order to distinguish page tables
  s390/mm: use full 4KB page for 2KB PTE
  s390/cmma: rework no-dat handling
  s390/cmma: move arch_set_page_dat() to header file
  s390/cmma: move set_page_stable() and friends to header file
  s390/cmma: move parsing of cmma kernel parameter to early boot code
  s390/cmma: cleanup inline assemblies
  s390/ap: fix vanishing crypto cards in SE environment
  s390/zcrypt: don't report online if card or queue is in check-stop state
  s390: add USER_STACKTRACE support
  s390/perf: implement perf_callchain_user()
  s390/ap: fix AP bus crash on early config change callback invocation
  s390/ap: re-enable interrupt for AP queues
  s390/ap: rework to use irq info from ap queue status
  s390/mm: add missing conversion to use ptdescs

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 0787010139f7..94f440e38303 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -6,9 +6,12 @@
  */
 
 #include <linux/stacktrace.h>
+#include <linux/uaccess.h>
+#include <linux/compat.h>
 #include <asm/stacktrace.h>
 #include <asm/unwind.h>
 #include <asm/kprobes.h>
+#include <asm/ptrace.h>
 
 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
 		     struct task_struct *task, struct pt_regs *regs)
@@ -58,3 +61,43 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
 		return -EINVAL;
 	return 0;
 }
+
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+			  const struct pt_regs *regs)
+{
+	struct stack_frame_user __user *sf;
+	unsigned long ip, sp;
+	bool first = true;
+
+	if (is_compat_task())
+		return;
+	if (!consume_entry(cookie, instruction_pointer(regs)))
+		return;
+	sf = (void __user *)user_stack_pointer(regs);
+	pagefault_disable();
+	while (1) {
+		if (__get_user(sp, &sf->back_chain))
+			break;
+		if (__get_user(ip, &sf->gprs[8]))
+			break;
+		if (ip & 0x1) {
+			/*
+			 * If the instruction address is invalid, and this
+			 * is the first stack frame, assume r14 has not
+			 * been written to the stack yet. Otherwise exit.
+			 */
+			if (first && !(regs->gprs[14] & 0x1))
+				ip = regs->gprs[14];
+			else
+				break;
+		}
+		if (!consume_entry(cookie, ip))
+			break;
+		/* Sanity check: ABI requires SP to be aligned 8 bytes. */
+		if (!sp || sp & 0x7)
+			break;
+		sf = (void __user *)sp;
+		first = false;
+	}
+	pagefault_enable();
+}