Merge tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for stackleak feature. Also allow specifying
   architecture-specific stackleak poison function to enable faster
   implementation. On s390, the mvc-based implementation helps decrease
   typical overhead from a factor of 3 to just 25%

 - Convert all assembler files to use SYM* style macros, deprecating the
   ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS

 - Improve KASLR to also randomize module and special amode31 code base
   load addresses

 - Rework decompressor memory tracking to support memory holes and
   improve error handling

 - Add support for protected virtualization AP binding

 - Add support for set_direct_map() calls

 - Implement set_memory_rox() and noexec module_alloc()

 - Remove obsolete overriding of mem*() functions for KASAN

 - Rework kexec/kdump to avoid using nodat_stack to call purgatory

 - Convert the rest of the s390 code to use flexible-array member
   instead of a zero-length array

 - Clean up uaccess inline asm

 - Enable ARCH_HAS_MEMBARRIER_SYNC_CORE

 - Convert to using CONFIG_FUNCTION_ALIGNMENT and enable
   DEBUG_FORCE_FUNCTION_ALIGN_64B

 - Resolve last_break in userspace fault reports

 - Simplify one-level sysctl registration

 - Clean up branch prediction handling

 - Rework CPU counter facility to retrieve available counter sets just
   once

 - Other various small fixes and improvements all over the code

* tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (118 commits)
  s390/stackleak: provide fast __stackleak_poison() implementation
  stackleak: allow to specify arch specific stackleak poison function
  s390: select ARCH_USE_SYM_ANNOTATIONS
  s390/mm: use VM_FLUSH_RESET_PERMS in module_alloc()
  s390: wire up memfd_secret system call
  s390/mm: enable ARCH_HAS_SET_DIRECT_MAP
  s390/mm: use BIT macro to generate SET_MEMORY bit masks
  s390/relocate_kernel: adjust indentation
  s390/relocate_kernel: use SYM* macros instead of ENTRY(), etc.
  s390/entry: use SYM* macros instead of ENTRY(), etc.
  s390/purgatory: use SYM* macros instead of ENTRY(), etc.
  s390/kprobes: use SYM* macros instead of ENTRY(), etc.
  s390/reipl: use SYM* macros instead of ENTRY(), etc.
  s390/head64: use SYM* macros instead of ENTRY(), etc.
  s390/earlypgm: use SYM* macros instead of ENTRY(), etc.
  s390/mcount: use SYM* macros instead of ENTRY(), etc.
  s390/crc32le: use SYM* macros instead of ENTRY(), etc.
  s390/crc32be: use SYM* macros instead of ENTRY(), etc.
  s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc.
  s390/amode31: use SYM* macros instead of ENTRY(), etc.
  ...

1 files changed, 44 insertions, 8 deletions

diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index 1802be5abb5d..78f7b729b65f 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -189,17 +189,53 @@ static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
 	(rettype)r2;							\
 })
 
-#define call_on_stack_noreturn(fn, stack)				\
+/*
+ * Use call_nodat() to call a function with DAT disabled.
+ * Proper sign and zero extension of function arguments is done.
+ * Usage:
+ *
+ * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...)
+ *
+ * - nr specifies the number of function arguments of fn.
+ * - fn is the function to be called, where fn is a physical address.
+ * - rettype is the return type of fn.
+ * - t1, a1, ... are pairs, where t1 must match the type of the first
+ *   argument of fn, t2 the second, etc. a1 is the corresponding
+ *   first function argument (not name), etc.
+ *
+ * fn() is called with standard C function call ABI, with the exception
+ * that no useful stackframe or stackpointer is passed via register 15.
+ * Therefore the called function must not use r15 to access the stack.
+ */
+#define call_nodat(nr, rettype, fn, ...)				\
 ({									\
-	void (*__fn)(void) = fn;					\
+	rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn);		\
+	/* aligned since psw_leave must not cross page boundary */	\
+	psw_t __aligned(16) psw_leave;					\
+	psw_t psw_enter;						\
+	CALL_LARGS_##nr(__VA_ARGS__);					\
+	CALL_REGS_##nr;							\
 									\
+	CALL_TYPECHECK_##nr(__VA_ARGS__);				\
+	psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT;		\
+	psw_enter.addr = (unsigned long)__fn;				\
 	asm volatile(							\
-		"	la	15,0(%[_stack])\n"			\
-		"	xc	%[_bc](8,15),%[_bc](15)\n"		\
-		"	brasl	14,%[_fn]\n"				\
-		::[_bc] "i" (offsetof(struct stack_frame, back_chain)),	\
-		  [_stack] "a" (stack), [_fn] "X" (__fn));		\
-	BUG();								\
+		"	epsw	0,1\n"					\
+		"	risbg	1,0,0,31,32\n"				\
+		"	larl	7,1f\n"					\
+		"	stg	1,%[psw_leave]\n"			\
+		"	stg	7,8+%[psw_leave]\n"			\
+		"	la	7,%[psw_leave]\n"			\
+		"	lra	7,0(7)\n"				\
+		"	larl	1,0f\n"					\
+		"	lra	14,0(1)\n"				\
+		"	lpswe	%[psw_enter]\n"				\
+		"0:	lpswe	0(7)\n"					\
+		"1:\n"							\
+		: CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave)		\
+		: [psw_enter] "Q" (psw_enter)				\
+		: "7", CALL_CLOBBER_##nr);				\
+	(rettype)r2;							\
 })
 
 #endif /* _ASM_S390_STACKTRACE_H */