1 files changed, 42 insertions, 4 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index e98d9650764b..dc17896a001a 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -99,7 +99,6 @@ void cpu_detect_mhz_feature(void);
 
 extern const struct seq_operations cpuinfo_op;
 extern void execve_tail(void);
-extern void __bpon(void);
 unsigned long vdso_size(void);
 
 /*
@@ -119,6 +118,41 @@ unsigned long vdso_size(void);
 
 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 
+#define __stackleak_poison __stackleak_poison
+static __always_inline void __stackleak_poison(unsigned long erase_low,
+					       unsigned long erase_high,
+					       unsigned long poison)
+{
+	unsigned long tmp, count;
+
+	count = erase_high - erase_low;
+	if (!count)
+		return;
+	asm volatile(
+		"	cghi	%[count],8\n"
+		"	je	2f\n"
+		"	aghi	%[count],-(8+1)\n"
+		"	srlg	%[tmp],%[count],8\n"
+		"	ltgr	%[tmp],%[tmp]\n"
+		"	jz	1f\n"
+		"0:	stg	%[poison],0(%[addr])\n"
+		"	mvc	8(256-8,%[addr]),0(%[addr])\n"
+		"	la	%[addr],256(%[addr])\n"
+		"	brctg	%[tmp],0b\n"
+		"1:	stg	%[poison],0(%[addr])\n"
+		"	larl	%[tmp],3f\n"
+		"	ex	%[count],0(%[tmp])\n"
+		"	j	4f\n"
+		"2:	stg	%[poison],0(%[addr])\n"
+		"	j	4f\n"
+		"3:	mvc	8(1,%[addr]),0(%[addr])\n"
+		"4:\n"
+		: [addr] "+&a" (erase_low), [count] "+&d" (count), [tmp] "=&a" (tmp)
+		: [poison] "d" (poison)
+		: "memory", "cc"
+		);
+}
+
 /*
  * Thread structure
  */
@@ -227,6 +261,13 @@ static __always_inline unsigned long __current_stack_pointer(void)
 	return sp;
 }
 
+static __always_inline bool on_thread_stack(void)
+{
+	unsigned long ksp = S390_lowcore.kernel_stack;
+
+	return !((ksp ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
+}
+
 static __always_inline unsigned short stap(void)
 {
 	unsigned short cpu_address;
@@ -329,9 +370,6 @@ static __always_inline void __noreturn disabled_wait(void)
 
 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
 
-extern int s390_isolate_bp(void);
-extern int s390_isolate_bp_guest(void);
-
 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
 {
 	return arch_irqs_disabled_flags(regs->psw.mask);