1 files changed, 61 insertions, 0 deletions
diff --git a/arch/sparc64/lib/mcount.S b/arch/sparc64/lib/mcount.S
new file mode 100644
index 0000000..2ef2e26
--- /dev/null
+++ b/arch/sparc64/lib/mcount.S
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
+ *
+ * This file implements mcount(), which is used to collect profiling data.
+ * This can also be tweaked for kernel stack overflow detection.
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+
+#include <asm/ptrace.h>
+#include <asm/thread_info.h>
+
+/*
+ * This is the main variant and is called by C code.  GCC's -pg option
+ * automatically instruments every C function with a call to this.
+ */
+
+#ifdef CONFIG_STACK_DEBUG
+
+#define OVSTACKSIZE	4096		/* lets hope this is enough */
+
+	.data
+	.align		8
+panicstring:
+	.asciz		"Stack overflow\n"
+	.align		8
+ovstack:
+	.skip		OVSTACKSIZE
+#endif
+	.text
+	.align 32
+	.globl mcount, _mcount
+mcount:
+_mcount:
+#ifdef CONFIG_STACK_DEBUG
+	/*
+	 * Check whether %sp is dangerously low.
+	 */
+	ldub		[%g6 + TI_FPDEPTH], %g1
+	srl		%g1, 1, %g3
+	add		%g3, 1, %g3
+	sllx		%g3, 8, %g3			! each fpregs frame is 256b
+	add		%g3, 192, %g3
+	add		%g6, %g3, %g3			! where does task_struct+frame end?
+	sub		%g3, STACK_BIAS, %g3
+	cmp		%sp, %g3
+	bg,pt		%xcc, 1f
+	 sethi		%hi(panicstring), %g3
+	sethi		%hi(ovstack), %g7		! cant move to panic stack fast enough
+	 or		%g7, %lo(ovstack), %g7
+	add		%g7, OVSTACKSIZE, %g7
+	sub		%g7, STACK_BIAS, %g7
+	mov		%g7, %sp
+	call		prom_printf
+	 or		%g3, %lo(panicstring), %o0
+	call		prom_halt
+	 nop
+#endif
+1:	retl
+	 nop