added backtraces

1 files changed, 53 insertions, 0 deletions

diff --git a/src/arch/amd64/backtrace.c b/src/arch/amd64/backtrace.c
new file mode 100644
index 0000000..c882fa0
--- /dev/null
+++ b/src/arch/amd64/backtrace.c
@@ -0,0 +1,53 @@
+#include <backtrace.h>
+#include <lib.h>
+#include "serial.h"
+
+struct stackframe {
+	struct stackframe *rbp;
+	void *rip;
+};
+
+size_t backtrace(void **dst, size_t len) {
+	struct stackframe *rbp;
+	__asm__ volatile ("mov %%rbp, %0" : "=r"(rbp));
+	return backtrace_ex(dst, len, rbp->rip, rbp->rbp);
+}
+
+size_t backtrace_ex(void **dst, size_t len, void *ip, void *bp) {
+	struct stackframe *frame = bp;
+	__asm__ volatile ("mov %%rbp, %0" : "=r"(frame));
+	if(len > 0) {
+		dst[0] = ip;
+	}
+	size_t i;
+	for(i = 1; frame && i < len; i++) {
+		dst[i] = frame->rip;
+		frame = frame->rbp;
+	}
+	return i;
+}
+
+void log_backtrace() {
+	struct stackframe *rbp;
+	__asm__ volatile ("mov %%rbp, %0" : "=r"(rbp));
+	log_backtrace_ex(rbp->rip, rbp->rbp);
+}
+
+
+void log_backtrace_ex(void *ip, void *bp) {
+	struct stackframe *frame = bp;
+	char buf[20];
+	serial_out_str("Stack trace:\n");
+	ultoa((size_t)ip, buf, 16);
+	serial_out_str("  0x");
+	serial_out_str(buf);
+	serial_out_str("\n");
+	while(frame) {
+		ultoa((size_t)frame->rip, buf, 16);
+		serial_out_str("  0x");
+		serial_out_str(buf);
+		serial_out_str("\n");
+		frame = frame->rbp;
+	}
+
+}