Module Name: src
Committed By: riastradh
Date: Sat Nov 27 14:11:04 UTC 2021
Modified Files:
src/sys/arch/aarch64/aarch64: db_trace.c
Log Message:
aarch64: Fix stack traces from jump-to-null.
To generate a diff of this commit:
cvs rdiff -u -r1.13 -r1.14 src/sys/arch/aarch64/aarch64/db_trace.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/aarch64/aarch64/db_trace.c
diff -u src/sys/arch/aarch64/aarch64/db_trace.c:1.13 src/sys/arch/aarch64/aarch64/db_trace.c:1.14
--- src/sys/arch/aarch64/aarch64/db_trace.c:1.13 Fri Dec 11 18:03:33 2020
+++ src/sys/arch/aarch64/aarch64/db_trace.c Sat Nov 27 14:11:04 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: db_trace.c,v 1.13 2020/12/11 18:03:33 skrll Exp $ */
+/* $NetBSD: db_trace.c,v 1.14 2021/11/27 14:11:04 riastradh Exp $ */
/*
* Copyright (c) 2017 Ryo Shimizu <[email protected]>
@@ -28,7 +28,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.13 2020/12/11 18:03:33 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.14 2021/11/27 14:11:04 riastradh Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@@ -302,8 +302,21 @@ db_stack_trace_print(db_expr_t addr, boo
lastfp = (uint64_t)tf;
lastlr = lr;
lr = fp = 0;
- db_read_bytes((db_addr_t)&tf->tf_pc, sizeof(lr), (char *)&lr);
- db_read_bytes((db_addr_t)&tf->tf_reg[29], sizeof(fp), (char *)&fp);
+ db_read_bytes((db_addr_t)&tf->tf_pc, sizeof(lr),
+ (char *)&lr);
+ if (lr == 0) {
+ /*
+ * The exception may have been from a
+ * jump to null, so the null pc we
+ * would return to is useless. Try
+ * x[30] instead -- that will be the
+ * return address for the jump.
+ */
+ db_read_bytes((db_addr_t)&tf->tf_reg[30],
+ sizeof(lr), (char *)&lr);
+ }
+ db_read_bytes((db_addr_t)&tf->tf_reg[29], sizeof(fp),
+ (char *)&fp);
lr = aarch64_strip_pac(lr);
/*
