[src/trunk]: src/sys/arch/aarch64/aarch64 Functionalize frame pointer backtrace.

[ryo <ryo%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aabef033fc37
branches:  trunk
changeset: 366684:aabef033fc37
user:      ryo <ryo%NetBSD.org@localhost>
date:      Tue Jun 07 23:55:25 2022 +0000

description:
Functionalize frame pointer backtrace.

diffstat:

 sys/arch/aarch64/aarch64/db_trace.c |  161 +++++++++++++++++++----------------
 1 files changed, 85 insertions(+), 76 deletions(-)

diffs (192 lines):

diff -r 320a1f6b4adc -r aabef033fc37 sys/arch/aarch64/aarch64/db_trace.c
--- a/sys/arch/aarch64/aarch64/db_trace.c       Tue Jun 07 18:50:28 2022 +0000
+++ b/sys/arch/aarch64/aarch64/db_trace.c       Tue Jun 07 23:55:25 2022 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: db_trace.c,v 1.18 2022/06/07 08:08:31 ryo Exp $ */
+/* $NetBSD: db_trace.c,v 1.19 2022/06/07 23:55:25 ryo Exp $ */
 
 /*
  * Copyright (c) 2017 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -28,7 +28,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.18 2022/06/07 08:08:31 ryo Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.19 2022/06/07 23:55:25 ryo Exp $");
 
 #include <sys/param.h>
 #include <sys/bitops.h>
@@ -598,11 +598,90 @@
        }
 }
 
+static void
+db_fp_trace(struct trapframe *tf, db_addr_t fp, db_expr_t count, int flags,
+    void (*pr)(const char *, ...) __printflike(1, 2))
+{
+       uint64_t lr;
+       uint64_t lastlr, lastfp;
+
+       if (tf != NULL) {
+               pr_frame(tf, pr);
+               lastfp = lastlr = 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);
+               lr = aarch64_strip_pac(lr);
+
+               pr_traceaddr("fp", fp, lr - 4, flags, pr);
+       }
+
+       for (; (count > 0) && (fp != 0); count--) {
+
+               lastfp = fp;
+               fp = lr = 0;
+               /*
+                * normal stack frame
+                *  fp[0]  saved fp(x29) value
+                *  fp[1]  saved lr(x30) value
+                */
+               db_read_bytes(lastfp + 0, sizeof(fp), (char *)&fp);
+               db_read_bytes(lastfp + 8, sizeof(lr), (char *)&lr);
+               lr = aarch64_strip_pac(lr);
+
+               if (lr == 0 || ((flags & TRACEFLAG_USERSPACE) == 0 &&
+                   IN_USER_VM_ADDRESS(lr)))
+                       break;
+
+               if (((char *)(lr - 4) == (char *)el0_trap) ||
+                   ((char *)(lr - 4) == (char *)el1_trap)) {
+
+                       tf = (struct trapframe *)fp;
+
+                       lastfp = (uint64_t)tf;
+                       lastlr = lr;
+                       lr = fp = 0;
+                       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);
+
+                       pr_traceaddr("tf", (db_addr_t)tf, lastlr - 4, flags, pr);
+
+                       if (lr == 0)
+                               break;
+
+                       pr_frame(tf, pr);
+                       tf = NULL;
+
+                       if ((flags & TRACEFLAG_USERSPACE) == 0 &&
+                           IN_USER_VM_ADDRESS(lr))
+                               break;
+
+                       pr_traceaddr("fp", fp, lr, flags, pr);
+               } else {
+                       pr_traceaddr("fp", fp, lr - 4, flags, pr);
+               }
+       }
+}
+
 void
 db_stack_trace_print(db_expr_t addr, bool have_addr, db_expr_t count,
     const char *modif, void (*pr)(const char *, ...) __printflike(1, 2))
 {
-       uint64_t lr, fp, lastlr, lastfp;
+       uint64_t fp;
        struct trapframe *tf = NULL;
        int flags = 0;
        bool trace_thread = false;
@@ -734,78 +813,8 @@
        if (trace_sp) {
                /* trace $lr pushed to sp */
                db_sp_trace(tf, fp, count, flags, pr);
-               return;
-       }
-
-       /* trace $fp linked list */
-       if (tf != NULL) {
-               pr_frame(tf, pr);
-               lastfp = lastlr = 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);
-               lr = aarch64_strip_pac(lr);
-
-               pr_traceaddr("fp", fp, lr - 4, flags, pr);
-       }
-
-       for (; (count > 0) && (fp != 0); count--) {
-
-               lastfp = fp;
-               fp = lr = 0;
-               /*
-                * normal stack frame
-                *  fp[0]  saved fp(x29) value
-                *  fp[1]  saved lr(x30) value
-                */
-               db_read_bytes(lastfp + 0, sizeof(fp), (char *)&fp);
-               db_read_bytes(lastfp + 8, sizeof(lr), (char *)&lr);
-               lr = aarch64_strip_pac(lr);
-
-               if (lr == 0 || ((flags & TRACEFLAG_USERSPACE) == 0 &&
-                   IN_USER_VM_ADDRESS(lr)))
-                       break;
-
-               if (((char *)(lr - 4) == (char *)el0_trap) ||
-                   ((char *)(lr - 4) == (char *)el1_trap)) {
-
-                       tf = (struct trapframe *)fp;
-
-                       lastfp = (uint64_t)tf;
-                       lastlr = lr;
-                       lr = fp = 0;
-                       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);
-
-                       pr_traceaddr("tf", (db_addr_t)tf, lastlr - 4, flags, pr);
-
-                       if (lr == 0)
-                               break;
-
-                       pr_frame(tf, pr);
-                       tf = NULL;
-
-                       if ((flags & TRACEFLAG_USERSPACE) == 0 &&
-                           IN_USER_VM_ADDRESS(lr))
-                               break;
-
-                       pr_traceaddr("fp", fp, lr, flags, pr);
-               } else {
-                       pr_traceaddr("fp", fp, lr - 4, flags, pr);
-               }
+       } else {
+               /* trace $fp linked list */
+               db_fp_trace(tf, fp, count, flags, pr);
        }
 }