git: 65d1a4cfda73 - main - Handle KDB_WHY_TRAP return on arm and mips

[Mitchell Horne]

The branch main has been updated by mhorne:

URL: https://cgit.FreeBSD.org/src/commit/?id=65d1a4cfda73201e34768d881a0b9206d00d4a71

commit 65d1a4cfda73201e34768d881a0b9206d00d4a71
Author:     Mitchell Horne <mhorne at FreeBSD.org>
AuthorDate: 2021-01-02 23:07:04 +0000
Commit:     Mitchell Horne <mhorne at FreeBSD.org>
CommitDate: 2021-01-02 23:07:04 +0000

    Handle KDB_WHY_TRAP return on arm and mips
    
    Upon exit from the debugger, checking the return code of kdb_trap()
    allows one to retry the fatal page fault. This matches what is done on
    all other architectures.
    
    Reviewed by:    jhb (earlier version)
    Differential Revision:  https://reviews.freebsd.org/D27535
---
 sys/arm/arm/trap-v6.c | 7 ++++++-
 sys/mips/mips/trap.c  | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/sys/arm/arm/trap-v6.c b/sys/arm/arm/trap-v6.c
index e35187da6d07..16f166e83114 100644
--- a/sys/arm/arm/trap-v6.c
+++ b/sys/arm/arm/trap-v6.c
@@ -562,6 +562,9 @@ abort_fatal(struct trapframe *tf, u_int idx, u_int fsr, u_int far,
 	bool usermode;
 	const char *mode;
 	const char *rw_mode;
+#ifdef KDB
+	bool handled;
+#endif
 
 	usermode = TRAPF_USERMODE(tf);
 #ifdef KDTRACE_HOOKS
@@ -609,8 +612,10 @@ abort_fatal(struct trapframe *tf, u_int idx, u_int fsr, u_int far,
 #ifdef KDB
 	if (debugger_on_trap) {
 		kdb_why = KDB_WHY_TRAP;
-		kdb_trap(fsr, 0, tf);
+		handled = kdb_trap(fsr, 0, tf);
 		kdb_why = KDB_WHY_UNSET;
+		if (handled)
+			return (0);
 	}
 #endif
 	panic("Fatal abort");
diff --git a/sys/mips/mips/trap.c b/sys/mips/mips/trap.c
index 78e7c0ed8113..96a2de4ee817 100644
--- a/sys/mips/mips/trap.c
+++ b/sys/mips/mips/trap.c
@@ -524,6 +524,9 @@ trap(struct trapframe *trapframe)
 	register_t pc;
 	int cop, error;
 	register_t *frame_regs;
+#ifdef KDB
+	bool handled;
+#endif
 
 	trapdebug_enter(trapframe, 0);
 #ifdef KDB
@@ -1091,8 +1094,10 @@ err:
 #ifdef KDB
 		if (debugger_on_trap) {
 			kdb_why = KDB_WHY_TRAP;
-			kdb_trap(type, 0, trapframe);
+			handled = kdb_trap(type, 0, trapframe);
 			kdb_why = KDB_WHY_UNSET;
+			if (handled)
+				return (trapframe->pc);
 		}
 #endif
 		panic("trap");