Index: share/man/man4/ddb.4 =================================================================== --- share/man/man4/ddb.4 +++ share/man/man4/ddb.4 @@ -87,6 +87,15 @@ unless the .Dv KDB_UNATTENDED option is specified. +Similarly, if the +.Va debug.debugger_on_recursive_panic +variable is set to a non-zero value, +then the debugger will be invoked on a recursive kernel panic. +This variable has a default value of +.Va 0 +and no visible effect if +.Va debug.debugger_on_panic +is already set non-zero. .Pp The current location is called .Va dot . Index: sys/kern/kern_shutdown.c =================================================================== --- sys/kern/kern_shutdown.c +++ sys/kern/kern_shutdown.c @@ -127,6 +127,11 @@ CTLFLAG_RWTUN | CTLFLAG_SECURE, &debugger_on_panic, 0, "Run debugger on kernel panic"); +static bool debugger_on_recursive_panic = false; +SYSCTL_BOOL(_debug, OID_AUTO, debugger_on_recursive_panic, + CTLFLAG_RWTUN | CTLFLAG_SECURE, + &debugger_on_recursive_panic, 0, "Run debugger on recursive kernel panic"); + int debugger_on_trap = 0; SYSCTL_INT(_debug, OID_AUTO, debugger_on_trap, CTLFLAG_RWTUN | CTLFLAG_SECURE, @@ -899,6 +904,8 @@ kdb_backtrace(); if (debugger_on_panic) kdb_enter(KDB_WHY_PANIC, "panic"); + else if (!newpanic && debugger_on_recursive_panic) + kdb_enter(KDB_WHY_PANIC, "re-panic"); #endif /*thread_lock(td); */ td->td_flags |= TDF_INPANIC;