1 /*- 2 * Copyright (c) 2015 EMC Corporation 3 * Copyright (c) 2005 Antoine Brodin 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "opt_stack.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/stack.h> 40 41 #include <machine/pcb.h> 42 #include <machine/smp.h> 43 44 #include <vm/vm.h> 45 #include <vm/vm_param.h> 46 #include <vm/pmap.h> 47 48 #include <x86/stack.h> 49 50 #ifdef __i386__ 51 #define PCB_FP(pcb) ((pcb)->pcb_ebp) 52 #define TF_FP(tf) ((tf)->tf_ebp) 53 #define TF_PC(tf) ((tf)->tf_eip) 54 55 typedef struct i386_frame *x86_frame_t; 56 #else 57 #define PCB_FP(pcb) ((pcb)->pcb_rbp) 58 #define TF_FP(tf) ((tf)->tf_rbp) 59 #define TF_PC(tf) ((tf)->tf_rip) 60 61 typedef struct amd64_frame *x86_frame_t; 62 #endif 63 64 #ifdef STACK 65 static struct stack *nmi_stack; 66 static volatile struct thread *nmi_pending; 67 68 #ifdef SMP 69 static struct mtx nmi_lock; 70 MTX_SYSINIT(nmi_lock, &nmi_lock, "stack_nmi", MTX_SPIN); 71 #endif 72 #endif 73 74 static void 75 stack_capture(struct thread *td, struct stack *st, register_t fp) 76 { 77 x86_frame_t frame; 78 vm_offset_t callpc; 79 80 stack_zero(st); 81 frame = (x86_frame_t)fp; 82 while (1) { 83 if (!INKERNEL((long)frame)) 84 break; 85 callpc = frame->f_retaddr; 86 if (!INKERNEL(callpc)) 87 break; 88 if (stack_put(st, callpc) == -1) 89 break; 90 if (frame->f_frame <= frame || 91 (vm_offset_t)frame->f_frame >= td->td_kstack + 92 td->td_kstack_pages * PAGE_SIZE) 93 break; 94 frame = frame->f_frame; 95 } 96 } 97 98 int 99 stack_nmi_handler(struct trapframe *tf) 100 { 101 102 #ifdef STACK 103 /* Don't consume an NMI that wasn't meant for us. */ 104 if (nmi_stack == NULL || curthread != nmi_pending) 105 return (0); 106 107 if (INKERNEL(TF_PC(tf))) 108 stack_capture(curthread, nmi_stack, TF_FP(tf)); 109 else 110 /* We interrupted a thread in user mode. */ 111 nmi_stack->depth = 0; 112 113 atomic_store_rel_ptr((long *)&nmi_pending, (long)NULL); 114 return (1); 115 #else 116 return (0); 117 #endif 118 } 119 120 void 121 stack_save_td(struct stack *st, struct thread *td) 122 { 123 124 if (TD_IS_SWAPPED(td)) 125 panic("stack_save_td: swapped"); 126 if (TD_IS_RUNNING(td)) 127 panic("stack_save_td: running"); 128 129 stack_capture(td, st, PCB_FP(td->td_pcb)); 130 } 131 132 int 133 stack_save_td_running(struct stack *st, struct thread *td) 134 { 135 136 #ifdef STACK 137 THREAD_LOCK_ASSERT(td, MA_OWNED); 138 MPASS(TD_IS_RUNNING(td)); 139 140 if (td == curthread) { 141 stack_save(st); 142 return (0); 143 } 144 145 #ifdef SMP 146 mtx_lock_spin(&nmi_lock); 147 148 nmi_stack = st; 149 nmi_pending = td; 150 ipi_cpu(td->td_oncpu, IPI_TRACE); 151 while ((void *)atomic_load_acq_ptr((long *)&nmi_pending) != NULL) 152 cpu_spinwait(); 153 nmi_stack = NULL; 154 155 mtx_unlock_spin(&nmi_lock); 156 157 if (st->depth == 0) 158 /* We interrupted a thread in user mode. */ 159 return (EAGAIN); 160 #else /* !SMP */ 161 KASSERT(0, ("curthread isn't running")); 162 #endif /* SMP */ 163 return (0); 164 #else /* !STACK */ 165 return (EOPNOTSUPP); 166 #endif /* STACK */ 167 } 168 169 void 170 stack_save(struct stack *st) 171 { 172 register_t fp; 173 174 #ifdef __i386__ 175 __asm __volatile("movl %%ebp,%0" : "=g" (fp)); 176 #else 177 __asm __volatile("movq %%rbp,%0" : "=g" (fp)); 178 #endif 179 stack_capture(curthread, st, fp); 180 } 181