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_FLAGS(tf) ((tf)->tf_eflags) 53 #define TF_FP(tf) ((tf)->tf_ebp) 54 #define TF_PC(tf) ((tf)->tf_eip) 55 56 typedef struct i386_frame *x86_frame_t; 57 #else 58 #define PCB_FP(pcb) ((pcb)->pcb_rbp) 59 #define TF_FLAGS(tf) ((tf)->tf_rflags) 60 #define TF_FP(tf) ((tf)->tf_rbp) 61 #define TF_PC(tf) ((tf)->tf_rip) 62 63 typedef struct amd64_frame *x86_frame_t; 64 #endif 65 66 #ifdef STACK 67 static struct stack *nmi_stack; 68 static volatile struct thread *nmi_pending; 69 70 #ifdef SMP 71 static struct mtx nmi_lock; 72 MTX_SYSINIT(nmi_lock, &nmi_lock, "stack_nmi", MTX_SPIN); 73 #endif 74 #endif 75 76 static void 77 stack_capture(struct thread *td, struct stack *st, register_t fp) 78 { 79 x86_frame_t frame; 80 vm_offset_t callpc; 81 82 stack_zero(st); 83 frame = (x86_frame_t)fp; 84 while (1) { 85 if (!INKERNEL((long)frame)) 86 break; 87 callpc = frame->f_retaddr; 88 if (!INKERNEL(callpc)) 89 break; 90 if (stack_put(st, callpc) == -1) 91 break; 92 if (frame->f_frame <= frame || 93 (vm_offset_t)frame->f_frame >= td->td_kstack + 94 td->td_kstack_pages * PAGE_SIZE) 95 break; 96 frame = frame->f_frame; 97 } 98 } 99 100 int 101 stack_nmi_handler(struct trapframe *tf) 102 { 103 104 #ifdef STACK 105 /* Don't consume an NMI that wasn't meant for us. */ 106 if (nmi_stack == NULL || curthread != nmi_pending) 107 return (0); 108 109 if (INKERNEL(TF_PC(tf)) && (TF_FLAGS(tf) & PSL_I) != 0) 110 stack_capture(curthread, nmi_stack, TF_FP(tf)); 111 else 112 /* We were running in usermode or had interrupts disabled. */ 113 nmi_stack->depth = 0; 114 115 atomic_store_rel_ptr((long *)&nmi_pending, (long)NULL); 116 return (1); 117 #else 118 return (0); 119 #endif 120 } 121 122 void 123 stack_save_td(struct stack *st, struct thread *td) 124 { 125 126 if (TD_IS_SWAPPED(td)) 127 panic("stack_save_td: swapped"); 128 if (TD_IS_RUNNING(td)) 129 panic("stack_save_td: running"); 130 131 stack_capture(td, st, PCB_FP(td->td_pcb)); 132 } 133 134 int 135 stack_save_td_running(struct stack *st, struct thread *td) 136 { 137 138 #ifdef STACK 139 THREAD_LOCK_ASSERT(td, MA_OWNED); 140 MPASS(TD_IS_RUNNING(td)); 141 142 if (td == curthread) { 143 stack_save(st); 144 return (0); 145 } 146 147 #ifdef SMP 148 mtx_lock_spin(&nmi_lock); 149 150 nmi_stack = st; 151 nmi_pending = td; 152 ipi_cpu(td->td_oncpu, IPI_TRACE); 153 while ((void *)atomic_load_acq_ptr((long *)&nmi_pending) != NULL) 154 cpu_spinwait(); 155 nmi_stack = NULL; 156 157 mtx_unlock_spin(&nmi_lock); 158 159 if (st->depth == 0) 160 return (EAGAIN); 161 #else /* !SMP */ 162 KASSERT(0, ("curthread isn't running")); 163 #endif /* SMP */ 164 return (0); 165 #else /* !STACK */ 166 return (EOPNOTSUPP); 167 #endif /* STACK */ 168 } 169 170 void 171 stack_save(struct stack *st) 172 { 173 register_t fp; 174 175 #ifdef __i386__ 176 __asm __volatile("movl %%ebp,%0" : "=g" (fp)); 177 #else 178 __asm __volatile("movq %%rbp,%0" : "=g" (fp)); 179 #endif 180 stack_capture(curthread, st, fp); 181 } 182