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 SMP 67 static struct stack *stack_intr_stack; 68 static struct thread *stack_intr_td; 69 static struct mtx intr_lock; 70 MTX_SYSINIT(intr_lock, &intr_lock, "stack intr", MTX_DEF); 71 #endif 72 73 static void __nosanitizeaddress __nosanitizememory 74 stack_capture(struct thread *td, struct stack *st, register_t fp) 75 { 76 x86_frame_t frame; 77 vm_offset_t callpc; 78 79 stack_zero(st); 80 frame = (x86_frame_t)fp; 81 while (1) { 82 if (!kstack_contains(td, (vm_offset_t)frame, sizeof(*frame))) 83 break; 84 callpc = frame->f_retaddr; 85 if (!INKERNEL(callpc)) 86 break; 87 if (stack_put(st, callpc) == -1) 88 break; 89 if (frame->f_frame <= frame) 90 break; 91 frame = frame->f_frame; 92 } 93 } 94 95 #ifdef SMP 96 void 97 stack_capture_intr(void) 98 { 99 struct thread *td; 100 101 td = curthread; 102 stack_capture(td, stack_intr_stack, TF_FP(td->td_intr_frame)); 103 atomic_store_rel_ptr((void *)&stack_intr_td, (uintptr_t)td); 104 } 105 #endif 106 107 int 108 stack_save_td(struct stack *st, struct thread *td) 109 { 110 int cpuid, error; 111 bool done; 112 113 THREAD_LOCK_ASSERT(td, MA_OWNED); 114 KASSERT(!TD_IS_SWAPPED(td), 115 ("stack_save_td: thread %p is swapped", td)); 116 if (TD_IS_RUNNING(td) && td != curthread) 117 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 118 119 if (td == curthread) { 120 stack_save(st); 121 return (0); 122 } 123 124 for (done = false, error = 0; !done;) { 125 if (!TD_IS_RUNNING(td)) { 126 /* 127 * The thread will not start running so long as we hold 128 * its lock. 129 */ 130 stack_capture(td, st, PCB_FP(td->td_pcb)); 131 error = 0; 132 break; 133 } 134 135 #ifdef SMP 136 thread_unlock(td); 137 cpuid = atomic_load_int(&td->td_oncpu); 138 if (cpuid == NOCPU) { 139 cpu_spinwait(); 140 } else { 141 mtx_lock(&intr_lock); 142 stack_intr_td = NULL; 143 stack_intr_stack = st; 144 ipi_cpu(cpuid, IPI_TRACE); 145 while (atomic_load_acq_ptr((void *)&stack_intr_td) == 146 (uintptr_t)NULL) 147 cpu_spinwait(); 148 if (stack_intr_td == td) { 149 done = true; 150 error = st->depth > 0 ? 0 : EBUSY; 151 } 152 stack_intr_td = NULL; 153 mtx_unlock(&intr_lock); 154 } 155 thread_lock(td); 156 #else 157 (void)cpuid; 158 KASSERT(0, ("%s: multiple running threads", __func__)); 159 #endif 160 } 161 162 return (error); 163 } 164 165 void 166 stack_save(struct stack *st) 167 { 168 register_t fp; 169 170 #ifdef __i386__ 171 __asm __volatile("movl %%ebp,%0" : "=g" (fp)); 172 #else 173 __asm __volatile("movq %%rbp,%0" : "=g" (fp)); 174 #endif 175 stack_capture(curthread, st, fp); 176 } 177