+extern pmap_t kdp_pmap;
+extern uint32_t kdp_src_high32;
+
+#define RETURN_OFFSET 4
+int
+machine_trace_thread(thread_t thread, char *tracepos, char *tracebound, int nframes, boolean_t user_p)
+{
+ uint32_t *tracebuf = (uint32_t *)tracepos;
+ uint32_t fence = 0;
+ uint32_t stackptr = 0;
+ uint32_t stacklimit = 0xfc000000;
+ int framecount = 0;
+ uint32_t init_eip = 0;
+ uint32_t prevsp = 0;
+ uint32_t framesize = 2 * sizeof(vm_offset_t);
+
+ if (user_p) {
+ x86_saved_state32_t *iss32;
+
+ iss32 = USER_REGS32(thread);
+
+ init_eip = iss32->eip;
+ stackptr = iss32->ebp;
+
+ /* This bound isn't useful, but it doesn't hinder us*/
+ stacklimit = 0xffffffff;
+ kdp_pmap = thread->task->map->pmap;
+ }
+ else {
+ /*Examine the i386_saved_state at the base of the kernel stack*/
+ stackptr = STACK_IKS(thread->kernel_stack)->k_ebp;
+ init_eip = STACK_IKS(thread->kernel_stack)->k_eip;
+ }
+
+ *tracebuf++ = init_eip;
+
+ for (framecount = 0; framecount < nframes; framecount++) {
+
+ if ((uint32_t)(tracebound - ((char *)tracebuf)) < (4 * framesize)) {
+ tracebuf--;
+ break;
+ }
+
+ *tracebuf++ = stackptr;
+/* Invalid frame, or hit fence */
+ if (!stackptr || (stackptr == fence)) {
+ break;
+ }
+ /* Stack grows downward */
+ if (stackptr < prevsp) {
+ break;
+ }
+ /* Unaligned frame */
+ if (stackptr & 0x0000003) {
+ break;
+ }
+ if (stackptr > stacklimit) {
+ break;
+ }
+
+ if (kdp_vm_read((caddr_t) (stackptr + RETURN_OFFSET), (caddr_t) tracebuf, sizeof(caddr_t)) != sizeof(caddr_t)) {
+ break;
+ }
+ tracebuf++;
+
+ prevsp = stackptr;
+ if (kdp_vm_read((caddr_t) stackptr, (caddr_t) &stackptr, sizeof(caddr_t)) != sizeof(caddr_t)) {
+ *tracebuf++ = 0;
+ break;
+ }
+ }
+
+ kdp_pmap = 0;
+
+ return (uint32_t) (((char *) tracebuf) - tracepos);
+}
+
+#define RETURN_OFFSET64 8
+/* Routine to encapsulate the 64-bit address read hack*/
+unsigned
+machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len)
+{
+ uint32_t kdp_vm_read_low32;
+ unsigned retval;
+
+ kdp_src_high32 = srcaddr >> 32;
+ kdp_vm_read_low32 = srcaddr & 0x00000000FFFFFFFFUL;
+ retval = kdp_vm_read((caddr_t)kdp_vm_read_low32, dstaddr, len);
+ kdp_src_high32 = 0;
+ return retval;
+}
+
+int
+machine_trace_thread64(thread_t thread, char *tracepos, char *tracebound, int nframes, boolean_t user_p)
+{
+ uint64_t *tracebuf = (uint64_t *)tracepos;
+ uint32_t fence = 0;
+ addr64_t stackptr = 0;
+ uint64_t stacklimit = 0xfc000000;
+ int framecount = 0;
+ addr64_t init_rip = 0;
+ addr64_t prevsp = 0;
+ unsigned framesize = 2 * sizeof(addr64_t);
+
+ if (user_p) {
+ x86_saved_state64_t *iss64;
+ iss64 = USER_REGS64(thread);
+ init_rip = iss64->isf.rip;
+ stackptr = iss64->rbp;
+ stacklimit = 0xffffffffffffffffULL;
+ kdp_pmap = thread->task->map->pmap;
+ }
+ else {
+ /* DRK: This would need to adapt for a 64-bit kernel, if any */
+ stackptr = STACK_IKS(thread->kernel_stack)->k_ebp;
+ init_rip = STACK_IKS(thread->kernel_stack)->k_eip;
+ }
+
+ *tracebuf++ = init_rip;
+
+ for (framecount = 0; framecount < nframes; framecount++) {
+
+ if ((uint32_t)(tracebound - ((char *)tracebuf)) < (4 * framesize)) {
+ tracebuf--;
+ break;
+ }
+
+ *tracebuf++ = stackptr;
+
+ if (!stackptr || (stackptr == fence)){
+ break;
+ }
+ if (stackptr < prevsp) {
+ break;
+ }
+ if (stackptr & 0x0000003) {
+ break;
+ }
+ if (stackptr > stacklimit) {
+ break;
+ }
+
+ if (machine_read64(stackptr + RETURN_OFFSET64, (caddr_t) tracebuf, sizeof(addr64_t)) != sizeof(addr64_t)) {
+ break;
+ }
+ tracebuf++;
+
+ prevsp = stackptr;
+ if (machine_read64(stackptr, (caddr_t) &stackptr, sizeof(addr64_t)) != sizeof(addr64_t)) {
+ *tracebuf++ = 0;
+ break;
+ }
+ }
+
+ kdp_pmap = NULL;
+
+ return (uint32_t) (((char *) tracebuf) - tracepos);
+}
+
+static struct kdp_callout {
+ struct kdp_callout *callout_next;
+ kdp_callout_fn_t callout_fn;
+ void *callout_arg;
+} *kdp_callout_list = NULL;
+
+
+/*
+ * Called from kernel context to register a kdp event callout.
+ */
+void
+kdp_register_callout(
+ kdp_callout_fn_t fn,
+ void *arg)
+{
+ struct kdp_callout *kcp;
+ struct kdp_callout *list_head;
+
+ kcp = kalloc(sizeof(*kcp));
+ if (kcp == NULL)
+ panic("kdp_register_callout() kalloc failed");
+
+ kcp->callout_fn = fn;
+ kcp->callout_arg = arg;
+
+ /* Lock-less list insertion using compare and exchange. */
+ do {
+ list_head = kdp_callout_list;
+ kcp->callout_next = list_head;
+ } while(!atomic_cmpxchg((uint32_t *) &kdp_callout_list,
+ (uint32_t) list_head,
+ (uint32_t) kcp));
+}
+
+/*
+ * Called at exception/panic time when extering or exiting kdp.
+ * We are single-threaded at this time and so we don't use locks.
+ */
+static void
+kdp_callouts(kdp_event_t event)
+{
+ struct kdp_callout *kcp = kdp_callout_list;
+
+ while (kcp) {
+ kcp->callout_fn(kcp->callout_arg, event);
+ kcp = kcp->callout_next;
+ }
+}
+
+void
+kdp_ml_enter_debugger(void)
+{
+ __asm__ __volatile__("int3");
+}
projects / apple / xnu.git / blobdiff