X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4d15aeb193b2c68f1d38666c317f8d3734f5f083..5ba3f43ea354af8ad55bea84372a2bc834d8757c:/bsd/dev/arm/sdt_arm.c

diff --git a/bsd/dev/arm/sdt_arm.c b/bsd/dev/arm/sdt_arm.c
new file mode 100644
index 000000000..b8db51b52
--- /dev/null
+++ b/bsd/dev/arm/sdt_arm.c
@@ -0,0 +1,166 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/* #pragma ident	"@(#)sdt.c	1.6	06/03/24 SMI" */
+
+#ifdef KERNEL
+#ifndef _KERNEL
+#define _KERNEL /* Solaris vs. Darwin */
+#endif
+#endif
+
+#define MACH__POSIX_C_SOURCE_PRIVATE 1 /* pulls in suitable savearea from mach/ppc/thread_status.h */
+#include <kern/cpu_data.h>
+#include <kern/thread.h>
+#include <mach/thread_status.h>
+#include <mach/vm_param.h>
+
+#include <sys/dtrace.h>
+#include <sys/dtrace_impl.h>
+
+#include <sys/dtrace_glue.h>
+
+#include <sys/sdt_impl.h>
+
+extern sdt_probe_t      **sdt_probetab;
+
+int
+sdt_invop(__unused uintptr_t addr, __unused uintptr_t *stack, __unused uintptr_t eax)
+{
+#pragma unused(eax)
+	sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
+
+	for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
+		if ((uintptr_t) sdt->sdp_patchpoint == addr) {
+			struct arm_saved_state* regs = (struct arm_saved_state*) stack;
+			uintptr_t stack4 = *((uintptr_t*) regs->sp);
+
+			dtrace_probe(sdt->sdp_id, regs->r[0], regs->r[1], regs->r[2], regs->r[3], stack4);
+                
+			return (DTRACE_INVOP_NOP);
+		}
+	}
+
+	return (0);
+}
+
+struct frame {
+	struct frame *backchain;
+	uintptr_t retaddr;
+};
+
+/*ARGSUSED*/
+uint64_t
+sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
+{
+#pragma unused(arg,id,parg)	/* __APPLE__ */
+  	uint64_t val = 0;
+	struct frame *fp = (struct frame *)__builtin_frame_address(0);
+	uintptr_t *stack;
+	uintptr_t pc;
+	int i;
+
+	/*
+	 * On ARM, up to four args are passed via registers; r0,r1,r2,r3
+	 * So coming into this function, arg >= 4 should be on the stack.
+	 * e.g. arg==5 refers to the 6th arg passed to the probed function.
+	 */
+	int inreg = 4;
+	
+	for (i = 1; i <= aframes; i++) {
+		fp = fp->backchain;
+		pc = fp->retaddr;
+
+		if (dtrace_invop_callsite_pre != NULL
+			&& pc  >  (uintptr_t)dtrace_invop_callsite_pre
+			&& pc  <= (uintptr_t)dtrace_invop_callsite_post) {
+
+ 			/*
+                         * When we pass through the invalid op handler,
+			 * we expect to find the save area structure,
+			 * pushed on the stack where we took the trap.
+			 * If the argument we seek is passed in a register, then
+			 * we can load it directly from this saved area.
+			 * If the argument we seek is passed on the stack, then
+			 * we increment the frame pointer further, to find the
+			 * pushed args
+ 			 */
+
+			/* fp points to the dtrace_invop activation */
+			fp = fp->backchain; /* to the fbt_perfCallback activation */
+			fp = fp->backchain; /* to the sleh_undef activation */
+
+#if __BIGGEST_ALIGNMENT__ > 4
+			/**
+			 * rdar://problem/24228656: On armv7k, the stack is realigned in sleh_undef2 to
+			 * be 16-bytes aligned and the old value is pushed to
+			 * the stack, so we retrieve it from here
+			 */
+			arm_saved_state_t *saved_state = (arm_saved_state_t *)(uintptr_t*)*((uintptr_t *)&fp[1]);
+#else
+			arm_saved_state_t *saved_state = (arm_saved_state_t *)((uintptr_t *)&fp[1]);
+#endif
+			if (argno <= inreg) {
+				/* For clarity only... should not get here */
+				stack = (uintptr_t *)&saved_state->r[0];
+			} else {
+				fp = (struct frame *)(saved_state->sp);
+				stack = (uintptr_t *)&fp[0]; /* Find marshalled arguments */
+				argno -= inreg;
+			}
+			goto load;
+ 		}
+	}
+
+	/*
+	 * We know that we did not come through a trap to get into
+	 * dtrace_probe() --  We arrive here when the provider has
+	 * called dtrace_probe() directly.
+	 * The probe ID is the first argument to dtrace_probe().
+	 * We must advance beyond that to get the argX.
+	 */
+	argno++; /* Advance past probeID */
+
+        if (argno <= inreg) {
+		/*
+		 * This shouldn't happen.  If the argument is passed in a
+		 * register then it should have been, well, passed in a
+		 * register...
+		 */
+		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+		return (0);
+	}
+	
+	argno -= (inreg + 1);
+	stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
+
+load:
+	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
+        /* dtrace_probe arguments arg0 .. arg4 are 64bits wide */
+	val = (uint64_t)(*(((uintptr_t *)stack) + argno));
+	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
+	return (val);
+
+}