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Date:      Sat, 5 Dec 2015 09:32:36 +0000 (UTC)
From:      Andrew Turner <andrew@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r291852 - in head/sys: arm/arm arm/include cddl/dev/fbt/arm
Message-ID:  <201512050932.tB59Waii003325@repo.freebsd.org>
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Author: andrew
Date: Sat Dec  5 09:32:36 2015
New Revision: 291852
URL: https://svnweb.freebsd.org/changeset/base/291852

Log:
  Move the check to see if we are tracing a function with the DTrace Function
  Boundary Trace to assembly to reduce the overhead of these checks.
  
  Submitted by:	Howard Su <howard0su@gmail.com>
  Relnotes:	Yes
  Differential Revision:	https://reviews.freebsd.org/D4266

Modified:
  head/sys/arm/arm/exception.S
  head/sys/arm/arm/genassym.c
  head/sys/arm/arm/trap-v6.c
  head/sys/arm/arm/undefined.c
  head/sys/arm/include/trap.h
  head/sys/cddl/dev/fbt/arm/fbt_isa.c

Modified: head/sys/arm/arm/exception.S
==============================================================================
--- head/sys/arm/arm/exception.S	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/arm/arm/exception.S	Sat Dec  5 09:32:36 2015	(r291852)
@@ -52,13 +52,15 @@
 #include <machine/asm.h>
 #include <machine/armreg.h>
 #include <machine/asmacros.h>
+#include <machine/trap.h>
+
 __FBSDID("$FreeBSD$");
 
 #ifdef KDTRACE_HOOKS
 	.bss
 	.align 4
-	.global	_C_LABEL(dtrace_invop_calltrap_addr)
-_C_LABEL(dtrace_invop_calltrap_addr):
+	.global _C_LABEL(dtrace_invop_jump_addr)
+_C_LABEL(dtrace_invop_jump_addr):
 	.word 0
 	.word 0
 #endif
@@ -361,9 +363,39 @@ END(data_abort_entry)
  */
 ASENTRY_NP(undefined_entry)
 	PUSHFRAMEINSVC			/* mode stack, build trapframe there. */
+	mov	r4, r0			/* R0 contains SPSR */
 	adr	lr, exception_exit      /* Return from handler via standard */
-	mov	r0, sp			/* exception exit routine.  Pass the */
-	b	undefinedinstruction	/* trapframe to the handler. */
+	mov	r0, sp			/* exception exit routine. pass frame */
+
+	ldr	r2, [sp, #(TF_PC)]	/* load pc */
+#if __ARM_ARCH >= 7
+	tst	r4, #(PSR_T)		/* test if PSR_T */
+	subne	r2, r2, #(THUMB_INSN_SIZE)
+	subeq	r2, r2, #(INSN_SIZE)
+#else
+	sub	r2, r2, #(INSN_SIZE)	/* fix pc */
+#endif
+	str	r2, [sp, #TF_PC]	/* store pc */
+
+#ifdef KDTRACE_HOOKS
+	/* Check if dtrace is enabled */
+	ldr	r1, =_C_LABEL(dtrace_invop_jump_addr)
+	ldr	r3, [r1]
+	cmp	r3, #0
+	beq	undefinedinstruction
+
+	and	r4, r4, #(PSR_MODE)	/* Mask out unneeded bits */
+	cmp	r4, #(PSR_USR32_MODE)	/* Check if we came from usermode */
+	beq	undefinedinstruction
+
+	ldr	r4, [r2]		/* load instrution */
+	ldr	r1, =FBT_BREAKPOINT	/* load fbt inv op */
+	cmp	r1, r4
+	bne	undefinedinstruction
+
+	bx	r3			/* call invop_jump_addr */
+#endif
+	b	undefinedinstruction	/* call stadnard handler */
 END(undefined_entry)
 
 /*

Modified: head/sys/arm/arm/genassym.c
==============================================================================
--- head/sys/arm/arm/genassym.c	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/arm/arm/genassym.c	Sat Dec  5 09:32:36 2015	(r291852)
@@ -118,6 +118,7 @@ ASSYM(MD_TP, offsetof(struct mdthread, m
 ASSYM(MD_RAS_START, offsetof(struct mdthread, md_ras_start));
 ASSYM(MD_RAS_END, offsetof(struct mdthread, md_ras_end));
 
+ASSYM(TF_SPSR, offsetof(struct trapframe, tf_spsr));
 ASSYM(TF_R0, offsetof(struct trapframe, tf_r0));
 ASSYM(TF_R1, offsetof(struct trapframe, tf_r1));
 ASSYM(TF_PC, offsetof(struct trapframe, tf_pc));

Modified: head/sys/arm/arm/trap-v6.c
==============================================================================
--- head/sys/arm/arm/trap-v6.c	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/arm/arm/trap-v6.c	Sat Dec  5 09:32:36 2015	(r291852)
@@ -66,6 +66,10 @@ __FBSDID("$FreeBSD$");
 #include <machine/db_machdep.h>
 #endif
 
+#ifdef KDTRACE_HOOKS
+#include <sys/dtrace_bsd.h>
+#endif
+
 extern char fusubailout[];
 extern char cachebailout[];
 
@@ -561,6 +565,13 @@ abort_fatal(struct trapframe *tf, u_int 
 	const char *rw_mode;
 
 	usermode = TRAPF_USERMODE(tf);
+#ifdef KDTRACE_HOOKS
+	if (!usermode) {
+		if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, far))
+			return (0);
+	}
+#endif
+
 	mode = usermode ? "user" : "kernel";
 	rw_mode  = fsr & FSR_WNR ? "write" : "read";
 	disable_interrupts(PSR_I|PSR_F);

Modified: head/sys/arm/arm/undefined.c
==============================================================================
--- head/sys/arm/arm/undefined.c	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/arm/arm/undefined.c	Sat Dec  5 09:32:36 2015	(r291852)
@@ -99,10 +99,6 @@ __FBSDID("$FreeBSD$");
 
 #define	COPROC_VFP	10
 
-#ifdef KDTRACE_HOOKS
-int (*dtrace_invop_jump_addr)(struct trapframe *);
-#endif
-
 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
 
 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
@@ -206,12 +202,6 @@ undefinedinstruction(struct trapframe *f
 
 	PCPU_INC(cnt.v_trap);
 
-#if __ARM_ARCH >= 7
-	if ((frame->tf_spsr & PSR_T) != 0)
-		frame->tf_pc -= THUMB_INSN_SIZE;
-	else
-#endif
-		frame->tf_pc -= INSN_SIZE;
 	fault_pc = frame->tf_pc;
 
 	/*
@@ -350,12 +340,6 @@ undefinedinstruction(struct trapframe *f
 #endif
 			return;
 		}
-#ifdef KDTRACE_HOOKS
-		else if (dtrace_invop_jump_addr != 0) {
-			dtrace_invop_jump_addr(frame);
-			return;
-		}
-#endif
 		else
 			panic("Undefined instruction in kernel.\n");
 	}

Modified: head/sys/arm/include/trap.h
==============================================================================
--- head/sys/arm/include/trap.h	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/arm/include/trap.h	Sat Dec  5 09:32:36 2015	(r291852)
@@ -7,4 +7,5 @@
 #define GDB5_BREAKPOINT		0xe7ffdefe
 #define PTRACE_BREAKPOINT	0xe7fffff0
 #define KERNEL_BREAKPOINT	0xe7ffffff
+#define FBT_BREAKPOINT		0xe7f000f0
 #endif /* _MACHINE_TRAP_H_ */

Modified: head/sys/cddl/dev/fbt/arm/fbt_isa.c
==============================================================================
--- head/sys/cddl/dev/fbt/arm/fbt_isa.c	Sat Dec  5 08:52:37 2015	(r291851)
+++ head/sys/cddl/dev/fbt/arm/fbt_isa.c	Sat Dec  5 09:32:36 2015	(r291852)
@@ -35,11 +35,10 @@
 #include <sys/param.h>
 
 #include <sys/dtrace.h>
+#include <machine/trap.h>
 
 #include "fbt.h"
 
-#define	FBT_PATCHVAL		0xe7f000f0 /* Specified undefined instruction */
-
 #define	FBT_PUSHM		0xe92d0000
 #define	FBT_POPM		0xe8bd0000
 #define	FBT_JUMP		0xea000000
@@ -53,15 +52,20 @@ fbt_invop(uintptr_t addr, uintptr_t *sta
 	struct trapframe *frame = (struct trapframe *)stack;
 	solaris_cpu_t *cpu = &solaris_cpu[curcpu];
 	fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
+	register_t fifthparam;
 
 	for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
 		if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
 			cpu->cpu_dtrace_caller = addr;
 
-			/* TODO: Need 5th parameter from stack */
+			/* Get 5th parameter from stack */
+			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
+			fifthparam = *(register_t *)frame->tf_usr_sp;
+			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
+
 			dtrace_probe(fbt->fbtp_id, frame->tf_r0,
 			    frame->tf_r1, frame->tf_r2,
-			    frame->tf_r3, 0);
+			    frame->tf_r3, fifthparam);
 
 			cpu->cpu_dtrace_caller = 0;
 
@@ -77,7 +81,7 @@ fbt_patch_tracepoint(fbt_probe_t *fbt, f
 {
 
 	*fbt->fbtp_patchpoint = val;
-	cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4);
+	cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val));
 }
 
 int
@@ -104,13 +108,6 @@ fbt_provide_module_function(linker_file_
 	if (name[0] == '_' && name[1] == '_')
 		return (0);
 
-	/*
-	 * Architecture-specific exclusion list, largely to do with FBT trap
-	 * processing, to prevent reentrance.
-	 */
-	if (strcmp(name, "undefinedinstruction") == 0)
-		return (0);
-
 	instr = (uint32_t *)symval->value;
 	limit = (uint32_t *)(symval->value + symval->size);
 
@@ -125,12 +122,12 @@ fbt_provide_module_function(linker_file_
 	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
 	fbt->fbtp_name = name;
 	fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
-	    name, FBT_ENTRY, 3, fbt);
+	    name, FBT_ENTRY, 2, fbt);
 	fbt->fbtp_patchpoint = instr;
 	fbt->fbtp_ctl = lf;
 	fbt->fbtp_loadcnt = lf->loadcnt;
 	fbt->fbtp_savedval = *instr;
-	fbt->fbtp_patchval = FBT_PATCHVAL;
+	fbt->fbtp_patchval = FBT_BREAKPOINT;
 	fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
 	fbt->fbtp_symindx = symindx;
 
@@ -157,7 +154,6 @@ again:
 			start = (uint32_t *)symval->value;
 			if (target >= limit || target < start)
 				break;
-			instr++; /* skip delay slot */
 		}
 	}
 
@@ -171,7 +167,7 @@ again:
 	fbt->fbtp_name = name;
 	if (retfbt == NULL) {
 		fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
-		    name, FBT_RETURN, 3, fbt);
+		    name, FBT_RETURN, 2, fbt);
 	} else {
 		retfbt->fbtp_next = fbt;
 		fbt->fbtp_id = retfbt->fbtp_id;
@@ -187,7 +183,7 @@ again:
 	else
 		fbt->fbtp_rval = DTRACE_INVOP_POPM;
 	fbt->fbtp_savedval = *instr;
-	fbt->fbtp_patchval = FBT_PATCHVAL;
+	fbt->fbtp_patchval = FBT_BREAKPOINT;
 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
 	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;

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