From: anton <anton@openbsd.org>
Date: Sat, 18 Dec 2021 08:24:31 +0000 (+0000)
Subject: Reduce the overhead of the trace compare routines by checking if kcov is
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=d3edd1e5aa85394515258a0ced34e41dcc895546;p=openbsd

Reduce the overhead of the trace compare routines by checking if kcov is
enabled for the current thread before doing anything else.
---

diff --git a/sys/dev/kcov.c b/sys/dev/kcov.c
index 800c38080ea..b49c6d03a7e 100644
--- a/sys/dev/kcov.c
+++ b/sys/dev/kcov.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kcov.c,v 1.38 2021/07/05 05:50:19 anton Exp $	*/
+/*	$OpenBSD: kcov.c,v 1.39 2021/12/18 08:24:31 anton Exp $	*/
 
 /*
  * Copyright (c) 2018 Anton Lindqvist <anton@openbsd.org>
@@ -157,15 +157,11 @@ __sanitizer_cov_trace_pc(void)
  * its corresponding coverage buffer.
  */
 void
-trace_cmp(uint64_t type, uint64_t arg1, uint64_t arg2, uintptr_t pc)
+trace_cmp(struct kcov_dev *kd, uint64_t type, uint64_t arg1, uint64_t arg2,
+    uintptr_t pc)
 {
-	struct kcov_dev *kd;
 	uint64_t idx;
 
-	kd = kd_curproc(KCOV_MODE_TRACE_CMP);
-	if (kd == NULL)
-		return;
-
 	if ((idx = kd_claim(kd, KCOV_STRIDE_TRACE_CMP, 1))) {
 		kd->kd_buf[idx] = type;
 		kd->kd_buf[idx + 1] = arg1;
@@ -174,68 +170,73 @@ trace_cmp(uint64_t type, uint64_t arg1, uint64_t arg2, uintptr_t pc)
 	}
 }
 
+#define TRACE_CMP(type, arg1, arg2) do {				\
+	struct kcov_dev *kd;						\
+	if ((kd = kd_curproc(KCOV_MODE_TRACE_CMP)) == NULL)		\
+		return;							\
+	trace_cmp(kd, (type), (arg1), (arg2),				\
+	    (uintptr_t)__builtin_return_address(0));			\
+} while (0)
+
 void
 __sanitizer_cov_trace_cmp1(uint8_t arg1, uint8_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(0), arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(0), arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_cmp2(uint16_t arg1, uint16_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(1), arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(1), arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_cmp4(uint32_t arg1, uint32_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(2), arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(2), arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_cmp8(uint64_t arg1, uint64_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(3), arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(3), arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_const_cmp1(uint8_t arg1, uint8_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(0) | KCOV_CMP_CONST, arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(0) | KCOV_CMP_CONST, arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_const_cmp2(uint16_t arg1, uint16_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(1) | KCOV_CMP_CONST, arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(1) | KCOV_CMP_CONST, arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_const_cmp4(uint32_t arg1, uint32_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(2) | KCOV_CMP_CONST, arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(2) | KCOV_CMP_CONST, arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_const_cmp8(uint64_t arg1, uint64_t arg2)
 {
-	trace_cmp(KCOV_CMP_SIZE(3) | KCOV_CMP_CONST, arg1, arg2,
-	    (uintptr_t)__builtin_return_address(0));
+	TRACE_CMP(KCOV_CMP_SIZE(3) | KCOV_CMP_CONST, arg1, arg2);
 }
 
 void
 __sanitizer_cov_trace_switch(uint64_t val, uint64_t *cases)
 {
+	struct kcov_dev *kd;
 	uint64_t i, nbits, ncases, type;
 	uintptr_t pc;
 
+	kd = kd_curproc(KCOV_MODE_TRACE_CMP);
+	if (kd == NULL)
+		return;
+
 	pc = (uintptr_t)__builtin_return_address(0);
 	ncases = cases[0];
 	nbits = cases[1];
@@ -259,7 +260,7 @@ __sanitizer_cov_trace_switch(uint64_t val, uint64_t *cases)
 	type |= KCOV_CMP_CONST;
 
 	for (i = 0; i < ncases; i++)
-		trace_cmp(type, cases[i + 2], val, pc);
+		trace_cmp(kd, type, cases[i + 2], val, pc);
 }
 
 void