btrace(8) retrieves the types of the arguments of each tracepoint

from the kernel.  Add them to a cache when needed, and print them
with btrace -l.  If the argument is of type int, print the value
as %d signed integer.  This gives pretty output for refcnt changes.
All other types still use %ul.
The probe and argument number can be used as array index.  Remove
the qsort and search for probe number to simplify the code.  Use
array index for both probes and argument types.
OK mpi@

1 files changed, 69 insertions, 36 deletions

diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index b5d43829134..ae583a5e15f 100644
--- a/usr.sbin/btrace/btrace.c
+++ b/usr.sbin/btrace/btrace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: btrace.c,v 1.68 2022/12/28 21:30:16 jmc Exp $ */
+/*	$OpenBSD: btrace.c,v 1.69 2023/03/10 23:02:30 bluhm Exp $ */
 
 /*
  * Copyright (c) 2019 - 2021 Martin Pieuchot <mpi@openbsd.org>
@@ -61,7 +61,7 @@ char			*read_btfile(const char *, size_t *);
  * Retrieve & parse probe information.
  */
 void			 dtpi_cache(int);
-void			 dtpi_print_list(void);
+void			 dtpi_print_list(int);
 const char		*dtpi_func(struct dtioc_probe_info *);
 int			 dtpi_is_unit(const char *);
 struct dtioc_probe_info	*dtpi_get_by_value(const char *, const char *,
@@ -72,7 +72,7 @@ struct dtioc_probe_info	*dtpi_get_by_value(const char *, const char *,
  */
 void			 rules_do(int);
 void			 rules_setup(int);
-void			 rules_apply(struct dt_evt *);
+void			 rules_apply(int, struct dt_evt *);
 void			 rules_teardown(int);
 void			 rule_eval(struct bt_rule *, struct dt_evt *);
 void			 rule_printmaps(struct bt_rule *);
@@ -114,6 +114,7 @@ void			 debug_dump_filter(struct bt_rule *);
 
 struct dtioc_probe_info	*dt_dtpis;	/* array of available probes */
 size_t			 dt_ndtpi;	/* # of elements in the array */
+struct dtioc_arg_info  **dt_args;	/* array of probe arguments */
 
 struct dt_evt		 bt_devt;	/* fake event for BEGIN/END */
 uint64_t		 bt_filtered;	/* # of events filtered out */
@@ -207,7 +208,7 @@ main(int argc, char *argv[])
 
 	if (showprobes) {
 		dtpi_cache(fd);
-		dtpi_print_list();
+		dtpi_print_list(fd);
 	}
 
 	if (!TAILQ_EMPTY(&g_rules))
@@ -256,18 +257,6 @@ read_btfile(const char *filename, size_t *len)
 	return fcontent;
 }
 
-static int
-dtpi_cmp(const void *a, const void *b)
-{
-	const struct dtioc_probe_info *ai = a, *bi = b;
-
-	if (ai->dtpi_pbn > bi->dtpi_pbn)
-		return 1;
-	if (ai->dtpi_pbn < bi->dtpi_pbn)
-		return -1;
-	return 0;
-}
-
 void
 dtpi_cache(int fd)
 {
@@ -280,28 +269,65 @@ dtpi_cache(int fd)
 	if (ioctl(fd, DTIOCGPLIST, &dtpr))
 		err(1, "DTIOCGPLIST");
 
-	dt_ndtpi = (dtpr.dtpr_size / sizeof(*dt_dtpis));
+	dt_ndtpi = dtpr.dtpr_size / sizeof(*dt_dtpis);
 	dt_dtpis = reallocarray(NULL, dt_ndtpi, sizeof(*dt_dtpis));
 	if (dt_dtpis == NULL)
-		err(1, "malloc");
+		err(1, NULL);
 
 	dtpr.dtpr_probes = dt_dtpis;
 	if (ioctl(fd, DTIOCGPLIST, &dtpr))
 		err(1, "DTIOCGPLIST");
+}
 
-	qsort(dt_dtpis, dt_ndtpi, sizeof(*dt_dtpis), dtpi_cmp);
+void
+dtai_cache(int fd, struct dtioc_probe_info *dtpi)
+{
+	struct dtioc_arg dtar;
+
+	if (dt_args == NULL) {
+		dt_args = calloc(dt_ndtpi, sizeof(*dt_args));
+		if (dt_args == NULL)
+			err(1, NULL);
+	}
+
+	if (dt_args[dtpi->dtpi_pbn - 1] != NULL)
+		return;
+
+	dt_args[dtpi->dtpi_pbn - 1] = reallocarray(NULL, dtpi->dtpi_nargs,
+	    sizeof(**dt_args));
+	if (dt_args[dtpi->dtpi_pbn - 1] == NULL)
+		err(1, NULL);
+
+	dtar.dtar_pbn = dtpi->dtpi_pbn;
+	dtar.dtar_size = dtpi->dtpi_nargs * sizeof(**dt_args);
+	dtar.dtar_args = dt_args[dtpi->dtpi_pbn - 1];
+	if (ioctl(fd, DTIOCGARGS, &dtar))
+		err(1, "DTIOCGARGS");
 }
 
 void
-dtpi_print_list(void)
+dtpi_print_list(int fd)
 {
 	struct dtioc_probe_info *dtpi;
-	size_t i;
+	struct dtioc_arg_info *dtai;
+	size_t i, j;
 
 	dtpi = dt_dtpis;
 	for (i = 0; i < dt_ndtpi; i++, dtpi++) {
-		printf("%s:%s:%s\n", dtpi->dtpi_prov, dtpi_func(dtpi),
+		printf("%s:%s:%s", dtpi->dtpi_prov, dtpi_func(dtpi),
 		    dtpi->dtpi_name);
+		if (strncmp(dtpi->dtpi_prov, "tracepoint", DTNAMESIZE) == 0) {
+			dtai_cache(fd, dtpi);
+			dtai = dt_args[dtpi->dtpi_pbn - 1];
+			printf("(");
+			for (j = 0; j < dtpi->dtpi_nargs; j++, dtai++) {
+				if (j > 0)
+					printf(", ");
+				printf("%s", dtai->dtai_argtype);
+			}
+			printf(")");
+		}
+		printf("\n");
 	}
 }
 
@@ -365,15 +391,6 @@ dtpi_get_by_value(const char *prov, const char *func, const char *name)
 	return NULL;
 }
 
-static struct dtioc_probe_info *
-dtpi_get_by_id(unsigned int pbn)
-{
-	struct dtioc_probe_info d;
-
-	d.dtpi_pbn = pbn;
-	return bsearch(&d, dt_dtpis, dt_ndtpi, sizeof(*dt_dtpis), dtpi_cmp);
-}
-
 void
 rules_do(int fd)
 {
@@ -408,7 +425,7 @@ rules_do(int fd)
 			err(1, "incorrect read");
 
 		for (i = 0; i < rlen / sizeof(struct dt_evt); i++)
-			rules_apply(&devtbuf[i]);
+			rules_apply(fd, &devtbuf[i]);
 	}
 
 	rules_teardown(fd);
@@ -530,7 +547,7 @@ rules_setup(int fd)
 }
 
 void
-rules_apply(struct dt_evt *dtev)
+rules_apply(int fd, struct dt_evt *dtev)
 {
 	struct bt_rule *r;
 	struct bt_probe *bp;
@@ -541,6 +558,7 @@ rules_apply(struct dt_evt *dtev)
 			    bp->bp_pbn != dtev->dtev_pbn)
 				continue;
 
+			dtai_cache(fd, &dt_dtpis[dtev->dtev_pbn - 1]);
 			rule_eval(r, dtev);
 		}
 	}
@@ -723,9 +741,24 @@ const char *
 builtin_arg(struct dt_evt *dtev, enum bt_argtype dat)
 {
 	static char buf[sizeof("18446744073709551615")]; /* UINT64_MAX */
+	unsigned int argn;
+	struct dtioc_arg_info *dtai;
+	const char *argtype, *fmt;
+	long value;
+
+	dtai = dt_args[dtev->dtev_pbn - 1];
+	argn = dat - B_AT_BI_ARG0;
+	argtype = dtai[argn].dtai_argtype;
+
+	if (strncmp(argtype, "int", DTNAMESIZE) == 0) {
+		fmt = "%d";
+		value = (int)dtev->dtev_args[argn];
+	} else {
+		fmt = "%lu";
+		value = dtev->dtev_args[argn];
+	}
 
-	snprintf(buf, sizeof(buf), "%lu",
-	    dtev->dtev_args[dat - B_AT_BI_ARG0]);
+	snprintf(buf, sizeof(buf), fmt, dtev->dtev_args[argn]);
 
 	return buf;
 }
@@ -1524,7 +1557,7 @@ ba2str(struct bt_arg *ba, struct dt_evt *dtev)
 		str = buf;
 		break;
 	case B_AT_BI_PROBE:
-		dtpi = dtpi_get_by_id(dtev->dtev_pbn);
+		dtpi = &dt_dtpis[dtev->dtev_pbn - 1];
 		if (dtpi != NULL)
 			snprintf(buf, sizeof(buf), "%s:%s:%s",
 			    dtpi->dtpi_prov, dtpi_func(dtpi), dtpi->dtpi_name);