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@

diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index b5d4382..ae583a5 100644 (file)
--- 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);