[DTrace-devel] [PATCH 05/12] Add provider-dependent struct in dt_probe_t
eugene.loh at oracle.com
eugene.loh at oracle.com
Sat Jul 11 17:38:29 PDT 2020
From: Eugene Loh <eugene.loh at oracle.com>
The dt_probe_t struct had members like event_id and event_fd.
This made sense for the providers we were supporting, since they
were all tracepoint-like. For future providers, however, those
members might not make sense and others will be needed. Therefore,
replace event_id and event_fd with an opaque pointer to a
provider-dependent struct.
Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
libdtrace/dt_bpf.c | 10 +++---
libdtrace/dt_probe.c | 31 +++++++---------
libdtrace/dt_probe.h | 6 ++--
libdtrace/dt_prov_dtrace.c | 25 ++++++-------
libdtrace/dt_prov_fbt.c | 23 ++++++------
libdtrace/dt_prov_sdt.c | 72 +++++++++++++++++++++++++++++--------
libdtrace/dt_prov_syscall.c | 22 +++++++-----
libdtrace/dt_provider.h | 20 ++++++++---
8 files changed, 135 insertions(+), 74 deletions(-)
diff --git a/libdtrace/dt_bpf.c b/libdtrace/dt_bpf.c
index d5282b94..e7780b56 100644
--- a/libdtrace/dt_bpf.c
+++ b/libdtrace/dt_bpf.c
@@ -323,11 +323,13 @@ dt_bpf_load_prog(dtrace_hdl_t *dtp, const dt_probe_t *prp,
int
dt_bpf_attach(dtrace_hdl_t *dtp, dt_probe_t *prp, int bpf_fd)
{
+ tp_probe_t *datap = prp->prv_data;
+
/*
* If we have not yet created a perf event for this probe, do that now
* and cache the file descriptor so we only need to do this once.
*/
- if (prp->event_fd == -1) {
+ if (datap->event_fd == -1) {
int fd;
struct perf_event_attr attr = { 0, };
@@ -335,16 +337,16 @@ dt_bpf_attach(dtrace_hdl_t *dtp, dt_probe_t *prp, int bpf_fd)
attr.sample_type = PERF_SAMPLE_RAW;
attr.sample_period = 1;
attr.wakeup_events = 1;
- attr.config = prp->event_id;
+ attr.config = datap->event_id;
fd = perf_event_open(&attr, -1, 0, -1, 0);
if (fd < 0)
return dt_set_errno(dtp, errno);
- prp->event_fd = fd;
+ datap->event_fd = fd;
}
- if (ioctl(prp->event_fd, PERF_EVENT_IOC_SET_BPF, bpf_fd) < 0)
+ if (ioctl(datap->event_fd, PERF_EVENT_IOC_SET_BPF, bpf_fd) < 0)
return dt_set_errno(dtp, errno);
return 0;
diff --git a/libdtrace/dt_probe.c b/libdtrace/dt_probe.c
index 5add8ae6..30f178f6 100644
--- a/libdtrace/dt_probe.c
+++ b/libdtrace/dt_probe.c
@@ -666,7 +666,8 @@ dt_probe_tag(dt_probe_t *prp, uint_t argn, dt_node_t *dnp)
dt_probe_t *
dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
- const char *mod, const char *fun, const char *prb)
+ const char *mod, const char *fun, const char *prb,
+ void *datap)
{
dt_probe_t *prp;
dtrace_probedesc_t *desc;
@@ -678,12 +679,12 @@ dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
if (nprobes_sz < dtp->dt_probes_sz) { /* overflow */
dt_set_errno(dtp, EDT_NOMEM);
- return NULL;
+ goto err;
}
nprobes = dt_calloc(dtp, nprobes_sz, sizeof(dt_probe_t *));
if (nprobes == NULL)
- return NULL;
+ goto err;
if (dtp->dt_probes)
memcpy(nprobes, dtp->dt_probes,
@@ -696,11 +697,11 @@ dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
/* Allocate the new probe and fill in its basic info. */
if ((prp = dt_zalloc(dtp, sizeof(dt_probe_t))) == NULL)
- return NULL;
+ goto err;
if ((desc = dt_alloc(dtp, sizeof(dtrace_probedesc_t))) == NULL) {
dt_free(dtp, prp);
- return NULL;
+ goto err;
}
desc->id = dtp->dt_probe_id++;
@@ -711,8 +712,7 @@ dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
prp->desc = desc;
prp->prov = prov;
- prp->event_id = -1;
- prp->event_fd = -1;
+ prp->prv_data = datap;
dt_htab_insert(dtp->dt_byprv, prp);
dt_htab_insert(dtp->dt_bymod, prp);
@@ -723,6 +723,11 @@ dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov, const char *prv,
dtp->dt_probes[dtp->dt_probe_id - 1] = prp;
return prp;
+
+err:
+ if (prov->impl->probe_destroy)
+ prov->impl->probe_destroy(dtp, datap);
+ return NULL;
}
static int
@@ -872,26 +877,16 @@ dt_probe_delete(dtrace_hdl_t *dtp, dt_probe_t *prp)
static void
dt_probe_args_info(dtrace_hdl_t *dtp, dt_probe_t *prp)
{
- int id = DTRACE_IDNONE;
int argc = 0;
dt_argdesc_t *argv = NULL;
int i, nc, xc;
dtrace_typeinfo_t dtt;
- /*
- * If we already have an event ID information for this probe, there is
- * no need to retrieve it again.
- */
- if (prp->event_id != -1)
- return;
-
if (!prp->prov->impl->probe_info)
return;
- if (prp->prov->impl->probe_info(dtp, prp, &id, &argc, &argv) < 0)
+ if (prp->prov->impl->probe_info(dtp, prp, &argc, &argv) < 0)
return;
- if (id > 0)
- prp->event_id = id;
if (!argc || !argv)
return;
diff --git a/libdtrace/dt_probe.h b/libdtrace/dt_probe.h
index 7feeeff2..8ec6ebc5 100644
--- a/libdtrace/dt_probe.h
+++ b/libdtrace/dt_probe.h
@@ -38,8 +38,7 @@ typedef struct dt_probe {
struct dt_hentry he_fun; /* function name htab links */
struct dt_hentry he_prb; /* probe name htab link */
struct dt_hentry he_fqn; /* fully qualified name htab link */
- int event_id; /* tracing event id */
- int event_fd; /* perf event file descriptor */
+ void *prv_data; /* provider-specific data */
dt_ident_t *pr_ident; /* pointer to probe identifier */
const char *pr_name; /* pointer to name component */
dt_node_t *nargs; /* native argument list */
@@ -71,7 +70,8 @@ extern dt_node_t *dt_probe_tag(dt_probe_t *, uint_t, dt_node_t *);
extern dt_probe_t *dt_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov,
const char *prv, const char *mod,
- const char *fun, const char *prb);
+ const char *fun, const char *prb,
+ void *datap);
extern dt_probe_t *dt_probe_lookup(dtrace_hdl_t *dtp,
const dtrace_probedesc_t *pdp);
extern dt_probe_t *dt_probe_lookup_by_name(dtrace_hdl_t *dtp, const char *name);
diff --git a/libdtrace/dt_prov_dtrace.c b/libdtrace/dt_prov_dtrace.c
index fe9759de..a5dc1eb0 100644
--- a/libdtrace/dt_prov_dtrace.c
+++ b/libdtrace/dt_prov_dtrace.c
@@ -40,11 +40,11 @@ static int populate(dtrace_hdl_t *dtp)
if (prv == NULL)
return 0;
- if (dt_probe_insert(dtp, prv, prvname, modname, funname, "BEGIN"))
+ if (tp_probe_insert(dtp, prv, prvname, modname, funname, "BEGIN"))
n++;
- if (dt_probe_insert(dtp, prv, prvname, modname, funname, "END"))
+ if (tp_probe_insert(dtp, prv, prvname, modname, funname, "END"))
n++;
- if (dt_probe_insert(dtp, prv, prvname, modname, funname, "ERROR"))
+ if (tp_probe_insert(dtp, prv, prvname, modname, funname, "ERROR"))
n++;
return n;
@@ -230,7 +230,7 @@ out:
}
static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
- int *idp, int *argcp, dt_argdesc_t **argvp)
+ int *argcp, dt_argdesc_t **argvp)
{
char *spec;
char *fn = NULL;
@@ -238,8 +238,12 @@ static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
FILE *f;
int rc = -ENOENT;
size_t len;
+ tp_probe_t *datap = prp->prv_data;
+
+ /* if we have an event ID, no need to retrieve it again */
+ if (datap->event_id != -1)
+ return -1;
- *idp = -1;
*argcp = 0; /* no arguments */
*argvp = NULL;
@@ -271,7 +275,7 @@ static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
if (f == NULL)
goto out;
- rc = tp_event_info(dtp, f, 0, idp, NULL, NULL);
+ rc = tp_event_info(dtp, f, 0, datap, NULL, NULL);
fclose(f);
out:
@@ -292,19 +296,15 @@ out:
* for some reason we are out of luck - fortunately it is not harmful to the
* system as a whole.
*/
-static int probe_fini(dtrace_hdl_t *dtp, dt_probe_t *prp)
+static int probe_fini(dtrace_hdl_t *dtp, const dt_probe_t *prp)
{
int fd;
- if (prp->event_fd != -1) {
- close(prp->event_fd);
- prp->event_fd = -1;
- }
+ tp_probe_fini(dtp, prp);
fd = open(UPROBE_EVENTS, O_WRONLY | O_APPEND);
if (fd == -1)
return -1;
-
dprintf(fd, "-:" GROUP_FMT "/%s\n", GROUP_DATA, prp->desc->prb);
close(fd);
@@ -317,5 +317,6 @@ dt_provimpl_t dt_dtrace = {
.populate = &populate,
.trampoline = &trampoline,
.probe_info = &probe_info,
+ .probe_destroy = &tp_probe_destroy,
.probe_fini = &probe_fini,
};
diff --git a/libdtrace/dt_prov_fbt.c b/libdtrace/dt_prov_fbt.c
index 1aa3ca3c..d01d1932 100644
--- a/libdtrace/dt_prov_fbt.c
+++ b/libdtrace/dt_prov_fbt.c
@@ -136,9 +136,9 @@ static int populate(dtrace_hdl_t *dtp)
if (dt_probe_lookup(dtp, &pd) != NULL)
continue;
- if (dt_probe_insert(dtp, prv, prvname, mod, buf, "entry"))
+ if (tp_probe_insert(dtp, prv, prvname, mod, buf, "entry"))
n++;
- if (dt_probe_insert(dtp, prv, prvname, mod, buf, "return"))
+ if (tp_probe_insert(dtp, prv, prvname, mod, buf, "return"))
n++;
}
@@ -273,15 +273,19 @@ static void trampoline(dt_pcb_t *pcb)
}
static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
- int *idp, int *argcp, dt_argdesc_t **argvp)
+ int *argcp, dt_argdesc_t **argvp)
{
int fd;
char *fn;
size_t len;
FILE *f;
int rc = -1;
+ tp_probe_t *datap = prp->prv_data;
+
+ /* if we have an event ID, no need to retrieve it again */
+ if (datap->event_id != -1)
+ return -1;
- *idp = -1;
*argcp = 0; /* no arguments by default */
*argvp = NULL;
@@ -312,7 +316,7 @@ static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
if (f == NULL)
goto out;
- rc = tp_event_info(dtp, f, 0, idp, NULL, NULL);
+ rc = tp_event_info(dtp, f, 0, datap, NULL, NULL);
fclose(f);
out:
@@ -332,19 +336,15 @@ out:
* for some reason we are out of luck - fortunately it is not harmful to the
* system as a whole.
*/
-static int probe_fini(dtrace_hdl_t *dtp, dt_probe_t *prp)
+static int probe_fini(dtrace_hdl_t *dtp, const dt_probe_t *prp)
{
int fd;
- if (prp->event_fd != -1) {
- close(prp->event_fd);
- prp->event_fd = -1;
- }
+ tp_probe_fini(dtp, prp);
fd = open(KPROBE_EVENTS, O_WRONLY | O_APPEND);
if (fd == -1)
return -1;
-
dprintf(fd, "-:" FBT_GROUP_FMT "/%s\n", FBT_GROUP_DATA,
prp->desc->fun);
close(fd);
@@ -358,5 +358,6 @@ dt_provimpl_t dt_fbt = {
.populate = &populate,
.trampoline = &trampoline,
.probe_info = &probe_info,
+ .probe_destroy = &tp_probe_destroy,
.probe_fini = &probe_fini,
};
diff --git a/libdtrace/dt_prov_sdt.c b/libdtrace/dt_prov_sdt.c
index 6d99653a..9223951b 100644
--- a/libdtrace/dt_prov_sdt.c
+++ b/libdtrace/dt_prov_sdt.c
@@ -57,6 +57,22 @@ static const dtrace_pattr_t pattr = {
{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
};
+dt_probe_t *tp_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov,
+ const char *prv, const char *mod,
+ const char *fun, const char *prb)
+{
+ tp_probe_t *datap;
+
+ datap = dt_zalloc(dtp, sizeof (tp_probe_t));
+ if (datap == NULL)
+ return NULL;
+
+ datap->event_id = -1;
+ datap->event_fd = -1;
+
+ return dt_probe_insert(dtp, prov, prv, mod, fun, prb, datap);
+}
+
/*
* Parse the EVENTSFS/<group>/<event>/format file to determine the event id and
* the argument types.
@@ -79,8 +95,8 @@ static const dtrace_pattr_t pattr = {
* specify an additional numbe of fields to skip (using the 'skip' parameter)
* before we get to the actual arguments.
*/
-int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip, int *idp, int *argcp,
- dt_argdesc_t **argvp)
+int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip, tp_probe_t *datap,
+ int *argcp, dt_argdesc_t **argvp)
{
char buf[1024];
int argc;
@@ -88,7 +104,7 @@ int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip, int *idp, int *argcp,
dt_argdesc_t *argv = NULL;
char *strp;
- *idp = -1;
+ datap->event_id = -1;
/*
* Let skip be the total number of fields to skip.
@@ -104,7 +120,7 @@ int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip, int *idp, int *argcp,
while (fgets(buf, sizeof(buf), f)) {
char *p = buf;
- if (sscanf(buf, "ID: %d\n", idp) == 1)
+ if (sscanf(buf, "ID: %d\n", &datap->event_id) == 1)
continue;
if (sscanf(buf, " field:%[^;]", p) <= 0)
@@ -223,6 +239,29 @@ done:
return 0;
}
+int tp_probe_destroy(dtrace_hdl_t *dtp, void *datap)
+{
+ dt_free(dtp, datap);
+ datap = NULL;
+
+ return 0;
+}
+
+int tp_probe_fini(dtrace_hdl_t *dtp, const dt_probe_t *prp)
+{
+ tp_probe_t *datap = prp->prv_data;
+
+ if (datap->event_fd != -1) {
+ close(datap->event_fd);
+ datap->event_fd = -1;
+ }
+ datap->event_id = -1;
+
+ tp_probe_destroy(dtp, prp->prv_data);
+
+ return 0;
+}
+
/*
* The PROBE_LIST file lists all tracepoints in a <group>:<name> format.
* We need to ignore these groups:
@@ -247,8 +286,8 @@ static int populate(dtrace_hdl_t *dtp)
return 0;
while (fgets(buf, sizeof(buf), f)) {
- int dummy;
- char str[sizeof(buf)];
+ int dummy;
+ char str[sizeof(buf)];
p = strchr(buf, '\n');
if (p)
@@ -273,10 +312,10 @@ static int populate(dtrace_hdl_t *dtp)
strcmp(buf, UPROBES) == 0)
continue;
- if (dt_probe_insert(dtp, prv, prvname, buf, "", p))
+ if (tp_probe_insert(dtp, prv, prvname, buf, "", p))
n++;
} else {
- if (dt_probe_insert(dtp, prv, prvname, modname, "",
+ if (tp_probe_insert(dtp, prv, prvname, modname, "",
buf))
n++;
}
@@ -380,13 +419,16 @@ static void trampoline(dt_pcb_t *pcb)
}
static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
- int *idp, int *argcp, dt_argdesc_t **argvp)
+ int *argcp, dt_argdesc_t **argvp)
{
- FILE *f;
- char fn[256];
- int rc;
+ FILE *f;
+ char fn[256];
+ int rc;
+ tp_probe_t *datap = prp->prv_data;
- *idp = -1;
+ /* if we have an event ID, no need to retrieve it again */
+ if (datap->event_id != -1)
+ return -1;
strcpy(fn, EVENTSFS);
strcat(fn, prp->desc->mod);
@@ -398,7 +440,7 @@ static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
if (!f)
return -ENOENT;
- rc = tp_event_info(dtp, f, 0, idp, argcp, argvp);
+ rc = tp_event_info(dtp, f, 0, datap, argcp, argvp);
fclose(f);
return rc;
@@ -410,4 +452,6 @@ dt_provimpl_t dt_sdt = {
.populate = &populate,
.trampoline = &trampoline,
.probe_info = &probe_info,
+ .probe_destroy = &tp_probe_destroy,
+ .probe_fini = &tp_probe_fini,
};
diff --git a/libdtrace/dt_prov_syscall.c b/libdtrace/dt_prov_syscall.c
index a7061d21..1c9145c0 100644
--- a/libdtrace/dt_prov_syscall.c
+++ b/libdtrace/dt_prov_syscall.c
@@ -109,18 +109,19 @@ static int populate(dtrace_hdl_t *dtp)
continue;
p += sizeof(PROV_PREFIX) - 1;
+
/*
* Now p will be just "event", and we are only interested in
* events that match "sys_enter_*" or "sys_exit_*".
*/
if (!memcmp(p, ENTRY_PREFIX, sizeof(ENTRY_PREFIX) - 1)) {
p += sizeof(ENTRY_PREFIX) - 1;
- if (dt_probe_insert(dtp, prv, prvname, modname, p,
+ if (tp_probe_insert(dtp, prv, prvname, modname, p,
"entry"))
n++;
} else if (!memcmp(p, EXIT_PREFIX, sizeof(EXIT_PREFIX) - 1)) {
p += sizeof(EXIT_PREFIX) - 1;
- if (dt_probe_insert(dtp, prv, prvname, modname, p,
+ if (tp_probe_insert(dtp, prv, prvname, modname, p,
"return"))
n++;
}
@@ -235,13 +236,16 @@ static void trampoline(dt_pcb_t *pcb)
}
static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
- int *idp, int *argcp, dt_argdesc_t **argvp)
+ int *argcp, dt_argdesc_t **argvp)
{
- FILE *f;
- char fn[256];
- int rc;
+ FILE *f;
+ char fn[256];
+ int rc;
+ tp_probe_t *datap = prp->prv_data;
- *idp = -1;
+ /* if we have an event ID, no need to retrieve it again */
+ if (datap->event_id != -1)
+ return -1;
/*
* We know that the probe name is either "entry" or "return", so we can
@@ -259,7 +263,7 @@ static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
if (!f)
return -ENOENT;
- rc = tp_event_info(dtp, f, SKIP_EXTRA_FIELDS, idp, argcp, argvp);
+ rc = tp_event_info(dtp, f, SKIP_EXTRA_FIELDS, datap, argcp, argvp);
fclose(f);
return rc;
@@ -271,4 +275,6 @@ dt_provimpl_t dt_syscall = {
.populate = &populate,
.trampoline = &trampoline,
.probe_info = &probe_info,
+ .probe_destroy = &tp_probe_destroy,
+ .probe_fini = &tp_probe_fini,
};
diff --git a/libdtrace/dt_provider.h b/libdtrace/dt_provider.h
index 4f488460..85fe2227 100644
--- a/libdtrace/dt_provider.h
+++ b/libdtrace/dt_provider.h
@@ -63,14 +63,18 @@ typedef struct dt_provimpl {
const dtrace_probedesc_t *pdp);
int (*probe_info)(dtrace_hdl_t *dtp, /* get probe info */
const struct dt_probe *prp,
- int *idp, int *argcp, dt_argdesc_t **argvp);
+ int *argcp, dt_argdesc_t **argvp);
void (*trampoline)(dt_pcb_t *pcb); /* generate BPF trampoline */
+ int (*probe_destroy)(dtrace_hdl_t *dtp, /* free provider-specific data */
+ void *datap);
int (*probe_fini)(dtrace_hdl_t *dtp, /* probe cleanup */
- struct dt_probe *prb);
+ const struct dt_probe *prb);
} dt_provimpl_t;
-extern int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip, int *idp,
- int *argcp, dt_argdesc_t **argvp);
+typedef struct tp_probe {
+ int event_id;
+ int event_fd;
+} tp_probe_t;
extern dt_provimpl_t dt_dtrace;
extern dt_provimpl_t dt_fbt;
@@ -91,6 +95,14 @@ typedef struct dt_provider {
uint_t pv_flags; /* flags (see below) */
} dt_provider_t;
+extern struct dt_probe *tp_probe_insert(dtrace_hdl_t *dtp, dt_provider_t *prov,
+ const char *prv, const char *mod,
+ const char *fun, const char *prb);
+extern int tp_probe_destroy(dtrace_hdl_t *dtp, void *datap);
+extern int tp_event_info(dtrace_hdl_t *dtp, FILE *f, int skip,
+ tp_probe_t *datap, int *argcp, dt_argdesc_t **argvp);
+extern int tp_probe_fini(dtrace_hdl_t *dtp, const struct dt_probe *prb);
+
#define DT_PROVIDER_INTF 0x1 /* provider interface declaration */
#define DT_PROVIDER_IMPL 0x2 /* provider implementation is loaded */
--
2.18.2
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