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4474 DTrace Userland CTF Support
4475 DTrace userland Keyword
4476 DTrace tests should be better citizens
4479 pid provider types
4480 dof emulation missing checks
Reviewed by: Bryan Cantrill <bryan@joyent.com>
@@ -21,25 +21,30 @@
/*
* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
+/*
+ * Copyright (c) 2013, Joyent, Inc. All rights reserved.
+ */
#include <assert.h>
#include <strings.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <alloca.h>
#include <libgen.h>
#include <stddef.h>
+#include <sys/sysmacros.h>
#include <dt_impl.h>
#include <dt_program.h>
#include <dt_pid.h>
#include <dt_string.h>
+#include <dt_module.h>
typedef struct dt_pid_probe {
dtrace_hdl_t *dpp_dtp;
dt_pcb_t *dpp_pcb;
dt_proc_t *dpp_dpr;
@@ -753,5 +758,164 @@
(void) dt_ioctl(dtp, DTRACEIOC_ENABLE, NULL);
}
return (ret);
}
+
+/*
+ * libdtrace has a backroom deal with us to ask us for type information on
+ * behalf of pid provider probes when fasttrap doesn't return any type
+ * information. Instead we'll look up the module and see if there is type
+ * information available. However, if there is no type information available due
+ * to a lack of CTF data, then we want to make sure that DTrace still carries on
+ * in face of that. As such we don't have a meaningful exit code about failure.
+ * We emit information about why we failed to the dtrace debug log so someone
+ * can figure it out by asking nicely for DTRACE_DEBUG.
+ */
+void
+dt_pid_get_types(dtrace_hdl_t *dtp, const dtrace_probedesc_t *pdp,
+ dtrace_argdesc_t *adp, int *nargs)
+{
+ dt_module_t *dmp;
+ ctf_file_t *fp;
+ ctf_funcinfo_t f;
+ ctf_id_t argv[32];
+ GElf_Sym sym;
+ prsyminfo_t si;
+ struct ps_prochandle *p;
+ int i, args;
+ char buf[DTRACE_ARGTYPELEN];
+ const char *mptr;
+ char *eptr;
+ int ret = 0;
+ int argc = sizeof (argv) / sizeof (ctf_id_t);
+ Lmid_t lmid;
+
+ /* Set up a potential outcome */
+ args = *nargs;
+ *nargs = 0;
+
+ /*
+ * If we don't have an entry or return probe then we can just stop right
+ * now as we don't have arguments for offset probes.
+ */
+ if (strcmp(pdp->dtpd_name, "entry") != 0 &&
+ strcmp(pdp->dtpd_name, "return") != 0)
+ return;
+
+ dmp = dt_module_create(dtp, pdp->dtpd_provider);
+ if (dmp == NULL) {
+ dt_dprintf("failed to find module for %s\n",
+ pdp->dtpd_provider);
+ return;
+ }
+ if (dt_module_load(dtp, dmp) != 0) {
+ dt_dprintf("failed to load module for %s\n",
+ pdp->dtpd_provider);
+ return;
+ }
+
+ /*
+ * We may be working with a module that doesn't have ctf. If that's the
+ * case then we just return now and move on with life.
+ */
+ fp = dt_module_getctflib(dtp, dmp, pdp->dtpd_mod);
+ if (fp == NULL) {
+ dt_dprintf("no ctf container for %s\n",
+ pdp->dtpd_mod);
+ return;
+ }
+ p = dt_proc_grab(dtp, dmp->dm_pid, 0, PGRAB_RDONLY | PGRAB_FORCE);
+ if (p == NULL) {
+ dt_dprintf("failed to grab pid\n");
+ return;
+ }
+ dt_proc_lock(dtp, p);
+
+ /*
+ * Check to see if the D module has a link map ID and separate that out
+ * for properly interrogating libproc.
+ */
+ if ((mptr = strchr(pdp->dtpd_mod, '`')) != NULL) {
+ if (strlen(pdp->dtpd_mod) < 3) {
+ dt_dprintf("found weird modname with linkmap, "
+ "aborting: %s\n", pdp->dtpd_mod);
+ goto out;
+ }
+ if (pdp->dtpd_mod[0] != 'L' || pdp->dtpd_mod[1] != 'M') {
+ dt_dprintf("missing leading 'LM', "
+ "aborting: %s\n", pdp->dtpd_mod);
+ goto out;
+ }
+ errno = 0;
+ lmid = strtol(pdp->dtpd_mod + 2, &eptr, 16);
+ if (errno == ERANGE || eptr != mptr) {
+ dt_dprintf("failed to parse out lmid, aborting: %s\n",
+ pdp->dtpd_mod);
+ goto out;
+ }
+ mptr++;
+ } else {
+ mptr = pdp->dtpd_mod;
+ lmid = 0;
+ }
+
+ if (Pxlookup_by_name(p, lmid, mptr, pdp->dtpd_func,
+ &sym, &si) != 0) {
+ dt_dprintf("failed to find function %s in %s`%s\n",
+ pdp->dtpd_func, pdp->dtpd_provider, pdp->dtpd_mod);
+ goto out;
+ }
+ if (ctf_func_info(fp, si.prs_id, &f) == CTF_ERR) {
+ dt_dprintf("failed to get ctf information for %s in %s`%s\n",
+ pdp->dtpd_func, pdp->dtpd_provider, pdp->dtpd_mod);
+ goto out;
+ }
+
+ (void) snprintf(buf, sizeof (buf), "%s`%s", pdp->dtpd_provider,
+ pdp->dtpd_mod);
+
+ if (strcmp(pdp->dtpd_name, "return") == 0) {
+ if (args < 2)
+ goto out;
+
+ bzero(adp, sizeof (dtrace_argdesc_t));
+ adp->dtargd_ndx = 0;
+ adp->dtargd_id = pdp->dtpd_id;
+ adp->dtargd_mapping = adp->dtargd_ndx;
+ /*
+ * We explicitly leave out the library here, we only care that
+ * it is some int. We are assuming that there is no ctf
+ * container in here that is lying about what an int is.
+ */
+ (void) snprintf(adp->dtargd_native, DTRACE_ARGTYPELEN,
+ "user %s`%s", pdp->dtpd_provider, "int");
+ adp++;
+ bzero(adp, sizeof (dtrace_argdesc_t));
+ adp->dtargd_ndx = 1;
+ adp->dtargd_id = pdp->dtpd_id;
+ adp->dtargd_mapping = adp->dtargd_ndx;
+ ret = snprintf(adp->dtargd_native, DTRACE_ARGTYPELEN,
+ "userland ");
+ (void) ctf_type_qname(fp, f.ctc_return, adp->dtargd_native +
+ ret, DTRACE_ARGTYPELEN - ret, buf);
+ *nargs = 2;
+ } else {
+ if (ctf_func_args(fp, si.prs_id, argc, argv) == CTF_ERR)
+ goto out;
+
+ *nargs = MIN(args, f.ctc_argc);
+ for (i = 0; i < *nargs; i++, adp++) {
+ bzero(adp, sizeof (dtrace_argdesc_t));
+ adp->dtargd_ndx = i;
+ adp->dtargd_id = pdp->dtpd_id;
+ adp->dtargd_mapping = adp->dtargd_ndx;
+ ret = snprintf(adp->dtargd_native, DTRACE_ARGTYPELEN,
+ "userland ");
+ (void) ctf_type_qname(fp, argv[i], adp->dtargd_native +
+ ret, DTRACE_ARGTYPELEN - ret, buf);
+ }
+ }
+out:
+ dt_proc_unlock(dtp, p);
+ dt_proc_release(dtp, p);
+}