freebsd-skq/lib/librtld_db/rtld_db.c
markj 91d5d12d67 Hook up support for userland CTF support in DTrace. This required some
modifications to libproc to support fetching the CTF info for a given file.

With this change, dtrace(1) is able to resolve type info for function and
USDT probe arguments, and function return values. In particular, the args[n]
syntax should now work for referencing arguments of userland probes,
provided that the requisite CTF info is available.

The uctf tests pass if the test programs are compiled with CTF info. The
current infrastructure around the DTrace test suite doesn't support this
yet.

Differential Revision:	https://reviews.freebsd.org/D891
MFC after:		1 month
Relnotes:		yes
Sponsored by:		EMC / Isilon Storage Division
2014-10-03 23:20:37 +00:00

255 lines
5.6 KiB
C

/*
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Rui Paulo under sponsorship from the
* FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <machine/_inttypes.h>
#include <sys/types.h>
#include <sys/user.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <libproc.h>
#include <libutil.h>
#include "rtld_db.h"
static int _librtld_db_debug = 0;
#define DPRINTF(...) do { \
if (_librtld_db_debug) { \
fprintf(stderr, "librtld_db: DEBUG: "); \
fprintf(stderr, __VA_ARGS__); \
} \
} while (0)
void
rd_delete(rd_agent_t *rdap)
{
free(rdap);
}
const char *
rd_errstr(rd_err_e rderr)
{
switch (rderr) {
case RD_ERR:
return "generic error";
case RD_OK:
return "no error";
case RD_NOCAPAB:
return "capability not supported";
case RD_DBERR:
return "database error";
case RD_NOBASE:
return "NOBASE";
case RD_NOMAPS:
return "NOMAPS";
default:
return "unknown error";
}
}
rd_err_e
rd_event_addr(rd_agent_t *rdap, rd_event_e event, rd_notify_t *notify)
{
rd_err_e ret;
DPRINTF("%s rdap %p event %d notify %p\n", __func__, rdap, event,
notify);
ret = RD_OK;
switch (event) {
case RD_NONE:
break;
case RD_PREINIT:
notify->type = RD_NOTIFY_BPT;
notify->u.bptaddr = rdap->rda_preinit_addr;
break;
case RD_POSTINIT:
notify->type = RD_NOTIFY_BPT;
notify->u.bptaddr = rdap->rda_postinit_addr;
break;
case RD_DLACTIVITY:
notify->type = RD_NOTIFY_BPT;
notify->u.bptaddr = rdap->rda_dlactivity_addr;
break;
default:
ret = RD_ERR;
break;
}
return (ret);
}
rd_err_e
rd_event_enable(rd_agent_t *rdap __unused, int onoff)
{
DPRINTF("%s onoff %d\n", __func__, onoff);
return (RD_OK);
}
rd_err_e
rd_event_getmsg(rd_agent_t *rdap __unused, rd_event_msg_t *msg)
{
DPRINTF("%s\n", __func__);
msg->type = RD_POSTINIT;
msg->u.state = RD_CONSISTENT;
return (RD_OK);
}
rd_err_e
rd_init(int version)
{
char *debug = NULL;
if (version == RD_VERSION) {
debug = getenv("LIBRTLD_DB_DEBUG");
_librtld_db_debug = debug ? atoi(debug) : 0;
return (RD_OK);
} else
return (RD_NOCAPAB);
}
rd_err_e
rd_loadobj_iter(rd_agent_t *rdap, rl_iter_f *cb, void *clnt_data)
{
int cnt, i, lastvn = 0;
rd_loadobj_t rdl;
struct kinfo_vmentry *kves, *kve;
DPRINTF("%s\n", __func__);
if ((kves = kinfo_getvmmap(proc_getpid(rdap->rda_php), &cnt)) == NULL) {
warn("ERROR: kinfo_getvmmap() failed");
return (RD_ERR);
}
for (i = 0; i < cnt; i++) {
kve = kves + i;
if (kve->kve_type == KVME_TYPE_VNODE)
lastvn = i;
memset(&rdl, 0, sizeof(rdl));
/*
* Map the kinfo_vmentry struct to the rd_loadobj structure.
*/
rdl.rdl_saddr = kve->kve_start;
rdl.rdl_eaddr = kve->kve_end;
rdl.rdl_offset = kve->kve_offset;
if (kve->kve_protection & KVME_PROT_READ)
rdl.rdl_prot |= RD_RDL_R;
if (kve->kve_protection & KVME_PROT_WRITE)
rdl.rdl_prot |= RD_RDL_W;
if (kve->kve_protection & KVME_PROT_EXEC)
rdl.rdl_prot |= RD_RDL_X;
strlcpy(rdl.rdl_path, kves[lastvn].kve_path,
sizeof(rdl.rdl_path));
(*cb)(&rdl, clnt_data);
}
free(kves);
return (RD_OK);
}
void
rd_log(const int onoff)
{
DPRINTF("%s\n", __func__);
(void)onoff;
}
rd_agent_t *
rd_new(struct proc_handle *php)
{
rd_agent_t *rdap;
rdap = malloc(sizeof(rd_agent_t));
if (rdap) {
memset(rdap, 0, sizeof(rd_agent_t));
rdap->rda_php = php;
rd_reset(rdap);
}
return (rdap);
}
rd_err_e
rd_objpad_enable(rd_agent_t *rdap, size_t padsize)
{
DPRINTF("%s\n", __func__);
(void)rdap;
(void)padsize;
return (RD_ERR);
}
rd_err_e
rd_plt_resolution(rd_agent_t *rdap, uintptr_t pc, struct proc *proc,
uintptr_t plt_base, rd_plt_info_t *rpi)
{
DPRINTF("%s\n", __func__);
(void)rdap;
(void)pc;
(void)proc;
(void)plt_base;
(void)rpi;
return (RD_ERR);
}
rd_err_e
rd_reset(rd_agent_t *rdap)
{
GElf_Sym sym;
if (proc_name2sym(rdap->rda_php, "ld-elf.so.1", "r_debug_state",
&sym, NULL) < 0)
return (RD_ERR);
DPRINTF("found r_debug_state at 0x%lx\n", (unsigned long)sym.st_value);
rdap->rda_preinit_addr = sym.st_value;
rdap->rda_dlactivity_addr = sym.st_value;
if (proc_name2sym(rdap->rda_php, "ld-elf.so.1", "_r_debug_postinit",
&sym, NULL) < 0)
return (RD_ERR);
DPRINTF("found _r_debug_postinit at 0x%lx\n",
(unsigned long)sym.st_value);
rdap->rda_postinit_addr = sym.st_value;
return (RD_OK);
}