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agent/src/os/bsd/libproc_impl.c@2394a89e89f4 (annotated)

agent/src/os/bsd/libproc_impl.c

Wed, 13 Feb 2013 09:46:19 +0100

author

rbackman

date

Wed, 13 Feb 2013 09:46:19 +0100

changeset 4599

2394a89e89f4

parent 3156

f08d439fab8c

child 4750

39432a1cefdd

permissions

-rw-r--r--

8008088: SA can hang the VM
Reviewed-by: mgronlun, sla, dholmes

never@3156	1	/*
rbackman@4599	2	* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
never@3156	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
never@3156	4	*
never@3156	5	* This code is free software; you can redistribute it and/or modify it
never@3156	6	* under the terms of the GNU General Public License version 2 only, as
never@3156	7	* published by the Free Software Foundation.
never@3156	8	*
never@3156	9	* This code is distributed in the hope that it will be useful, but WITHOUT
never@3156	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
never@3156	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
never@3156	12	* version 2 for more details (a copy is included in the LICENSE file that
never@3156	13	* accompanied this code).
never@3156	14	*
never@3156	15	* You should have received a copy of the GNU General Public License version
never@3156	16	* 2 along with this work; if not, write to the Free Software Foundation,
never@3156	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
never@3156	18	*
never@3156	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
never@3156	20	* or visit www.oracle.com if you need additional information or have any
never@3156	21	* questions.
never@3156	22	*
never@3156	23	*/
never@3156	24	#include <stdarg.h>
never@3156	25	#include <stdio.h>
never@3156	26	#include <stdlib.h>
never@3156	27	#include <string.h>
never@3156	28	#include <fcntl.h>
never@3156	29	#include <thread_db.h>
never@3156	30	#include "libproc_impl.h"
never@3156	31
never@3156	32	static const char* alt_root = NULL;
never@3156	33	static int alt_root_len = -1;
never@3156	34
never@3156	35	#define SA_ALTROOT "SA_ALTROOT"
never@3156	36
never@3156	37	static void init_alt_root() {
never@3156	38	if (alt_root_len == -1) {
never@3156	39	alt_root = getenv(SA_ALTROOT);
never@3156	40	if (alt_root) {
never@3156	41	alt_root_len = strlen(alt_root);
never@3156	42	} else {
never@3156	43	alt_root_len = 0;
never@3156	44	}
never@3156	45	}
never@3156	46	}
never@3156	47
never@3156	48	int pathmap_open(const char* name) {
never@3156	49	int fd;
never@3156	50	char alt_path[PATH_MAX + 1];
never@3156	51
never@3156	52	init_alt_root();
never@3156	53	fd = open(name, O_RDONLY);
never@3156	54	if (fd >= 0) {
never@3156	55	return fd;
never@3156	56	}
never@3156	57
never@3156	58	if (alt_root_len > 0) {
never@3156	59	strcpy(alt_path, alt_root);
never@3156	60	strcat(alt_path, name);
never@3156	61	fd = open(alt_path, O_RDONLY);
never@3156	62	if (fd >= 0) {
never@3156	63	print_debug("path %s substituted for %s\n", alt_path, name);
never@3156	64	return fd;
never@3156	65	}
never@3156	66
never@3156	67	if (strrchr(name, '/')) {
never@3156	68	strcpy(alt_path, alt_root);
never@3156	69	strcat(alt_path, strrchr(name, '/'));
never@3156	70	fd = open(alt_path, O_RDONLY);
never@3156	71	if (fd >= 0) {
never@3156	72	print_debug("path %s substituted for %s\n", alt_path, name);
never@3156	73	return fd;
never@3156	74	}
never@3156	75	}
never@3156	76	}
never@3156	77
never@3156	78	return -1;
never@3156	79	}
never@3156	80
never@3156	81	static bool _libsaproc_debug;
never@3156	82
never@3156	83	void print_debug(const char* format,...) {
never@3156	84	if (_libsaproc_debug) {
never@3156	85	va_list alist;
never@3156	86
never@3156	87	va_start(alist, format);
never@3156	88	fputs("libsaproc DEBUG: ", stderr);
never@3156	89	vfprintf(stderr, format, alist);
never@3156	90	va_end(alist);
never@3156	91	}
never@3156	92	}
never@3156	93
rbackman@4599	94	void print_error(const char* format,...) {
rbackman@4599	95	va_list alist;
rbackman@4599	96	va_start(alist, format);
rbackman@4599	97	fputs("ERROR: ", stderr);
rbackman@4599	98	vfprintf(stderr, format, alist);
rbackman@4599	99	va_end(alist);
rbackman@4599	100	}
rbackman@4599	101
never@3156	102	bool is_debug() {
never@3156	103	return _libsaproc_debug;
never@3156	104	}
never@3156	105
never@3156	106	// initialize libproc
never@3156	107	bool init_libproc(bool debug) {
never@3156	108	// init debug mode
never@3156	109	_libsaproc_debug = debug;
never@3156	110
never@3156	111	// initialize the thread_db library
never@3156	112	if (td_init() != TD_OK) {
never@3156	113	print_debug("libthread_db's td_init failed\n");
never@3156	114	return false;
never@3156	115	}
never@3156	116
never@3156	117	return true;
never@3156	118	}
never@3156	119
never@3156	120	static void destroy_lib_info(struct ps_prochandle* ph) {
never@3156	121	lib_info* lib = ph->libs;
never@3156	122	while (lib) {
never@3156	123	lib_info *next = lib->next;
never@3156	124	if (lib->symtab) {
never@3156	125	destroy_symtab(lib->symtab);
never@3156	126	}
never@3156	127	free(lib);
never@3156	128	lib = next;
never@3156	129	}
never@3156	130	}
never@3156	131
never@3156	132	static void destroy_thread_info(struct ps_prochandle* ph) {
never@3156	133	thread_info* thr = ph->threads;
never@3156	134	while (thr) {
never@3156	135	thread_info *next = thr->next;
never@3156	136	free(thr);
never@3156	137	thr = next;
never@3156	138	}
never@3156	139	}
never@3156	140
never@3156	141	// ps_prochandle cleanup
never@3156	142
never@3156	143	// ps_prochandle cleanup
never@3156	144	void Prelease(struct ps_prochandle* ph) {
never@3156	145	// do the "derived class" clean-up first
never@3156	146	ph->ops->release(ph);
never@3156	147	destroy_lib_info(ph);
never@3156	148	destroy_thread_info(ph);
never@3156	149	free(ph);
never@3156	150	}
never@3156	151
never@3156	152	lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) {
never@3156	153	return add_lib_info_fd(ph, libname, -1, base);
never@3156	154	}
never@3156	155
never@3156	156	lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
never@3156	157	lib_info* newlib;
never@3156	158
never@3156	159	if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) {
never@3156	160	print_debug("can't allocate memory for lib_info\n");
never@3156	161	return NULL;
never@3156	162	}
never@3156	163
never@3156	164	strncpy(newlib->name, libname, sizeof(newlib->name));
never@3156	165	newlib->base = base;
never@3156	166
never@3156	167	if (fd == -1) {
never@3156	168	if ( (newlib->fd = pathmap_open(newlib->name)) < 0) {
never@3156	169	print_debug("can't open shared object %s\n", newlib->name);
never@3156	170	free(newlib);
never@3156	171	return NULL;
never@3156	172	}
never@3156	173	} else {
never@3156	174	newlib->fd = fd;
never@3156	175	}
never@3156	176
never@3156	177	// check whether we have got an ELF file. /proc/<pid>/map
never@3156	178	// gives out all file mappings and not just shared objects
never@3156	179	if (is_elf_file(newlib->fd) == false) {
never@3156	180	close(newlib->fd);
never@3156	181	free(newlib);
never@3156	182	return NULL;
never@3156	183	}
never@3156	184
never@3156	185	newlib->symtab = build_symtab(newlib->fd);
never@3156	186	if (newlib->symtab == NULL) {
never@3156	187	print_debug("symbol table build failed for %s\n", newlib->name);
never@3156	188	}
never@3156	189	else {
never@3156	190	print_debug("built symbol table for %s\n", newlib->name);
never@3156	191	}
never@3156	192
never@3156	193	// even if symbol table building fails, we add the lib_info.
never@3156	194	// This is because we may need to read from the ELF file for core file
never@3156	195	// address read functionality. lookup_symbol checks for NULL symtab.
never@3156	196	if (ph->libs) {
never@3156	197	ph->lib_tail->next = newlib;
never@3156	198	ph->lib_tail = newlib;
never@3156	199	} else {
never@3156	200	ph->libs = ph->lib_tail = newlib;
never@3156	201	}
never@3156	202	ph->num_libs++;
never@3156	203
never@3156	204	return newlib;
never@3156	205	}
never@3156	206
never@3156	207	// lookup for a specific symbol
never@3156	208	uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name,
never@3156	209	const char* sym_name) {
never@3156	210	// ignore object_name. search in all libraries
never@3156	211	// FIXME: what should we do with object_name?? The library names are obtained
never@3156	212	// by parsing /proc/<pid>/maps, which may not be the same as object_name.
never@3156	213	// What we need is a utility to map object_name to real file name, something
never@3156	214	// dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For
never@3156	215	// now, we just ignore object_name and do a global search for the symbol.
never@3156	216
never@3156	217	lib_info* lib = ph->libs;
never@3156	218	while (lib) {
never@3156	219	if (lib->symtab) {
never@3156	220	uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL);
never@3156	221	if (res) return res;
never@3156	222	}
never@3156	223	lib = lib->next;
never@3156	224	}
never@3156	225
never@3156	226	print_debug("lookup failed for symbol '%s' in obj '%s'\n",
never@3156	227	sym_name, object_name);
never@3156	228	return (uintptr_t) NULL;
never@3156	229	}
never@3156	230
never@3156	231
never@3156	232	const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) {
never@3156	233	const char* res = NULL;
never@3156	234	lib_info* lib = ph->libs;
never@3156	235	while (lib) {
never@3156	236	if (lib->symtab && addr >= lib->base) {
never@3156	237	res = nearest_symbol(lib->symtab, addr - lib->base, poffset);
never@3156	238	if (res) return res;
never@3156	239	}
never@3156	240	lib = lib->next;
never@3156	241	}
never@3156	242	return NULL;
never@3156	243	}
never@3156	244
never@3156	245	// add a thread to ps_prochandle
never@3156	246	thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) {
never@3156	247	thread_info* newthr;
never@3156	248	if ( (newthr = (thread_info*) calloc(1, sizeof(thread_info))) == NULL) {
never@3156	249	print_debug("can't allocate memory for thread_info\n");
never@3156	250	return NULL;
never@3156	251	}
never@3156	252
never@3156	253	// initialize thread info
never@3156	254	newthr->pthread_id = pthread_id;
never@3156	255	newthr->lwp_id = lwp_id;
never@3156	256
never@3156	257	// add new thread to the list
never@3156	258	newthr->next = ph->threads;
never@3156	259	ph->threads = newthr;
never@3156	260	ph->num_threads++;
never@3156	261	return newthr;
never@3156	262	}
never@3156	263
never@3156	264
never@3156	265	// struct used for client data from thread_db callback
never@3156	266	struct thread_db_client_data {
never@3156	267	struct ps_prochandle* ph;
never@3156	268	thread_info_callback callback;
never@3156	269	};
never@3156	270
never@3156	271	// callback function for libthread_db
never@3156	272	static int thread_db_callback(const td_thrhandle_t *th_p, void *data) {
never@3156	273	struct thread_db_client_data* ptr = (struct thread_db_client_data*) data;
never@3156	274	td_thrinfo_t ti;
never@3156	275	td_err_e err;
never@3156	276
never@3156	277	memset(&ti, 0, sizeof(ti));
never@3156	278	err = td_thr_get_info(th_p, &ti);
never@3156	279	if (err != TD_OK) {
never@3156	280	print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n");
never@3156	281	return err;
never@3156	282	}
never@3156	283
never@3156	284	print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid);
never@3156	285
never@3156	286	if (ptr->callback(ptr->ph, (pthread_t)ti.ti_tid, ti.ti_lid) != true)
never@3156	287	return TD_ERR;
never@3156	288
never@3156	289	return TD_OK;
never@3156	290	}
never@3156	291
never@3156	292	// read thread_info using libthread_db
never@3156	293	bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) {
never@3156	294	struct thread_db_client_data mydata;
never@3156	295	td_thragent_t* thread_agent = NULL;
never@3156	296	if (td_ta_new(ph, &thread_agent) != TD_OK) {
never@3156	297	print_debug("can't create libthread_db agent\n");
never@3156	298	return false;
never@3156	299	}
never@3156	300
never@3156	301	mydata.ph = ph;
never@3156	302	mydata.callback = cb;
never@3156	303
never@3156	304	// we use libthread_db iterator to iterate thru list of threads.
never@3156	305	if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata,
never@3156	306	TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
never@3156	307	TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) {
never@3156	308	td_ta_delete(thread_agent);
never@3156	309	return false;
never@3156	310	}
never@3156	311
never@3156	312	// delete thread agent
never@3156	313	td_ta_delete(thread_agent);
never@3156	314	return true;
never@3156	315	}
never@3156	316
never@3156	317
never@3156	318	// get number of threads
never@3156	319	int get_num_threads(struct ps_prochandle* ph) {
never@3156	320	return ph->num_threads;
never@3156	321	}
never@3156	322
never@3156	323	// get lwp_id of n'th thread
never@3156	324	lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) {
never@3156	325	int count = 0;
never@3156	326	thread_info* thr = ph->threads;
never@3156	327	while (thr) {
never@3156	328	if (count == index) {
never@3156	329	return thr->lwp_id;
never@3156	330	}
never@3156	331	count++;
never@3156	332	thr = thr->next;
never@3156	333	}
never@3156	334	return -1;
never@3156	335	}
never@3156	336
never@3156	337	// get regs for a given lwp
never@3156	338	bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) {
never@3156	339	return ph->ops->get_lwp_regs(ph, lwp_id, regs);
never@3156	340	}
never@3156	341
never@3156	342	// get number of shared objects
never@3156	343	int get_num_libs(struct ps_prochandle* ph) {
never@3156	344	return ph->num_libs;
never@3156	345	}
never@3156	346
never@3156	347	// get name of n'th solib
never@3156	348	const char* get_lib_name(struct ps_prochandle* ph, int index) {
never@3156	349	int count = 0;
never@3156	350	lib_info* lib = ph->libs;
never@3156	351	while (lib) {
never@3156	352	if (count == index) {
never@3156	353	return lib->name;
never@3156	354	}
never@3156	355	count++;
never@3156	356	lib = lib->next;
never@3156	357	}
never@3156	358	return NULL;
never@3156	359	}
never@3156	360
never@3156	361	// get base address of a lib
never@3156	362	uintptr_t get_lib_base(struct ps_prochandle* ph, int index) {
never@3156	363	int count = 0;
never@3156	364	lib_info* lib = ph->libs;
never@3156	365	while (lib) {
never@3156	366	if (count == index) {
never@3156	367	return lib->base;
never@3156	368	}
never@3156	369	count++;
never@3156	370	lib = lib->next;
never@3156	371	}
never@3156	372	return (uintptr_t)NULL;
never@3156	373	}
never@3156	374
never@3156	375	bool find_lib(struct ps_prochandle* ph, const char *lib_name) {
never@3156	376	lib_info *p = ph->libs;
never@3156	377	while (p) {
never@3156	378	if (strcmp(p->name, lib_name) == 0) {
never@3156	379	return true;
never@3156	380	}
never@3156	381	p = p->next;
never@3156	382	}
never@3156	383	return false;
never@3156	384	}
never@3156	385
never@3156	386	//--------------------------------------------------------------------------
never@3156	387	// proc service functions
never@3156	388
never@3156	389	// ps_pglobal_lookup() looks up the symbol sym_name in the symbol table
never@3156	390	// of the load object object_name in the target process identified by ph.
never@3156	391	// It returns the symbol's value as an address in the target process in
never@3156	392	// *sym_addr.
never@3156	393
never@3156	394	ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name,
never@3156	395	const char *sym_name, psaddr_t *sym_addr) {
never@3156	396	*sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name);
never@3156	397	return (*sym_addr ? PS_OK : PS_NOSYM);
never@3156	398	}
never@3156	399
never@3156	400	// read "size" bytes info "buf" from address "addr"
never@3156	401	ps_err_e ps_pread(struct ps_prochandle *ph, psaddr_t addr,
never@3156	402	void *buf, size_t size) {
never@3156	403	return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR;
never@3156	404	}
never@3156	405
never@3156	406	// write "size" bytes of data to debuggee at address "addr"
never@3156	407	ps_err_e ps_pwrite(struct ps_prochandle *ph, psaddr_t addr,
never@3156	408	const void *buf, size_t size) {
never@3156	409	return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR;
never@3156	410	}
never@3156	411
never@3156	412	// fill in ptrace_lwpinfo for lid
never@3156	413	ps_err_e ps_linfo(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) {
never@3156	414	return ph->ops->get_lwp_info(ph, lwp_id, linfo)? PS_OK: PS_ERR;
never@3156	415	}
never@3156	416
never@3156	417	// needed for when libthread_db is compiled with TD_DEBUG defined
never@3156	418	void
never@3156	419	ps_plog (const char *format, ...)
never@3156	420	{
never@3156	421	va_list alist;
never@3156	422
never@3156	423	va_start(alist, format);
never@3156	424	vfprintf(stderr, format, alist);
never@3156	425	va_end(alist);
never@3156	426	}
never@3156	427
never@3156	428	// ------------------------------------------------------------------------
never@3156	429	// Functions below this point are not yet implemented. They are here only
never@3156	430	// to make the linker happy.
never@3156	431
never@3156	432	ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) {
never@3156	433	print_debug("ps_lsetfpregs not implemented\n");
never@3156	434	return PS_OK;
never@3156	435	}
never@3156	436
never@3156	437	ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) {
never@3156	438	print_debug("ps_lsetregs not implemented\n");
never@3156	439	return PS_OK;
never@3156	440	}
never@3156	441
never@3156	442	ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) {
never@3156	443	print_debug("ps_lgetfpregs not implemented\n");
never@3156	444	return PS_OK;
never@3156	445	}
never@3156	446
never@3156	447	ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) {
never@3156	448	print_debug("ps_lgetfpregs not implemented\n");
never@3156	449	return PS_OK;
never@3156	450	}
never@3156	451
never@3156	452	ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lid) {
never@3156	453	print_debug("ps_lstop not implemented\n");
never@3156	454	return PS_OK;
never@3156	455	}
never@3156	456
never@3156	457	ps_err_e ps_pcontinue(struct ps_prochandle *ph) {
never@3156	458	print_debug("ps_pcontinue not implemented\n");
never@3156	459	return PS_OK;
never@3156	460	}