diff options
Diffstat (limited to 'lib/librtld_db/rtld_db.c')
| -rw-r--r-- | lib/librtld_db/rtld_db.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/lib/librtld_db/rtld_db.c b/lib/librtld_db/rtld_db.c new file mode 100644 index 000000000000..0d2adf88e089 --- /dev/null +++ b/lib/librtld_db/rtld_db.c @@ -0,0 +1,405 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2010 The FreeBSD Foundation + * + * 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/param.h> +#include <sys/sysctl.h> +#include <sys/user.h> + +#include <assert.h> +#include <err.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <machine/elf.h> + +#include <libelf.h> +#include <libproc.h> +#include <libprocstat.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) +{ + + if (rdap->rda_procstat != NULL) + procstat_close(rdap->rda_procstat); + 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) +{ + struct kinfo_vmentry *kves, *kve; + const char *path; + uint64_t fileid; + rd_loadobj_t rdl; + rd_err_e ret; + uintptr_t base; + uint32_t offset; + int cnt, i; + + DPRINTF("%s\n", __func__); + + if ((kves = kinfo_getvmmap(proc_getpid(rdap->rda_php), &cnt)) == NULL) { + warn("ERROR: kinfo_getvmmap() failed"); + return (RD_ERR); + } + + base = 0; + fileid = 0; + path = NULL; + ret = RD_OK; + for (i = 0; i < cnt; i++) { + kve = &kves[i]; + /* + * Cache the base offset of the file mapping. The kve_offset + * field gives the file offset of a particular mapping into the + * file, but we want the mapping offset relative to the base + * mapping. + */ + if (kve->kve_type == KVME_TYPE_VNODE) { + if (kve->kve_vn_fileid != fileid) { + base = kve->kve_start; + fileid = kve->kve_vn_fileid; + } + path = kve->kve_path; + offset = kve->kve_start - base; + } else { + path = NULL; + offset = 0; + } + 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 = 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; + if (path != NULL) + strlcpy(rdl.rdl_path, path, sizeof(rdl.rdl_path)); + if ((*cb)(&rdl, clnt_data) != 0) { + ret = RD_ERR; + break; + } + } + free(kves); + return (ret); +} + +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(*rdap)); + if (rdap == NULL) + return (NULL); + + memset(rdap, 0, sizeof(rd_agent_t)); + rdap->rda_php = php; + rdap->rda_procstat = procstat_open_sysctl(); + + if (rd_reset(rdap) != RD_OK) { + rd_delete(rdap); + rdap = NULL; + } + 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); +} + +static int +rtld_syms(rd_agent_t *rdap, const char *rtldpath, u_long base) +{ + GElf_Shdr shdr; + GElf_Sym sym; + Elf *e; + Elf_Data *data; + Elf_Scn *scn; + const char *symname; + Elf64_Word strscnidx; + int fd, i, ret; + + ret = 1; + e = NULL; + + fd = open(rtldpath, O_RDONLY); + if (fd < 0) + goto err; + + if (elf_version(EV_CURRENT) == EV_NONE) + goto err; + e = elf_begin(fd, ELF_C_READ, NULL); + if (e == NULL) + goto err; + + scn = NULL; + while ((scn = elf_nextscn(e, scn)) != NULL) { + gelf_getshdr(scn, &shdr); + if (shdr.sh_type == SHT_DYNSYM) + break; + } + if (scn == NULL) + goto err; + + strscnidx = shdr.sh_link; + data = elf_getdata(scn, NULL); + if (data == NULL) + goto err; + + for (i = 0; gelf_getsym(data, i, &sym) != NULL; i++) { + if (GELF_ST_TYPE(sym.st_info) != STT_FUNC || + GELF_ST_BIND(sym.st_info) != STB_GLOBAL) + continue; + symname = elf_strptr(e, strscnidx, sym.st_name); + if (symname == NULL) + continue; + + if (strcmp(symname, "r_debug_state") == 0) { + rdap->rda_preinit_addr = sym.st_value + base; + rdap->rda_dlactivity_addr = sym.st_value + base; + } else if (strcmp(symname, "_r_debug_postinit") == 0) { + rdap->rda_postinit_addr = sym.st_value + base; + } + } + + if (rdap->rda_preinit_addr != 0 && + rdap->rda_postinit_addr != 0 && + rdap->rda_dlactivity_addr != 0) + ret = 0; + +err: + if (e != NULL) + (void)elf_end(e); + if (fd >= 0) + (void)close(fd); + return (ret); +} + +rd_err_e +rd_reset(rd_agent_t *rdap) +{ + struct kinfo_proc *kp; + struct kinfo_vmentry *kve; + Elf_Auxinfo *auxv; + const char *rtldpath; + u_long base; + rd_err_e rderr; + int count, i; + + kp = NULL; + auxv = NULL; + kve = NULL; + rderr = RD_ERR; + + kp = procstat_getprocs(rdap->rda_procstat, KERN_PROC_PID, + proc_getpid(rdap->rda_php), &count); + if (kp == NULL) + return (RD_ERR); + assert(count == 1); + + auxv = procstat_getauxv(rdap->rda_procstat, kp, &count); + if (auxv == NULL) + goto err; + + base = 0; + for (i = 0; i < count; i++) { + if (auxv[i].a_type == AT_BASE) { + base = auxv[i].a_un.a_val; + break; + } + } + if (i == count) + goto err; + + rtldpath = NULL; + kve = procstat_getvmmap(rdap->rda_procstat, kp, &count); + if (kve == NULL) + goto err; + for (i = 0; i < count; i++) { + if (kve[i].kve_start == base) { + rtldpath = kve[i].kve_path; + break; + } + } + if (i == count) + goto err; + + if (rtld_syms(rdap, rtldpath, base) != 0) + goto err; + + rderr = RD_OK; + +err: + if (kve != NULL) + procstat_freevmmap(rdap->rda_procstat, kve); + if (auxv != NULL) + procstat_freeauxv(rdap->rda_procstat, auxv); + if (kp != NULL) + procstat_freeprocs(rdap->rda_procstat, kp); + return (rderr); +} |