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Diffstat (limited to 'lib/libdtrace/common/drti.c')
| -rw-r--r-- | lib/libdtrace/common/drti.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/lib/libdtrace/common/drti.c b/lib/libdtrace/common/drti.c new file mode 100644 index 000000000000..c983c5b595a8 --- /dev/null +++ b/lib/libdtrace/common/drti.c @@ -0,0 +1,206 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License, Version 1.0 only + * (the "License"). You may not use this file except in compliance + * with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2005 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +#include <unistd.h> +#include <fcntl.h> +#include <dlfcn.h> +#include <link.h> +#include <sys/dtrace.h> + +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +/* + * In Solaris 10 GA, the only mechanism for communicating helper information + * is through the DTrace helper pseudo-device node in /devices; there is + * no /dev link. Because of this, USDT providers and helper actions don't + * work inside of non-global zones. This issue was addressed by adding + * the /dev and having this initialization code use that /dev link. If the + * /dev link doesn't exist it falls back to looking for the /devices node + * as this code may be embedded in a binary which runs on Solaris 10 GA. + * + * Users may set the following environment variable to affect the way + * helper initialization takes place: + * + * DTRACE_DOF_INIT_DEBUG enable debugging output + * DTRACE_DOF_INIT_DISABLE disable helper loading + * DTRACE_DOF_INIT_DEVNAME set the path to the helper node + */ + +static const char *devnamep = "/dev/dtrace/helper"; +static const char *olddevname = "/devices/pseudo/dtrace@0:helper"; + +static const char *modname; /* Name of this load object */ +static int gen; /* DOF helper generation */ +extern dof_hdr_t __SUNW_dof; /* DOF defined in the .SUNW_dof section */ + +static void +dprintf(int debug, const char *fmt, ...) +{ + va_list ap; + + if (debug && getenv("DTRACE_DOF_INIT_DEBUG") == NULL) + return; + + va_start(ap, fmt); + + if (modname == NULL) + (void) fprintf(stderr, "dtrace DOF: "); + else + (void) fprintf(stderr, "dtrace DOF %s: ", modname); + + (void) vfprintf(stderr, fmt, ap); + + if (fmt[strlen(fmt) - 1] != '\n') + (void) fprintf(stderr, ": %s\n", strerror(errno)); + + va_end(ap); +} + +#if defined(sun) +#pragma init(dtrace_dof_init) +#else +static void dtrace_dof_init(void) __attribute__ ((constructor)); +#endif + +static void +dtrace_dof_init(void) +{ + dof_hdr_t *dof = &__SUNW_dof; +#ifdef _LP64 + Elf64_Ehdr *elf; +#else + Elf32_Ehdr *elf; +#endif + dof_helper_t dh; +#if defined(sun) + Link_map *lmp; + Lmid_t lmid; +#else + struct link_map *lmp; + u_long lmid = 0; +#endif + int fd; + const char *p; + + if (getenv("DTRACE_DOF_INIT_DISABLE") != NULL) + return; + + if (dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &lmp) == -1 || lmp == NULL) { + dprintf(1, "couldn't discover module name or address\n"); + return; + } + +#if defined(sun) + if (dlinfo(RTLD_SELF, RTLD_DI_LMID, &lmid) == -1) { + dprintf(1, "couldn't discover link map ID\n"); + return; + } +#endif + + if ((modname = strrchr(lmp->l_name, '/')) == NULL) + modname = lmp->l_name; + else + modname++; + + if (dof->dofh_ident[DOF_ID_MAG0] != DOF_MAG_MAG0 || + dof->dofh_ident[DOF_ID_MAG1] != DOF_MAG_MAG1 || + dof->dofh_ident[DOF_ID_MAG2] != DOF_MAG_MAG2 || + dof->dofh_ident[DOF_ID_MAG3] != DOF_MAG_MAG3) { + dprintf(0, ".SUNW_dof section corrupt\n"); + return; + } + + elf = (void *)lmp->l_addr; + + dh.dofhp_dof = (uintptr_t)dof; + dh.dofhp_addr = elf->e_type == ET_DYN ? (uintptr_t) lmp->l_addr : 0; + + if (lmid == 0) { + (void) snprintf(dh.dofhp_mod, sizeof (dh.dofhp_mod), + "%s", modname); + } else { + (void) snprintf(dh.dofhp_mod, sizeof (dh.dofhp_mod), + "LM%lu`%s", lmid, modname); + } + + if ((p = getenv("DTRACE_DOF_INIT_DEVNAME")) != NULL) + devnamep = p; + + if ((fd = open64(devnamep, O_RDWR)) < 0) { + dprintf(1, "failed to open helper device %s", devnamep); + + /* + * If the device path wasn't explicitly set, try again with + * the old device path. + */ + if (p != NULL) + return; + + devnamep = olddevname; + + if ((fd = open64(devnamep, O_RDWR)) < 0) { + dprintf(1, "failed to open helper device %s", devnamep); + return; + } + } + + if ((gen = ioctl(fd, DTRACEHIOC_ADDDOF, &dh)) == -1) + dprintf(1, "DTrace ioctl failed for DOF at %p", dof); + else + dprintf(1, "DTrace ioctl succeeded for DOF at %p\n", dof); + + (void) close(fd); +} + +#if defined(sun) +#pragma fini(dtrace_dof_fini) +#else +static void dtrace_dof_fini(void) __attribute__ ((destructor)); +#endif + +static void +dtrace_dof_fini(void) +{ + int fd; + + if ((fd = open64(devnamep, O_RDWR)) < 0) { + dprintf(1, "failed to open helper device %s", devnamep); + return; + } + + if ((gen = ioctl(fd, DTRACEHIOC_REMOVE, gen)) == -1) + dprintf(1, "DTrace ioctl failed to remove DOF (%d)\n", gen); + else + dprintf(1, "DTrace ioctl removed DOF (%d)\n", gen); + + (void) close(fd); +} |