diff options
Diffstat (limited to 'usr/src/lib/libdtrace/common/dlink_common.c')
| -rw-r--r-- | usr/src/lib/libdtrace/common/dlink_common.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/usr/src/lib/libdtrace/common/dlink_common.c b/usr/src/lib/libdtrace/common/dlink_common.c new file mode 100644 index 0000000000..c47ec273ab --- /dev/null +++ b/usr/src/lib/libdtrace/common/dlink_common.c @@ -0,0 +1,166 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (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 2008 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +/* + * Copyright (c) 2012 by Delphix. All rights reserved. + */ + +/* + * Common functions for helper provider loading both compiled into the + * executable via drti.o and dtrace(1M) -G, and the libdaudit.so library. + */ + +#include <errno.h> +#include <fcntl.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <dlink.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. + */ +const char *devname = "/dev/dtrace/helper"; +static const char *olddevname = "/devices/pseudo/dtrace@0:helper"; + +static boolean_t dof_init_debug = B_FALSE; + +void +dprintf(int debug, const char *fmt, ...) +{ + va_list ap; + + if (debug && !dof_init_debug) + return; + + va_start(ap, fmt); + + (void) fprintf(stderr, "dtrace DOF: "); + + (void) vfprintf(stderr, fmt, ap); + + if (fmt[strlen(fmt) - 1] != '\n') + (void) fprintf(stderr, ": %s\n", strerror(errno)); + + va_end(ap); +} + +/* + * 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 + */ +void +dtrace_link_init(void) +{ + if (getenv("DTRACE_DOF_INIT_DEBUG") != NULL) + dof_init_debug = B_TRUE; +} + +void +dtrace_link_dof(dof_hdr_t *dof, Lmid_t lmid, const char *name, uintptr_t addr) +{ + const char *modname; + const char *p; +#ifdef _LP64 + Elf64_Ehdr *elf; +#else + Elf32_Ehdr *elf; +#endif + dof_helper_t dh; + int fd; + + if (getenv("DTRACE_DOF_INIT_DISABLE") != NULL) + return; + + if ((modname = strrchr(name, '/')) == NULL) + modname = 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 for %s\n", modname); + return; + } + + elf = (void *)addr; + + dh.dofhp_dof = (uintptr_t)dof; + dh.dofhp_addr = elf->e_type == ET_DYN ? addr : 0; + + if (lmid == LM_ID_BASE) { + (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) + devname = p; + + if ((fd = open64(devname, O_RDWR)) < 0) { + dprintf(1, "failed to open helper device %s", devname); + + /* + * If the device path wasn't explicitly set, try again with + * the old device path. + */ + if (p != NULL) + return; + + devname = olddevname; + + if ((fd = open64(devname, O_RDWR)) < 0) { + dprintf(1, "failed to open helper device %s", devname); + return; + } + } + + if (ioctl(fd, DTRACEHIOC_ADDDOF, &dh) == -1) { + dprintf(1, "DTrace ioctl failed for DOF at %p in %s", dof, + name); + } else { + dprintf(1, "DTrace ioctl succeeded for DOF at %p in %s\n", dof, + name); + } + (void) close(fd); +} |