1 files changed, 361 insertions, 0 deletions
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c
new file mode 100644
index 000000000000..3b4a38ce34ab
--- /dev/null
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c
@@ -0,0 +1,361 @@
+/*
+ * 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.
+ */
+
+#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>
+#include <libelf.h>
+#include <gelf.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";
+#if defined(sun)
+static const char *olddevname = "/devices/pseudo/dtrace@0:helper";
+#endif
+
+static const char *modname;	/* Name of this load object */
+static int gen;			/* DOF helper generation */
+#if defined(sun)
+extern dof_hdr_t __SUNW_dof;	/* DOF defined in the .SUNW_dof section */
+#endif
+static boolean_t dof_init_debug = B_FALSE;	/* From DTRACE_DOF_INIT_DEBUG */
+
+static void
+dprintf(int debug, const char *fmt, ...)
+{
+	va_list ap;
+
+	if (debug && !dof_init_debug)
+		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)
+static void
+fixsymbol(Elf *e, Elf_Data *data, size_t idx, int nprobes, char *buf,
+    dof_sec_t *sec, int *fixedprobes, char *dofstrtab)
+{
+	GElf_Sym sym;
+	char *s;
+	unsigned char *funcname;
+	dof_probe_t *prb;
+	int j = 0;
+	int ndx;
+
+	while (gelf_getsym(data, j++, &sym) != NULL) {
+		prb = (dof_probe_t *)(void *)(buf + sec->dofs_offset);
+
+		for (ndx = nprobes; ndx; ndx--, prb += 1) {
+			funcname = dofstrtab + prb->dofpr_func;
+			s = elf_strptr(e, idx, sym.st_name);
+			if (strcmp(s, funcname) == 0) {
+				dprintf(1, "fixing %s() symbol\n", s);
+				prb->dofpr_addr = sym.st_value;
+				(*fixedprobes)++;
+			}
+		}
+		if (*fixedprobes == nprobes)
+			break;
+	}
+}
+#endif
+
+#if defined(sun)
+#pragma init(dtrace_dof_init)
+#else
+static void dtrace_dof_init(void) __attribute__ ((constructor));
+#endif
+
+static void
+dtrace_dof_init(void)
+{
+#if defined(sun)
+	dof_hdr_t *dof = &__SUNW_dof;
+#else
+	dof_hdr_t *dof = NULL;
+#endif
+#ifdef _LP64
+	Elf64_Ehdr *elf;
+#else
+	Elf32_Ehdr *elf;
+#endif
+	dof_helper_t dh;
+	Link_map *lmp;
+#if defined(sun)
+	Lmid_t lmid;
+#else
+	u_long lmid = 0;
+	dof_sec_t *sec;
+	size_t i;
+#endif
+	int fd;
+	const char *p;
+#if !defined(sun)
+	Elf *e;
+	Elf_Scn *scn = NULL;
+	Elf_Data *symtabdata = NULL, *dynsymdata = NULL;
+	GElf_Shdr shdr;
+	int efd, nprobes;
+	char *s;
+	size_t shstridx, symtabidx = 0, dynsymidx = 0;
+	unsigned char *dofstrtab = NULL;
+	unsigned char *buf;
+	int fixedprobes = 0;
+#endif
+
+	if (getenv("DTRACE_DOF_INIT_DISABLE") != NULL)
+		return;
+
+	if (getenv("DTRACE_DOF_INIT_DEBUG") != NULL)
+		dof_init_debug = B_TRUE;
+
+	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 !defined(sun)
+	elf_version(EV_CURRENT);
+	if ((efd = open(lmp->l_name, O_RDONLY, 0)) < 0) {
+		dprintf(1, "couldn't open file for reading\n");
+		return;
+	}
+	if ((e = elf_begin(efd, ELF_C_READ, NULL)) == NULL) {
+		dprintf(1, "elf_begin failed\n");
+		close(efd);
+		return;
+	}
+	elf_getshdrstrndx(e, &shstridx);
+	dof = NULL;
+	while ((scn = elf_nextscn(e, scn)) != NULL) {
+		gelf_getshdr(scn, &shdr);
+		if (shdr.sh_type == SHT_SYMTAB) {
+			symtabidx = shdr.sh_link;
+			symtabdata = elf_getdata(scn, NULL);
+		} else if (shdr.sh_type == SHT_DYNSYM) {
+			dynsymidx = shdr.sh_link;
+			dynsymdata = elf_getdata(scn, NULL);
+		} else if (shdr.sh_type == SHT_PROGBITS) {
+			s = elf_strptr(e, shstridx, shdr.sh_name);
+			if  (s && strcmp(s, ".SUNW_dof") == 0) {
+				dof = elf_getdata(scn, NULL)->d_buf;
+			}
+		}
+	}
+	if (dof == NULL) {
+		dprintf(1, "SUNW_dof section not found\n");
+		elf_end(e);
+		close(efd);
+		return;
+	}
+#endif
+
+	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 defined(sun)
+		/*
+		 * 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;
+		}
+#else
+		return;
+#endif
+	}
+#if !defined(sun)
+	/*
+	 * We need to fix the base address of each probe since this wasn't
+	 * done by ld(1). (ld(1) needs to grow support for parsing the
+	 * SUNW_dof section).
+	 *
+	 * The complexity of this is not that great. The first for loop
+	 * iterates over the sections inside the DOF file. There are usually
+	 * 10 sections here. We asume the STRTAB section comes first and the
+	 * PROBES section comes after. Since we are only interested in fixing
+	 * data inside the PROBES section we quit the for loop after processing
+	 * the PROBES section. It's usually the case that the first section
+	 * is the STRTAB section and the second section is the PROBES section,
+	 * so this for loop is not meaningful when doing complexity analysis.
+	 *
+	 * After finding the probes section, we iterate over the symbols
+	 * in the symtab section. When we find a symbol name that matches
+	 * the probe function name, we fix it. If we have fixed all the
+	 * probes, we exit all the loops and we are done.
+	 * The number of probes is given by the variable 'nprobes' and this
+	 * depends entirely on the user, but some optimizations were done.
+	 *
+	 * We are assuming the number of probes is less than the number of
+	 * symbols (libc can have 4k symbols, for example).
+	 */
+	sec = (dof_sec_t *)(dof + 1);
+	buf = (char *)dof;
+	for (i = 0; i < dof->dofh_secnum; i++, sec++) {
+		if (sec->dofs_type == DOF_SECT_STRTAB)
+			dofstrtab = (unsigned char *)(buf + sec->dofs_offset);
+		else if (sec->dofs_type == DOF_SECT_PROBES && dofstrtab)
+			break;
+	
+	}
+	nprobes = sec->dofs_size / sec->dofs_entsize;
+	fixsymbol(e, symtabdata, symtabidx, nprobes, buf, sec, &fixedprobes,
+	    dofstrtab);
+	if (fixedprobes != nprobes) {
+		/*
+		 * If we haven't fixed all the probes using the
+		 * symtab section, look inside the dynsym
+		 * section.
+		 */
+		fixsymbol(e, dynsymdata, dynsymidx, nprobes, buf, sec,
+		    &fixedprobes, dofstrtab);
+	}
+	if (fixedprobes != nprobes) {
+		fprintf(stderr, "WARNING: number of probes "
+		    "fixed does not match the number of "
+		    "defined probes (%d != %d, "
+		    "respectively)\n", fixedprobes, nprobes);
+		fprintf(stderr, "WARNING: some probes might "
+		    "not fire or your program might crash\n");
+	}
+#endif
+	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);
+#if !defined(sun)
+		gen = dh.gen;
+#endif
+	}
+
+	(void) close(fd);
+#if !defined(sun)
+	elf_end(e);
+	(void) close(efd);
+#endif
+}
+
+#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);
+}