When our linker merges .SUNW_dof sections from multiple files, it simply

concatenates the DOF tables into one section. Previously, the USDT init
code in drti.o would only look at the first table in the DOF section; with
this change, it iterates over all the tables, passing each DOF table to
the kernel.

PR:		186821
Submitted by:	Fedor Indutny <fedor@indutny.com>
MFC after:	1 month

1 files changed, 58 insertions, 30 deletions

diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c
index 3b4a38c..bb02d8c 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c
@@ -20,6 +20,7 @@
  */
 /*
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2013 Voxer Inc. All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -144,7 +145,8 @@ dtrace_dof_init(void)
 	Lmid_t lmid;
 #else
 	u_long lmid = 0;
-	dof_sec_t *sec;
+	dof_sec_t *sec, *secstart, *dofstrtab, *dofprobes;
+	dof_provider_t *dofprovider;
 	size_t i;
 #endif
 	int fd;
@@ -152,14 +154,15 @@ dtrace_dof_init(void)
 #if !defined(sun)
 	Elf *e;
 	Elf_Scn *scn = NULL;
-	Elf_Data *symtabdata = NULL, *dynsymdata = NULL;
+	Elf_Data *symtabdata = NULL, *dynsymdata = NULL, *dofdata = NULL;
+	dof_hdr_t *dof_next = NULL;
 	GElf_Shdr shdr;
 	int efd, nprobes;
 	char *s;
+	char *dofstrtabraw;
 	size_t shstridx, symtabidx = 0, dynsymidx = 0;
-	unsigned char *dofstrtab = NULL;
 	unsigned char *buf;
-	int fixedprobes = 0;
+	int fixedprobes;
 #endif
 
 	if (getenv("DTRACE_DOF_INIT_DISABLE") != NULL)
@@ -209,7 +212,8 @@ dtrace_dof_init(void)
 		} 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;
+				dofdata = elf_getdata(scn, NULL);
+				dof = dofdata->d_buf;
 			}
 		}
 	}
@@ -219,6 +223,10 @@ dtrace_dof_init(void)
 		close(efd);
 		return;
 	}
+
+	while ((char *) dof < (char *) dofdata->d_buf + dofdata->d_size) {
+		fixedprobes = 0;
+		dof_next = (void *) ((char *) dof + dof->dofh_filesz);
 #endif
 
 	if (dof->dofh_ident[DOF_ID_MAG0] != DOF_MAG_MAG0 ||
@@ -290,34 +298,49 @@ dtrace_dof_init(void)
 	 * 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);
+	secstart = 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)
+		if (sec->dofs_type != DOF_SECT_PROVIDER)
+			continue;
+
+		dofprovider = (void *) (buf + sec->dofs_offset);
+		dofstrtab = secstart + dofprovider->dofpv_strtab;
+		dofprobes = secstart + dofprovider->dofpv_probes;
+
+		if (dofstrtab->dofs_type != DOF_SECT_STRTAB) {
+			fprintf(stderr, "WARNING: expected STRTAB section, but got %d\n",
+					dofstrtab->dofs_type);
 			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");
+		}
+		if (dofprobes->dofs_type != DOF_SECT_PROBES) {
+			fprintf(stderr, "WARNING: expected PROBES section, but got %d\n",
+			    dofprobes->dofs_type);
+			break;
+		}
+
+		dprintf(1, "found provider %p\n", dofprovider);
+		dofstrtabraw = (char *)(buf + dofstrtab->dofs_offset);
+		nprobes = dofprobes->dofs_size / dofprobes->dofs_entsize;
+		fixsymbol(e, symtabdata, symtabidx, nprobes, buf, dofprobes, &fixedprobes,
+				dofstrtabraw);
+		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, dofprobes,
+					&fixedprobes, dofstrtabraw);
+		}
+		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)
@@ -330,7 +353,12 @@ dtrace_dof_init(void)
 	}
 
 	(void) close(fd);
+
 #if !defined(sun)
+		/* End of while loop */
+		dof = dof_next;
+	}
+
 	elf_end(e);
 	(void) close(efd);
 #endif