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Date:      Mon, 11 Nov 2013 16:57:57 +0000 (UTC)
From:      Mark Johnston <markj@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r258000 - head/lib/libproc
Message-ID:  <201311111657.rABGvvX9034385@svn.freebsd.org>
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Author: markj
Date: Mon Nov 11 16:57:57 2013
New Revision: 258000
URL: http://svnweb.freebsd.org/changeset/base/258000

Log:
  Consistently add the relocation offset only when the ELF type is not
  ET_EXEC. This fixes several problems with the DTrace pid provider not
  being able to match probes.
  
  Reviewed by:	rpaulo
  MFC after:	2 weeks

Modified:
  head/lib/libproc/proc_sym.c

Modified: head/lib/libproc/proc_sym.c
==============================================================================
--- head/lib/libproc/proc_sym.c	Mon Nov 11 16:52:02 2013	(r257999)
+++ head/lib/libproc/proc_sym.c	Mon Nov 11 16:57:57 2013	(r258000)
@@ -284,7 +284,10 @@ proc_addr2sym(struct proc_handle *p, uin
 		 * Calculate the address mapped to the virtual memory
 		 * by rtld.
 		 */
-		rsym = map->pr_vaddr + sym.st_value;
+		if (ehdr.e_type != ET_EXEC)
+			rsym = map->pr_vaddr + sym.st_value;
+		else
+			rsym = sym.st_value;
 		if (addr >= rsym && addr < rsym + sym.st_size) {
 			s = elf_strptr(e, dynsymstridx, sym.st_name);
 			if (s) {
@@ -309,8 +312,6 @@ symtab:
 	 * Iterate over the Symbols Table to find the symbol.
 	 * Then look up the string name in STRTAB (.dynstr)
 	 */
-	if (symtabscn == NULL)
-		goto err2;
 	if ((data = elf_getdata(symtabscn, NULL)) == NULL) {
 		DPRINTFX("ERROR: elf_getdata() failed: %s", elf_errmsg(-1));
 		goto err2;
@@ -465,7 +466,8 @@ proc_name2sym(struct proc_handle *p, con
 			s = elf_strptr(e, dynsymstridx, sym.st_name);
 			if (s && strcmp(s, symbol) == 0) {
 				memcpy(symcopy, &sym, sizeof(sym));
-				symcopy->st_value = map->pr_vaddr + sym.st_value;
+				if (ehdr.e_type != ET_EXEC)
+					symcopy->st_value += map->pr_vaddr;
 				error = 0;
 				goto out;
 			}
@@ -475,20 +477,21 @@ proc_name2sym(struct proc_handle *p, con
 	 * Iterate over the Symbols Table to find the symbol.
 	 * Then look up the string name in STRTAB (.dynstr)
 	 */
-	if (symtabscn == NULL)
-		goto err2;
 	if ((data = elf_getdata(symtabscn, NULL))) {
 		i = 0;
 		while (gelf_getsym(data, i++, &sym) != NULL) {
 			s = elf_strptr(e, symtabstridx, sym.st_name);
 			if (s && strcmp(s, symbol) == 0) {
 				memcpy(symcopy, &sym, sizeof(sym));
+				if (ehdr.e_type != ET_EXEC)
+					symcopy->st_value += map->pr_vaddr;
 				error = 0;
 				goto out;
 			}
 		}
 	}
 out:
+	DPRINTFX("found addr 0x%lx for %s", symcopy->st_value, symbol);
 err2:
 	elf_end(e);
 err1:
@@ -509,6 +512,7 @@ proc_iter_symbyaddr(struct proc_handle *
 	prmap_t *map;
 	Elf_Scn *scn, *foundscn = NULL;
 	Elf_Data *data;
+	GElf_Ehdr ehdr;
 	GElf_Shdr shdr;
 	GElf_Sym sym;
 	unsigned long stridx = -1;
@@ -525,6 +529,10 @@ proc_iter_symbyaddr(struct proc_handle *
 		DPRINTFX("ERROR: elf_begin() failed: %s", elf_errmsg(-1));
 		goto err1;
 	}
+	if (gelf_getehdr(e, &ehdr) == NULL) {
+		DPRINTFX("ERROR: gelf_getehdr() failed: %s", elf_errmsg(-1));
+		goto err2;
+	}
 	/*
 	 * Find the section we are looking for.
 	 */
@@ -575,7 +583,8 @@ proc_iter_symbyaddr(struct proc_handle *
 		    (mask & TYPE_FILE) == 0)
 			continue;
 		s = elf_strptr(e, stridx, sym.st_name);
-		sym.st_value += map->pr_vaddr;
+		if (ehdr.e_type != ET_EXEC)
+			sym.st_value += map->pr_vaddr;
 		(*func)(cd, &sym, s);
 	}
 	error = 0;

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