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Date:      Tue, 7 Aug 2018 18:26:46 +0000 (UTC)
From:      Konstantin Belousov <kib@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r337430 - head/sys/kern
Message-ID:  <201808071826.w77IQktX082477@repo.freebsd.org>
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Author: kib
Date: Tue Aug  7 18:26:46 2018
New Revision: 337430
URL: https://svnweb.freebsd.org/changeset/base/337430

Log:
  Add missed handling of local relocs against ifunc target in the obj modules.
  
  Reported and tested by:	wulf
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/kern/link_elf_obj.c

Modified: head/sys/kern/link_elf_obj.c
==============================================================================
--- head/sys/kern/link_elf_obj.c	Tue Aug  7 17:45:49 2018	(r337429)
+++ head/sys/kern/link_elf_obj.c	Tue Aug  7 18:26:46 2018	(r337430)
@@ -142,7 +142,7 @@ static int	link_elf_each_function_name(linker_file_t,
 static int	link_elf_each_function_nameval(linker_file_t,
 				linker_function_nameval_callback_t,
 				void *);
-static int	link_elf_reloc_local(linker_file_t);
+static int	link_elf_reloc_local(linker_file_t, bool);
 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
 
@@ -441,10 +441,9 @@ link_elf_link_preload(linker_class_t cls, const char *
 	}
 
 	/* Local intra-module relocations */
-	error = link_elf_reloc_local(lf);
+	error = link_elf_reloc_local(lf, false);
 	if (error != 0)
 		goto out;
-
 	*result = lf;
 	return (0);
 
@@ -479,13 +478,18 @@ link_elf_link_preload_finish(linker_file_t lf)
 	ef = (elf_file_t)lf;
 	error = relocate_file(ef);
 	if (error)
-		return error;
+		return (error);
 
 	/* Notify MD code that a module is being loaded. */
 	error = elf_cpu_load_file(lf);
 	if (error)
 		return (error);
 
+	/* Now ifuncs. */
+	error = link_elf_reloc_local(lf, true);
+	if (error != 0)
+		return (error);
+
 	/* Invoke .ctors */
 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 	return (0);
@@ -969,7 +973,7 @@ link_elf_load_file(linker_class_t cls, const char *fil
 	}
 
 	/* Local intra-module relocations */
-	error = link_elf_reloc_local(lf);
+	error = link_elf_reloc_local(lf, false);
 	if (error != 0)
 		goto out;
 
@@ -990,6 +994,11 @@ link_elf_load_file(linker_class_t cls, const char *fil
 	if (error)
 		goto out;
 
+	/* Now ifuncs. */
+	error = link_elf_reloc_local(lf, true);
+	if (error != 0)
+		goto out;
+
 	/* Invoke .ctors */
 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
 
@@ -1374,7 +1383,10 @@ elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int 
 
 	/* Quick answer if there is a definition included. */
 	if (sym->st_shndx != SHN_UNDEF) {
-		*res = sym->st_value;
+		res1 = (Elf_Addr)sym->st_value;
+		if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
+			res1 = ((Elf_Addr (*)(void))res1)();
+		*res = res1;
 		return (0);
 	}
 
@@ -1470,7 +1482,7 @@ link_elf_fix_link_set(elf_file_t ef)
 }
 
 static int
-link_elf_reloc_local(linker_file_t lf)
+link_elf_reloc_local(linker_file_t lf, bool ifuncs)
 {
 	elf_file_t ef = (elf_file_t)lf;
 	const Elf_Rel *rellim;
@@ -1505,8 +1517,13 @@ link_elf_reloc_local(linker_file_t lf)
 			/* Only do local relocs */
 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 				continue;
-			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
-			    elf_obj_lookup);
+			if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) ==
+			    ifuncs)
+				elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
+				    elf_obj_lookup);
+			else if (ifuncs)
+				elf_reloc_ifunc(lf, base, rel, ELF_RELOC_REL,
+				    elf_obj_lookup);
 		}
 	}
 
@@ -1531,8 +1548,13 @@ link_elf_reloc_local(linker_file_t lf)
 			/* Only do local relocs */
 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 				continue;
-			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
-			    elf_obj_lookup);
+			if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) ==
+			    ifuncs)
+				elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
+				    elf_obj_lookup);
+			else if (ifuncs)
+				elf_reloc_ifunc(lf, base, rela, ELF_RELOC_RELA,
+				    elf_obj_lookup);
 		}
 	}
 	return (0);

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