Implement support for ELF filters in rtld. Both normal and auxillary

filters are implemented.

Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.

Consolidate common arguments of the symbol lookup functions in the
SymLook structure.  Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.

Reviewed by:	kan
Tested by:	Mykola Dzham <i levsha me>, nwhitehorn (powerpc)

1 files changed, 8 insertions, 5 deletions

diff --git a/libexec/rtld-elf/mips/reloc.c b/libexec/rtld-elf/mips/reloc.c
index 0195df6..682adcd 100644
--- a/libexec/rtld-elf/mips/reloc.c
+++ b/libexec/rtld-elf/mips/reloc.c
@@ -238,7 +238,8 @@ _mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
         const Obj_Entry *defobj;
         Elf_Addr target;
 
-        def = find_symdef(reloff, obj, &defobj, SYMLOOK_IN_PLT, NULL);
+        def = find_symdef(reloff, obj, &defobj, SYMLOOK_IN_PLT, NULL,
+	    NULL);
         if (def == NULL)
 		_rtld_error("bind failed no symbol");
 
@@ -253,7 +254,7 @@ _mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
 }
 
 int
-reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
+reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, RtldLockState *lockstate)
 {
 	const Elf_Rel *rel;
 	const Elf_Rel *rellim;
@@ -312,7 +313,8 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
 			 * to 0 if there are non-PLT references, but older
 			 * versions of GNU ld do not do this.
 			 */
-			def = find_symdef(i, obj, &defobj, false, NULL);
+			def = find_symdef(i, obj, &defobj, false, NULL,
+			    lockstate);
 			if (def == NULL)
 				return -1;
 			*got = def->st_value + (Elf_Addr)defobj->relocbase;
@@ -353,7 +355,8 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
 			}
 		} else {
 			/* TODO: add cache here */
-			def = find_symdef(i, obj, &defobj, false, NULL);
+			def = find_symdef(i, obj, &defobj, false, NULL,
+			    lockstate);
 			if (def == NULL) {
 				dbg("Warning4, cant find symbole %d", i);
 				return -1;
@@ -487,7 +490,7 @@ reloc_plt(Obj_Entry *obj)
  * LD_BIND_NOW was set - force relocation for all jump slots
  */
 int
-reloc_jmpslots(Obj_Entry *obj)
+reloc_jmpslots(Obj_Entry *obj, RtldLockState *lockstate)
 {
 	/* Do nothing */
 	obj->jmpslots_done = true;