move dynamic linker to its own top-level directory, ldso

this eliminates the last need for the SHARED macro to control how
files in the src tree are compiled. the same code is used for both
libc.a and libc.so, with additional code for the dynamic linker (from
the new ldso tree) being added to libc.so but not libc.a. separate .o
and .lo object files still exist for the src tree, but the only
difference is that the .lo files are built as PIC.

in the future, if/when we add dlopen support for static-linked
programs, much of the code in dynlink.c may be moved back into the src
tree, but properly factored into separate source files. in that case,
the code in the ldso tree will be reduced to just the dynamic linker
entry point, self-relocation, and loading of libraries needed by the
main application.

diff --git a/Makefile b/Makefile
index 3a60cfc030ab189b154a4a9f59531d8078b2a895..7c2cd77b42bd062b23c43a4f17f63bacc68a009d 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -22,6 +22,8 @@ BASE_OBJS = $(patsubst $(srcdir)/%,%.o,$(basename $(BASE_SRCS)))
 ARCH_SRCS = $(wildcard $(srcdir)/src/*/$(ARCH)/*.[csS])
 ARCH_OBJS = $(patsubst $(srcdir)/%,%.o,$(basename $(ARCH_SRCS)))
 REPLACED_OBJS = $(sort $(subst /$(ARCH)/,/,$(ARCH_OBJS)))
+LDSO_SRCS = $(sort $(wildcard $(srcdir)/ldso/*.c))
+LDSO_OBJS = $(patsubst $(srcdir)/%,obj/%.lo,$(basename $(LDSO_SRCS)))
 OBJS = $(addprefix obj/, $(filter-out $(REPLACED_OBJS), $(sort $(BASE_OBJS) $(ARCH_OBJS))))
 LOBJS = $(OBJS:.o=.lo)
 GENH = obj/include/bits/alltypes.h
@@ -72,7 +74,7 @@ endif
 
 all: $(ALL_LIBS) $(ALL_TOOLS)
 
-OBJ_DIRS = $(sort $(patsubst %/,%,$(dir $(ALL_LIBS) $(ALL_TOOLS) $(OBJS) $(GENH) $(GENH_INT))) $(addprefix obj/, crt crt/$(ARCH) include))
+OBJ_DIRS = $(sort $(patsubst %/,%,$(dir $(ALL_LIBS) $(ALL_TOOLS) $(OBJS) $(LDSO_OBJS) $(GENH) $(GENH_INT))) $(addprefix obj/, crt crt/$(ARCH) include))
 
 $(ALL_LIBS) $(ALL_TOOLS) $(CRT_LIBS:lib/%=obj/crt/%) $(OBJS) $(LOBJS) $(GENH) $(GENH_INT): | $(OBJ_DIRS)
 
@@ -95,11 +97,11 @@ obj/src/internal/version.h: $(wildcard $(srcdir)/VERSION $(srcdir)/.git)
 
 obj/src/internal/version.o obj/src/internal/version.lo: obj/src/internal/version.h
 
-obj/crt/rcrt1.o obj/src/ldso/dlstart.lo obj/src/ldso/dynlink.lo: $(srcdir)/src/internal/dynlink.h $(srcdir)/arch/$(ARCH)/reloc.h
+obj/crt/rcrt1.o obj/ldso/dlstart.lo obj/ldso/dynlink.lo: $(srcdir)/src/internal/dynlink.h $(srcdir)/arch/$(ARCH)/reloc.h
 
-obj/crt/crt1.o obj/crt/scrt1.o obj/crt/rcrt1.o obj/src/ldso/dlstart.lo: $(srcdir)/arch/$(ARCH)/crt_arch.h
+obj/crt/crt1.o obj/crt/scrt1.o obj/crt/rcrt1.o obj/ldso/dlstart.lo: $(srcdir)/arch/$(ARCH)/crt_arch.h
 
-obj/crt/rcrt1.o: $(srcdir)/src/ldso/dlstart.c
+obj/crt/rcrt1.o: $(srcdir)/ldso/dlstart.c
 
 obj/crt/Scrt1.o obj/crt/rcrt1.o: CFLAGS_ALL += -fPIC
 
@@ -117,12 +119,12 @@ NOSSP_SRCS = $(wildcard crt/*.c) \
        src/env/__libc_start_main.c src/env/__init_tls.c \
        src/thread/__set_thread_area.c src/env/__stack_chk_fail.c \
        src/string/memset.c src/string/memcpy.c \
-       src/ldso/dlstart.c src/ldso/dynlink.c
+       ldso/dlstart.c ldso/dynlink.c
 $(NOSSP_SRCS:%.c=obj/%.o) $(NOSSP_SRCS:%.c=obj/%.lo): CFLAGS_ALL += $(CFLAGS_NOSSP)
 
 $(CRT_LIBS:lib/%=obj/crt/%): CFLAGS_ALL += -DCRT
 
-$(LOBJS): CFLAGS_ALL += -fPIC -DSHARED
+$(LOBJS) $(LDSO_OBJS): CFLAGS_ALL += -fPIC
 
 CC_CMD = $(CC) $(CFLAGS_ALL) -c -o $@ $<
 
@@ -151,10 +153,10 @@ obj/%.lo: $(srcdir)/%.S
 obj/%.lo: $(srcdir)/%.c $(GENH) $(IMPH)
        $(CC_CMD)
 
-lib/libc.so: $(LOBJS)
+lib/libc.so: $(LOBJS) $(LDSO_OBJS)
        $(CC) $(CFLAGS_ALL) $(LDFLAGS_ALL) -nostdlib -shared \
        -Wl,-e,_dlstart -Wl,-Bsymbolic-functions \
-       -o $@ $(LOBJS) $(LIBCC)
+       -o $@ $(LOBJS) $(LDSO_OBJS) $(LIBCC)
 
 lib/libc.a: $(OBJS)
        rm -f $@

diff --git a/crt/rcrt1.c b/crt/rcrt1.c
index 9be117fdaa5416381c70f3c751c21473b40c9497..e763d0ab1555a189f1d36dbcd3aaafa140c99795 100644 (file)
--- a/crt/rcrt1.c
+++ b/crt/rcrt1.c
@@ -1,7 +1,7 @@
 #define SHARED
 #define START "_start"
 #define _dlstart_c _start_c
-#include "../src/ldso/dlstart.c"
+#include "../ldso/dlstart.c"
 
 int main();
 void _init() __attribute__((weak));

diff --git a/src/ldso/dlstart.c b/ldso/dlstart.c
similarity index 99%
rename from src/ldso/dlstart.c
rename to ldso/dlstart.c
index 46f50114c0c434329ec0d0c37fdce28fc766ae66..4482d5250b8255265d894ea7b12f2eb7fd12ca56 100644 (file)
--- a/src/ldso/dlstart.c
+++ b/ldso/dlstart.c
@@ -1,8 +1,6 @@
 #include <stddef.h>
 #include "dynlink.h"
 
-#ifdef SHARED
-
 #ifndef START
 #define START "_dlstart"
 #endif
@@ -146,5 +144,3 @@ void _dlstart_c(size_t *sp, size_t *dynv)
        GETFUNCSYM(&dls2, __dls2, base+dyn[DT_PLTGOT]);
        dls2((void *)base, sp);
 }
-
-#endif

diff --git a/src/ldso/dynlink.c b/ldso/dynlink.c
similarity index 99%
rename from src/ldso/dynlink.c
rename to ldso/dynlink.c
index e328679b877e913710de7cd0b353296e9eb36864..26a60b4ccb958a9d677308f90a1fd13a5b8e552b 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -1,4 +1,3 @@
-#ifdef SHARED
 #define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
@@ -1930,4 +1929,3 @@ static void error(const char *fmt, ...)
        __dl_vseterr(fmt, ap);
        va_end(ap);
 }
-#endif

diff --git a/src/ldso/tlsdesc.c b/src/ldso/tlsdesc.c
index 4bc654fa5cbf4c11de62c88270ca9ca0baa52684..a2985cb64a20a40c3efe53e30b55d2a167bd891a 100644 (file)
--- a/src/ldso/tlsdesc.c
+++ b/src/ldso/tlsdesc.c
@@ -1,5 +1,3 @@
-#ifdef SHARED
-
 #include <stddef.h>
 #include "libc.h"
 
@@ -12,5 +10,3 @@ ptrdiff_t __tlsdesc_static()
 }
 
 weak_alias(__tlsdesc_static, __tlsdesc_dynamic);
-
-#endif