From 2c58afdb3ae6f900583cf7264cba6ab8a797e3e2 Mon Sep 17 00:00:00 2001 From: linted Date: Sat, 23 Jul 2022 16:25:41 -0400 Subject: Added support for creation of Static Position-Independent Executables (PIE) on i386, x86_64, and arm. This patch adds the generation of rcrt1.o which is used by gcc when compiling with the --static-pie flag. rcrt1.o differs from crt1.o and Scrt1.o in that it the executable has a dynamic section but no relocations have been performed prior to _start being called. crt1.o assumes there to be no dynamic relocations, and Scrt1.o has all relocations performed prior to execution by lsdo. The new reloc_static_pie function handles parsing the dynamic section, and performing the relocations in a architecture agnostic method. It also sets _dl_load_base which is used when initalizing TLS to ensure loading from the proper location. This allows for easier porting of static-pie support to additional architectures as only modifications to crt1.S to find the load address are required. Signed-off-by: linted --- libpthread/nptl/sysdeps/generic/Makefile.in | 4 ++++ libpthread/nptl/sysdeps/generic/libc-tls.c | 4 ++++ 2 files changed, 8 insertions(+) (limited to 'libpthread') diff --git a/libpthread/nptl/sysdeps/generic/Makefile.in b/libpthread/nptl/sysdeps/generic/Makefile.in index eb656ee17..a5ba9bbe8 100644 --- a/libpthread/nptl/sysdeps/generic/Makefile.in +++ b/libpthread/nptl/sysdeps/generic/Makefile.in @@ -13,6 +13,10 @@ subdirs += libpthread/nptl/sysdeps/generic libpthread_generic_DIR := $(top_srcdir)libpthread/nptl/sysdeps/generic libpthread_generic_OUT := $(top_builddir)libpthread/nptl/sysdeps/generic +ifeq ($(STATIC_PIE),y) +CFLAGS-libc-tls.c := -DSTATIC_PIE +endif + libpthread_generic_libc_a_CSRC = libc-tls.c libpthread_generic_libc_a_COBJ = $(patsubst %.c,$(libpthread_generic_OUT)/%.o,$(libpthread_generic_libc_a_CSRC)) libpthread_generic_libc_a_OBJS = $(libpthread_generic_libc_a_COBJ) diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c index d746c9a38..0c8c558d0 100644 --- a/libpthread/nptl/sysdeps/generic/libc-tls.c +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c @@ -142,6 +142,10 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign) initimage = (void *) &__tdata_start; #else initimage = (void *) phdr->p_vaddr; +#if !defined(SHARED) && defined(STATIC_PIE) + extern ElfW(Addr) _dl_load_base; + initimage += _dl_load_base; +#endif #endif align = phdr->p_align; if (phdr->p_align > max_align) -- cgit v1.2.3