#
# HAVE_NO_PIC is not set
DOPIC=y
+# HAVE_NO_SHARED is not set
HAVE_SHARED=y
+# ARCH_HAS_NO_LDSO is not set
BUILD_UCLIBC_LDSO=y
+# UCLIBC_PIE_SUPPORT is not set
LDSO_LDD_SUPPORT=y
UCLIBC_CTOR_DTOR=y
+# UCLIBC_PROPOLICE is not set
# UCLIBC_PROFILING is not set
+# HAS_NO_THREADS is not set
UCLIBC_HAS_THREADS=y
PTHREADS_DEBUG_SUPPORT=y
UCLIBC_HAS_LFS=y
little bit smaller and guarantee that no memory will be wasted by badly
coded shared libraries.
+config UCLIBC_PIE_SUPPORT
+ bool "Support ET_DYN in shared library loader"
+ select FORCE_SHAREABLE_TEXT_SEGMENTS
+ default n
+ help
+ If you answer Y here, the uClibc native shared library loader will
+ support ET_DYN/PIE executables.
+ It requires binutils-2.14.90.0.6 or later and the usage of the
+ -pie option.
+ More about ET_DYN/PIE binaries on <http://pageexec.virtualave.net/> .
+ WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so all
+ libraries have to be built with -fPIC or -fpic, and all assembler
+ functions must be written as position independent code (PIC).
+
config LDSO_LDD_SUPPORT
bool "Native shared library loader 'ldd' support"
depends on BUILD_UCLIBC_LDSO
then you definitely want to answer Y here. If you don't need ctors
or dtors and want your binaries to be as small as possible, then
answer N.
+
+config UCLIBC_PROPOLICE
+ bool "Support for propolice stack protection"
+ default n
+ help
+ Propolice stack protection.
+ More about it on <http://www.research.ibm.com/trl/projects/security/ssp> .
+ To be able to use it, you'll also need a propolice patched gcc,
+ supporting the -fstack-protector[-all] options. It is a specially patched
+ gcc version, were __guard and __stack_smash_handler are removed from libgcc.
+ Most people will answer N.
config UCLIBC_PROFILING
bool "Support gprof profiling"
app_tpnt = LD_MALLOC(sizeof(struct elf_resolve));
_dl_memset(app_tpnt, 0, sizeof(struct elf_resolve));
+#ifdef __UCLIBC_PIE_SUPPORT__
+ /* Find the runtime load address of the main executable, this may be
+ * different from what the ELF header says for ET_DYN/PIE executables.
+ */
+ {
+ ElfW(Phdr) *ppnt;
+ int i;
+
+ ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
+ for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
+ if (ppnt->p_type == PT_PHDR) {
+ app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
+ break;
+ }
+ }
+
+#ifdef __SUPPORT_LD_DEBUG_EARLY__
+ SEND_STDERR("app_tpnt->loadaddr=");
+ SEND_ADDRESS_STDERR(app_tpnt->loadaddr, 1);
+#endif
+#endif
+
/*
* This is used by gdb to locate the chain of shared libraries that are currently loaded.
*/
ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
if (ppnt->p_type == PT_DYNAMIC) {
+#ifndef __UCLIBC_PIE_SUPPORT__
dpnt = (Elf32_Dyn *) ppnt->p_vaddr;
+#else
+ dpnt = (Elf32_Dyn *) (ppnt->p_vaddr + app_tpnt->loadaddr);
+#endif
while (dpnt->d_tag) {
#if defined(__mips__)
if (dpnt->d_tag == DT_MIPS_GOTSYM)
ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
+#ifndef __UCLIBC_PIE_SUPPORT__
_dl_mprotect((void *) (ppnt->p_vaddr & PAGE_ALIGN),
(ppnt->p_vaddr & ADDR_ALIGN) +
+#else
+ _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
+ ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
+#endif
(unsigned long) ppnt->p_filesz,
PROT_READ | PROT_WRITE | PROT_EXEC);
}
ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
if (ppnt->p_type == PT_LOAD) {
+#ifndef __UCLIBC_PIE_SUPPORT__
if (ppnt->p_vaddr + ppnt->p_memsz > brk_addr)
brk_addr = ppnt->p_vaddr + ppnt->p_memsz;
+#else
+ if (ppnt->p_vaddr + app_tpnt->loadaddr + ppnt->p_memsz > brk_addr)
+ brk_addr = ppnt->p_vaddr + app_tpnt->loadaddr + ppnt->p_memsz;
+#endif
}
if (ppnt->p_type == PT_DYNAMIC) {
#ifndef ALLOW_ZERO_PLTGOT
continue;
#endif
/* OK, we have what we need - slip this one into the list. */
+#ifndef __UCLIBC_PIE_SUPPORT__
app_tpnt = _dl_add_elf_hash_table("", 0,
app_tpnt->dynamic_info, ppnt->p_vaddr, ppnt->p_filesz);
+#else
+ app_tpnt = _dl_add_elf_hash_table("", (char *)app_tpnt->loadaddr,
+ app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
+#endif
_dl_loaded_modules->libtype = elf_executable;
_dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_ptr;
_dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
rpnt->dyn = _dl_loaded_modules;
app_tpnt->usage_count++;
app_tpnt->symbol_scope = _dl_symbol_tables;
+#ifndef __UCLIBC_PIE_SUPPORT__
lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
+#else
+ lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT] + app_tpnt->loadaddr);
+#endif
#ifdef ALLOW_ZERO_PLTGOT
if (lpnt)
#endif
#include <features.h>
#include <unistd.h>
#include <stdlib.h>
+#ifdef __UCLIBC_PROPOLICE__
+extern void __guard_setup(void);
+#endif
/*
}
#endif
+#ifdef __UCLIBC_PROPOLICE__
+ __guard_setup ();
+#endif
+
/* Note: It is possible that any initialization done above could
* have resulted in errno being set nonzero, so set it to 0 before
* we call main.
ifeq ($(strip $(UCLIBC_PROFILING)),y)
CSRC+=gmon.c
endif
+ifeq ($(strip $(UCLIBC_PROPOLICE)),y)
+CSRC+=ssp.c
+endif
COBJS=$(patsubst %.c,%.o, $(CSRC))
MSRC=syscalls.c
--- /dev/null
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#ifdef _POSIX_SOURCE
+#include <signal.h>
+#endif
+
+#if defined(HAVE_SYSLOG)
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <sys/syslog.h>
+#ifndef _PATH_LOG
+#define _PATH_LOG "/dev/log"
+#endif
+#endif
+
+long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+void __guard_setup (void)
+{
+ int fd;
+ if (__guard[0]!=0) return;
+ fd = open ("/dev/urandom", 0);
+ if (fd != -1) {
+ ssize_t size = read (fd, (char*)&__guard, sizeof(__guard));
+ close (fd) ;
+ if (size == sizeof(__guard)) return;
+ }
+ /* If a random generator can't be used, the protector switches the guard
+ to the "terminator canary" */
+ ((char*)__guard)[0] = 0; ((char*)__guard)[1] = 0;
+ ((char*)__guard)[2] = '\n'; ((char*)__guard)[3] = 255;
+}
+
+void __stack_smash_handler (char func[], int damaged)
+{
+#if defined (__GNU_LIBRARY__)
+ extern char * __progname;
+#endif
+ const char message[] = ": stack smashing attack in function ";
+ int bufsz = 512, len;
+ char buf[bufsz];
+#if defined(HAVE_SYSLOG)
+ int LogFile;
+ struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
+#endif
+#ifdef _POSIX_SOURCE
+ {
+ sigset_t mask;
+ sigfillset(&mask);
+ sigdelset(&mask, SIGABRT); /* Block all signal handlers */
+ sigprocmask(SIG_BLOCK, &mask, NULL); /* except SIGABRT */
+ }
+#endif
+
+ strcpy(buf, "<2>"); len=3; /* send LOG_CRIT */
+#if defined (__GNU_LIBRARY__)
+ strncat(buf, __progname, bufsz-len-1); len = strlen(buf);
+#endif
+ if (bufsz>len) {strncat(buf, message, bufsz-len-1); len = strlen(buf);}
+ if (bufsz>len) {strncat(buf, func, bufsz-len-1); len = strlen(buf);}
+ /* print error message */
+ write (STDERR_FILENO, buf+3, len-3);
+#if defined(HAVE_SYSLOG)
+ if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) != -1) {
+
+ /*
+ * Send "found" message to the "/dev/log" path
+ */
+ SyslogAddr.sun_family = AF_UNIX;
+ (void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
+ sizeof(SyslogAddr.sun_path) - 1);
+ SyslogAddr.sun_path[sizeof(SyslogAddr.sun_path) - 1] = '\0';
+ sendto(LogFile, buf, len, 0, (struct sockaddr *)&SyslogAddr,
+ sizeof(SyslogAddr));
+ }
+#endif
+
+#ifdef _POSIX_SOURCE
+ { /* Make sure the default handler is associated with SIGABRT */
+ struct sigaction sa;
+
+ memset(&sa, 0, sizeof(struct sigaction));
+ sigfillset(&sa.sa_mask); /* Block all signals */
+ sa.sa_flags = 0;
+ sa.sa_handler = SIG_DFL;
+ sigaction(SIGABRT, &sa, NULL);
+ (void)kill(getpid(), SIGABRT);
+ }
+#endif
+ _exit(127);
+}
+
CRT0_SRC = crt0.S
CRT0_OBJ = crt0.o crt1.o gcrt1.o
+ifeq ($(strip $(UCLIBC_PIE_SUPPORT)),y)
+CRT0_OBJ += Scrt0.o Scrt1.o
+endif
CRT0_DEPS=gmon-start.S
CTOR_TARGETS=$(TOPDIR)lib/crti.o $(TOPDIR)lib/crtn.o
ar-target: $(OBJS) $(CRT0_OBJ) $(CTOR_TARGETS)
$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
cp $(CRT0_OBJ) $(TOPDIR)lib/
+ifeq ($(strip $(UCLIBC_PIE_SUPPORT)),y)
+ifeq ($(strip $(UCLIBC_CTOR_DTOR)),y)
+ $(RM) $(TOPDIR)lib/Scrt0.o
+else
+ mv $(TOPDIR)lib/Scrt0.o $(TOPDIR)lib/Scrt1.o
+endif
+endif
$(CRT0_OBJ): $(CRT0_SRC)
$(CC) $(CFLAGS) -DL_$* $< -c -o $*.o
/* Based on the code from GNU libc, but hacked up by John Beppu and Erik Andersen */
+/* adapted by PaX Team for ET_DYN/PIE binaries */
/*
When we enter this piece of code, the program stack looks like this:
.global _start
.type _start,%function
-#if defined L_crt0 || ! defined __UCLIBC_CTOR_DTOR__
+#if defined L_crt0 || defined L_Scrt0 || ! defined __UCLIBC_CTOR_DTOR__
.type __uClibc_main,%function
#else
.weak _init
pushl %ebp /* callers %ebp (frame pointer) */
movl %esp,%ebp /* mark callers stack frame as invalid */
-#if (defined L_crt1 || defined L_gcrt1 ) && defined __UCLIBC_CTOR_DTOR__
+#if defined L_Scrt0 || defined L_Scrt1
+ call .L0
+.L0:
+ pop %edx
+ addl $_GLOBAL_OFFSET_TABLE_+[.-.L0],%edx
+#endif
+
+#if (defined L_crt1 || defined L_Scrt1 || defined L_gcrt1 ) && defined __UCLIBC_CTOR_DTOR__
/* Push .init and .fini arguments to __uClibc_start_main() on the stack */
+#ifdef L_Scrt1
+ pushl _fini@GOT(%edx)
+ pushl _init@GOT(%edx)
+#else
pushl $_fini
pushl $_init
+#endif
/* Push envp, argc, and argc arguments to __uClibc_start_main() on the stack */
pushl %eax /* Environment pointer */
pushl %ecx /* And the argument count */
/* Ok, now run uClibc's main() -- shouldn't return */
+#ifdef L_Scrt1
+ call *__uClibc_start_main@GOT(%edx)
+#else
call __uClibc_start_main
+#endif
#else
/* Push envp, argc, and argc arguments to __uClibc_start_main() on the stack */
pushl %eax /* Environment pointer */
pushl %ebx /* Argument pointer */
pushl %ecx /* And the argument count */
+#ifdef L_Scrt0
+ call *__uClibc_main@GOT(%edx)
+#else
call __uClibc_main
#endif
+#endif
/* Crash if somehow `exit' returns anyways. */
hlt
OSDN Git Service
