- Invert all FORCE_SHAREABLE_TEXT_SEGMENTS checks.
- Define FORCE_SHAREABLE_TEXT_SEGMENTS in the Makefile,
so it can be configured by the config system.
- linuxelf.h inspects that we don't combine FORCE_SHAREABLE_TEXT_SEGMENTS
and SVR4_BUGCOMPAT
- Add a new config option for FORCE_SHAREABLE_TEXT_SEGMENTS
be built for your target architecture. If this option is available,
to you, then you almost certainly want to answer Y.
+config FORCE_SHAREABLE_TEXT_SEGMENTS
+ bool "Only load shared libraries which can share their text segment"
+ depends on BUILD_UCLIBC_LDSO && UCLIBC_COMPLETELY_PIC
+ default n
+ help
+ If you answer Y here, the uClibc native shared library loader will
+ only load shared libraries, which do not need to modify any non-writable
+ segments. These libraries haven't set the DT_TEXTREL tag in the dynamic
+ section (==> objdump). So all your libraries must be compiled with
+ -fPIC or -fpic, and all assembler function must be written as position
+ independend code (PIC).
+ Enabling this option will makes uClibc's shared library loader a
+ little bit smaller and guarantee that no memory will be wasted by badly
+ coded shared libraries.
+
config LDSO_LDD_SUPPORT
bool "Native shared library loader 'ldd' support"
depends on BUILD_UCLIBC_LDSO
bool
default y
+config UCLIBC_COMPLETELY_PIC
+ bool
+ default y
+
choice
prompt "Target Processor Type"
default CONFIG_SH4
XXFLAGS+=-D__SUPPORT_LD_DEBUG_EARLY__
endif
+ifeq ($(strip $(FORCE_SHAREABLE_TEXT_SEGMENTS)),y)
+XXFLAGS+=-DFORCE_SHAREABLE_TEXT_SEGMENTS
+endif
all: lib
back again later. */
if (dynamic_info[DT_TEXTREL]) {
-#ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+#ifndef FORCE_SHAREABLE_TEXT_SEGMENTS
ppnt = (elf_phdr *)(intptr_t) & header[epnt->e_phoff];
for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
* SUCH DAMAGE.
*/
-/* Enable mprotect protection munging. ARM and MIPS Linux needs this
- * it seems, so leave this enabled by default */
-#define FORCE_SHAREABLE_TEXT_SEGMENTS
-
// Support a list of library preloads in /etc/ld.so.preload
//#define SUPPORT_LDSO_PRELOAD_FILE
}
app_tpnt->dynamic_info[dpnt->d_tag] = dpnt->d_un.d_val;
if (dpnt->d_tag == DT_DEBUG)
-#ifndef FORCE_SHAREABLE_TEXT_SEGMENTS
+#ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
dpnt->d_un.d_val = (unsigned long) debug_addr;
#else
dpnt_debug = dpnt;
tpnt->elf_buckets = hash_addr;
hash_addr += tpnt->nbucket;
-#ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+#ifndef FORCE_SHAREABLE_TEXT_SEGMENTS
/* Ugly, ugly. We need to call mprotect to change the protection of
the text pages so that we can do the dynamic linking. We can set the
protection back again once we are done */
*_dl_envp = (unsigned long) envp;
}
-#ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+#ifndef FORCE_SHAREABLE_TEXT_SEGMENTS
{
unsigned int j;
elf_phdr *myppnt;
#ifndef SVR4_BUGCOMPAT
-#define SVR4_BUGCOMPAT 1
+# ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+# define SVR4_BUGCOMPAT 0
+# else
+# define SVR4_BUGCOMPAT 1
+# endif
+#else
+# ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+# error option SVR4_BUGCOMPAT combined with option FORCE_SHAREABLE_TEXT_SEGMENTS makes no sense
+# endif
#endif
#if ELF_CLASS == ELFCLASS32
back again later. */
if (dynamic_info[DT_TEXTREL]) {
-#ifdef FORCE_SHAREABLE_TEXT_SEGMENTS
+#ifndef FORCE_SHAREABLE_TEXT_SEGMENTS
ppnt = (elf_phdr *)(intptr_t) & header[epnt->e_phoff];
for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))