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-rw-r--r--libc/Makefile4
-rw-r--r--libc/misc/internals/__uClibc_main.c167
-rw-r--r--libc/sysdeps/linux/arm/crt0.S28
-rw-r--r--libc/sysdeps/linux/i386/crt0.S27
-rw-r--r--libc/sysdeps/linux/mips/crt0.S17
-rw-r--r--libc/sysdeps/linux/sh/crt0.S49
6 files changed, 185 insertions, 107 deletions
diff --git a/libc/Makefile b/libc/Makefile
index 401a56695..1809779d6 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -53,9 +53,9 @@ shared: $(TOPDIR)lib/$(LIBNAME)
/bin/sh $(TOPDIR)../extra/scripts/get-needed-libgcc-objects.sh)
$(LD) $(LDFLAGS) $(VERSION_SCRIPT) -soname=$(SHARED_MAJORNAME) -o $(SHARED_FULLNAME) \
--whole-archive ./tmp/libgcc-need.a $(LIBNAME) --no-whole-archive \
- $(TOPDIR)/libc/misc/internals/interp.o \
+ -init __uClibc_init $(TOPDIR)/libc/misc/internals/interp.o \
$(LIBGCC)
- @/bin/true #rm -rf tmp
+ @true #rm -rf tmp
install -d $(TOPDIR)lib
rm -f $(TOPDIR)lib/$(SHARED_FULLNAME)
install -m 644 $(SHARED_FULLNAME) $(TOPDIR)lib
diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c
index 53f897d9f..aa4655cec 100644
--- a/libc/misc/internals/__uClibc_main.c
+++ b/libc/misc/internals/__uClibc_main.c
@@ -20,8 +20,6 @@
* Prototypes.
*/
extern int main(int argc, char **argv, char **envp);
-extern void weak_function _init(void);
-extern void weak_function _fini(void);
extern void weak_function _stdio_init(void);
extern int *weak_const_function __errno_location(void);
extern int *weak_const_function __h_errno_location(void);
@@ -36,10 +34,11 @@ extern void weak_function __pthread_initialize_minimal(void);
+
/*
* Declare the __environ global variable and create a weak alias environ.
- * Note: Apparently we must initialize __environ for the weak environ
- * symbol to be included.
+ * Note: Apparently we must initialize __environ to ensure that the weak
+ * environ symbol is also included.
*/
char **__environ = 0;
@@ -47,68 +46,124 @@ weak_alias(__environ, environ);
+/* __uClibc_init completely initialize uClibc so it is ready to use.
+ *
+ * On ELF systems (with a dynamic loader) this function must be called
+ * from the dynamic loader (see TIS and ELF Specification), so that
+ * constructors of shared libraries (which depend on libc) can use all
+ * the libc code without restriction. For this we link the shared
+ * version of the uClibc with -init __uClibc_init so DT_INIT for
+ * uClibc is the address of __uClibc_init
+ *
+ * In all other cases we call it from the main stub
+ * __uClibc_start_main.
+ */
-void __attribute__ ((__noreturn__))
-__uClibc_main(int argc, char **argv, char **envp)
+void __uClibc_init(void)
{
- /* If we are dynamically linked the shared lib loader
- * already did this for us. But if we are statically
- * linked, we need to do this for ourselves. */
- if (__environ==NULL) {
- /* Statically linked. */
- __environ = envp;
- }
+ static int been_there_done_that = 0;
+
+ if (been_there_done_that)
+ return;
+ been_there_done_that++;
#ifdef __UCLIBC_HAS_THREADS__
- if (likely(__pthread_initialize_minimal!=NULL))
- __pthread_initialize_minimal();
+ /* Before we start initialzing uClibc we have to call
+ * __pthread_initialize_minimal so we can use pthread_locks
+ * whenever they are needed.
+ */
+ if (likely(__pthread_initialize_minimal!=NULL))
+ __pthread_initialize_minimal();
#endif
#if 0
- /* Some security at this point. Prevent starting a SUID binary
- * where the standard file descriptors are not opened. We have
- * to do this only for statically linked applications since
- * otherwise the dynamic loader did the work already. */
- if (unlikely (__libc_enable_secure!=NULL))
- __libc_check_standard_fds ();
+ /* Some security at this point. Prevent starting a SUID binary
+ * where the standard file descriptors are not opened. We have
+ * to do this only for statically linked applications since
+ * otherwise the dynamic loader did the work already. */
+ if (unlikely (__libc_enable_secure!=NULL))
+ __libc_check_standard_fds ();
#endif
#ifdef __UCLIBC_HAS_LOCALE__
- /* Initialize the global locale structure. */
- if (likely(_locale_init!=NULL))
- _locale_init();
+ /* Initialize the global locale structure. */
+ if (likely(_locale_init!=NULL))
+ _locale_init();
#endif
- /*
- * Initialize stdio here. In the static library case, this will
- * be bypassed if not needed because of the weak alias above.
- */
- if (likely(_stdio_init != NULL))
- _stdio_init();
-
- /* Arrange for dtors to run at exit. */
- if (likely(_fini!=NULL && atexit)) {
- atexit (&_fini);
- }
-
- /* Run all ctors now. */
- if (likely(_init!=NULL))
- _init();
-
- /*
- * 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.
- */
- if (likely(__errno_location!=NULL))
- *(__errno_location()) = 0;
-
- /* Set h_errno to 0 as well */
- if (likely(__h_errno_location!=NULL))
- *(__h_errno_location()) = 0;
-
- /*
- * Finally, invoke application's main and then exit.
- */
- exit(main(argc, argv, envp));
+ /*
+ * Initialize stdio here. In the static library case, this will
+ * be bypassed if not needed because of the weak alias above.
+ */
+ if (likely(_stdio_init != NULL))
+ _stdio_init();
+
+}
+
+
+/* __uClibc_start_main is the new main stub for uClibc. This function is
+ * called from crt0 (version 0.9.16 or newer), after ALL shared libraries
+ * are initialized, just before we call the application's main function.
+ */
+void __attribute__ ((__noreturn__))
+__uClibc_start_main(int argc, char **argv, char **envp,
+ void (*app_init)(void), void (*app_fini)(void))
+{
+
+ /* If we are dynamically linked the shared lib loader already
+ * did this for us. But if we are statically linked, we need
+ * to do this for ourselves. */
+ if (__environ==NULL) {
+ /* Statically linked. */
+ __environ = envp;
+ }
+
+ /* We need to initialize uClibc. If we are dynamically linked this
+ * may have already been completed by the shared lib loader. We call
+ * __uClibc_init() regardless, to be sure the right thing happens. */
+ __uClibc_init();
+
+ /* Arrange for the application's dtors to run before we exit. */
+ if (app_fini!=NULL && atexit) {
+ atexit (app_fini);
+ }
+
+ /* Run all the application's ctors now. */
+ if (app_init!=NULL) {
+ app_init();
+ }
+
+ /* 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.
+ */
+ if (likely(__errno_location!=NULL))
+ *(__errno_location()) = 0;
+
+ /* Set h_errno to 0 as well */
+ if (likely(__h_errno_location!=NULL))
+ *(__h_errno_location()) = 0;
+
+ /*
+ * Finally, invoke application's main and then exit.
+ */
+ exit(main(argc, argv, envp));
+}
+
+
+/* __uClibc_main is the old main stub of the uClibc. This
+ * function is called from crt0 (uClibc 0.9.15 and older) after
+ * ALL shared libraries are initialized, and just before we call
+ * the application's main() function.
+ *
+ * Attention: This stub does not call the .init/.fini sections of
+ * the application. If you need this, please fix your uClibc port
+ * so that __uClibc_start_main is called by your crt0.S with
+ * _init and _fini properly set.
+*/
+void __attribute__ ((__noreturn__))
+__uClibc_main(int argc, char **argv, char ** envp)
+{
+ __uClibc_start_main(argc, argv, envp, NULL, NULL);
}
+
diff --git a/libc/sysdeps/linux/arm/crt0.S b/libc/sysdeps/linux/arm/crt0.S
index 442c9e84b..dc0ec87d8 100644
--- a/libc/sysdeps/linux/arm/crt0.S
+++ b/libc/sysdeps/linux/arm/crt0.S
@@ -50,20 +50,10 @@ ARM register quick reference:
.text
.global _start
- .global __uClibc_main
-
.type _start,%function
- .type __uClibc_main,%function
.text
_start:
-#if 0 /* some old code the I feel should not be here - davidm */
- @ adjust the data segment base pointer
- ldr r3,=__data_start
- sub sl,sl,r3
- mov BASEREG,sl
-#endif
-
/* clear the frame pointer */
mov fp, #0
@@ -78,10 +68,11 @@ _start:
we find there (hopefully the environment) in r2 */
add r2, r1, r0, lsl #2
add r2, r2, #4
+
#else
/*
- * uClinux stacks look a little different to MMU stacks
- * for no good reason
+ * uClinux stacks look a little different from normal
+ * MMU-full Linux stacks (for no good reason)
*/
/* pull argc, argv and envp off the stack */
ldr r0,[sp, #0]
@@ -89,8 +80,19 @@ _start:
ldr r2,[sp, #8]
#endif
+ /* Store the address of _init in r3 as an argument to main() */
+ ldr r3, =_init
+
+ /* Push _fini onto the stack as the final argument to main() */
+ stmfd sp!, {r0}
+ ldr a1, =_fini
+ stmfd sp!, {r0}
+
/* Ok, now run uClibc's main() -- shouldn't return */
- bl __uClibc_main
+ bl __uClibc_start_main
+
+ /* Crash if somehow `exit' returns anyways. */
+ bl abort
/* Stick in a dummy reference to main(), so that if an application
* is linking when the main() function is in a static library (.a)
diff --git a/libc/sysdeps/linux/i386/crt0.S b/libc/sysdeps/linux/i386/crt0.S
index 3623fe821..97f1fde63 100644
--- a/libc/sysdeps/linux/i386/crt0.S
+++ b/libc/sysdeps/linux/i386/crt0.S
@@ -33,11 +33,11 @@ Cambridge, MA 02139, USA. */
.text
.align 4
-.globl _start
- .type _start,@function
+ .globl _start
+ .type _start,@function
_start:
- /* First locate the start of the environment variables */
+ /* locate the start of the environment variables */
popl %ecx /* Store argc into %ecx */
movl %esp,%ebx /* Store argv into ebx */
movl %esp,%eax /* Store argv into eax as well*/
@@ -52,7 +52,6 @@ _start:
%eax = env ; argv + (argc * 4) + 4
*/
-
/* Set up an invalid (NULL return address, NULL frame pointer)
callers stack frame so anybody unrolling the stack knows where
to stop */
@@ -62,20 +61,18 @@ _start:
pushl %ebp /* callers %ebp (frame pointer) */
movl %esp,%ebp /* mark callers stack frame as invalid */
- /* Now set the environment, argc, and argv where the app can get to them */
- pushl %eax /* Environment pointer */
- pushl %ebx /* Argument pointer */
- pushl %ecx /* And the argument count */
+ /* Push .init and .fini arguments to __uClibc_start_main() on the stack */
+ pushl $_fini
+ pushl $_init
-#if 0
- /* Make sure we are not using iBCS2 personality. (i.e. force linux). */
- movl $136,%eax
- sub %ebx,%ebx
- int $0x80
-#endif
+ /* 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 */
/* Ok, now run uClibc's main() -- shouldn't return */
- call __uClibc_main
+ call __uClibc_start_main
+
/* Crash if somehow `exit' returns anyways. */
hlt
diff --git a/libc/sysdeps/linux/mips/crt0.S b/libc/sysdeps/linux/mips/crt0.S
index 6770ab0b1..7ff3b253f 100644
--- a/libc/sysdeps/linux/mips/crt0.S
+++ b/libc/sysdeps/linux/mips/crt0.S
@@ -30,9 +30,22 @@ __start:
addu a2, a0, 1 /* load envp */
sll a2, a2, 2
add a2, a2, a1
+
+ /* Store the address of _init in a3 as an argument to __uClibc_start_main() */
+ la a3, _init
+
+ /* Push _fini onto the stack as the final argument to __uClibc_start_main()
+ I don't think I am doing this properly but it at least compiles...
+ */
+ la t0, _fini
+ sw t0,16(sp)
+
/* Ok, now run uClibc's main() -- shouldn't return */
- jal __uClibc_main
- hlt: b hlt /* Crash if somehow it does return. */
+ jal __uClibc_start_main
+
+ /* Crash if somehow `exit' returns anyways. */
+hlt:
+ b hlt
/* Stick in a dummy reference to main(), so that if an application
* is linking when the main() function is in a static library (.a)
diff --git a/libc/sysdeps/linux/sh/crt0.S b/libc/sysdeps/linux/sh/crt0.S
index 10915d545..e74ae86c4 100644
--- a/libc/sysdeps/linux/sh/crt0.S
+++ b/libc/sysdeps/linux/sh/crt0.S
@@ -26,13 +26,6 @@
At this entry point, most registers' values are unspecified, except:
- r4 Contains a function pointer to be registered with `atexit'.
- This is how the dynamic linker arranges to have DT_FINI
- functions called for shared libraries that have been loaded
- before this code runs.
- WARNING: At that stage only static linker is supported. For
- uCLinux we won't bother with r4.
-
sp The stack contains the arguments and environment:
0(sp) argc
4(sp) argv[0]
@@ -42,18 +35,26 @@
...
NULL
*/
+ .file "crt0.S"
.text
.globl _start
.type _start,@function
.size _start,_start_end - _start
_start:
- /* Clear the frame pointer since this is the outermost frame. (in delay slot) */
+ /* Clear the frame pointer since this is the outermost frame. */
mov #0, r14
/* Pop argc off the stack and save a pointer to argv */
mov.l @r15+,r4
mov r15, r5
+ /* Push the finip argument to __uClibc_start_main() onto the stack */
+ mov.l L_fini,r6
+ mov.l r6,@-r15
+
+ /* Setup the value for the initp argument */
+ mov.l L_init, r7
+
/*
* Setup the value for the environment pointer:
* r6 = (argc + 1) * 4
@@ -62,27 +63,39 @@ _start:
mov r4,r6
add #1,r6
shll2 r6
- add r5,r6
- /* call main */
+ /* jump to __uClibc_start_main (argc, argv, envp, app_init, app_fini) */
mov.l L_main, r0
jsr @r0
- nop /* delay slot */
-
+ add r5, r6 /* delay slot */
/* We should not get here. */
mov.l L_abort, r0
- jsr @r0
- nop /* delay slot */
+ jmp @r0
+ nop
_start_end:
.align 2
+ .weak _init
+ .type _init,@function
+_init:
+ rts
+ nop
+
+.Lfe1:
+ .size _init,.Lfe1-_init
+ .weak _fini
+ .set _fini,_init
L_main:
- .long __uClibc_main
+ .long __uClibc_start_main /* in libuClibc.*.so */
-L_abort:
- .long abort
+L_init:
+ .long _init
+L_fini:
+ .long _fini
+L_abort:
+ .long abort
/* Stick in a dummy reference to main(), so that if an application
* is linking when the main() function is in a static library (.a)
@@ -90,5 +103,3 @@ L_abort:
L_dummy_main_reference:
.long main
- .data
-