Patch from Steven J. Hill <sjhill@realitydiluted.com>:

    I am very pleased to announce that the MIPS dynamic linker/loader
    for uClibc is now working. It works on big and little endian
    platforms.

A few minor changes were needed to avoid breaking ldd, and since this
makes some non-trivial changes, I have tested on x86, arm, and powerpc
to be sure thoese arches didn't get broken.  Excellent work Steven!

1 files changed, 117 insertions, 58 deletions

diff --git a/ldso/ldso/mips/dl-sysdep.h b/ldso/ldso/mips/dl-sysdep.h
index 8bc6aaccd..f54e812b7 100644
--- a/ldso/ldso/mips/dl-sysdep.h
+++ b/ldso/ldso/mips/dl-sysdep.h
@@ -1,5 +1,7 @@
+/* vi: set sw=4 ts=4: */
+
 /*
- * Various assmbly language/system dependent  hacks that are required
+ * Various assmbly language/system dependent hacks that are required
  * so that we can minimize the amount of platform specific code.
  */
 
@@ -20,46 +22,102 @@
 /*
  * Initialization sequence for the application GOT.
  */
-#define INIT_GOT(GOT_BASE,MODULE)	_dl_init_got(GOT_BASE,MODULE)
+#define INIT_GOT(GOT_BASE,MODULE)										\
+do {																	\
+	Elf32_Sym *sym;														\
+	char *strtab;														\
+	unsigned long i;													\
+																		\
+	/* Check if this is the dynamic linker itself */					\
+	if (MODULE->libtype == program_interpreter)							\
+		continue;														\
+																		\
+	/* Fill in first two GOT entries according to the ABI */			\
+	GOT_BASE[0] = (unsigned long) _dl_linux_resolve;					\
+	GOT_BASE[1] = (unsigned long) MODULE;								\
+																		\
+	/* Add load address displacement to all local GOT entries */		\
+	i = 2;																\
+	while (i < MODULE->mips_local_gotno)								\
+		GOT_BASE[i++] += (unsigned long) MODULE->loadaddr;				\
+																		\
+	/* Handle global GOT entries */										\
+	GOT_BASE += MODULE->mips_local_gotno;								\
+	sym = (Elf32_Sym *) (MODULE->dynamic_info[DT_SYMTAB] +				\
+		(unsigned long) MODULE->loadaddr) + MODULE->mips_gotsym;		\
+	strtab = (char *) (MODULE->dynamic_info[DT_STRTAB] +				\
+		(unsigned long) MODULE->loadaddr);								\
+	i = MODULE->mips_symtabno - MODULE->mips_gotsym;					\
+	while (i--) {														\
+		if (sym->st_shndx == SHN_UNDEF) {								\
+			if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&				\
+				sym->st_value)											\
+				*GOT_BASE = sym->st_value +								\
+					(unsigned long) MODULE->loadaddr;					\
+			else {														\
+				*GOT_BASE = (unsigned long) _dl_find_hash(strtab +		\
+					sym->st_name, MODULE->symbol_scope, NULL, 0);		\
+			}															\
+		}																\
+		else if (sym->st_shndx == SHN_COMMON) {							\
+			*GOT_BASE = (unsigned long) _dl_find_hash(strtab +			\
+				sym->st_name, MODULE->symbol_scope, NULL, 0);			\
+		}																\
+		else if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&				\
+			*GOT_BASE != sym->st_value)									\
+			*GOT_BASE += (unsigned long) MODULE->loadaddr;				\
+		else if (ELF32_ST_TYPE(sym->st_info) == STT_SECTION) {			\
+			if (sym->st_other == 0)										\
+				*GOT_BASE += (unsigned long) MODULE->loadaddr;			\
+		}																\
+		else {															\
+			*GOT_BASE = (unsigned long) _dl_find_hash(strtab +			\
+				sym->st_name, MODULE->symbol_scope, NULL, 0);			\
+		}																\
+																		\
+		++GOT_BASE;														\
+		++sym;															\
+	}																	\
+} while (0)
 
 
 /*
- * Here is a macro to perform the GOT relocation.  This is only
+ * Here is a macro to perform the GOT relocation. This is only
  * used when bootstrapping the dynamic loader.
  */
-#define PERFORM_BOOTSTRAP_GOT(got)					\
-do {									\
-	Elf32_Sym *sym;							\
-	unsigned long i;						\
-									\
-	/* Add load address displacement to all local GOT entries */	\
-	i = 2;								\
-	while (i < mips_local_gotno)					\
-		got[i++] += load_addr;					\
-									\
-	/* Handle global GOT entries */					\
-	got += mips_local_gotno;					\
-	sym = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] +		\
-		 load_addr) + mips_gotsym;				\
-	i = mips_symtabno - mips_gotsym;				\
-									\
-	while (i--) {							\
-		if (sym->st_shndx == SHN_UNDEF ||			\
-			sym->st_shndx == SHN_COMMON)			\
-			*got = load_addr + sym->st_value;		\
-		else if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&	\
-			*got != sym->st_value)				\
-			*got += load_addr;				\
-		else if (ELF32_ST_TYPE(sym->st_info) == STT_SECTION) {	\
-			if (sym->st_other == 0)				\
-				*got += load_addr;			\
-		}							\
-		else							\
-			*got = load_addr + sym->st_value;		\
-									\
-		got++;							\
-		sym++;							\
-	}								\
+#define PERFORM_BOOTSTRAP_GOT(got)										\
+do {																	\
+	Elf32_Sym *sym;														\
+	unsigned long i;													\
+																		\
+	/* Add load address displacement to all local GOT entries */		\
+	i = 2;																\
+	while (i < tpnt->mips_local_gotno)									\
+		got[i++] += load_addr;											\
+																		\
+	/* Handle global GOT entries */										\
+	got += tpnt->mips_local_gotno;										\
+	sym = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] +				\
+		 load_addr) + tpnt->mips_gotsym;								\
+	i = tpnt->mips_symtabno - tpnt->mips_gotsym;						\
+																		\
+	while (i--) {														\
+		if (sym->st_shndx == SHN_UNDEF ||								\
+			sym->st_shndx == SHN_COMMON)								\
+			*got = load_addr + sym->st_value;							\
+		else if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&				\
+			*got != sym->st_value)										\
+			*got += load_addr;											\
+		else if (ELF32_ST_TYPE(sym->st_info) == STT_SECTION) {			\
+			if (sym->st_other == 0)										\
+				*got += load_addr;										\
+		}																\
+		else															\
+			*got = load_addr + sym->st_value;							\
+																		\
+		got++;															\
+		sym++;															\
+	}																	\
 } while (0)
 
 
@@ -67,31 +125,33 @@ do {									\
  * Here is a macro to perform a relocation.  This is only used when
  * bootstrapping the dynamic loader.
  */
-#define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD)			\
-	switch(ELF32_R_TYPE((RELP)->r_info)) {				\
-	case R_MIPS_REL32:						\
-		if (symtab_index) {					\
-			if (symtab_index < mips_gotsym)			\
-				*REL += SYMBOL + LOAD;			\
-		}							\
-		else {							\
-			*REL += LOAD;					\
-		}							\
-		break;							\
-	case R_MIPS_NONE:						\
-		break;							\
-	default:							\
-		SEND_STDERR("Aiieeee!");				\
-		_dl_exit(1);						\
+#define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD)					\
+	switch(ELF32_R_TYPE((RELP)->r_info)) {								\
+	case R_MIPS_REL32:													\
+		if (symtab_index) {												\
+			if (symtab_index < tpnt->mips_gotsym)						\
+				*REL += SYMBOL;											\
+		}																\
+		else {															\
+			*REL += LOAD;												\
+		}																\
+		break;															\
+	case R_MIPS_NONE:													\
+		break;															\
+	default:															\
+		SEND_STDERR("Aiieeee!");										\
+		_dl_exit(1);													\
 	}
 
 
 /*
  * Transfer control to the user's application, once the dynamic loader
  * is done.  This routine has to exit the current function, then 
- * call the _dl_elf_main function.
+ * call the _dl_elf_main function. For MIPS, we do it in assembly
+ * because the stack doesn't get properly restored otherwise. Got look
+ * at boot1_arch.h
  */
-#define START()   return (void) _dl_elf_main;      
+#define START()
 
 
 /* Here we define the magic numbers that this dynamic loader should accept */
@@ -103,9 +163,8 @@ do {									\
 #define ELF_TARGET "MIPS"
 
 
-struct elf_resolve;
-extern unsigned long _dl_linux_resolver(struct elf_resolve * tpnt,
-	int reloc_entry);
-void _dl_init_got(unsigned long *got, struct elf_resolve *tpnt);
+unsigned long _dl_linux_resolver(unsigned long sym_index,
+	unsigned long old_gpreg);
+
 
 #define do_rem(result, n, base)  result = (n % base)