OSDN Git Service

- non-pic support for MIPS (Catherine Moore, clm at codesourcery com)
authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Mon, 22 Dec 2008 09:58:25 +0000 (09:58 -0000)
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Mon, 22 Dec 2008 09:58:25 +0000 (09:58 -0000)
include/elf.h
ldso/ldso/dl-hash.c
ldso/ldso/mips/dl-sysdep.h
ldso/ldso/mips/elfinterp.c
ldso/ldso/mips/resolve.S

index 4c6d090..9f00970 100644 (file)
@@ -1544,6 +1544,7 @@ typedef struct
 #define STO_MIPS_INTERNAL              0x1
 #define STO_MIPS_HIDDEN                        0x2
 #define STO_MIPS_PROTECTED             0x3
+#define STO_MIPS_PLT                   0x8
 #define STO_MIPS_SC_ALIGN_UNUSED       0xff
 
 /* MIPS specific values for `st_info'.  */
@@ -1689,8 +1690,11 @@ typedef struct
 #define R_MIPS_TLS_TPREL64     48      /* TP-relative offset, 64 bit */
 #define R_MIPS_TLS_TPREL_HI16  49      /* TP-relative offset, high 16 bits */
 #define R_MIPS_TLS_TPREL_LO16  50      /* TP-relative offset, low 16 bits */
+#define R_MIPS_GLOB_DAT                51
+#define R_MIPS_COPY            126
+#define R_MIPS_JUMP_SLOT        127
 /* Keep this the last entry.  */
-#define R_MIPS_NUM             51
+#define R_MIPS_NUM             128
 
 /* Legal values for p_type field of Elf32_Phdr.  */
 
@@ -1756,7 +1760,13 @@ typedef struct
 #define DT_MIPS_COMPACT_SIZE 0x7000002f /* (O32)Size of compact rel section. */
 #define DT_MIPS_GP_VALUE     0x70000030 /* GP value for aux GOTs.  */
 #define DT_MIPS_AUX_DYNAMIC  0x70000031 /* Address of aux .dynamic.  */
-#define DT_MIPS_NUM         0x32
+/* The address of .got.plt in an executable using the new non-PIC ABI.  */
+#define DT_MIPS_PLTGOT      0x70000032
+/* The base of the PLT in an executable using the new non-PIC ABI if that
+   PLT is writable.  For a non-writable PLT, this is omitted or has a zero
+   value.  */
+#define DT_MIPS_RWPLT        0x70000034
+#define DT_MIPS_NUM         0x35
 
 /* Legal values for DT_MIPS_FLAGS Elf32_Dyn entry.  */
 
index b44bd3a..a251aaf 100644 (file)
@@ -160,6 +160,11 @@ check_match (const ElfW(Sym) *sym, char *strtab, const char* undef_name, int typ
                /* undefined symbol itself */
                return NULL;
 
+#ifdef __mips__
+    if (sym->st_shndx == SHN_UNDEF && !(sym->st_other & STO_MIPS_PLT))
+        return NULL;
+#endif
+
        if (sym->st_value == 0)
                /* No value */
                return NULL;
index 7287792..8f303fb 100644 (file)
@@ -93,10 +93,11 @@ typedef struct
 
 #include <link.h>
 
-#define ARCH_NUM 3
+#define ARCH_NUM 4
 #define DT_MIPS_GOTSYM_IDX     (DT_NUM + OS_NUM)
 #define DT_MIPS_LOCAL_GOTNO_IDX        (DT_NUM + OS_NUM +1)
 #define DT_MIPS_SYMTABNO_IDX   (DT_NUM + OS_NUM +2)
+#define DT_MIPS_PLTGOT_IDX     (DT_NUM + OS_NUM +3)
 
 #define ARCH_DYNAMIC_INFO(dpnt,  dynamic, debug_addr) \
 do { \
@@ -106,6 +107,8 @@ else if (dpnt->d_tag == DT_MIPS_LOCAL_GOTNO) \
      dynamic[DT_MIPS_LOCAL_GOTNO_IDX] = dpnt->d_un.d_val; \
 else if (dpnt->d_tag == DT_MIPS_SYMTABNO) \
      dynamic[DT_MIPS_SYMTABNO_IDX] = dpnt->d_un.d_val; \
+else if (dpnt->d_tag == DT_MIPS_PLTGOT) \
+     dynamic[DT_MIPS_PLTGOT_IDX] = dpnt->d_un.d_val; \
 else if (dpnt->d_tag == DT_MIPS_RLD_MAP) \
      *(ElfW(Addr) *)(dpnt->d_un.d_ptr) =  (ElfW(Addr)) debug_addr; \
 } while (0)
@@ -114,6 +117,7 @@ else if (dpnt->d_tag == DT_MIPS_RLD_MAP) \
 #define INIT_GOT(GOT_BASE,MODULE)                                              \
 do {                                                                           \
        unsigned long idx;                                                      \
+       unsigned long *pltgot;                                                  \
                                                                                \
        /* Check if this is the dynamic linker itself */                        \
        if (MODULE->libtype == program_interpreter)                             \
@@ -123,6 +127,12 @@ do {                                                                               \
        GOT_BASE[0] = (unsigned long) _dl_runtime_resolve;                      \
        GOT_BASE[1] = (unsigned long) MODULE;                                   \
                                                                                \
+       pltgot = MODULE->dynamic_info[DT_MIPS_PLTGOT_IDX];                      \
+       if (pltgot) {                                                           \
+               pltgot[0] = (unsigned long) _dl_runtime_pltresolve;             \
+               pltgot[1] = (unsigned long) MODULE;                             \
+       }                                                                       \
+                                                                               \
        /* Add load address displacement to all local GOT entries */            \
        idx = 2;                                                                        \
        while (idx < MODULE->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX])             \
@@ -151,9 +161,9 @@ void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
 #define OFFS_ALIGN (0x10000000000UL-0x1000)
 #endif /* O32 || N32 */
 
-#define elf_machine_type_class(type)           ELF_RTYPE_CLASS_PLT
-/* MIPS does not have COPY relocs */
-#define DL_NO_COPY_RELOCS
+#define elf_machine_type_class(type) \
+  ((((type) == R_MIPS_JUMP_SLOT) * ELF_RTYPE_CLASS_PLT)        \
+   | (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
 
 #define OFFSET_GP_GOT 0x7ff0
 
index 1b03d94..0ed2757 100644 (file)
@@ -30,6 +30,7 @@
 #include "ldso.h"
 
 extern int _dl_runtime_resolve(void);
+extern int _dl_runtime_pltresolve(void);
 
 #define OFFSET_GP_GOT 0x7ff0
 
@@ -83,6 +84,61 @@ unsigned long __dl_runtime_resolve(unsigned long sym_index,
        return new_addr;
 }
 
+unsigned long
+__dl_runtime_pltresolve(struct elf_resolve *tpnt, int reloc_entry)
+{
+       int reloc_type;
+       ELF_RELOC *this_reloc;
+       char *strtab;
+       Elf32_Sym *symtab;
+       int symtab_index;
+       char *rel_addr;
+       char *new_addr;
+       char **got_addr;
+       unsigned long instr_addr;
+       char *symname;
+
+       rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
+       this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry);
+       reloc_type = ELF32_R_TYPE(this_reloc->r_info);
+       symtab_index = ELF32_R_SYM(this_reloc->r_info);
+
+       symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
+       strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+       symname = strtab + symtab[symtab_index].st_name;
+
+       /* Address of the jump instruction to fix up. */
+       instr_addr = ((unsigned long)this_reloc->r_offset +
+                     (unsigned long)tpnt->loadaddr);
+       got_addr = (char **)instr_addr;
+
+       /* Get the address of the GOT entry. */
+       new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
+       if (unlikely(!new_addr)) {
+               _dl_dprintf(2, "%s: can't resolve symbol '%s' in lib '%s'.\n", _dl_progname, symname, tpnt->libname);
+               _dl_exit(1);
+       }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+       if ((unsigned long)got_addr < 0x40000000) {
+               if (_dl_debug_bindings) {
+                       _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
+                       if (_dl_debug_detail)
+                               _dl_dprintf(_dl_debug_file,
+                                           "\n\tpatched: %x ==> %x @ %x",
+                                           *got_addr, new_addr, got_addr);
+               }
+       }
+       if (!_dl_debug_nofixups) {
+               *got_addr = new_addr;
+       }
+#else
+       *got_addr = new_addr;
+#endif
+
+       return (unsigned long)new_addr;
+}
+
 void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
        unsigned long rel_addr, unsigned long rel_size)
 {
@@ -115,6 +171,7 @@ int _dl_parse_relocation_information(struct dyn_elf *xpnt,
        got = (unsigned long *) tpnt->dynamic_info[DT_PLTGOT];
 
        for (i = 0; i < rel_size; i++, rpnt++) {
+               char *symname = NULL;
                reloc_addr = (unsigned long *) (tpnt->loadaddr +
                        (unsigned long) rpnt->r_offset);
                reloc_type = ELF_R_TYPE(rpnt->r_info);
@@ -128,6 +185,16 @@ int _dl_parse_relocation_information(struct dyn_elf *xpnt,
                        old_val = *reloc_addr;
 #endif
 
+               if (reloc_type == R_MIPS_JUMP_SLOT || reloc_type == R_MIPS_COPY) {
+                       symname = strtab + symtab[symtab_index].st_name;
+                       symbol_addr = (unsigned long)_dl_find_hash(symname,
+                                                                  tpnt->symbol_scope,
+                                                                  tpnt,
+                                                                  elf_machine_type_class(reloc_type));
+                       if (unlikely(!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK))
+                               return 1;
+               }
+
                switch (reloc_type) {
 #if _MIPS_SIM == _MIPS_SIM_ABI64
                case (R_MIPS_64 << 8) | R_MIPS_REL32:
@@ -148,6 +215,24 @@ int _dl_parse_relocation_information(struct dyn_elf *xpnt,
                                *reloc_addr += (unsigned long) tpnt->loadaddr;
                        }
                        break;
+               case R_MIPS_JUMP_SLOT:
+                       *reloc_addr = symbol_addr;
+                       break;
+               case R_MIPS_COPY:
+                       if (symbol_addr) {
+#if defined (__SUPPORT_LD_DEBUG__)
+                               if (_dl_debug_move)
+                                       _dl_dprintf(_dl_debug_file,
+                                                   "\n%s move %d bytes from %x to %x",
+                                                   symname, symtab[symtab_index].st_size,
+                                                   symbol_addr, reloc_addr);
+#endif
+
+                               _dl_memcpy((char *)reloc_addr,
+                                          (char *)symbol_addr,
+                                          symtab[symtab_index].st_size);
+                       }
+                       break;
                case R_MIPS_NONE:
                        break;
                default:
index f5d988a..d7951a1 100644 (file)
@@ -112,3 +112,54 @@ _dl_runtime_resolve:
 .end   _dl_runtime_resolve
 .previous
 
+/* Assembler veneer called from the PLT header code when using the
+   non-PIC ABI.
+
+   Code in each PLT entry puts the caller's return address into t7 ($15),
+   the PLT entry index into t8 ($24), the address of _dl_runtime_pltresolve
+   into t9 ($25) and the address of .got.plt into gp ($28).  __dl_runtime_pltresolve
+   needs a0 ($4) to hold the link map and a1 ($5) to hold the index into
+   .rel.plt (== PLT entry index * 4).  */
+
+       .text
+       .align  2
+       .globl  _dl_runtime_pltresolve
+       .type   _dl_runtime_pltresolve,@function
+       .ent    _dl_runtime_pltresolve
+_dl_runtime_pltresolve:
+       .frame  $29, 40, $31
+       .set noreorder
+       # Save arguments and sp value in stack.
+       subu    $29, 40
+       lw      $10, 4($28)
+       # Modify t9 ($25) so as to point .cpload instruction.
+       addiu   $25, 12
+       # Compute GP.
+       .cpload $25
+       .set reorder
+
+       /* Store function arguments from registers to stack */
+       sw      $15, 36($29)
+       sw      $4, 16($29)
+       sw      $5, 20($29)
+       sw      $6, 24($29)
+       sw      $7, 28($29)
+
+       /* Setup functions args and call __dl_runtime_pltresolve.  */
+       move    $4, $10
+       sll     $5, $24, 3
+       jal     __dl_runtime_pltresolve
+
+       /* Restore function arguments from stack to registers */
+       lw      $31, 36($29)
+       lw      $4, 16($29)
+       lw      $5, 20($29)
+       lw      $6, 24($29)
+       lw      $7, 28($29)
+
+       /* Do a tail call to the original function */
+       addiu   $29, 40
+       move    $25, $2
+       jr      $25
+       .end    _dl_runtime_pltresolve
+       .previous