Merge "[MIPS64] Dynamic linker"

libc/Android.mk

@@ -622,6 +622,10 @@ ifeq ($(TARGET_ARCH),$(filter $(TARGET_ARCH),mips mips64))
   libc_common_cflags += -fstrict-aliasing
   libc_crt_target_cflags += $(TARGET_GLOBAL_CFLAGS)
 endif # mips
+ifeq ($(TARGET_ARCH),mips64)
+  libc_crt_target_ldflags := -melf64ltsmip
+endif
+
 
 ifeq ($(TARGET_ARCH),x86)
   libc_crt_target_cflags += -m32

linker/arch/mips64/begin.S

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+#define ELF_DYNSZ       8
+#define ELF_DYN_TAG     0
+#define ELF_DYN_VAL     4
+#define GOTENT_SZ       4
+#else
+#define ELF_DYNSZ       16
+#define ELF_DYN_TAG     0
+#define ELF_DYN_VAL     8
+#define GOTENT_SZ       8
+#endif
+
+    .text
+    .align	4
+    .type	__start,@function
+
+    .ent	__start
+    .globl	__start
+__start:
+    .set	noreorder
+    bal		1f
+     nop
+1:
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    .cpload	ra
+#else
+    .cpsetup	ra, $0, 1b
+#endif
+    .set	reorder
+
+    /* Discover the load address */
+    LA		t0, 1b
+    PTR_SUBU	t0, ra, t0
+
+#define DT_PLTGOT 3
+#define DT_MIPS_LOCAL_GOTNO 0x7000000a
+
+    /* Search dynamic table for DT_MIPS_LOCAL_GOTNO and DT_PLTGOT values */
+    LA		t1, _DYNAMIC
+    PTR_ADDU	t1, t0
+    LI		t3, DT_PLTGOT
+    LI		ta0, DT_MIPS_LOCAL_GOTNO
+0:
+    REG_L	t2, ELF_DYN_TAG(t1)
+    beqz	t2, .Lrelocate_local_got
+
+    bne		t2, t3, 1f	/* DT_PLTGOT? */
+    REG_L	s0, ELF_DYN_VAL(t1)
+    PTR_ADDU	s0, t0
+    b		2f
+
+1:
+    bne		t2, ta0, 2f    /* DT_MIPS_LOCAL_GOTNO? */
+    REG_L	s1, ELF_DYN_VAL(t1)
+
+2:  PTR_ADDU    t1, ELF_DYNSZ
+    b		0b
+
+.Lrelocate_local_got:
+    /*
+     * Relocate the local GOT entries
+     * got[0] is address of lazy resolver function
+     * got[1] may be used for a GNU extension
+     */
+
+    PTR_ADDU	s0, GOTENT_SZ
+    SUBU	s1, 1
+    PTR_L	t1, (s0)
+    bgez	t1, 9f
+    PTR_ADDU	s0, GOTENT_SZ
+    SUBU	s1, 1
+    b		9f
+
+1:  PTR_L	t1, (s0)
+    PTR_ADDU	t1, t0
+    PTR_S	t1, (s0)
+    PTR_ADDU	s0, GOTENT_SZ
+9:  SUBU	s1, 1
+    bgez	s1, 1b
+
+    /* call linker_init */
+    move	a0, sp
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    PTR_SUBU	sp, 4*REGSZ       /* space for arg saves in linker_init */
+#endif
+    jal		__linker_init
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    PTR_ADDU	sp, 4*REGSZ        /* restore sp */
+#endif
+    move	t9, v0
+    j		t9
+    .end    __start
+
+/* FIXME:Is this still needed? */
+    .section .ctors, "wa"
+    .globl __CTOR_LIST__
+__CTOR_LIST__:
+    .long -1

linker/dlfcn.cpp

@@ -178,7 +178,7 @@ int dlclose(void* handle) {
 #  define ANDROID_LIBDL_STRTAB \
     "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0"
 #else
-#  error Unsupported architecture. Only arm, arm64, mips, x86, and x86_64 are presently supported.
+#  error Unsupported architecture. Only arm, arm64, mips, mips64, x86 and x86_64 are presently supported.
 #endif
 
 static ElfW(Sym) gLibDlSymtab[] = {

linker/linker.cpp

@@ -858,7 +858,7 @@ int do_dlclose(soinfo* si) {
 }
 
 #if defined(USE_RELA)
-static int soinfo_relocate_a(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo* needed[]) {
+static int soinfo_relocate(soinfo* si, ElfW(Rela)* rela, unsigned count, soinfo* needed[]) {
   ElfW(Sym)* symtab = si->symtab;
   const char* strtab = si->strtab;
   ElfW(Sym)* s;
@@ -1155,7 +1155,9 @@ static int soinfo_relocate_a(soinfo* si, ElfW(Rela)* rela, unsigned count, soinf
   }
   return 0;
 }
-#else
+
+#else // REL, not RELA.
+
 static int soinfo_relocate(soinfo* si, ElfW(Rel)* rel, unsigned count, soinfo* needed[]) {
     ElfW(Sym)* symtab = si->symtab;
     const char* strtab = si->strtab;
@@ -1337,10 +1339,21 @@ static int soinfo_relocate(soinfo* si, ElfW(Rel)* rel, unsigned count, soinfo* n
             break;
 #elif defined(__mips__)
         case R_MIPS_REL32:
+#if defined(__LP64__)
+            // MIPS Elf64_Rel entries contain compound relocations
+            // We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
+            if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
+                ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
+                DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%d)",
+                       type, (unsigned)ELF64_R_TYPE2(rel->r_info),
+                       (unsigned)ELF64_R_TYPE3(rel->r_info), rel, (int) (rel - start));
+                return -1;
+            }
+#endif
             count_relocation(kRelocAbsolute);
             MARK(rel->r_offset);
-            TRACE_TYPE(RELO, "RELO REL32 %08x <- %08x %s",
+            TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
-                       reloc, sym_addr, (sym_name) ? sym_name : "*SECTIONHDR*");
+                       static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
             if (s) {
                 *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
             } else {
@@ -1376,7 +1389,7 @@ static int soinfo_relocate(soinfo* si, ElfW(Rel)* rel, unsigned count, soinfo* n
 
 #if defined(__mips__)
 static bool mips_relocate_got(soinfo* si, soinfo* needed[]) {
-    unsigned* got = si->plt_got;
+    ElfW(Addr)** got = si->plt_got;
     if (got == NULL) {
         return true;
     }
@@ -1385,55 +1398,43 @@ static bool mips_relocate_got(soinfo* si, soinfo* needed[]) {
     unsigned symtabno = si->mips_symtabno;
     ElfW(Sym)* symtab = si->symtab;
 
-    /*
+    // got[0] is the address of the lazy resolver function.
-     * got[0] is address of lazy resolver function
+    // got[1] may be used for a GNU extension.
-     * got[1] may be used for a GNU extension
+    // Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
-     * set it to a recognizable address in case someone calls it
+    // FIXME: maybe this should be in a separate routine?
-     * (should be _rtld_bind_start)
-     * FIXME: maybe this should be in a separate routine
-     */
-
     if ((si->flags & FLAG_LINKER) == 0) {
         size_t g = 0;
-        got[g++] = 0xdeadbeef;
+        got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
-        if (got[g] & 0x80000000) {
+        if (reinterpret_cast<intptr_t>(got[g]) < 0) {
-            got[g++] = 0xdeadfeed;
+            got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
         }
-        /*
+        // Relocate the local GOT entries.
-         * Relocate the local GOT entries need to be relocated
-         */
         for (; g < local_gotno; g++) {
-            got[g] += si->load_bias;
+            got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + si->load_bias);
         }
     }
 
-    /* Now for the global GOT entries */
+    // Now for the global GOT entries...
     ElfW(Sym)* sym = symtab + gotsym;
     got = si->plt_got + local_gotno;
     for (size_t g = gotsym; g < symtabno; g++, sym++, got++) {
-        const char* sym_name;
+        // This is an undefined reference... try to locate it.
-        ElfW(Sym)* s;
+        const char* sym_name = si->strtab + sym->st_name;
         soinfo* lsi;
-
+        ElfW(Sym)* s = soinfo_do_lookup(si, sym_name, &lsi, needed);
-        /* This is an undefined reference... try to locate it */
-        sym_name = si->strtab + sym->st_name;
-        s = soinfo_do_lookup(si, sym_name, &lsi, needed);
         if (s == NULL) {
-            /* We only allow an undefined symbol if this is a weak
+            // We only allow an undefined symbol if this is a weak reference.
-               reference..   */
             s = &symtab[g];
             if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
                 DL_ERR("cannot locate \"%s\"...", sym_name);
                 return false;
             }
             *got = 0;
-        }
+        } else {
-        else {
+            // FIXME: is this sufficient?
-            /* FIXME: is this sufficient?
+            // For reference see NetBSD link loader
-             * For reference see NetBSD link loader
+            // http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
-             * http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
+            *got = reinterpret_cast<ElfW(Addr)*>(lsi->load_bias + s->st_value);
-             */
-             *got = lsi->load_bias + s->st_value;
         }
     }
     return true;
@@ -1664,19 +1665,25 @@ static bool soinfo_link_image(soinfo* si) {
             si->plt_rel_count = d->d_un.d_val / sizeof(ElfW(Rel));
 #endif
             break;
-#if !defined(__LP64__)
+#if defined(__mips__)
         case DT_PLTGOT:
-            // Used by 32-bit MIPS.
+            // Used by mips and mips64.
-            si->plt_got = (unsigned *)(base + d->d_un.d_ptr);
+            si->plt_got = reinterpret_cast<ElfW(Addr)**>(base + d->d_un.d_ptr);
             break;
 #endif
         case DT_DEBUG:
             // Set the DT_DEBUG entry to the address of _r_debug for GDB
             // if the dynamic table is writable
+// FIXME: not working currently for N64
+// The flags for the LOAD and DYNAMIC program headers do not agree.
+// The LOAD section containng the dynamic table has been mapped as
+// read-only, but the DYNAMIC header claims it is writable.
+#if !(defined(__mips__) && defined(__LP64__))
             if ((dynamic_flags & PF_W) != 0) {
                 d->d_un.d_val = reinterpret_cast<uintptr_t>(&_r_debug);
             }
             break;
+#endif
 #if defined(USE_RELA)
          case DT_RELA:
             si->rela = (ElfW(Rela)*) (base + d->d_un.d_ptr);
@@ -1868,13 +1875,13 @@ static bool soinfo_link_image(soinfo* si) {
 #if defined(USE_RELA)
     if (si->plt_rela != NULL) {
         DEBUG("[ relocating %s plt ]\n", si->name );
-        if (soinfo_relocate_a(si, si->plt_rela, si->plt_rela_count, needed)) {
+        if (soinfo_relocate(si, si->plt_rela, si->plt_rela_count, needed)) {
             return false;
         }
     }
     if (si->rela != NULL) {
         DEBUG("[ relocating %s ]\n", si->name );
-        if (soinfo_relocate_a(si, si->rela, si->rela_count, needed)) {
+        if (soinfo_relocate(si, si->rela, si->rela_count, needed)) {
             return false;
         }
     }

linker/linker.h

@@ -56,6 +56,20 @@
 #define ELFW(what) ELF32_ ## what
 #endif
 
+// mips64 interprets Elf64_Rel structures' r_info field differently.
+// bionic (like other C libraries) has macros that assume regular ELF files,
+// but the dynamic linker needs to be able to load mips64 ELF files.
+#if defined(__mips__) && defined(__LP64__)
+#undef ELF64_R_SYM
+#undef ELF64_R_TYPE
+#undef ELF64_R_INFO
+#define ELF64_R_SYM(info)   (((info) >> 0) & 0xffffffff)
+#define ELF64_R_SSYM(info)  (((info) >> 32) & 0xff)
+#define ELF64_R_TYPE3(info) (((info) >> 40) & 0xff)
+#define ELF64_R_TYPE2(info) (((info) >> 48) & 0xff)
+#define ELF64_R_TYPE(info)  (((info) >> 56) & 0xff)
+#endif
+
 // Returns the address of the page containing address 'x'.
 #define PAGE_START(x)  ((x) & PAGE_MASK)
 
@@ -74,8 +88,8 @@
 
 typedef void (*linker_function_t)();
 
-// Android uses REL for 32-bit but only uses RELA for 64-bit.
+// Android uses RELA for aarch64 and x86_64. mips64 still uses REL.
-#if defined(__LP64__)
+#if defined(__aarch64__) || defined(__x86_64__)
 #define USE_RELA 1
 #endif
 
@@ -110,10 +124,10 @@ struct soinfo {
   unsigned* bucket;
   unsigned* chain;
 
-#if !defined(__LP64__)
+#if defined(__mips__) || !defined(__LP64__)
-  // This is only used by 32-bit MIPS, but needs to be here for
+  // This is only used by mips and mips64, but needs to be here for
   // all 32-bit architectures to preserve binary compatibility.
-  unsigned* plt_got;
+  ElfW(Addr)** plt_got;
 #endif
 
 #if defined(USE_RELA)