summaryrefslogtreecommitdiff
path: root/ports/sysdeps/mips/dl-trampoline.c
diff options
context:
space:
mode:
Diffstat (limited to 'ports/sysdeps/mips/dl-trampoline.c')
-rw-r--r--ports/sysdeps/mips/dl-trampoline.c386
1 files changed, 386 insertions, 0 deletions
diff --git a/ports/sysdeps/mips/dl-trampoline.c b/ports/sysdeps/mips/dl-trampoline.c
new file mode 100644
index 0000000000..3454eb306f
--- /dev/null
+++ b/ports/sysdeps/mips/dl-trampoline.c
@@ -0,0 +1,386 @@
+/* PLT trampoline. MIPS version.
+ Copyright (C) 1996-2001, 2002, 2003, 2004, 2005
+ Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* FIXME: Profiling of shared libraries is not implemented yet. */
+
+#include <sysdep.h>
+#include <link.h>
+#include <elf.h>
+#include <ldsodefs.h>
+#include <dl-machine.h>
+#include <sysdep-cancel.h>
+
+/* Get link map for callers object containing STUB_PC. */
+static inline struct link_map *
+elf_machine_runtime_link_map (ElfW(Addr) gpreg, ElfW(Addr) stub_pc)
+{
+ extern int _dl_mips_gnu_objects;
+
+ /* got[1] is reserved to keep its link map address for the shared
+ object generated by the gnu linker. If all are such objects, we
+ can find the link map from current GPREG simply. If not so, get
+ the link map for caller's object containing STUB_PC. */
+
+ if (_dl_mips_gnu_objects)
+ {
+ ElfW(Addr) *got = elf_mips_got_from_gpreg (gpreg);
+ ElfW(Word) g1;
+
+ g1 = ((ElfW(Word) *) got)[1];
+
+ if ((g1 & ELF_MIPS_GNU_GOT1_MASK) != 0)
+ {
+ struct link_map *l =
+ (struct link_map *) (g1 & ~ELF_MIPS_GNU_GOT1_MASK);
+ ElfW(Addr) base, limit;
+ const ElfW(Phdr) *p = l->l_phdr;
+ ElfW(Half) this, nent = l->l_phnum;
+
+ /* For the common case of a stub being called from the containing
+ object, STUB_PC will point to somewhere within the object that
+ is described by the link map fetched via got[1]. Otherwise we
+ have to scan all maps. */
+ for (this = 0; this < nent; this++)
+ {
+ if (p[this].p_type == PT_LOAD)
+ {
+ base = p[this].p_vaddr + l->l_addr;
+ limit = base + p[this].p_memsz;
+ if (stub_pc >= base && stub_pc < limit)
+ return l;
+ }
+ }
+ }
+ }
+
+ struct link_map *l;
+ Lmid_t nsid;
+
+ for (nsid = 0; nsid < DL_NNS; ++nsid)
+ for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
+ {
+ ElfW(Addr) base, limit;
+ const ElfW(Phdr) *p = l->l_phdr;
+ ElfW(Half) this, nent = l->l_phnum;
+
+ for (this = 0; this < nent; ++this)
+ {
+ if (p[this].p_type == PT_LOAD)
+ {
+ base = p[this].p_vaddr + l->l_addr;
+ limit = base + p[this].p_memsz;
+ if (stub_pc >= base && stub_pc < limit)
+ return l;
+ }
+ }
+ }
+
+ _dl_signal_error (0, NULL, NULL, "cannot find runtime link map");
+ return NULL;
+}
+
+/* Define mips specific runtime resolver. The function __dl_runtime_resolve
+ is called from assembler function _dl_runtime_resolve which converts
+ special argument registers t7 ($15) and t8 ($24):
+ t7 address to return to the caller of the function
+ t8 index for this function symbol in .dynsym
+ to usual c arguments.
+
+ Other architectures call fixup from dl-runtime.c in
+ _dl_runtime_resolve. MIPS instead calls __dl_runtime_resolve. We
+ have to use our own version because of the way the got section is
+ treated on MIPS (we've also got ELF_MACHINE_PLT defined). */
+
+/* The flag _dl_mips_gnu_objects is set if all dynamic objects are
+ generated by the gnu linker. */
+int _dl_mips_gnu_objects = 1;
+
+#define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
+
+/* This is called from assembly stubs below which the compiler can't see. */
+static ElfW(Addr)
+__dl_runtime_resolve (ElfW(Word), ElfW(Word), ElfW(Addr), ElfW(Addr))
+ __attribute_used__;
+
+static ElfW(Addr)
+__dl_runtime_resolve (ElfW(Word) sym_index,
+ ElfW(Word) return_address,
+ ElfW(Addr) old_gpreg,
+ ElfW(Addr) stub_pc)
+{
+ struct link_map *l = elf_machine_runtime_link_map (old_gpreg, stub_pc);
+ const ElfW(Sym) *const symtab
+ = (const ElfW(Sym) *) D_PTR (l, l_info[DT_SYMTAB]);
+ const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
+ ElfW(Addr) *got
+ = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
+ const ElfW(Word) local_gotno
+ = (const ElfW(Word)) l->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
+ const ElfW(Word) gotsym
+ = (const ElfW(Word)) l->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
+ const ElfW(Sym) *sym = &symtab[sym_index];
+ struct link_map *sym_map;
+ ElfW(Addr) value;
+
+ /* FIXME: The symbol versioning stuff is not tested yet. */
+ if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
+ {
+ switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
+ {
+ default:
+ {
+ const ElfW(Half) *vernum =
+ (const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]);
+ ElfW(Half) ndx = vernum[sym_index] & 0x7fff;
+ const struct r_found_version *version = &l->l_versions[ndx];
+
+ if (version->hash != 0)
+ {
+ /* We need to keep the scope around so do some locking. This is
+ not necessary for objects which cannot be unloaded or when
+ we are not using any threads (yet). */
+ if (!RTLD_SINGLE_THREAD_P)
+ THREAD_GSCOPE_SET_FLAG ();
+
+ sym_map = _dl_lookup_symbol_x (strtab + sym->st_name, l,
+ &sym, l->l_scope, version,
+ ELF_RTYPE_CLASS_PLT, 0, 0);
+
+ /* We are done with the global scope. */
+ if (!RTLD_SINGLE_THREAD_P)
+ THREAD_GSCOPE_RESET_FLAG ();
+
+ break;
+ }
+ /* Fall through. */
+ }
+ case 0:
+ {
+ /* We need to keep the scope around so do some locking. This is
+ not necessary for objects which cannot be unloaded or when
+ we are not using any threads (yet). */
+ int flags = DL_LOOKUP_ADD_DEPENDENCY;
+ if (!RTLD_SINGLE_THREAD_P)
+ {
+ THREAD_GSCOPE_SET_FLAG ();
+ flags |= DL_LOOKUP_GSCOPE_LOCK;
+ }
+
+ sym_map = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
+ l->l_scope, 0, ELF_RTYPE_CLASS_PLT,
+ flags, 0);
+
+ /* We are done with the global scope. */
+ if (!RTLD_SINGLE_THREAD_P)
+ THREAD_GSCOPE_RESET_FLAG ();
+ }
+ }
+
+ /* Currently value contains the base load address of the object
+ that defines sym. Now add in the symbol offset. */
+ value = (sym ? sym_map->l_addr + sym->st_value : 0);
+ }
+ else
+ /* We already found the symbol. The module (and therefore its load
+ address) is also known. */
+ value = l->l_addr + sym->st_value;
+
+ /* Apply the relocation with that value. */
+ *(got + local_gotno + sym_index - gotsym) = value;
+
+ return value;
+}
+
+#if _MIPS_SIM == _ABIO32
+#define ELF_DL_FRAME_SIZE 40
+
+#define ELF_DL_SAVE_ARG_REGS "\
+ sw $15, 36($29)\n \
+ sw $4, 16($29)\n \
+ sw $5, 20($29)\n \
+ sw $6, 24($29)\n \
+ sw $7, 28($29)\n \
+"
+
+#define ELF_DL_RESTORE_ARG_REGS "\
+ lw $31, 36($29)\n \
+ lw $4, 16($29)\n \
+ lw $5, 20($29)\n \
+ lw $6, 24($29)\n \
+ lw $7, 28($29)\n \
+"
+
+/* The PLT resolver should also save and restore $2 and $3, which are used
+ as arguments to MIPS16 stub functions. */
+#define ELF_DL_PLT_FRAME_SIZE 48
+
+#define ELF_DL_PLT_SAVE_ARG_REGS \
+ ELF_DL_SAVE_ARG_REGS "\
+ sw $2, 40($29)\n \
+ sw $3, 44($29)\n \
+"
+
+#define ELF_DL_PLT_RESTORE_ARG_REGS \
+ ELF_DL_RESTORE_ARG_REGS "\
+ lw $2, 40($29)\n \
+ lw $3, 44($29)\n \
+"
+
+#define IFABIO32(X) X
+#define IFNEWABI(X)
+
+#else /* _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64 */
+
+#define ELF_DL_FRAME_SIZE 80
+
+#define ELF_DL_SAVE_ARG_REGS "\
+ sd $15, 72($29)\n \
+ sd $4, 8($29)\n \
+ sd $5, 16($29)\n \
+ sd $6, 24($29)\n \
+ sd $7, 32($29)\n \
+ sd $8, 40($29)\n \
+ sd $9, 48($29)\n \
+ sd $10, 56($29)\n \
+ sd $11, 64($29)\n \
+"
+
+#define ELF_DL_RESTORE_ARG_REGS "\
+ ld $31, 72($29)\n \
+ ld $4, 8($29)\n \
+ ld $5, 16($29)\n \
+ ld $6, 24($29)\n \
+ ld $7, 32($29)\n \
+ ld $8, 40($29)\n \
+ ld $9, 48($29)\n \
+ ld $10, 56($29)\n \
+ ld $11, 64($29)\n \
+"
+
+/* The PLT resolver should also save and restore $2 and $3, which are used
+ as arguments to MIPS16 stub functions. */
+#define ELF_DL_PLT_FRAME_SIZE 96
+
+#define ELF_DL_PLT_SAVE_ARG_REGS \
+ ELF_DL_SAVE_ARG_REGS "\
+ sd $2, 80($29)\n \
+ sd $3, 88($29)\n \
+"
+
+#define ELF_DL_PLT_RESTORE_ARG_REGS \
+ ELF_DL_RESTORE_ARG_REGS "\
+ ld $2, 80($29)\n \
+ ld $3, 88($29)\n \
+"
+
+#define IFABIO32(X)
+#define IFNEWABI(X) X
+
+#endif
+
+asm ("\n\
+ .text\n\
+ .align 2\n\
+ .globl _dl_runtime_resolve\n\
+ .type _dl_runtime_resolve,@function\n\
+ .ent _dl_runtime_resolve\n\
+_dl_runtime_resolve:\n\
+ .frame $29, " STRINGXP(ELF_DL_FRAME_SIZE) ", $31\n\
+ .set noreorder\n\
+ # Save GP.\n\
+1: move $3, $28\n\
+ # Save arguments and sp value in stack.\n\
+ " STRINGXP(PTR_SUBIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n\
+ # Modify t9 ($25) so as to point .cpload instruction.\n\
+ " IFABIO32(STRINGXP(PTR_ADDIU) " $25, (2f-1b)\n") "\
+ # Compute GP.\n\
+2: " STRINGXP(SETUP_GP) "\n\
+ " STRINGXV(SETUP_GP64 (0, _dl_runtime_resolve)) "\n\
+ .set reorder\n\
+ # Save slot call pc.\n\
+ move $2, $31\n\
+ " IFABIO32(STRINGXP(CPRESTORE(32))) "\n\
+ " ELF_DL_SAVE_ARG_REGS "\
+ move $4, $24\n\
+ move $5, $15\n\
+ move $6, $3\n\
+ move $7, $2\n\
+ jal __dl_runtime_resolve\n\
+ " ELF_DL_RESTORE_ARG_REGS "\
+ " STRINGXP(RESTORE_GP64) "\n\
+ " STRINGXP(PTR_ADDIU) " $29, " STRINGXP(ELF_DL_FRAME_SIZE) "\n\
+ move $25, $2\n\
+ jr $25\n\
+ .end _dl_runtime_resolve\n\
+ .previous\n\
+");
+
+/* Assembler veneer called from the PLT header code when using PLTs.
+
+ Code in each PLT entry and the PLT header fills in the arguments to
+ this function:
+
+ - $15 (o32 t7, n32/n64 t3) - caller's return address
+ - $24 (t8) - PLT entry index
+ - $25 (t9) - address of _dl_runtime_pltresolve
+ - o32 $28 (gp), n32/n64 $14 (t2) - address of .got.plt
+
+ Different registers are used for .got.plt because the ABI was
+ originally designed for o32, where gp was available (call
+ clobbered). On n32/n64 gp is call saved.
+
+ _dl_fixup needs:
+
+ - $4 (a0) - link map address
+ - $5 (a1) - .rel.plt offset (== PLT entry index * 8) */
+
+asm ("\n\
+ .text\n\
+ .align 2\n\
+ .globl _dl_runtime_pltresolve\n\
+ .type _dl_runtime_pltresolve,@function\n\
+ .ent _dl_runtime_pltresolve\n\
+_dl_runtime_pltresolve:\n\
+ .frame $29, " STRINGXP(ELF_DL_PLT_FRAME_SIZE) ", $31\n\
+ .set noreorder\n\
+ # Save arguments and sp value in stack.\n\
+1: " STRINGXP(PTR_SUBIU) " $29, " STRINGXP(ELF_DL_PLT_FRAME_SIZE) "\n\
+ " IFABIO32(STRINGXP(PTR_L) " $13, " STRINGXP(PTRSIZE) "($28)") "\n\
+ " IFNEWABI(STRINGXP(PTR_L) " $13, " STRINGXP(PTRSIZE) "($14)") "\n\
+ # Modify t9 ($25) so as to point .cpload instruction.\n\
+ " IFABIO32(STRINGXP(PTR_ADDIU) " $25, (2f-1b)\n") "\
+ # Compute GP.\n\
+2: " STRINGXP(SETUP_GP) "\n\
+ " STRINGXV(SETUP_GP64 (0, _dl_runtime_pltresolve)) "\n\
+ .set reorder\n\
+ " IFABIO32(STRINGXP(CPRESTORE(32))) "\n\
+ " ELF_DL_PLT_SAVE_ARG_REGS "\
+ move $4, $13\n\
+ sll $5, $24, " STRINGXP(PTRLOG) " + 1\n\
+ jal _dl_fixup\n\
+ move $25, $2\n\
+ " ELF_DL_PLT_RESTORE_ARG_REGS "\
+ " STRINGXP(RESTORE_GP64) "\n\
+ " STRINGXP(PTR_ADDIU) " $29, " STRINGXP(ELF_DL_PLT_FRAME_SIZE) "\n\
+ jr $25\n\
+ .end _dl_runtime_pltresolve\n\
+ .previous\n\
+");
+
View Lorry Controller Status