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-rw-r--r--ports/sysdeps/alpha/dl-machine.h528
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diff --git a/ports/sysdeps/alpha/dl-machine.h b/ports/sysdeps/alpha/dl-machine.h
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+++ b/ports/sysdeps/alpha/dl-machine.h
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+/* Machine-dependent ELF dynamic relocation inline functions. Alpha version.
+ Copyright (C) 1996-2005, 2006, 2011 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Richard Henderson <rth@tamu.edu>.
+
+ 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/>. */
+
+/* This was written in the absence of an ABI -- don't expect
+ it to remain unchanged. */
+
+#ifndef dl_machine_h
+#define dl_machine_h 1
+
+#define ELF_MACHINE_NAME "alpha"
+
+#include <string.h>
+
+
+/* Mask identifying addresses reserved for the user program,
+ where the dynamic linker should not map anything. */
+#define ELF_MACHINE_USER_ADDRESS_MASK 0x120000000UL
+
+/* Translate a processor specific dynamic tag to the index in l_info array. */
+#define DT_ALPHA(x) (DT_ALPHA_##x - DT_LOPROC + DT_NUM)
+
+/* Return nonzero iff ELF header is compatible with the running host. */
+static inline int
+elf_machine_matches_host (const Elf64_Ehdr *ehdr)
+{
+ return ehdr->e_machine == EM_ALPHA;
+}
+
+/* Return the link-time address of _DYNAMIC. The multiple-got-capable
+ linker no longer allocates the first .got entry for this. But not to
+ worry, no special tricks are needed. */
+static inline Elf64_Addr
+elf_machine_dynamic (void)
+{
+#ifndef NO_AXP_MULTI_GOT_LD
+ return (Elf64_Addr) &_DYNAMIC;
+#else
+ register Elf64_Addr *gp __asm__ ("$29");
+ return gp[-4096];
+#endif
+}
+
+/* Return the run-time load address of the shared object. */
+
+static inline Elf64_Addr
+elf_machine_load_address (void)
+{
+ /* This relies on the compiler using gp-relative addresses for static symbols. */
+ static void *dot = &dot;
+ return (void *)&dot - dot;
+}
+
+/* Set up the loaded object described by L so its unrelocated PLT
+ entries will jump to the on-demand fixup code in dl-runtime.c. */
+
+static inline int
+elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
+{
+ extern char _dl_runtime_resolve_new[] attribute_hidden;
+ extern char _dl_runtime_profile_new[] attribute_hidden;
+ extern char _dl_runtime_resolve_old[] attribute_hidden;
+ extern char _dl_runtime_profile_old[] attribute_hidden;
+
+ struct pltgot {
+ char *resolve;
+ struct link_map *link;
+ };
+
+ struct pltgot *pg;
+ long secureplt;
+ char *resolve;
+
+ if (map->l_info[DT_JMPREL] == 0 || !lazy)
+ return lazy;
+
+ /* Check to see if we're using the read-only plt form. */
+ secureplt = map->l_info[DT_ALPHA(PLTRO)] != 0;
+
+ /* If the binary uses the read-only secure plt format, PG points to
+ the .got.plt section, which is the right place for ld.so to place
+ its hooks. Otherwise, PG is currently pointing at the start of
+ the plt; the hooks go at offset 16. */
+ pg = (struct pltgot *) D_PTR (map, l_info[DT_PLTGOT]);
+ pg += !secureplt;
+
+ /* This function will be called to perform the relocation. They're
+ not declared as functions to convince the compiler to use gp
+ relative relocations for them. */
+ if (secureplt)
+ resolve = _dl_runtime_resolve_new;
+ else
+ resolve = _dl_runtime_resolve_old;
+
+ if (__builtin_expect (profile, 0))
+ {
+ if (secureplt)
+ resolve = _dl_runtime_profile_new;
+ else
+ resolve = _dl_runtime_profile_old;
+
+ if (GLRO(dl_profile) && _dl_name_match_p (GLRO(dl_profile), map))
+ {
+ /* This is the object we are looking for. Say that we really
+ want profiling and the timers are started. */
+ GL(dl_profile_map) = map;
+ }
+ }
+
+ pg->resolve = resolve;
+ pg->link = map;
+
+ return lazy;
+}
+
+/* Initial entry point code for the dynamic linker.
+ The C function `_dl_start' is the real entry point;
+ its return value is the user program's entry point. */
+
+#define RTLD_START asm ("\
+ .section .text \n\
+ .set at \n\
+ .globl _start \n\
+ .ent _start \n\
+_start: \n\
+ .frame $31,0,$31,0 \n\
+ br $gp, 0f \n\
+0: ldgp $gp, 0($gp) \n\
+ .prologue 0 \n\
+ /* Pass pointer to argument block to _dl_start. */ \n\
+ mov $sp, $16 \n\
+ bsr $26, _dl_start !samegp \n\
+ .end _start \n\
+ /* FALLTHRU */ \n\
+ .globl _dl_start_user \n\
+ .ent _dl_start_user \n\
+_dl_start_user: \n\
+ .frame $31,0,$31,0 \n\
+ .prologue 0 \n\
+ /* Save the user entry point address in s0. */ \n\
+ mov $0, $9 \n\
+ /* See if we were run as a command with the executable \n\
+ file name as an extra leading argument. */ \n\
+ ldah $1, _dl_skip_args($gp) !gprelhigh \n\
+ ldl $1, _dl_skip_args($1) !gprellow \n\
+ bne $1, $fixup_stack \n\
+$fixup_stack_ret: \n\
+ /* The special initializer gets called with the stack \n\
+ just as the application's entry point will see it; \n\
+ it can switch stacks if it moves these contents \n\
+ over. */ \n\
+" RTLD_START_SPECIAL_INIT " \n\
+ /* Call _dl_init(_dl_loaded, argc, argv, envp) to run \n\
+ initializers. */ \n\
+ ldah $16, _rtld_local($gp) !gprelhigh \n\
+ ldq $16, _rtld_local($16) !gprellow \n\
+ ldq $17, 0($sp) \n\
+ lda $18, 8($sp) \n\
+ s8addq $17, 8, $19 \n\
+ addq $19, $18, $19 \n\
+ bsr $26, _dl_init_internal !samegp \n\
+ /* Pass our finalizer function to the user in $0. */ \n\
+ ldah $0, _dl_fini($gp) !gprelhigh \n\
+ lda $0, _dl_fini($0) !gprellow \n\
+ /* Jump to the user's entry point. */ \n\
+ mov $9, $27 \n\
+ jmp ($9) \n\
+$fixup_stack: \n\
+ /* Adjust the stack pointer to skip _dl_skip_args words.\n\
+ This involves copying everything down, since the \n\
+ stack pointer must always be 16-byte aligned. */ \n\
+ ldah $7, _dl_argv_internal($gp) !gprelhigh \n\
+ ldq $2, 0($sp) \n\
+ ldq $5, _dl_argv_internal($7) !gprellow \n\
+ subq $31, $1, $6 \n\
+ subq $2, $1, $2 \n\
+ s8addq $6, $5, $5 \n\
+ mov $sp, $4 \n\
+ s8addq $1, $sp, $3 \n\
+ stq $2, 0($sp) \n\
+ stq $5, _dl_argv_internal($7) !gprellow \n\
+ /* Copy down argv. */ \n\
+0: ldq $5, 8($3) \n\
+ addq $4, 8, $4 \n\
+ addq $3, 8, $3 \n\
+ stq $5, 0($4) \n\
+ bne $5, 0b \n\
+ /* Copy down envp. */ \n\
+1: ldq $5, 8($3) \n\
+ addq $4, 8, $4 \n\
+ addq $3, 8, $3 \n\
+ stq $5, 0($4) \n\
+ bne $5, 1b \n\
+ /* Copy down auxiliary table. */ \n\
+2: ldq $5, 8($3) \n\
+ ldq $6, 16($3) \n\
+ addq $4, 16, $4 \n\
+ addq $3, 16, $3 \n\
+ stq $5, -8($4) \n\
+ stq $6, 0($4) \n\
+ bne $5, 2b \n\
+ br $fixup_stack_ret \n\
+ .end _dl_start_user \n\
+ .set noat \n\
+.previous");
+
+#ifndef RTLD_START_SPECIAL_INIT
+#define RTLD_START_SPECIAL_INIT /* nothing */
+#endif
+
+/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry
+ or TLS variables, so undefined references should not be allowed
+ to define the value.
+
+ ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve
+ to one of the main executable's symbols, as for a COPY reloc.
+ This is unused on Alpha. */
+
+# define elf_machine_type_class(type) \
+ (((type) == R_ALPHA_JMP_SLOT \
+ || (type) == R_ALPHA_DTPMOD64 \
+ || (type) == R_ALPHA_DTPREL64 \
+ || (type) == R_ALPHA_TPREL64) * ELF_RTYPE_CLASS_PLT)
+
+/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
+#define ELF_MACHINE_JMP_SLOT R_ALPHA_JMP_SLOT
+
+/* The alpha never uses Elf64_Rel relocations. */
+#define ELF_MACHINE_NO_REL 1
+
+/* We define an initialization functions. This is called very early in
+ * _dl_sysdep_start. */
+#define DL_PLATFORM_INIT dl_platform_init ()
+
+static inline void __attribute__ ((unused))
+dl_platform_init (void)
+{
+ if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
+ /* Avoid an empty string which would disturb us. */
+ GLRO(dl_platform) = NULL;
+}
+
+/* Fix up the instructions of a PLT entry to invoke the function
+ rather than the dynamic linker. */
+static inline Elf64_Addr
+elf_machine_fixup_plt (struct link_map *map, lookup_t t,
+ const Elf64_Rela *reloc,
+ Elf64_Addr *got_addr, Elf64_Addr value)
+{
+ const Elf64_Rela *rela_plt;
+ Elf64_Word *plte;
+ long int edisp;
+
+ /* Store the value we are going to load. */
+ *got_addr = value;
+
+ /* If this binary uses the read-only secure plt format, we're done. */
+ if (map->l_info[DT_ALPHA(PLTRO)])
+ return value;
+
+ /* Otherwise we have to modify the plt entry in place to do the branch. */
+
+ /* Recover the PLT entry address by calculating reloc's index into the
+ .rela.plt, and finding that entry in the .plt. */
+ rela_plt = (const Elf64_Rela *) D_PTR (map, l_info[DT_JMPREL]);
+ plte = (Elf64_Word *) (D_PTR (map, l_info[DT_PLTGOT]) + 32);
+ plte += 3 * (reloc - rela_plt);
+
+ /* Find the displacement from the plt entry to the function. */
+ edisp = (long int) (value - (Elf64_Addr)&plte[3]) / 4;
+
+ if (edisp >= -0x100000 && edisp < 0x100000)
+ {
+ /* If we are in range, use br to perfect branch prediction and
+ elide the dependency on the address load. This case happens,
+ e.g., when a shared library call is resolved to the same library. */
+
+ int hi, lo;
+ hi = value - (Elf64_Addr)&plte[0];
+ lo = (short int) hi;
+ hi = (hi - lo) >> 16;
+
+ /* Emit "lda $27,lo($27)" */
+ plte[1] = 0x237b0000 | (lo & 0xffff);
+
+ /* Emit "br $31,function" */
+ plte[2] = 0xc3e00000 | (edisp & 0x1fffff);
+
+ /* Think about thread-safety -- the previous instructions must be
+ committed to memory before the first is overwritten. */
+ __asm__ __volatile__("wmb" : : : "memory");
+
+ /* Emit "ldah $27,hi($27)" */
+ plte[0] = 0x277b0000 | (hi & 0xffff);
+ }
+ else
+ {
+ /* Don't bother with the hint since we already know the hint is
+ wrong. Eliding it prevents the wrong page from getting pulled
+ into the cache. */
+
+ int hi, lo;
+ hi = (Elf64_Addr)got_addr - (Elf64_Addr)&plte[0];
+ lo = (short)hi;
+ hi = (hi - lo) >> 16;
+
+ /* Emit "ldq $27,lo($27)" */
+ plte[1] = 0xa77b0000 | (lo & 0xffff);
+
+ /* Emit "jmp $31,($27)" */
+ plte[2] = 0x6bfb0000;
+
+ /* Think about thread-safety -- the previous instructions must be
+ committed to memory before the first is overwritten. */
+ __asm__ __volatile__("wmb" : : : "memory");
+
+ /* Emit "ldah $27,hi($27)" */
+ plte[0] = 0x277b0000 | (hi & 0xffff);
+ }
+
+ /* At this point, if we've been doing runtime resolution, Icache is dirty.
+ This will be taken care of in _dl_runtime_resolve. If instead we are
+ doing this as part of non-lazy startup relocation, that bit of code
+ hasn't made it into Icache yet, so there's nothing to clean up. */
+
+ return value;
+}
+
+/* Return the final value of a plt relocation. */
+static inline Elf64_Addr
+elf_machine_plt_value (struct link_map *map, const Elf64_Rela *reloc,
+ Elf64_Addr value)
+{
+ return value + reloc->r_addend;
+}
+
+/* Names of the architecture-specific auditing callback functions. */
+#define ARCH_LA_PLTENTER alpha_gnu_pltenter
+#define ARCH_LA_PLTEXIT alpha_gnu_pltexit
+
+#endif /* !dl_machine_h */
+
+#ifdef RESOLVE_MAP
+
+/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
+ MAP is the object containing the reloc. */
+auto inline void
+__attribute__ ((always_inline))
+elf_machine_rela (struct link_map *map,
+ const Elf64_Rela *reloc,
+ const Elf64_Sym *sym,
+ const struct r_found_version *version,
+ void *const reloc_addr_arg,
+ int skip_ifunc)
+{
+ Elf64_Addr *const reloc_addr = reloc_addr_arg;
+ unsigned long int const r_type = ELF64_R_TYPE (reloc->r_info);
+
+#if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC && !defined SHARED
+ /* This is defined in rtld.c, but nowhere in the static libc.a; make the
+ reference weak so static programs can still link. This declaration
+ cannot be done when compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP)
+ because rtld.c contains the common defn for _dl_rtld_map, which is
+ incompatible with a weak decl in the same file. */
+ weak_extern (_dl_rtld_map);
+#endif
+
+ /* We cannot use a switch here because we cannot locate the switch
+ jump table until we've self-relocated. */
+
+#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
+ if (__builtin_expect (r_type == R_ALPHA_RELATIVE, 0))
+ {
+# if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
+ /* Already done in dynamic linker. */
+ if (map != &GL(dl_rtld_map))
+# endif
+ {
+ /* XXX Make some timings. Maybe it's preferable to test for
+ unaligned access and only do it the complex way if necessary. */
+ Elf64_Addr reloc_addr_val;
+
+ /* Load value without causing unaligned trap. */
+ memcpy (&reloc_addr_val, reloc_addr_arg, 8);
+ reloc_addr_val += map->l_addr;
+
+ /* Store value without causing unaligned trap. */
+ memcpy (reloc_addr_arg, &reloc_addr_val, 8);
+ }
+ }
+ else
+#endif
+ if (__builtin_expect (r_type == R_ALPHA_NONE, 0))
+ return;
+ else
+ {
+ struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
+ Elf64_Addr sym_value;
+ Elf64_Addr sym_raw_value;
+
+ sym_raw_value = sym_value = reloc->r_addend;
+ if (sym_map)
+ {
+ sym_raw_value += sym->st_value;
+ sym_value = sym_raw_value + sym_map->l_addr;
+ }
+
+ if (r_type == R_ALPHA_GLOB_DAT)
+ *reloc_addr = sym_value;
+#ifdef RESOLVE_CONFLICT_FIND_MAP
+ /* In .gnu.conflict section, R_ALPHA_JMP_SLOT relocations have
+ R_ALPHA_JMP_SLOT in lower 8 bits and the remaining 24 bits
+ are .rela.plt index. */
+ else if ((r_type & 0xff) == R_ALPHA_JMP_SLOT)
+ {
+ /* elf_machine_fixup_plt needs the map reloc_addr points into,
+ while in _dl_resolve_conflicts map is _dl_loaded. */
+ RESOLVE_CONFLICT_FIND_MAP (map, reloc_addr);
+ reloc = ((const Elf64_Rela *) D_PTR (map, l_info[DT_JMPREL]))
+ + (r_type >> 8);
+ elf_machine_fixup_plt (map, 0, reloc, reloc_addr, sym_value);
+ }
+#else
+ else if (r_type == R_ALPHA_JMP_SLOT)
+ elf_machine_fixup_plt (map, 0, reloc, reloc_addr, sym_value);
+#endif
+#ifndef RTLD_BOOTSTRAP
+ else if (r_type == R_ALPHA_REFQUAD)
+ {
+ /* Store value without causing unaligned trap. */
+ memcpy (reloc_addr_arg, &sym_value, 8);
+ }
+#endif
+ else if (r_type == R_ALPHA_DTPMOD64)
+ {
+# ifdef RTLD_BOOTSTRAP
+ /* During startup the dynamic linker is always index 1. */
+ *reloc_addr = 1;
+# else
+ /* Get the information from the link map returned by the
+ resolv function. */
+ if (sym_map != NULL)
+ *reloc_addr = sym_map->l_tls_modid;
+# endif
+ }
+ else if (r_type == R_ALPHA_DTPREL64)
+ {
+# ifndef RTLD_BOOTSTRAP
+ /* During relocation all TLS symbols are defined and used.
+ Therefore the offset is already correct. */
+ *reloc_addr = sym_raw_value;
+# endif
+ }
+ else if (r_type == R_ALPHA_TPREL64)
+ {
+# ifdef RTLD_BOOTSTRAP
+ *reloc_addr = sym_raw_value + map->l_tls_offset;
+# else
+ if (sym_map)
+ {
+ CHECK_STATIC_TLS (map, sym_map);
+ *reloc_addr = sym_raw_value + sym_map->l_tls_offset;
+ }
+# endif
+ }
+ else
+ _dl_reloc_bad_type (map, r_type, 0);
+ }
+}
+
+/* Let do-rel.h know that on Alpha if l_addr is 0, all RELATIVE relocs
+ can be skipped. */
+#define ELF_MACHINE_REL_RELATIVE 1
+
+auto inline void
+__attribute__ ((always_inline))
+elf_machine_rela_relative (Elf64_Addr l_addr, const Elf64_Rela *reloc,
+ void *const reloc_addr_arg)
+{
+ /* XXX Make some timings. Maybe it's preferable to test for
+ unaligned access and only do it the complex way if necessary. */
+ Elf64_Addr reloc_addr_val;
+
+ /* Load value without causing unaligned trap. */
+ memcpy (&reloc_addr_val, reloc_addr_arg, 8);
+ reloc_addr_val += l_addr;
+
+ /* Store value without causing unaligned trap. */
+ memcpy (reloc_addr_arg, &reloc_addr_val, 8);
+}
+
+auto inline void
+__attribute__ ((always_inline))
+elf_machine_lazy_rel (struct link_map *map,
+ Elf64_Addr l_addr, const Elf64_Rela *reloc,
+ int skip_ifunc)
+{
+ Elf64_Addr * const reloc_addr = (void *)(l_addr + reloc->r_offset);
+ unsigned long int const r_type = ELF64_R_TYPE (reloc->r_info);
+
+ if (r_type == R_ALPHA_JMP_SLOT)
+ {
+ /* Perform a RELATIVE reloc on the .got entry that transfers
+ to the .plt. */
+ *reloc_addr += l_addr;
+ }
+ else if (r_type == R_ALPHA_NONE)
+ return;
+ else
+ _dl_reloc_bad_type (map, r_type, 1);
+}
+
+#endif /* RESOLVE_MAP */
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