diff options
author | Roland McGrath <roland@gnu.org> | 1995-05-31 13:23:14 +0000 |
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committer | Roland McGrath <roland@gnu.org> | 1995-05-31 13:23:14 +0000 |
commit | a1a9d215963c548aef245cacd8efa944de69503b (patch) | |
tree | ff96263310f3c2e3c1f90d4ec8b332b7af028d84 | |
parent | 4174072112e4e2b43cc65a5093a433b4270aed49 (diff) | |
download | glibc-a1a9d215963c548aef245cacd8efa944de69503b.tar.gz glibc-a1a9d215963c548aef245cacd8efa944de69503b.tar.xz glibc-a1a9d215963c548aef245cacd8efa944de69503b.zip |
Tue May 30 15:52:32 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>
* mach/Makefile (server-interfaces): Removed notify and device_reply. For shlibs with eager binding, libmachuser.so must not refer to any functions not defined in libc.
-rw-r--r-- | ChangeLog | 6 | ||||
-rw-r--r-- | elf/dl-error.c | 10 | ||||
-rw-r--r-- | elf/dl-fini.c | 2 | ||||
-rw-r--r-- | elf/dl-init.c | 10 | ||||
-rw-r--r-- | elf/dl-load.c | 21 | ||||
-rw-r--r-- | elf/dl-lookup.c | 11 | ||||
-rw-r--r-- | elf/dl-reloc.c | 2 | ||||
-rw-r--r-- | elf/do-rel.h | 53 | ||||
-rw-r--r-- | elf/dynamic-link.h | 12 | ||||
-rw-r--r-- | elf/rtld.c | 9 | ||||
-rw-r--r-- | sysdeps/i386/dl-machine.h | 43 | ||||
-rw-r--r-- | sysdeps/i386/dl-runtime.c | 15 | ||||
-rw-r--r-- | sysdeps/mach/hurd/dl-sysdep.c | 15 | ||||
-rw-r--r-- | sysdeps/mach/hurd/i386/init-first.c | 71 |
14 files changed, 193 insertions, 87 deletions
diff --git a/ChangeLog b/ChangeLog index 356fdf4c47..48af781cae 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +Tue May 30 15:52:32 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> + + * mach/Makefile (server-interfaces): Removed notify and + device_reply. For shlibs with eager binding, libmachuser.so must + not refer to any functions not defined in libc. + Sat May 27 16:23:22 1995 Jim Meyering (meyering@comco.com) * sysdeps/generic/memchr.c: Cast RHS to const unsigned char * diff --git a/elf/dl-error.c b/elf/dl-error.c index acb21a0414..b5af2e323f 100644 --- a/elf/dl-error.c +++ b/elf/dl-error.c @@ -43,8 +43,14 @@ _dl_catch_error (const char **errstring, signalled_errstring = signalled_objname = NULL; errcode = setjmp (catch_env); - (*operate) (); + if (errcode == 0) + { + (*operate) (); + return 0; + } + + /* We get here only if we longjmp'd out of OPERATE. */ *errstring = signalled_errstring; *objname = signalled_objname; - return *errstring ? errcode : 0; + return errcode == -1 ? 0 : errcode; } diff --git a/elf/dl-fini.c b/elf/dl-fini.c index cbc05252d2..69ff83d488 100644 --- a/elf/dl-fini.c +++ b/elf/dl-fini.c @@ -26,5 +26,5 @@ _dl_fini (void) for (l = _dl_loaded; l; l = l->l_next) if (l->l_init_called && l->l_info[DT_FINI]) - (*(void (*) (void)) l->l_info[DT_FINI]->d_un.d_ptr) (); + (*(void (*) (void)) (l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr)) (); } diff --git a/elf/dl-init.c b/elf/dl-init.c index e3bfc2ccea..36eb32aa78 100644 --- a/elf/dl-init.c +++ b/elf/dl-init.c @@ -46,15 +46,17 @@ _dl_init_next (void) { /* Find each dependency in order, and see if it needs to run an initializer. */ + const char *strtab + = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); const Elf32_Dyn *d; for (d = l->l_ld; d->d_tag != DT_NULL; ++d) if (d->d_tag == DT_NEEDED) { - struct link_map *needed = _dl_map_object - (l, (const char *) (l->l_addr + d->d_un.d_ptr), NULL); + struct link_map *needed + = _dl_map_object (l, strtab + d->d_un.d_val, NULL); Elf32_Addr init; --needed->l_opencount; - init = next_init (l); /* Recurse on this dependency. */ + init = next_init (needed); /* Recurse on this dependency. */ if (init != 0) return init; } @@ -74,7 +76,7 @@ _dl_init_next (void) } /* Look for the first initializer not yet called. */ - l = _dl_loaded; + l = _dl_loaded->l_next; /* Skip the executable itself. */ do { init = next_init (l); diff --git a/elf/dl-load.c b/elf/dl-load.c index f8b37ba346..bb1ad972d4 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -158,11 +158,12 @@ _dl_map_object (struct link_map *loader, const char *name, size_t namelen = strlen (name) + 1; - void trypath (const char *dirpath) + inline void trypath (const char *dirpath) { fd = open_path (name, namelen, dirpath, &realname); } + fd = -1; if (loader && loader->l_info[DT_RPATH]) trypath ((const char *) (loader->l_addr + loader->l_info[DT_RPATH]->d_un.d_ptr)); @@ -317,14 +318,14 @@ _dl_map_object (struct link_map *loader, const char *name, if (ph->p_memsz > ph->p_filesz) { /* Extra zero pages should appear at the end of this segment, - after the data mapped from the file. Adjust MAPEND to map - only the data from the file. We will later allocate zero - pages following the data mapping. */ - caddr_t zero = mapat - mapstart + ph->p_filesz; - caddr_t zeroend = mapat - mapstart + ph->p_memsz; - caddr_t zeropage - = (caddr_t) ((Elf32_Addr) (zero + pagesize - 1) - & ~(pagesize - 1)); + after the data mapped from the file. */ + caddr_t zero, zeroend, zeropage; + + mapat += ph->p_vaddr - mapstart; + zero = mapat + ph->p_filesz; + zeroend = mapat + ph->p_memsz; + zeropage = (caddr_t) ((Elf32_Addr) (zero + pagesize - 1) + & ~(pagesize - 1)); if (zeroend < zeropage) /* All the extra data is in the last page of the segment. @@ -342,7 +343,7 @@ _dl_map_object (struct link_map *loader, const char *name, prot|PROT_WRITE) < 0) lose (errno, "cannot change memory protections"); } - memset (zero, 0, zeroend - zero); + memset (zero, 0, zeropage - zero); if ((prot & PROT_WRITE) == 0) mprotect ((caddr_t) ((Elf32_Addr) zero & ~(pagesize - 1)), diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index a7afcc79bb..4d5d795ee5 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -20,6 +20,7 @@ Cambridge, MA 02139, USA. */ #include <stddef.h> #include <libelf.h> #include <link.h> +#include <assert.h> /* Search loaded objects' symbol tables for a definition of the symbol UNDEF_NAME. Don't use a PLT defn in UNDEF_MAP, since @@ -70,13 +71,13 @@ _dl_lookup_symbol (const char *undef_name, const Elf32_Sym **ref, continue; } - if (sym == *ref) + if (sym->st_shndx == SHN_UNDEF) /* This is the same symbol we are looking for the value for. If it is a PLT entry, it will have a value of its own; but that is not what we are looking for. */ - continue; + continue; - if (strcmp (strtab + sym->st_name, undef_name)) + if (sym != *ref && strcmp (strtab + sym->st_name, undef_name)) /* Not the symbol we are looking for. */ continue; @@ -106,8 +107,8 @@ _dl_lookup_symbol (const char *undef_name, const Elf32_Sym **ref, const char msg[] = "undefined symbol: "; char buf[sizeof msg + strlen (undef_name)]; memcpy (buf, msg, sizeof msg - 1); - memcpy (&buf[sizeof msg - 1], undef_name, sizeof buf - sizeof msg); - _dl_signal_error (0, reference_name, msg); + memcpy (&buf[sizeof msg - 1], undef_name, sizeof buf - sizeof msg + 1); + _dl_signal_error (0, reference_name, buf); } *ref = weak_value.s; diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c index 94ffb71759..ebc31d07fa 100644 --- a/elf/dl-reloc.c +++ b/elf/dl-reloc.c @@ -83,7 +83,7 @@ _dl_relocate_object (struct link_map *l, int lazy) l->l_prev->l_next = l; } - if (l->l_info[DT_JMPREL] && ! lazy) + if (l->l_info[DT_JMPREL] && lazy) /* Set up the PLT so its unrelocated entries will jump to _dl_runtime_resolve, which will relocate them. */ elf_machine_runtime_setup (l); diff --git a/elf/do-rel.h b/elf/do-rel.h index 04643e8fac..acef25d3f8 100644 --- a/elf/do-rel.h +++ b/elf/do-rel.h @@ -30,37 +30,46 @@ Cambridge, MA 02139, USA. */ /* Perform the relocations in MAP on the running program image as specified by RELTAG, SZTAG. *RESOLVE is called to resolve symbol values; it modifies its argument pointer to point to the defining symbol, and - returns the base load address of the defining object. */ + returns the base load address of the defining object. If LAZY is + nonzero, this is the first pass on PLT relocations; they should be set + up to call _dl_runtime_resolve, rather than fully resolved now. */ static inline void elf_dynamic_do_rel (struct link_map *map, int reltag, int sztag, - Elf32_Addr (*resolve) (const Elf32_Sym **)) + Elf32_Addr (*resolve) (const Elf32_Sym **), + int lazy) { const Elf32_Sym *const symtab - = (const Elf32_Sym *) map->l_info[DT_SYMTAB]->d_un.d_ptr; - const Elf32_Rel *r = (const Elf32_Rel *) map->l_info[reltag]->d_un.d_ptr; + = (const Elf32_Sym *) (map->l_addr + map->l_info[DT_SYMTAB]->d_un.d_ptr); + const Elf32_Rel *r + = (const Elf32_Rel *) (map->l_addr + map->l_info[reltag]->d_un.d_ptr); const Elf32_Rel *end = &r[map->l_info[sztag]->d_un.d_val / sizeof *r]; - for (; r < end; ++r) - { - const Elf32_Sym *definer = &symtab[ELF32_R_SYM (r->r_info)]; - Elf32_Addr loadbase; + if (lazy) + /* Doing lazy PLT relocations; they need very little info. */ + for (; r < end; ++r) + elf_machine_lazy_rel (map, r); + else + for (; r < end; ++r) + { + const Elf32_Sym *definer = &symtab[ELF32_R_SYM (r->r_info)]; + Elf32_Addr loadbase; - if (ELF32_R_SYM (r->r_info) == STN_UNDEF) - loadbase = 0; /* This value will not be consulted. */ - else - { - if (resolve) - loadbase = (*resolve) (&definer); - else - { - assert (definer->st_shndx != SHN_UNDEF); - loadbase = map->l_addr; - } - } - elf_machine_rel (map, r, loadbase, definer); - } + if (ELF32_R_SYM (r->r_info) == STN_UNDEF) + loadbase = 0; /* This value will not be consulted. */ + else + { + if (resolve) + loadbase = (*resolve) (&definer); + else + { + assert (definer->st_shndx != SHN_UNDEF); + loadbase = map->l_addr; + } + } + elf_machine_rel (map, r, loadbase, definer); + } } #undef elf_dynamic_do_rel diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index fc5c585356..a7316eefe8 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -56,9 +56,9 @@ elf_get_dynamic_info (Elf32_Dyn *dyn, Elf32_Dyn *info[DT_NUM]) #include "do-rel.h" #define ELF_DYNAMIC_DO_REL(map, lazy, resolve) \ if ((map)->l_info[DT_REL]) \ - elf_dynamic_do_rel ((map), DT_REL, DT_RELSZ, (resolve)); \ - if (!(lazy) && (map)->l_info[DT_PLTREL]->d_un.d_val == DT_REL) \ - elf_dynamic_do_rel ((map), DT_JMPREL, DT_PLTRELSZ, (resolve)); + elf_dynamic_do_rel ((map), DT_REL, DT_RELSZ, (resolve), 0); \ + if ((map)->l_info[DT_PLTREL]->d_un.d_val == DT_REL) \ + elf_dynamic_do_rel ((map), DT_JMPREL, DT_PLTRELSZ, (resolve), (lazy)); #else #define ELF_DYNAMIC_DO_RELA(map, lazy, resolve) /* Nothing to do. */ #endif @@ -68,9 +68,9 @@ elf_get_dynamic_info (Elf32_Dyn *dyn, Elf32_Dyn *info[DT_NUM]) #include "do-rel.h" #define ELF_DYNAMIC_DO_RELA(map, lazy, resolve) \ if ((map)->l_info[DT_RELA]) \ - elf_dynamic_do_rela ((map), DT_RELA, DT_RELASZ, (resolve)); \ - if (!(lazy) && (map)->l_info[DT_PLTREL]->d_un.d_val == DT_RELA) \ - elf_dynamic_do_rela ((map), DT_JMPREL, DT_PLTRELSZ, (resolve); + elf_dynamic_do_rela ((map), DT_RELA, DT_RELASZ, (resolve), 0); \ + if ((map)->l_info[DT_PLTREL]->d_un.d_val == DT_RELA) \ + elf_dynamic_do_rela ((map), DT_JMPREL, DT_PLTRELSZ, (resolve), (lazy)); #else #define ELF_DYNAMIC_DO_RELA(map, lazy, resolve) /* Nothing to do. */ #endif diff --git a/elf/rtld.c b/elf/rtld.c index 85f258a948..409b9705d8 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -93,6 +93,8 @@ _dl_start (void *arg) void _start (void); +static int rtld_command; /* Nonzero if we were run directly. */ + static void dl_main (const Elf32_Phdr *phdr, Elf32_Word phent, @@ -138,6 +140,7 @@ file you run. This is mostly of use for maintainers to test new versions\n\ of this helper program; chances are you did not intend to run this program.\n" ); + rtld_command = 1; interpreter_name = _dl_argv[0]; --_dl_argc; ++_dl_argv; @@ -164,7 +167,7 @@ of this helper program; chances are you did not intend to run this program.\n" case PT_DYNAMIC: /* This tells us where to find the dynamic section, which tells us everything we need to do. */ - l->l_ld = (void *) ph->p_vaddr; + l->l_ld = (void *) l->l_addr + ph->p_vaddr; break; case PT_INTERP: /* This "interpreter segment" was used by the program loader to @@ -173,7 +176,7 @@ of this helper program; chances are you did not intend to run this program.\n" dlopen call or DT_NEEDED entry, for something that wants to link against the dynamic linker as a shared library, will know that the shared object is already loaded. */ - interpreter_name = (void *) ph->p_vaddr; + interpreter_name = (void *) l->l_addr + ph->p_vaddr; break; } assert (interpreter_name); /* How else did we get here? */ @@ -220,7 +223,7 @@ of this helper program; chances are you did not intend to run this program.\n" l->l_next->l_prev = l->l_prev; } - lazy = _dl_secure || *(getenv ("LD_BIND_NOW") ?: ""); + lazy = !_dl_secure && *(getenv ("LD_BIND_NOW") ?: "") == '\0'; /* Now we have all the objects loaded. Relocate them all. We do this in reverse order so that copy relocs of earlier diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 1797ae5b87..f387a887c1 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -75,7 +75,7 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, Elf32_Addr sym_loadaddr, const Elf32_Sym *sym) { - Elf32_Addr *const reloc_addr = (Elf32_Addr *) reloc->r_offset; + Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); const Elf32_Addr sym_value = sym_loadaddr + sym->st_value; switch (ELF32_R_TYPE (reloc->r_info)) @@ -102,6 +102,20 @@ elf_machine_rel (struct link_map *map, } } +static inline void +elf_machine_lazy_rel (struct link_map *map, const Elf32_Rel *reloc) +{ + Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_386_JMP_SLOT: + *reloc_addr += map->l_addr; + break; + default: + assert (! "unexpected PLT reloc type"); + break; + } +} /* The i386 never uses Elf32_Rela relocations. */ #define ELF_MACHINE_NO_RELA 1 @@ -113,12 +127,14 @@ elf_machine_rel (struct link_map *map, static inline void elf_machine_runtime_setup (struct link_map *l) { + Elf32_Addr *got; extern void _dl_runtime_resolve (Elf32_Word); + /* The GOT entries for functions in the PLT have not yet been filled in. Their initial contents will arrange when called to push an offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1], and then jump to _GLOBAL_OFFSET_TABLE[2]. */ - Elf32_Addr *got = (Elf32_Addr *) l->l_info[DT_PLTGOT]->d_un.d_ptr; + got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr); got[1] = (Elf32_Addr) l; /* Identify this shared object. */ /* This function will get called to fix up the GOT entry indicated by the offset on the stack, and then jump to the resolved address. */ @@ -140,9 +156,20 @@ _dl_start_user:\n\ # Save the user entry point address in %edi.\n\ movl %eax, %edi\n\ # Point %ebx at the GOT. -1: call 2f\n\ -2: popl %ebx\n\ - addl $_GLOBAL_OFFSET_TABLE_+[.-2b], %ebx\n\ + call 0f\n\ +0: popl %ebx\n\ + addl $_GLOBAL_OFFSET_TABLE_+[.-0b], %ebx\n\ + # See if we were run as a command with the executable file\n\ + # name as an extra leading argument.\n\ + movl rtld_command@GOT(%ebx), %eax\n\ + movl (%eax),%eax\n\ + testl %eax,%eax\n\ + jz 0f\n\ + # Pop the original argument count, decrement it, and replace\n\ + # the original first argument pointer with the new count.\n\ + popl %eax\n\ + decl %eax\n\ + movl %eax,(%esp)\n\ # Call _dl_init_next to return the address of an initializer\n\ # function to run.\n\ 0: call _dl_init_next@PLT\n\ @@ -150,7 +177,7 @@ _dl_start_user:\n\ testl %eax,%eax\n\ jz 1f\n\ # Call the shared object initializer function.\n\ - # NOTE: We depend only on the registers (%ebx)\n\ + # NOTE: We depend only on the registers (%ebx and %edi)\n\ # and the return address pushed by this call;\n\ # the initializer is called with the stack just\n\ # as it appears on entry, and it is free to move\n\ @@ -159,8 +186,8 @@ _dl_start_user:\n\ call *%eax\n\ # Loop to call _dl_init_next for the next initializer.\n\ jmp 0b\n\ - # Pass our finalizer function to the user in %edx, as per ELF ABI.\n\ - leal _dl_fini@GOT(%ebx), %edx\n\ +1: # Pass our finalizer function to the user in %edx, as per ELF ABI.\n\ + movl _dl_fini@GOT(%ebx), %edx\n\ # Jump to the user's entry point.\n\ jmp *%edi\n\ "); diff --git a/sysdeps/i386/dl-runtime.c b/sysdeps/i386/dl-runtime.c index 1bc569760c..8e218e2a62 100644 --- a/sysdeps/i386/dl-runtime.c +++ b/sysdeps/i386/dl-runtime.c @@ -34,15 +34,16 @@ void _dl_runtime_resolve (Elf32_Word reloc_offset) { __label__ return_insn; - struct link_map *l = (void *) &(&reloc_offset)[-1]; + struct link_map *l = (void *) (&reloc_offset)[-1]; const Elf32_Sym *const symtab - = (const Elf32_Sym *) l->l_info[DT_SYMTAB]->d_un.d_ptr; - const char *strtab - = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); + = (const Elf32_Sym *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr); + const char *strtab = + (const char *) (l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); - const Elf32_Rel *const reloc = (void *) (l->l_info[DT_JMPREL]->d_un.d_ptr - + reloc_offset); + const Elf32_Rel *const reloc + = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr + + reloc_offset); const Elf32_Sym *definer; Elf32_Addr loadbase; @@ -83,7 +84,7 @@ _dl_runtime_resolve (Elf32_Word reloc_offset) referred to by this PLT entry; once "ret" pops this address, the function in the shared object will run with the stack arranged just as when the user entered the PLT. */ - (&reloc_offset)[0] = *(Elf32_Word *) reloc->r_offset; + (&reloc_offset)[0] = *(Elf32_Word *) (l->l_addr + reloc->r_offset); return; diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c index 1dca319433..d4845213f4 100644 --- a/sysdeps/mach/hurd/dl-sysdep.c +++ b/sysdeps/mach/hurd/dl-sysdep.c @@ -36,6 +36,8 @@ Cambridge, MA 02139, USA. */ #include "dl-machine.h" +extern void __mach_init (void); + extern int _dl_argc; extern char **_dl_argv; extern char **_environ; @@ -52,8 +54,8 @@ _dl_sysdep_start (void **start_argptr, char **p; /* Cache the information in various global variables. */ - _dl_argc = *argdata++; - _dl_argv = (void *) argdata; + _dl_argc = *argdata; + _dl_argv = (void *) &argdata[1]; _environ = &_dl_argv[_dl_argc + 1]; for (p = _environ; *p; ++p); _dl_hurd_data = (void *) ++p; @@ -66,6 +68,12 @@ _dl_sysdep_start (void **start_argptr, _dl_hurd_data->phdrsz / sizeof (Elf32_Phdr), &_dl_hurd_data->user_entry); + /* Deallocate the reply port and task port rights acquired by + __mach_init. We are done with them now, and the user will + reacquire them for himself when he wants them. */ + __mig_dealloc_reply_port (MACH_PORT_NULL); + __mach_port_deallocate (__mach_task_self (), __mach_task_self_); + { extern void _dl_start_user (void); /* Unwind the stack to ARGDATA and simulate a return from _dl_start @@ -74,6 +82,9 @@ _dl_sysdep_start (void **start_argptr, } } + /* Set up so we can do RPCs. */ + __mach_init (); + /* See hurd/hurdstartup.c; this deals with getting information from the exec server and slicing up the arguments. Then it will call `go', above. */ diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c index d747e75c7d..74b15c8f2f 100644 --- a/sysdeps/mach/hurd/i386/init-first.c +++ b/sysdeps/mach/hurd/i386/init-first.c @@ -95,8 +95,8 @@ init1 (int argc, char *arg0, ...) __libc_init (argc, argv, __environ); } -static void -init (int *data, int retaddr) +static void +init (int *data, void *usercode, void **retaddrloc) { int argc = *data; char **argv = (void *) (data + 1); @@ -115,6 +115,11 @@ init (int *data, int retaddr) if (__hurd_threadvar_max < _HURD_THREADVAR_MAX) __hurd_threadvar_max = _HURD_THREADVAR_MAX; + + /* After possibly switching stacks, call `init1' (above) with the user + code as the return address, and the argument data immediately above + that on the stack. */ + if (_cthread_init_routine) { /* Initialize cthreads, which will allocate us a new stack to run on. */ @@ -136,13 +141,45 @@ init (int *data, int retaddr) /* Copy the Hurd startup data block to the new stack. */ *od = *d; - data = newsp; + /* Push the user code address on the top of the new stack. It will + be the return address for `init1'; we will jump there with NEWSP + as the stack pointer. */ + *--(void **) newsp = usercode; + /* Mutate our own return address to run the code below. */ + *retaddrloc = &&switch_stacks; + /* Force NEWSP into %ecx and &init1 into %eax, which are not restored + by function return. */ + asm volatile ("# a %0 c %1" : : "a" (&init1), "c" (newsp)); + return; + switch_stacks: + /* Our return address was redirected to here, so at this point our + stack is unwound and callers' registers restored. Only %ecx and + %eax are call-clobbered and thus still have the values we set just + above. Fetch from there the new stack pointer we will run on, and + jmp to the run-time address of `init1'; when it returns, it will + run the user code with the argument data at the top of the stack. */ + asm volatile ("movl %ecx, %esp; jmp *%eax"); + /* NOTREACHED */ + } + else + { + /* We are not switching stacks, but we must play some games with + the one we've got, similar to the stack-switching code above. */ + *retaddrloc = &&call_init1; + /* Force the user code address into %ecx and the run-time address of + `init1' into %eax, for use below. */ + asm volatile ("# a %0 c %1" : : "a" (&init1), "c" (usercode)); + return; + call_init1: + /* As in the stack-switching case, at this point our stack is unwound + and callers' registers restored, and only %ecx and %eax + communicate values from the lines above. In this case we have + stashed in %ecx the user code return address. Push it on the top + of the stack so it acts as init1's return address, and then jump + there. */ + asm volatile ("pushl %ecx; jmp *%eax"); + /* NOTREACHED */ } - - /* Call `init1' (above) with the user code as the return address, - and the argument data immediately above that on the stack. */ - *--data = retaddr; - asm volatile ("movl %0, %%esp; jmp %*%1" : : "g" (data), "r" (&init1)); } @@ -151,30 +188,32 @@ init (int *data, int retaddr) It is called just before the user _start code from i386/elf/start.S, with the stack set up as that code gets it. */ -static void soinit (int argc, ...) __attribute__ ((unused, section (".init"))); +/* NOTE! The linker notices the magical name `_init' and sets the DT_INIT + pointer in the dynamic section based solely on that. It is convention + for this function to be in the `.init' section, but the symbol name is + the only thing that really matters!! */ +/*void _init (int argc, ...) __attribute__ ((unused, section (".init")));*/ -static void -soinit (int argc, ...) +void +_init (int argc, ...) { /* Initialize data structures so we can do RPCs. */ __mach_init (); RUN_HOOK (_hurd_preinit_hook, ()); - init (&argc, (&argc)[-1]); - - (void) &soinit; /* Avoid gcc optimizing this fn out. */ + init (&argc, ((void **) &argc)[-1], &((void **) &argc)[-1]); } #endif void -__libc_init_first (int argc, ...) +__libc_init_first (int argc __attribute__ ((unused)), ...) { #ifndef PIC void doinit (int *data) { - init (data, (&argc)[-1]); + init (data, ((void **) &argc)[-1], &((void **) &data)[-1]); } /* Initialize data structures so we can do RPCs. */ |