diff options
Diffstat (limited to 'mdk-stage1/dietlibc/libdl/_dl_load.c')
| -rw-r--r-- | mdk-stage1/dietlibc/libdl/_dl_load.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/mdk-stage1/dietlibc/libdl/_dl_load.c b/mdk-stage1/dietlibc/libdl/_dl_load.c new file mode 100644 index 000000000..49e8db0be --- /dev/null +++ b/mdk-stage1/dietlibc/libdl/_dl_load.c @@ -0,0 +1,401 @@ +#include <string.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <dlfcn.h> +#include <elf.h> + +#include "_dl_int.h" + +#define _ELF_DWN_ROUND(ps,n) ((n)&(~((ps)-1))) +#define _ELF_UP_ROUND(ps,n) ((((n)&((ps)-1))?(ps):0)+ _ELF_DWN_ROUND((ps),(n))) +#define _ELF_RST_ROUND(ps,n) ((n)&((ps)-1)) + +/* this is an arch specific "return jump" for the relocation */ +void _dl_jump(); + +/* + * this file is a Q. & D. hack ... don't think this is bug free or meaningfull + */ + +static inline int map_flags(int flags) +{ + int perm = 0; + if (flags & PF_X) perm|=PROT_EXEC; + if (flags & PF_R) perm|=PROT_READ; + if (flags & PF_W) perm|=PROT_WRITE; + return perm; +} + +static inline void *do_map_in(void *base, unsigned long length, int flags, int fd, unsigned long offset) +{ + register int op = MAP_PRIVATE; + if (base) op|=MAP_FIXED; + return mmap(base, length, map_flags(flags), op, fd, offset); +} + +static struct _dl_handle *_dl_map_lib(const char*fn, const char*pathname, int fd, int flags) +{ + struct _dl_handle* ret=0; + int ps=getpagesize(); + int i; + unsigned char buf[1024]; + char *m=0,*d=0; + + unsigned long l; + struct stat st; + + Elf_Ehdr *eh; + Elf_Phdr *ph; + + int ld_nr=0; + Elf_Phdr **ld=0; + Elf_Phdr *dyn=0; + + if (fd==-1) return 0; + +#ifdef DEBUG + pf(__func__": "); pf(pathname); pf("\n"); +#endif + + if (fstat(fd,&st)<0) { + close(fd); + _dl_error=2; + return 0; + } + else { + // use st_dev and st_ino for identification + } + + if (read(fd, buf, 1024)<128) { + close(fd); + _dl_error=2; + return 0; + } + + eh=(Elf_Ehdr*)buf; + ph=(Elf_Phdr*)&buf[eh->e_phoff]; + + for (i=0; i<eh->e_phnum; i++) { + if (ph[i].p_type==PT_LOAD) ++ld_nr; + } + ld=alloca(ld_nr*sizeof(Elf_Phdr)); + + for (ld_nr=i=0; i<eh->e_phnum; i++) { + if (ph[i].p_type==PT_LOAD) { + ld[ld_nr++]=ph+i; + } + if (ph[i].p_type==PT_DYNAMIC) { + dyn=ph+i; + } + } + + if (ld_nr==1) { + unsigned long offset = _ELF_DWN_ROUND(ps,ld[0]->p_offset); + unsigned long off = _ELF_RST_ROUND(ps,ld[0]->p_offset); + unsigned long length = _ELF_UP_ROUND(ps,ld[0]->p_memsz+off); + ret = _dl_get_handle(); + + m = (char*)do_map_in(0, length, ld[0]->p_flags, fd, offset); + if (m==MAP_FAILED) { _dl_free_handle(ret); close(fd); return 0; } + + /* zero pad bss */ + l = ld[0]->p_offset+ld[0]->p_filesz; + memset(m+l,0,length-l); + + ret->mem_base=m; + ret->mem_size=length; + } + else if (ld_nr==2) { /* aem... yes Quick & Really Dirty / for the avarage 99% */ +// unsigned long text_addr = _ELF_DWN_ROUND(ps,ld[0]->p_vaddr); /* do we need this ? */ + unsigned long text_offset = _ELF_DWN_ROUND(ps,ld[0]->p_offset); + unsigned long text_off = _ELF_RST_ROUND(ps,ld[0]->p_offset); + unsigned long text_size = _ELF_UP_ROUND(ps,ld[0]->p_memsz+text_off); + + unsigned long data_addr = _ELF_DWN_ROUND(ps,ld[1]->p_vaddr); + unsigned long data_offset = _ELF_DWN_ROUND(ps,ld[1]->p_offset); + unsigned long data_off = _ELF_RST_ROUND(ps,ld[1]->p_offset); + unsigned long data_size = _ELF_UP_ROUND(ps,ld[1]->p_memsz+data_off); + unsigned long data_fsize = _ELF_UP_ROUND(ps,ld[1]->p_filesz+data_off); + + ret = _dl_get_handle(); + /* mmap all mem_blocks for *.so */ + m = (char*) do_map_in(0,text_size+data_size,ld[0]->p_flags,fd,text_offset); + if (m==MAP_FAILED) { _dl_free_handle(ret); close(fd); return 0; } + + /* release data,bss part */ + mprotect(m+data_addr, data_size, PROT_NONE); + + /* mmap data,bss part */ + d = (char*) do_map_in(m+data_addr,data_fsize,ld[1]->p_flags,fd,data_offset); + + /* zero pad bss */ + l = data_off+ld[1]->p_filesz; + memset(d+l,0,data_fsize-l); + + /* more bss ? */ + if (data_size>data_fsize) { + l = data_size-data_fsize; + mmap(d+data_fsize, l, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); + } + + ret->mem_base=m; + ret->mem_size=text_size+data_size; + } + + if (ret) { + ret->lnk_count=1; + ret->name=strdup(fn); + ret->dyn_str_tab=(char*)m+dyn->p_vaddr; /* missuse of field */ + } + + close(fd); + return ret; +} + +/* local alias */ +static struct _dl_handle* __dl_dyn_scan(struct _dl_handle* dh, void* dyn_addr, int flags) +__attribute__ ((alias("_dl_dyn_scan"))); + +struct _dl_handle* _dl_dyn_scan(struct _dl_handle* dh, void* dyn_addr, int flags) +{ + Elf_Dyn* dyn_tab = dyn_addr; + + void (*init)()=0; + unsigned long* got=0; + void* jmprel=0; + int pltreltype=0; + int pltrelsize=0; + unsigned long rel=0; + int relent=0; + int relsize=0; + + int i; + +#ifdef DEBUG + pf(__func__": pre dynamic scan "); ph((unsigned long)dh); pf("\n"); +#endif + dh->dyn_str_tab=0; + dh->flags=flags; + + for(i=0;dyn_tab[i].d_tag;i++) { +// DEBUG(printf("_dl_load dyn %d, %08lx\n",dyn_tab[i].d_tag, dyn_tab[i].d_un.d_val);) + if (dyn_tab[i].d_tag==DT_HASH) { + dh->hash_tab = (unsigned long*)(dh->mem_base+dyn_tab[i].d_un.d_ptr); +#ifdef DEBUG + pf(__func__": have hash @ "); ph((long)dh->hash_tab); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_SYMTAB) { + dh->dyn_sym_tab = (Elf_Sym*)(dh->mem_base+dyn_tab[i].d_un.d_ptr); +#ifdef DEBUG + pf(__func__": have dyn_sym_tab @ "); ph((long)dh->dyn_sym_tab); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_STRTAB) { + dh->dyn_str_tab = (char*)(dh->mem_base+dyn_tab[i].d_un.d_ptr); +#ifdef DEBUG + pf(__func__": have dyn_str_tab @ "); ph((long)dh->dyn_str_tab); pf("\n"); +#endif + } + + /* INIT / FINI */ + else if (dyn_tab[i].d_tag==DT_FINI) { + dh->fini = (void(*)(void))(dh->mem_base+dyn_tab[i].d_un.d_val); +#ifdef DEBUG + pf(__func__": have fini @ "); ph((long)dh->fini); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_INIT) { + init = (void(*)(void))(dh->mem_base+dyn_tab[i].d_un.d_val); +#ifdef DEBUG + pf(__func__": have init @ "); ph((long)init); pf("\n"); +#endif + } + + /* PLT / Relocation entries for PLT in GOT */ + else if (dyn_tab[i].d_tag==DT_PLTGOT) { + got=(unsigned long*)(dh->mem_base+dyn_tab[i].d_un.d_val); + dh->pltgot=got; +#ifdef DEBUG + pf(__func__": have plt got @ "); ph((long)dh->pltgot); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_PLTREL) { + pltreltype=dyn_tab[i].d_un.d_val; +#ifdef DEBUG + pf(__func__": have pltreltype @ "); ph((long)pltreltype); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_PLTRELSZ) { + pltrelsize=dyn_tab[i].d_un.d_val; +#ifdef DEBUG + pf(__func__": have pltrelsize @ "); ph((long)pltrelsize); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_JMPREL) { + jmprel=(dh->mem_base+dyn_tab[i].d_un.d_val); + dh->plt_rel=jmprel; +#ifdef DEBUG + pf(__func__": have jmprel @ "); ph((long)jmprel); pf("\n"); +#endif + } + + /* Relocation */ + else if (dyn_tab[i].d_tag==DT_REL) { + rel=(unsigned long)(dh->mem_base+dyn_tab[i].d_un.d_val); +#ifdef DEBUG + pf(__func__": have rel @ "); ph((long)rel); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_RELENT) { + relent=dyn_tab[i].d_un.d_val; +#ifdef DEBUG + pf(__func__": have relent @ "); ph((long)relent); pf("\n"); +#endif + } + else if (dyn_tab[i].d_tag==DT_RELSZ) { + relsize=dyn_tab[i].d_un.d_val; +#ifdef DEBUG + pf(__func__": have relsize @ "); ph((long)relsize); pf("\n"); +#endif + } + + else if (dyn_tab[i].d_tag==DT_TEXTREL) { + _dl_free_handle(dh); + _dl_error = 3; + return 0; + } + } + /* extra scan for rpath (if program) ... */ + if (dh->name==0) { + for(i=0;dyn_tab[i].d_tag;i++) { + if (dyn_tab[i].d_tag==DT_RPATH) { + char *rpath=dh->dyn_str_tab+dyn_tab[i].d_un.d_val; + _dl_set_rpath(rpath); +#ifdef DEBUG + pf(__func__": have runpath: "); pf(rpath); pf("\n"); +#endif + } + } + } + +#ifdef DEBUG + pf(__func__": post dynamic scan "); ph((unsigned long)dh); pf("\n"); +#endif + + if ((got=_dlsym(dh,"_GLOBAL_OFFSET_TABLE_"))) { +#ifdef DEBUG + pf(__func__": found a GOT @ "); ph((unsigned long)got); pf("\n"); +#endif + /* GOT */ + got[0]+=(unsigned long)dh->mem_base; /* reloc dynamic pointer */ + got[1] =(unsigned long)dh; + got[2] =(unsigned long)(_dl_jump); /* sysdep jump to _dl_rel */ + /* */ + } + else { + if (dh) { + munmap(dh->mem_base,dh->mem_size); + _dl_free_handle(dh); + } + _dl_error = 3; + return 0; + } + + /* load other libs */ + for(i=0;dyn_tab[i].d_tag;i++) { + if (dyn_tab[i].d_tag==DT_NEEDED) { + char *lib_name=dh->dyn_str_tab+dyn_tab[i].d_un.d_val; +#ifdef DEBUG + pf(__func__": needed for this lib: "); pf(lib_name); pf("\n"); +#endif + _dl_queue_lib(lib_name,flags); + } + } + + if (_dl_open_dep()) { + _dl_error = 1; + return 0; + } + + /* relocate */ + if (rel) { +#ifdef DEBUG + pf(__func__": try to relocate some values\n"); +#endif + if (_dl_relocate(dh,(Elf_Rel*)rel,relsize/relent)) { + munmap(dh->mem_base,dh->mem_size); + _dl_free_handle(dh); + return 0; + } + } + + /* do PTL / GOT relocation */ + if (pltreltype == DT_REL) { + Elf_Rel *tmp = jmprel; +#ifdef DEBUG + pf(__func__": rel got\n"); +#endif + for (;(char*)tmp<(((char*)jmprel)+pltrelsize);(char*)tmp=((char*)tmp)+sizeof(Elf_Rel)) { + if ((flags&RTLD_NOW)) { + unsigned long sym=(unsigned long)_dl_sym(dh,ELF_R_SYM(tmp->r_info)); + if (sym) *((unsigned long*)(dh->mem_base+tmp->r_offset))=sym; + else { + _dl_free_handle(dh); + _dl_error = 4; + return 0; + } + } + else + *((unsigned long*)(dh->mem_base+tmp->r_offset))+=(unsigned long)dh->mem_base; +#if 0 + DEBUG("_dl_load rel @ %08lx with type %d -> %d\n",(long)dh->mem_base+tmp->r_offset,ELF_R_TYPE(tmp->r_info),ELF_R_SYM(tmp->r_info)); + DEBUG("_dl_load -> %08lx\n",*((unsigned long*)(dh->mem_base+tmp->r_offset))); +#endif + } + } + if (pltreltype == DT_RELA) { + Elf_Rela *tmp = jmprel; +#ifdef DEBUG + pf(__func__": rela got\n"); +#endif + for (;(char*)tmp<(((char*)jmprel)+pltrelsize);(char*)tmp=((char*)tmp)+sizeof(Elf_Rela)) { + if ((flags&RTLD_NOW)) { + unsigned long sym=(unsigned long)_dl_sym(dh,ELF_R_SYM(tmp->r_info)); + if (sym) *((unsigned long*)(dh->mem_base+tmp->r_offset))=sym; + else { + _dl_free_handle(dh); + _dl_error = 4; + return 0; + } + } + else + *((unsigned long*)(dh->mem_base+tmp->r_offset))=(unsigned long)(dh->mem_base+tmp->r_addend); +#if 0 + DEBUG("_dl_load rela @ %08lx with type %d -> %d\n",(long)dh->mem_base+tmp->r_offset,ELF_R_TYPE(tmp->r_info),ELF_R_SYM(tmp->r_info)); + DEBUG("_dl_load -> %08lx\n",*((unsigned long*)(dh->mem_base+tmp->r_offset))); +#endif + } + } + + /* _dl_load depending libs ... */ +#ifdef DEBUG + pf(__func__": post resolve, pre init\n"); +#endif + if (init) init(); +#ifdef DEBUG + pf(__func__": post init\n"); +#endif + + return dh; +} + +void *_dl_load(const char*fn, const char*pathname, int fd, int flags) +{ + struct _dl_handle* ret=0; + if ((ret=_dl_map_lib(fn,pathname,fd,flags))) { + ret=__dl_dyn_scan(ret,(void*)(ret->dyn_str_tab),flags); + } + return ret; +} |