diff options
Diffstat (limited to 'mdk-stage1/dietlibc/libdl/_dl_open.c')
| -rw-r--r-- | mdk-stage1/dietlibc/libdl/_dl_open.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/mdk-stage1/dietlibc/libdl/_dl_open.c b/mdk-stage1/dietlibc/libdl/_dl_open.c new file mode 100644 index 000000000..1f907db21 --- /dev/null +++ b/mdk-stage1/dietlibc/libdl/_dl_open.c @@ -0,0 +1,207 @@ +#include <stdio.h> +#include <unistd.h> +#include <sys/mman.h> +#include <dlfcn.h> +#include <linux/elf.h> + +#include "_dl_int.h" + +struct _dl_handle dl_test; + +#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)) + +void _dl_jump(); + +/* + * this file is a Q. & D. hack ... don't think this is bug free or meaningfull + */ + +static void *do_map_in(void *base, unsigned long length, int flags, int fd, unsigned long offset) +{ + 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 mmap(base, length, perm, MAP_PRIVATE|((base)?MAP_FIXED:0), fd, offset); +} + +unsigned long do_rel(struct _dl_handle * tmp_dl, unsigned long off) +{ +// struct _dl_handle * tmp_dl = ((void*)*((&off)-1)); + Elf32_Rel *tmp = ((void*)tmp_dl->plt_rel)+off; + int sym=ELF32_R_SYM(tmp->r_info); + register unsigned long sym_val; + + printf("do_rel %08x %08x\n",tmp_dl,off); + + printf ("do_rel %08x+%x\n",tmp_dl->plt_rel,off); + printf("do_rel @ %08x with type %d -> %d\n",tmp->r_offset,ELF32_R_TYPE(tmp->r_info),sym); + + printf("do_rel sym %08x\n",tmp_dl->dyn_sym_tab[sym].st_value); + + /* modify GOT for REAL symbol */ + sym_val=((unsigned long)(tmp_dl->mem_base+tmp_dl->dyn_sym_tab[sym].st_value)); + *((unsigned long*)(tmp_dl->mem_base+tmp->r_offset))=sym_val; + + printf("do_rel sym %08x\n",sym_val); + /* HOWTO JUMP ?!? */ + return sym_val; +} + +void *_dl_open(const char*pathname, int fd, int flag) +{ + int ps=getpagesize(); + int i; + unsigned char buf[1024]; + char *m=0,*d; + struct _dl_handle *ret=0; + + unsigned long l; + + Elf32_Ehdr *eh; + Elf32_Phdr *ph; + + int ld_nr=0; + Elf32_Phdr *ld[4]={0,0,0,0}; + Elf32_Phdr *dyn=0; + + if (fd==-1) return 0; + + printf("_dl_open: %s\n",pathname); + + read(fd, buf, 1024); + eh=(Elf32_Ehdr*)buf; + ph=(Elf32_Phdr*)&buf[eh->e_phoff]; + + for (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); + m = (char*)do_map_in(0, length, ld[0]->p_flags, fd, offset); + + /* zero pad bss */ + l = ld[0]->p_offset+ld[0]->p_filesz; + memset(m+l,0,length-l); + + dl_test.mem_base=m; + dl_test.mem_size=length; + dl_test.lnk_count=0; + + ret = &dl_test; + } + 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); + 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); + + /* mmap all mem_blocks for *.so */ + l = text_size+data_size; + + dl_test.mem_size=l; + + m = (char*) do_map_in(0,l,ld[0]->p_flags,fd,text_offset); + + /* 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_size-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); + } + + dl_test.mem_base=m; + dl_test.lnk_count=0; + ret = &dl_test; + } + + printf("_dl_open pre resolv\n"); + if (ret) { + Elf32_Dyn* dyn_tab = (void*)m+dyn->p_vaddr; + void (*init)(); + unsigned long* got=0; + void* jmprel=0; + int pltreltype=0; + int pltrelsize=0; + + printf("_dl_open IN resolv\n"); + for(i=0;dyn_tab[i].d_tag;i++) { + if (dyn_tab[i].d_tag==DT_HASH) { + ret->hash_tab = (unsigned long*)(m+dyn_tab[i].d_un.d_ptr); + } + if (dyn_tab[i].d_tag==DT_SYMTAB) { + ret->dyn_sym_tab = (Elf32_Sym*)(m+dyn_tab[i].d_un.d_ptr); + } + if (dyn_tab[i].d_tag==DT_STRTAB) { + ret->dyn_str_tab = (char*)(m+dyn_tab[i].d_un.d_ptr); + } + if (dyn_tab[i].d_tag==DT_FINI) { + ret->fini = (void(*)(void))(m+dyn_tab[i].d_un.d_val); + } + if (dyn_tab[i].d_tag==DT_INIT) { + init = (void(*)(void))(m+dyn_tab[i].d_un.d_val); + printf("init @ %08x\n",init); + } + if (dyn_tab[i].d_tag==DT_PLTGOT) { + got=(unsigned long*)(m+dyn_tab[i].d_un.d_val); + } + if (dyn_tab[i].d_tag==DT_PLTREL) { + pltreltype=dyn_tab[i].d_un.d_val; + } + if (dyn_tab[i].d_tag==DT_PLTRELSZ) { + pltrelsize=dyn_tab[i].d_un.d_val; + } + if (dyn_tab[i].d_tag==DT_JMPREL) { + jmprel=(m+dyn_tab[i].d_un.d_val); + dl_test.plt_rel=jmprel; + } + } + /* GOT */ + got[0]+=(unsigned long)m; + got[1]=(unsigned long)&dl_test; +// got[2]=(unsigned long)do_rel; + got[2]=(unsigned long)(_dl_jump); + /* */ + + if (pltreltype == DT_REL) { + Elf32_Rel *tmp = jmprel; + for (;(char*)tmp<(((char*)jmprel)+pltrelsize);(char*)tmp=((char*)tmp)+sizeof(Elf32_Rel)) { + *((unsigned long*)(m+tmp->r_offset))+=(unsigned long)m; +// *((unsigned long*)(m+tmp->r_offset))+=(unsigned long)do_rel; + printf("rel @ %08x with type %d -> %d\n",tmp->r_offset,ELF32_R_TYPE(tmp->r_info),ELF32_R_SYM(tmp->r_info)); + } + } + + printf("_dl_open post resolv, pre init\n"); + init(); + } + printf("_dl_open post resolv, init\n"); + + close(fd); + return ret; +} |