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![Matthew Wilcox](/assets/img/avatar_default.png)
Fix compilation (missing include of a.out.h) Fix security hole (need to call unshare_files) Signed-off-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
321 lines
7.8 KiB
C
321 lines
7.8 KiB
C
/*
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* linux/fs/binfmt_som.c
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*
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* These are the functions used to load SOM format executables as used
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* by HP-UX.
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*
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* Copyright 1999 Matthew Wilcox <willy@bofh.ai>
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* based on binfmt_elf which is
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* Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/stat.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/binfmts.h>
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#include <linux/som.h>
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#include <linux/string.h>
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#include <linux/file.h>
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#include <linux/fcntl.h>
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#include <linux/ptrace.h>
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#include <linux/slab.h>
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#include <linux/shm.h>
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#include <linux/personality.h>
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#include <linux/init.h>
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#include <asm/a.out.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <linux/elf.h>
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static int load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs);
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static int load_som_library(struct file *);
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/*
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* If we don't support core dumping, then supply a NULL so we
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* don't even try.
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*/
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#if 0
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static int som_core_dump(long signr, struct pt_regs * regs);
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#else
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#define som_core_dump NULL
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#endif
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#define SOM_PAGESTART(_v) ((_v) & ~(unsigned long)(SOM_PAGESIZE-1))
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#define SOM_PAGEOFFSET(_v) ((_v) & (SOM_PAGESIZE-1))
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#define SOM_PAGEALIGN(_v) (((_v) + SOM_PAGESIZE - 1) & ~(SOM_PAGESIZE - 1))
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static struct linux_binfmt som_format = {
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.module = THIS_MODULE,
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.load_binary = load_som_binary,
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.load_shlib = load_som_library,
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.core_dump = som_core_dump,
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.min_coredump = SOM_PAGESIZE
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};
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/*
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* create_som_tables() parses the env- and arg-strings in new user
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* memory and creates the pointer tables from them, and puts their
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* addresses on the "stack", returning the new stack pointer value.
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*/
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static void create_som_tables(struct linux_binprm *bprm)
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{
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char **argv, **envp;
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int argc = bprm->argc;
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int envc = bprm->envc;
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unsigned long p;
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unsigned long *sp;
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/* Word-align the stack pointer */
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sp = (unsigned long *)((bprm->p + 3) & ~3);
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envp = (char **) sp;
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sp += envc + 1;
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argv = (char **) sp;
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sp += argc + 1;
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__put_user((unsigned long) envp,++sp);
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__put_user((unsigned long) argv,++sp);
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__put_user(argc, ++sp);
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bprm->p = (unsigned long) sp;
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p = current->mm->arg_start;
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while (argc-- > 0) {
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__put_user((char *)p,argv++);
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p += strlen_user((char *)p);
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}
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__put_user(NULL, argv);
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current->mm->arg_end = current->mm->env_start = p;
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while (envc-- > 0) {
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__put_user((char *)p,envp++);
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p += strlen_user((char *)p);
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}
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__put_user(NULL, envp);
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current->mm->env_end = p;
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}
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static int check_som_header(struct som_hdr *som_ex)
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{
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int *buf = (int *)som_ex;
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int i, ck;
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if (som_ex->system_id != SOM_SID_PARISC_1_0 &&
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som_ex->system_id != SOM_SID_PARISC_1_1 &&
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som_ex->system_id != SOM_SID_PARISC_2_0)
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return -ENOEXEC;
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if (som_ex->a_magic != SOM_EXEC_NONSHARE &&
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som_ex->a_magic != SOM_EXEC_SHARE &&
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som_ex->a_magic != SOM_EXEC_DEMAND)
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return -ENOEXEC;
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if (som_ex->version_id != SOM_ID_OLD &&
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som_ex->version_id != SOM_ID_NEW)
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return -ENOEXEC;
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ck = 0;
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for (i=0; i<32; i++)
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ck ^= buf[i];
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if (ck != 0)
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return -ENOEXEC;
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return 0;
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}
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static int map_som_binary(struct file *file,
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const struct som_exec_auxhdr *hpuxhdr)
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{
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unsigned long code_start, code_size, data_start, data_size;
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unsigned long bss_start, som_brk;
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int retval;
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int prot = PROT_READ | PROT_EXEC;
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int flags = MAP_FIXED|MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE;
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mm_segment_t old_fs = get_fs();
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set_fs(get_ds());
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code_start = SOM_PAGESTART(hpuxhdr->exec_tmem);
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code_size = SOM_PAGEALIGN(hpuxhdr->exec_tsize);
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current->mm->start_code = code_start;
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current->mm->end_code = code_start + code_size;
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down_write(¤t->mm->mmap_sem);
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retval = do_mmap(file, code_start, code_size, prot,
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flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
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up_write(¤t->mm->mmap_sem);
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if (retval < 0 && retval > -1024)
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goto out;
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data_start = SOM_PAGESTART(hpuxhdr->exec_dmem);
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data_size = SOM_PAGEALIGN(hpuxhdr->exec_dsize);
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current->mm->start_data = data_start;
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current->mm->end_data = bss_start = data_start + data_size;
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down_write(¤t->mm->mmap_sem);
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retval = do_mmap(file, data_start, data_size,
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prot | PROT_WRITE, flags,
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SOM_PAGESTART(hpuxhdr->exec_dfile));
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up_write(¤t->mm->mmap_sem);
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if (retval < 0 && retval > -1024)
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goto out;
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som_brk = bss_start + SOM_PAGEALIGN(hpuxhdr->exec_bsize);
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current->mm->start_brk = current->mm->brk = som_brk;
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down_write(¤t->mm->mmap_sem);
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retval = do_mmap(NULL, bss_start, som_brk - bss_start,
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prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE, 0);
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up_write(¤t->mm->mmap_sem);
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if (retval > 0 || retval < -1024)
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retval = 0;
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out:
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set_fs(old_fs);
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return retval;
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}
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/*
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* These are the functions used to load SOM executables and shared
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* libraries. There is no binary dependent code anywhere else.
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*/
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static int
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load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
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{
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int som_exec_fileno;
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int retval;
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unsigned int size;
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unsigned long som_entry;
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struct som_hdr *som_ex;
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struct som_exec_auxhdr *hpuxhdr;
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struct files_struct *files;
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/* Get the exec-header */
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som_ex = (struct som_hdr *) bprm->buf;
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retval = check_som_header(som_ex);
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if (retval != 0)
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goto out;
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/* Now read in the auxiliary header information */
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retval = -ENOMEM;
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size = som_ex->aux_header_size;
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if (size > SOM_PAGESIZE)
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goto out;
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hpuxhdr = kmalloc(size, GFP_KERNEL);
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if (!hpuxhdr)
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goto out;
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retval = kernel_read(bprm->file, som_ex->aux_header_location,
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(char *) hpuxhdr, size);
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if (retval != size) {
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if (retval >= 0)
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retval = -EIO;
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goto out_free;
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}
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files = current->files; /* Refcounted so ok */
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retval = unshare_files();
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if (retval < 0)
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goto out_free;
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if (files == current->files) {
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put_files_struct(files);
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files = NULL;
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}
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retval = get_unused_fd();
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if (retval < 0)
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goto out_free;
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get_file(bprm->file);
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fd_install(som_exec_fileno = retval, bprm->file);
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/* Flush all traces of the currently running executable */
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retval = flush_old_exec(bprm);
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if (retval)
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goto out_free;
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/* OK, This is the point of no return */
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current->flags &= ~PF_FORKNOEXEC;
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current->personality = PER_HPUX;
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/* Set the task size for HP-UX processes such that
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* the gateway page is outside the address space.
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* This can be fixed later, but for now, this is much
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* easier.
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*/
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current->thread.task_size = 0xc0000000;
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/* Set map base to allow enough room for hp-ux heap growth */
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current->thread.map_base = 0x80000000;
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retval = map_som_binary(bprm->file, hpuxhdr);
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if (retval < 0)
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goto out_free;
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som_entry = hpuxhdr->exec_entry;
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kfree(hpuxhdr);
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set_binfmt(&som_format);
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compute_creds(bprm);
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setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
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create_som_tables(bprm);
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current->mm->start_stack = bprm->p;
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#if 0
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printk("(start_brk) %08lx\n" , (unsigned long) current->mm->start_brk);
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printk("(end_code) %08lx\n" , (unsigned long) current->mm->end_code);
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printk("(start_code) %08lx\n" , (unsigned long) current->mm->start_code);
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printk("(end_data) %08lx\n" , (unsigned long) current->mm->end_data);
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printk("(start_stack) %08lx\n" , (unsigned long) current->mm->start_stack);
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printk("(brk) %08lx\n" , (unsigned long) current->mm->brk);
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#endif
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map_hpux_gateway_page(current,current->mm);
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start_thread_som(regs, som_entry, bprm->p);
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if (current->ptrace & PT_PTRACED)
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send_sig(SIGTRAP, current, 0);
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return 0;
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/* error cleanup */
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out_free:
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kfree(hpuxhdr);
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out:
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return retval;
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}
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static int load_som_library(struct file *f)
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{
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/* No lib support in SOM yet. gizza chance.. */
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return -ENOEXEC;
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}
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/* Install the SOM loader.
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* N.B. We *rely* on the table being the right size with the
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* right number of free slots...
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*/
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static int __init init_som_binfmt(void)
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{
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return register_binfmt(&som_format);
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}
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static void __exit exit_som_binfmt(void)
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{
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/* Remove the SOM loader. */
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unregister_binfmt(&som_format);
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}
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core_initcall(init_som_binfmt);
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module_exit(exit_som_binfmt);
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