Preliminary BSD user emulator support

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5544 c046a42c-6fe2-441c-8c8c-71466251a162

bsd-user/bsdload.c

@@ -0,0 +1,204 @@
+/* Code for loading BSD executables.  Mostly linux kernel code.  */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "qemu.h"
+
+#define NGROUPS 32
+
+/* ??? This should really be somewhere else.  */
+abi_long memcpy_to_target(abi_ulong dest, const void *src,
+                          unsigned long len)
+{
+    void *host_ptr;
+
+    host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
+    if (!host_ptr)
+        return -TARGET_EFAULT;
+    memcpy(host_ptr, src, len);
+    unlock_user(host_ptr, dest, 1);
+    return 0;
+}
+
+static int in_group_p(gid_t g)
+{
+    /* return TRUE if we're in the specified group, FALSE otherwise */
+    int         ngroup;
+    int         i;
+    gid_t       grouplist[NGROUPS];
+
+    ngroup = getgroups(NGROUPS, grouplist);
+    for(i = 0; i < ngroup; i++) {
+        if(grouplist[i] == g) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int count(char ** vec)
+{
+    int         i;
+
+    for(i = 0; *vec; i++) {
+        vec++;
+    }
+
+    return(i);
+}
+
+static int prepare_binprm(struct linux_binprm *bprm)
+{
+    struct stat         st;
+    int mode;
+    int retval, id_change;
+
+    if(fstat(bprm->fd, &st) < 0) {
+        return(-errno);
+    }
+
+    mode = st.st_mode;
+    if(!S_ISREG(mode)) {        /* Must be regular file */
+        return(-EACCES);
+    }
+    if(!(mode & 0111)) {        /* Must have at least one execute bit set */
+        return(-EACCES);
+    }
+
+    bprm->e_uid = geteuid();
+    bprm->e_gid = getegid();
+    id_change = 0;
+
+    /* Set-uid? */
+    if(mode & S_ISUID) {
+        bprm->e_uid = st.st_uid;
+        if(bprm->e_uid != geteuid()) {
+            id_change = 1;
+        }
+    }
+
+    /* Set-gid? */
+    /*
+     * If setgid is set but no group execute bit then this
+     * is a candidate for mandatory locking, not a setgid
+     * executable.
+     */
+    if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
+        bprm->e_gid = st.st_gid;
+        if (!in_group_p(bprm->e_gid)) {
+                id_change = 1;
+        }
+    }
+
+    memset(bprm->buf, 0, sizeof(bprm->buf));
+    retval = lseek(bprm->fd, 0L, SEEK_SET);
+    if(retval >= 0) {
+        retval = read(bprm->fd, bprm->buf, 128);
+    }
+    if(retval < 0) {
+        perror("prepare_binprm");
+        exit(-1);
+        /* return(-errno); */
+    }
+    else {
+        return(retval);
+    }
+}
+
+/* Construct the envp and argv tables on the target stack.  */
+abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
+                              abi_ulong stringp, int push_ptr)
+{
+    int n = sizeof(abi_ulong);
+    abi_ulong envp;
+    abi_ulong argv;
+
+    sp -= (envc + 1) * n;
+    envp = sp;
+    sp -= (argc + 1) * n;
+    argv = sp;
+    if (push_ptr) {
+        /* FIXME - handle put_user() failures */
+        sp -= n;
+        put_user_ual(envp, sp);
+        sp -= n;
+        put_user_ual(argv, sp);
+    }
+    sp -= n;
+    /* FIXME - handle put_user() failures */
+    put_user_ual(argc, sp);
+
+    while (argc-- > 0) {
+        /* FIXME - handle put_user() failures */
+        put_user_ual(stringp, argv);
+        argv += n;
+        stringp += target_strlen(stringp) + 1;
+    }
+    /* FIXME - handle put_user() failures */
+    put_user_ual(0, argv);
+    while (envc-- > 0) {
+        /* FIXME - handle put_user() failures */
+        put_user_ual(stringp, envp);
+        envp += n;
+        stringp += target_strlen(stringp) + 1;
+    }
+    /* FIXME - handle put_user() failures */
+    put_user_ual(0, envp);
+
+    return sp;
+}
+
+int loader_exec(const char * filename, char ** argv, char ** envp,
+             struct target_pt_regs * regs, struct image_info *infop)
+{
+    struct linux_binprm bprm;
+    int retval;
+    int i;
+
+    bprm.p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
+    for (i=0 ; i<MAX_ARG_PAGES ; i++)       /* clear page-table */
+            bprm.page[i] = 0;
+    retval = open(filename, O_RDONLY);
+    if (retval < 0)
+        return retval;
+    bprm.fd = retval;
+    bprm.filename = (char *)filename;
+    bprm.argc = count(argv);
+    bprm.argv = argv;
+    bprm.envc = count(envp);
+    bprm.envp = envp;
+
+    retval = prepare_binprm(&bprm);
+
+    infop->host_argv = argv;
+
+    if(retval>=0) {
+        if (bprm.buf[0] == 0x7f
+                && bprm.buf[1] == 'E'
+                && bprm.buf[2] == 'L'
+                && bprm.buf[3] == 'F') {
+            retval = load_elf_binary(&bprm,regs,infop);
+        } else {
+            fprintf(stderr, "Unknown binary format\n");
+            return -1;
+        }
+    }
+
+    if(retval>=0) {
+        /* success.  Initialize important registers */
+        do_init_thread(regs, infop);
+        return retval;
+    }
+
+    /* Something went wrong, return the inode and free the argument pages*/
+    for (i=0 ; i<MAX_ARG_PAGES ; i++) {
+        free(bprm.page[i]);
+    }
+    return(retval);
+}