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minix3/servers/vfs/exec.c

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/* This file handles the EXEC system call. It performs the work as follows:
* - see if the permissions allow the file to be executed
* - read the header and extract the sizes
* - fetch the initial args and environment from the user space
* - allocate the memory for the new process
* - copy the initial stack from PM to the process
* - read in the text and data segments and copy to the process
* - take care of setuid and setgid bits
* - fix up 'mproc' table
* - tell kernel about EXEC
* - save offset to initial argc (for ps)
*
* The entry points into this file are:
* pm_exec: perform the EXEC system call
*/
#include "fs.h"
#include <sys/stat.h>
#include <sys/mman.h>
#include <minix/callnr.h>
#include <minix/endpoint.h>
#include <minix/com.h>
#include <minix/u64.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <sys/dirent.h>
#include <sys/exec.h>
#include <sys/param.h>
#include "path.h"
#include "vnode.h"
#include "file.h"
#include <minix/vfsif.h>
#include <machine/vmparam.h>
#include <assert.h>
#include <fcntl.h>
#define _KERNEL /* for ELF_AUX_ENTRIES */
#include <libexec.h>
/* fields only used by elf and in VFS */
struct vfs_exec_info {
struct exec_info args; /* libexec exec args */
struct vnode *vp; /* Exec file's vnode */
struct vmnt *vmp; /* Exec file's vmnt */
struct stat sb; /* Exec file's stat structure */
int userflags; /* exec() flags from userland */
int is_dyn; /* Dynamically linked executable */
int elf_main_fd; /* Dyn: FD of main program execuatble */
char execname[PATH_MAX]; /* Full executable invocation */
int vmfd;
int vmfd_used;
};
static int patch_stack(struct vnode *vp, char stack[ARG_MAX],
size_t *stk_bytes, char path[PATH_MAX], vir_bytes *vsp);
static int is_script(struct vfs_exec_info *execi);
static int insert_arg(char stack[ARG_MAX], size_t *stk_bytes, char *arg,
vir_bytes *vsp, char replace);
static void clo_exec(struct fproc *rfp);
static int stack_prepare_elf(struct vfs_exec_info *execi,
char *curstack, size_t *frame_len, vir_bytes *vsp);
static int map_header(struct vfs_exec_info *execi);
static int read_seg(struct exec_info *execi, off_t off, vir_bytes seg_addr, size_t seg_bytes);
#define PTRSIZE sizeof(char *) /* Size of pointers in argv[] and envp[]. */
/* Array of loaders for different object file formats */
typedef int (*exechook_t)(struct vfs_exec_info *execpackage);
typedef int (*stackhook_t)(struct vfs_exec_info *execi, char *curstack,
size_t *frame_len, vir_bytes *vsp);
struct exec_loaders {
libexec_exec_loadfunc_t load_object; /* load executable into memory */
stackhook_t setup_stack; /* prepare stack before argc and argv push */
};
static const struct exec_loaders exec_loaders[] = {
{ libexec_load_elf, stack_prepare_elf },
{ NULL, NULL }
};
#define lock_exec() lock_proc(fproc_addr(VM_PROC_NR))
#define unlock_exec() unlock_proc(fproc_addr(VM_PROC_NR))
/*===========================================================================*
* get_read_vp *
*===========================================================================*/
static int get_read_vp(struct vfs_exec_info *execi,
char *fullpath, int copyprogname, int sugid, struct lookup *resolve, struct fproc *fp)
{
/* Make the executable that we want to exec() into the binary pointed
* to by 'fullpath.' This function fills in necessary details in the execi
* structure, such as opened vnode. It unlocks and releases the vnode if
* it was already there. This makes it easy to change the executable
* during the exec(), which is often necessary, by calling this function
* more than once. This is specifically necessary when we discover the
* executable is actually a script or a dynamically linked executable.
*/
int r;
/* Caller wants to switch vp to the file in 'fullpath.'
* unlock and put it first if there is any there.
*/
if(execi->vp) {
unlock_vnode(execi->vp);
put_vnode(execi->vp);
execi->vp = NULL;
}
/* Remember/overwrite the executable name if requested. */
if(copyprogname) {
char *cp = strrchr(fullpath, '/');
if(cp) cp++;
else cp = fullpath;
strlcpy(execi->args.progname, cp, sizeof(execi->args.progname));
execi->args.progname[sizeof(execi->args.progname)-1] = '\0';
}
/* Open executable */
if ((execi->vp = eat_path(resolve, fp)) == NULL)
return err_code;
unlock_vmnt(execi->vmp);
if (!S_ISREG(execi->vp->v_mode))
return ENOEXEC;
else if ((r = forbidden(fp, execi->vp, X_BIT)) != OK)
return r;
else
r = req_stat(execi->vp->v_fs_e, execi->vp->v_inode_nr,
VFS_PROC_NR, (vir_bytes) &(execi->sb));
if (r != OK) return r;
/* If caller wants us to, honour suid/guid mode bits. */
if (sugid) {
/* Deal with setuid/setgid executables */
if (execi->vp->v_mode & I_SET_UID_BIT) {
execi->args.new_uid = execi->vp->v_uid;
execi->args.allow_setuid = 1;
}
if (execi->vp->v_mode & I_SET_GID_BIT) {
execi->args.new_gid = execi->vp->v_gid;
execi->args.allow_setuid = 1;
}
}
/* Read in first chunk of file. */
if((r=map_header(execi)) != OK)
return r;
return OK;
}
#define FAILCHECK(expr) if((r=(expr)) != OK) { goto pm_execfinal; } while(0)
#define Get_read_vp(e,f,p,s,rs,fp) do { \
r=get_read_vp(&e,f,p,s,rs,fp); if(r != OK) { FAILCHECK(r); } \
} while(0)
static int vfs_memmap(struct exec_info *execi,
vir_bytes vaddr, vir_bytes len, vir_bytes foffset, u16_t clearend,
int protflags)
{
struct vfs_exec_info *vi = (struct vfs_exec_info *) execi->opaque;
struct vnode *vp = ((struct vfs_exec_info *) execi->opaque)->vp;
int r;
u16_t flags = 0;
if(protflags & PROT_WRITE)
flags |= MVM_WRITABLE;
r = minix_vfs_mmap(execi->proc_e, foffset, len,
vp->v_dev, vp->v_inode_nr, vi->vmfd, vaddr, clearend, flags);
if(r == OK) {
vi->vmfd_used = 1;
}
return r;
}
/*===========================================================================*
* pm_exec *
*===========================================================================*/
int pm_exec(vir_bytes path, size_t path_len, vir_bytes frame, size_t frame_len,
vir_bytes *pc, vir_bytes *newsp, vir_bytes *UNUSED(ps_str))
{
/* Perform the execve(name, argv, envp) call. The user library builds a
* complete stack image, including pointers, args, environ, etc. The stack
* is copied to a buffer inside VFS, and then to the new core image.
*
* ps_str is not currently used, but may be if the ps_strings structure has to
* be moved to another location.
*/
int r;
vir_bytes vsp;
static char mbuf[ARG_MAX]; /* buffer for stack and zeroes */
struct vfs_exec_info execi;
int i;
static char fullpath[PATH_MAX],
elf_interpreter[PATH_MAX],
firstexec[PATH_MAX],
finalexec[PATH_MAX];
struct lookup resolve;
struct fproc *vmfp = fproc_addr(VM_PROC_NR);
stackhook_t makestack = NULL;
struct filp *newfilp = NULL;
lock_exec();
/* unset execi values are 0. */
memset(&execi, 0, sizeof(execi));
execi.vmfd = -1;
/* passed from exec() libc code */
execi.userflags = 0;
execi.args.stack_high = kinfo.user_sp;
execi.args.stack_size = DEFAULT_STACK_LIMIT;
fp->text_size = 0;
fp->data_size = 0;
lookup_init(&resolve, fullpath, PATH_NOFLAGS, &execi.vmp, &execi.vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
/* Fetch the stack from the user before destroying the old core image. */
if (frame_len > ARG_MAX)
FAILCHECK(ENOMEM); /* stack too big */
r = sys_datacopy_wrapper(fp->fp_endpoint, (vir_bytes) frame, SELF, (vir_bytes) mbuf,
(size_t) frame_len);
if (r != OK) { /* can't fetch stack (e.g. bad virtual addr) */
printf("VFS: pm_exec: sys_datacopy failed\n");
FAILCHECK(r);
}
/* Compute the current virtual stack pointer, has to be done before calling
* patch_stack, which needs it, and will adapt as required. */
vsp = execi.args.stack_high - frame_len;
/* The default is to keep the original user and group IDs */
execi.args.new_uid = fp->fp_effuid;
execi.args.new_gid = fp->fp_effgid;
/* Get the exec file name. */
FAILCHECK(fetch_name(path, path_len, fullpath));
strlcpy(finalexec, fullpath, PATH_MAX);
strlcpy(firstexec, fullpath, PATH_MAX);
/* Get_read_vp will return an opened vn in execi.
* if necessary it releases the existing vp so we can
* switch after we find out what's inside the file.
* It reads the start of the file.
*/
Get_read_vp(execi, fullpath, 1, 1, &resolve, fp);
/* If this is a script (i.e. has a #!/interpreter line),
* retrieve the name of the interpreter and open that
* executable instead.
*/
if(is_script(&execi)) {
/* patch_stack will add interpreter name and
* args to stack and retrieve the new binary
* name into fullpath.
*/
FAILCHECK(fetch_name(path, path_len, fullpath));
FAILCHECK(patch_stack(execi.vp, mbuf, &frame_len, fullpath, &vsp));
strlcpy(finalexec, fullpath, PATH_MAX);
strlcpy(firstexec, fullpath, PATH_MAX);
Get_read_vp(execi, fullpath, 1, 0, &resolve, fp);
}
/* If this is a dynamically linked executable, retrieve
* the name of that interpreter in elf_interpreter and open that
* executable instead. But open the current executable in an
* fd for the current process.
*/
if(elf_has_interpreter(execi.args.hdr, execi.args.hdr_len,
elf_interpreter, sizeof(elf_interpreter))) {
/* Switch the executable vnode to the interpreter */
execi.is_dyn = 1;
/* The interpreter (loader) needs an fd to the main program,
* which is currently in finalexec
*/
if((r = execi.elf_main_fd = common_open(finalexec, O_RDONLY, 0)) < 0) {
printf("VFS: exec: dynamic: open main exec failed %s (%d)\n",
fullpath, r);
FAILCHECK(r);
}
/* ld.so is linked at 0, but it can relocate itself; we
* want it higher to trap NULL pointer dereferences.
* Let's put it below the stack, and reserve 10MB for ld.so.
*/
execi.args.load_offset =
execi.args.stack_high - execi.args.stack_size - 0xa00000;
/* Remember it */
strlcpy(execi.execname, finalexec, PATH_MAX);
/* The executable we need to execute first (loader)
* is in elf_interpreter, and has to be in fullpath to
* be looked up
*/
strlcpy(fullpath, elf_interpreter, PATH_MAX);
strlcpy(firstexec, elf_interpreter, PATH_MAX);
Get_read_vp(execi, fullpath, 0, 0, &resolve, fp);
}
/* We also want an FD for VM to mmap() the process in if possible. */
{
struct vnode *vp = execi.vp;
assert(vp);
if ((vp->v_vmnt->m_fs_flags & RES_HASPEEK) &&
major(vp->v_dev) != MEMORY_MAJOR) {
int newfd = -1;
if(get_fd(vmfp, 0, R_BIT, &newfd, &newfilp) == OK) {
assert(newfd >= 0 && newfd < OPEN_MAX);
assert(!vmfp->fp_filp[newfd]);
newfilp->filp_count = 1;
newfilp->filp_vno = vp;
newfilp->filp_flags = O_RDONLY;
vmfp->fp_filp[newfd] = newfilp;
/* dup_vnode(vp); */
execi.vmfd = newfd;
execi.args.memmap = vfs_memmap;
}
}
}
/* callback functions and data */
execi.args.copymem = read_seg;
execi.args.clearproc = libexec_clearproc_vm_procctl;
execi.args.clearmem = libexec_clear_sys_memset;
execi.args.allocmem_prealloc_cleared = libexec_alloc_mmap_prealloc_cleared;
execi.args.allocmem_prealloc_junk = libexec_alloc_mmap_prealloc_junk;
execi.args.allocmem_ondemand = libexec_alloc_mmap_ondemand;
execi.args.opaque = &execi;
execi.args.proc_e = fp->fp_endpoint;
execi.args.frame_len = frame_len;
execi.args.filesize = execi.vp->v_size;
for (i = 0; exec_loaders[i].load_object != NULL; i++) {
r = (*exec_loaders[i].load_object)(&execi.args);
/* Loaded successfully, so no need to try other loaders */
if (r == OK) { makestack = exec_loaders[i].setup_stack; break; }
}
FAILCHECK(r);
/* Inform PM */
FAILCHECK(libexec_pm_newexec(fp->fp_endpoint, &execi.args));
/* Save off PC */
*pc = execi.args.pc;
/* call a stack-setup function if this executable type wants it */
if(makestack) FAILCHECK(makestack(&execi, mbuf, &frame_len, &vsp));
/* Copy the stack from VFS to new core image. */
FAILCHECK(sys_datacopy_wrapper(SELF, (vir_bytes) mbuf, fp->fp_endpoint,
(vir_bytes) vsp, (phys_bytes)frame_len));
/* Return new stack pointer to caller */
*newsp = vsp;
clo_exec(fp);
if (execi.args.allow_setuid) {
/* If after loading the image we're still allowed to run with
* setuid or setgid, change credentials now */
fp->fp_effuid = execi.args.new_uid;
fp->fp_effgid = execi.args.new_gid;
}
/* Remember the new name of the process */
strlcpy(fp->fp_name, execi.args.progname, PROC_NAME_LEN);
fp->text_size = execi.args.text_size;
fp->data_size = execi.args.data_size;
pm_execfinal:
if(newfilp) unlock_filp(newfilp);
else if (execi.vp != NULL) {
unlock_vnode(execi.vp);
put_vnode(execi.vp);
}
if(execi.vmfd >= 0 && !execi.vmfd_used) {
if(OK != close_fd(vmfp, execi.vmfd)) {
printf("VFS: unexpected close fail of vm fd\n");
}
}
unlock_exec();
return(r);
}
/* This is a copy-paste of the same macro in minix/lib/libc/sys/stack_utils.c.
* Keep it synchronized. */
#define STACK_MIN_SZ \
( \
sizeof(int) + sizeof(void *) * 2 + \
sizeof(AuxInfo) * PMEF_AUXVECTORS + PMEF_EXECNAMELEN1 + \
sizeof(struct ps_strings) \
)
static int stack_prepare_elf(struct vfs_exec_info *execi, char *frame, size_t *frame_size,
vir_bytes *vsp)
{
AuxInfo *aux_vec, *aux_vec_end;
vir_bytes vap; /* Address in proc space of the first AuxVec. */
Elf_Ehdr const * const elf_header = (Elf_Ehdr *) execi->args.hdr;
struct ps_strings const * const psp = (struct ps_strings *)
(frame + (*frame_size - sizeof(struct ps_strings)));
size_t const execname_len = strlen(execi->execname);
if (!execi->is_dyn)
return OK;
if (execi->args.hdr_len < sizeof(*elf_header)) {
printf("VFS: malformed ELF headers for exec\n");
return ENOEXEC;
}
if (*frame_size < STACK_MIN_SZ) {
printf("VFS: malformed stack for exec(), smaller than minimum"
" possible size.\n");
return ENOEXEC;
}
/* Find first Aux vector in the stack frame. */
vap = (vir_bytes)(psp->ps_envstr + (psp->ps_nenvstr + 1));
aux_vec = (AuxInfo *) (frame + (vap - *vsp));
aux_vec_end = aux_vec + PMEF_AUXVECTORS;
if (((char *)aux_vec < frame) ||
((char *)aux_vec > (frame + *frame_size))) {
printf("VFS: malformed stack for exec(), first AuxVector is"
" not on the stack.\n");
return ENOEXEC;
}
if (((char *)aux_vec_end < frame) ||
((char *)aux_vec_end > (frame + *frame_size))) {
printf("VFS: malformed stack for exec(), last AuxVector is"
" not on the stack.\n");
return ENOEXEC;
}
/* Userland provides a fully filled stack frame, with argc, argv, envp
* and then all the argv and envp strings; consistent with ELF ABI,
* except for a list of Aux vectors that should be between envp points
* and the start of the strings.
*
* It would take some very unpleasant hackery to insert the aux vectors
* before the strings, and correct all the pointers, so the exec code
* in libc makes space for us.
*/
#define AUXINFO(a, type, value) \
do { \
if (a < aux_vec_end) { \
a->a_type = type; \
a->a_v = value; \
a++; \
} else { \
printf("VFS: No more room for ELF AuxVec type %d, skipping it for %s\n", type, execi->execname); \
(aux_vec_end - 1)->a_type = AT_NULL; \
(aux_vec_end - 1)->a_v = 0; \
} \
} while(0)
AUXINFO(aux_vec, AT_BASE, execi->args.load_base);
AUXINFO(aux_vec, AT_ENTRY, execi->args.pc);
AUXINFO(aux_vec, AT_EXECFD, execi->elf_main_fd);
#if 0
AUXINFO(aux_vec, AT_PHDR, XXX ); /* should be &phdr[0] */
AUXINFO(aux_vec, AT_PHENT, elf_header->e_phentsize);
AUXINFO(aux_vec, AT_PHNUM, elf_header->e_phnum);
AUXINFO(aux_vec, AT_RUID, XXX);
AUXINFO(aux_vec, AT_RGID, XXX);
#endif
AUXINFO(aux_vec, AT_EUID, execi->args.new_uid);
AUXINFO(aux_vec, AT_EGID, execi->args.new_gid);
AUXINFO(aux_vec, AT_PAGESZ, PAGE_SIZE);
if(execname_len < PMEF_EXECNAMELEN1) {
char *spacestart;
vir_bytes userp;
/* Empty space starts after aux_vec table; we can put the name
* here. */
spacestart = (char *) aux_vec + 2 * sizeof(AuxInfo);
strlcpy(spacestart, execi->execname, PMEF_EXECNAMELEN1);
memset(spacestart + execname_len, '\0',
PMEF_EXECNAMELEN1 - execname_len);
/* What will the address of the string for the user be */
userp = *vsp + (spacestart - frame);
/* Move back to where the AT_NULL is */
AUXINFO(aux_vec, AT_SUN_EXECNAME, userp);
}
/* Always terminate with AT_NULL */
AUXINFO(aux_vec, AT_NULL, 0);
return OK;
}
/*===========================================================================*
* is_script *
*===========================================================================*/
static int is_script(struct vfs_exec_info *execi)
{
/* Is Interpreted script? */
assert(execi->args.hdr != NULL);
return(execi->args.hdr[0] == '#' && execi->args.hdr[1] == '!'
&& execi->args.hdr_len >= 2);
}
/*===========================================================================*
* patch_stack *
*===========================================================================*/
static int patch_stack(vp, stack, stk_bytes, path, vsp)
struct vnode *vp; /* pointer for open script file */
char stack[ARG_MAX]; /* pointer to stack image within VFS */
size_t *stk_bytes; /* size of initial stack */
char path[PATH_MAX]; /* path to script file */
vir_bytes *vsp;
{
/* Patch the argument vector to include the path name of the script to be
* interpreted, and all strings on the #! line. Returns the path name of
* the interpreter.
*/
enum { INSERT=FALSE, REPLACE=TRUE };
int n, r;
off_t pos, new_pos;
char *sp, *interp = NULL;
unsigned int cum_io;
char buf[PAGE_SIZE];
/* Make 'path' the new argv[0]. */
if (!insert_arg(stack, stk_bytes, path, vsp, REPLACE)) return(ENOMEM);
pos = 0; /* Read from the start of the file */
/* Issue request */
r = req_readwrite(vp->v_fs_e, vp->v_inode_nr, pos, READING, VFS_PROC_NR,
(vir_bytes) buf, sizeof(buf), &new_pos, &cum_io);
if (r != OK) return(r);
n = vp->v_size;
if (n > sizeof(buf))
n = sizeof(buf);
if (n < 2) return ENOEXEC;
sp = &(buf[2]); /* just behind the #! */
n -= 2;
if (n > PATH_MAX) n = PATH_MAX;
/* Use the 'path' variable for temporary storage */
memcpy(path, sp, n);
if ((sp = memchr(path, '\n', n)) == NULL) /* must be a proper line */
return(ENOEXEC);
/* Move sp backwards through script[], prepending each string to stack. */
for (;;) {
/* skip spaces behind argument. */
while (sp > path && (*--sp == ' ' || *sp == '\t')) {}
if (sp == path) break;
sp[1] = 0;
/* Move to the start of the argument. */
while (sp > path && sp[-1] != ' ' && sp[-1] != '\t') --sp;
interp = sp;
if (!insert_arg(stack, stk_bytes, sp, vsp, INSERT)) {
printf("VFS: patch_stack: insert_arg failed\n");
return(ENOMEM);
}
}
if(!interp)
return ENOEXEC;
if (interp != path)
memmove(path, interp, strlen(interp)+1);
return(OK);
}
/*===========================================================================*
* insert_arg *
*===========================================================================*/
static int insert_arg(char stack[ARG_MAX], size_t *stk_bytes, char *arg,
vir_bytes *vsp, char replace)
{
/* Patch the stack so that arg will become argv[0]. Be careful, the
* stack may be filled with garbage, although it normally looks like
* this:
* nargs argv[0] ... argv[nargs-1] NULL envp[0] ... NULL
* followed by the strings "pointed" to by the argv[i] and the envp[i].
* The * pointers are in the new process address space.
*
* Return true iff the operation succeeded.
*/
struct ps_strings *psp;
int offset;
size_t old_bytes = *stk_bytes;
int const arg_len = strlen(arg) + 1;
/* Offset to argv[0][0] in the stack frame. */
int const a0 = (int)(((char **)stack)[1] - *vsp);
/* Check that argv[0] points within the stack frame. */
if ((a0 < 0) || (a0 >= old_bytes)) {
printf("vfs:: argv[0][] not within stack range!! %i\n", a0);
return FALSE;
}
if (!replace) {
/* Prepending arg adds one pointer, one string and a zero byte. */
offset = arg_len + PTRSIZE;
} else {
/* replacing argv[0] with arg adds the difference in length of
* the two strings. Make sure we don't go beyond the stack size
* when computing the length of the current argv[0]. */
offset = arg_len - strnlen(stack + a0, ARG_MAX - a0 - 1);
}
/* As ps_strings follows the strings, ensure the offset is word aligned. */
offset = offset + (PTRSIZE - ((PTRSIZE + offset) % PTRSIZE));
/* The stack will grow (or shrink) by offset bytes. */
if ((*stk_bytes += offset) > ARG_MAX) {
printf("vfs:: offset too big!! %d (max %d)\n", *stk_bytes,
ARG_MAX);
return FALSE;
}
/* Reposition the strings by offset bytes */
memmove(stack + a0 + offset, stack + a0, old_bytes - a0);
/* Put arg in the new space, leaving padding in front of it. */
strlcpy(stack + a0 + offset - arg_len, arg, arg_len);
if (!replace) {
/* Make space for a new argv[0]. */
memmove(stack + 2 * PTRSIZE,
stack + 1 * PTRSIZE, a0 - 2 * PTRSIZE);
((char **) stack)[0]++; /* nargs++; */
}
/* set argv[0] correctly */
((char **) stack)[1] = (char *) a0 - arg_len + *vsp;
/* Update stack pointer in the process address space. */
*vsp -= offset;
/* Update argv and envp in ps_strings */
psp = (struct ps_strings *) (stack + *stk_bytes - sizeof(struct ps_strings));
psp->ps_argvstr -= (offset / PTRSIZE);
if (!replace) {
psp->ps_nargvstr++;
}
psp->ps_envstr = psp->ps_argvstr + psp->ps_nargvstr + 1;
return TRUE;
}
/*===========================================================================*
* read_seg *
*===========================================================================*/
static int read_seg(struct exec_info *execi, off_t off, vir_bytes seg_addr, size_t seg_bytes)
{
/*
* The byte count on read is usually smaller than the segment count, because
* a segment is padded out to a click multiple, and the data segment is only
* partially initialized.
*/
int r;
off_t new_pos;
unsigned int cum_io;
struct vnode *vp = ((struct vfs_exec_info *) execi->opaque)->vp;
/* Make sure that the file is big enough */
if (off + seg_bytes > LONG_MAX) return(EIO);
if ((unsigned long) vp->v_size < off+seg_bytes) return(EIO);
if ((r = req_readwrite(vp->v_fs_e, vp->v_inode_nr, off, READING,
execi->proc_e, (vir_bytes) seg_addr, seg_bytes,
&new_pos, &cum_io)) != OK) {
printf("VFS: read_seg: req_readwrite failed (data)\n");
return(r);
}
if (r == OK && cum_io != seg_bytes)
printf("VFS: read_seg segment has not been read properly\n");
return(r);
}
/*===========================================================================*
* clo_exec *
*===========================================================================*/
static void clo_exec(struct fproc *rfp)
{
/* Files can be marked with the FD_CLOEXEC bit (in fp->fp_cloexec).
*/
int i;
/* Check the file desriptors one by one for presence of FD_CLOEXEC. */
for (i = 0; i < OPEN_MAX; i++)
if ( FD_ISSET(i, &rfp->fp_cloexec_set))
(void) close_fd(rfp, i);
}
/*===========================================================================*
* map_header *
*===========================================================================*/
static int map_header(struct vfs_exec_info *execi)
{
int r;
unsigned int cum_io;
off_t pos, new_pos;
static char hdr[PAGE_SIZE]; /* Assume that header is not larger than a page */
pos = 0; /* Read from the start of the file */
/* How much is sensible to read */
execi->args.hdr_len = MIN(execi->vp->v_size, sizeof(hdr));
execi->args.hdr = hdr;
r = req_readwrite(execi->vp->v_fs_e, execi->vp->v_inode_nr,
pos, READING, VFS_PROC_NR, (vir_bytes) hdr,
execi->args.hdr_len, &new_pos, &cum_io);
if (r != OK) {
printf("VFS: exec: map_header: req_readwrite failed\n");
return(r);
}
return(OK);
}
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