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vfs - use a static buffer instead of malloc()+free(), solving

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recently appeared ENOMEM problems during exec().
This commit is contained in:
Ben Gras 2010-12-15 14:43:59 +00:00
parent 7aab862a06
commit f0f34dd8d9
1 changed files with 17 additions and 13 deletions
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30
servers/vfs/exec.c
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@ -95,7 +95,10 @@ PUBLIC int pm_exec(int proc_e, char *path, vir_bytes path_len, char *frame,
if ((r = fetch_name(path, path_len, 0)) != OK) return(r);
/* Fetch the stack from the user before destroying the old core image. */
if (frame_len > ARG_MAX) return(ENOMEM); /* stack too big */
if (frame_len > ARG_MAX) {
printf("VFS: pm_exec: stack too big\n");
return(ENOMEM); /* stack too big */
}
r = sys_datacopy(proc_e, (vir_bytes) frame, SELF, (vir_bytes) mbuf,
(phys_bytes) frame_len);
if (r != OK) { /* can't fetch stack (e.g. bad virtual addr) */
@ -152,7 +155,6 @@ PUBLIC int pm_exec(int proc_e, char *path, vir_bytes path_len, char *frame,
printf("VFS pm_exec: 2nd fetch_name failed\n");
else if ((r = patch_stack(vp, mbuf, &frame_len)) != OK)
printf("VFS pm_exec: patch_stack failed\n");
free(execi.hdr);
put_vnode(vp);
if (r != OK) return(r);
}
@ -165,7 +167,6 @@ PUBLIC int pm_exec(int proc_e, char *path, vir_bytes path_len, char *frame,
/* Loaded successfully, so no need to try other loaders */
if (r == OK) break;
}
free(execi.hdr);
put_vnode(vp);
/* No exec loader could load the object */
@ -394,7 +395,10 @@ vir_bytes *stk_bytes /* size of initial stack */
char buf[_MAX_BLOCK_SIZE];
/* Make user_fullpath the new argv[0]. */
if (!insert_arg(stack, stk_bytes, user_fullpath, REPLACE)) return(ENOMEM);
if (!insert_arg(stack, stk_bytes, user_fullpath, REPLACE)) {
printf("VFS: patch_stack: insert_arg for argv[0] failed\n");
return(ENOMEM);
}
pos = 0; /* Read from the start of the file */
@ -429,7 +433,10 @@ vir_bytes *stk_bytes /* size of initial stack */
while (sp > user_fullpath && sp[-1] != ' ' && sp[-1] != '\t') --sp;
interp = sp;
if (!insert_arg(stack, stk_bytes, sp, INSERT)) return(ENOMEM);
if (!insert_arg(stack, stk_bytes, sp, INSERT)) {
printf("VFS: patch_stack: insert_arg failed\n");
return(ENOMEM);
}
}
/* Round *stk_bytes up to the size of a pointer for alignment contraints. */
@ -629,20 +636,17 @@ static int map_header(char **exec_hdr, const struct vnode *vp)
u64_t new_pos;
unsigned int cum_io;
off_t pos;
char *hdr;
static char hdr[PAGE_SIZE]; /* Assume that header is not larger than a page */
pos = 0; /* Read from the start of the file */
/* Assume that header is not larger than a page */
hdr = (char*)malloc(PAGE_SIZE);
if (hdr == NULL) {
return ENOMEM;
}
r = req_readwrite(vp->v_fs_e, vp->v_inode_nr, cvul64(pos), READING,
VFS_PROC_NR, hdr, MIN(vp->v_size, PAGE_SIZE),
&new_pos, &cum_io);
if (r != OK) return(r);
if (r != OK) {
printf("VFS: exec: map_header: req_readwrite failed\n");
return(r);
}
*exec_hdr = hdr;
return(OK);