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[PATCH] initramfs overwrite fix
This patch ensures that initramfs overwrites work correctly, even when dealing with device nodes of different types. Furthermore, when replacing a file which already exists, we must make very certain that we truncate the existing file. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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0538195424
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@ -30,6 +30,7 @@ static void __init free(void *where)
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static __initdata struct hash {
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int ino, minor, major;
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mode_t mode;
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struct hash *next;
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char name[N_ALIGN(PATH_MAX)];
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} *head[32];
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@ -41,7 +42,8 @@ static inline int hash(int major, int minor, int ino)
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return tmp & 31;
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}
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static char __init *find_link(int major, int minor, int ino, char *name)
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static char __init *find_link(int major, int minor, int ino,
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mode_t mode, char *name)
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{
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struct hash **p, *q;
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for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
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@ -51,14 +53,17 @@ static char __init *find_link(int major, int minor, int ino, char *name)
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continue;
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if ((*p)->major != major)
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continue;
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if (((*p)->mode ^ mode) & S_IFMT)
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continue;
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return (*p)->name;
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}
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q = (struct hash *)malloc(sizeof(struct hash));
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if (!q)
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panic("can't allocate link hash entry");
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q->ino = ino;
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q->minor = minor;
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q->major = major;
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q->minor = minor;
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q->ino = ino;
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q->mode = mode;
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strcpy(q->name, name);
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q->next = NULL;
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*p = q;
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@ -229,13 +234,25 @@ static int __init do_reset(void)
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static int __init maybe_link(void)
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{
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if (nlink >= 2) {
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char *old = find_link(major, minor, ino, collected);
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char *old = find_link(major, minor, ino, mode, collected);
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if (old)
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return (sys_link(old, collected) < 0) ? -1 : 1;
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}
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return 0;
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}
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static void __init clean_path(char *path, mode_t mode)
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{
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struct stat st;
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if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
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if (S_ISDIR(st.st_mode))
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sys_rmdir(path);
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else
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sys_unlink(path);
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}
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}
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static __initdata int wfd;
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static int __init do_name(void)
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@ -248,9 +265,15 @@ static int __init do_name(void)
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}
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if (dry_run)
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return 0;
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clean_path(collected, mode);
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if (S_ISREG(mode)) {
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if (maybe_link() >= 0) {
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wfd = sys_open(collected, O_WRONLY|O_CREAT, mode);
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int ml = maybe_link();
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if (ml >= 0) {
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int openflags = O_WRONLY|O_CREAT;
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if (ml != 1)
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openflags |= O_TRUNC;
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wfd = sys_open(collected, openflags, mode);
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if (wfd >= 0) {
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sys_fchown(wfd, uid, gid);
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sys_fchmod(wfd, mode);
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@ -291,6 +314,7 @@ static int __init do_copy(void)
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static int __init do_symlink(void)
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{
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collected[N_ALIGN(name_len) + body_len] = '\0';
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clean_path(collected, 0);
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sys_symlink(collected + N_ALIGN(name_len), collected);
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sys_lchown(collected, uid, gid);
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state = SkipIt;
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