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authorLinus Torvalds <torvalds@linux-foundation.org>2008-05-19 16:37:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-19 16:37:45 -0700
commite23a5f66877d32f21a2ac15a200ad4a2b4c8b0ee (patch)
treef1eafaf4796abd3289fdc3384f124046f752b9d6 /fs
parentc9091f9e571386992c8c5badcec84d49753b9df1 (diff)
parente9baf6e59842285bcf9570f5094e4c27674a0f7c (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: [PATCH] return to old errno choice in mkdir() et.al. [Patch] fs/binfmt_elf.c: fix wrong return values [PATCH] get rid of leak in compat_execve() [Patch] fs/binfmt_elf.c: fix a wrong free [PATCH] avoid multiplication overflows and signedness issues for max_fds [PATCH] dup_fd() part 4 - race fix [PATCH] dup_fd() - part 3 [PATCH] dup_fd() part 2 [PATCH] dup_fd() fixes, part 1 [PATCH] take init_files to fs/file.c
Diffstat (limited to 'fs')
-rw-r--r--fs/binfmt_elf.c9
-rw-r--r--fs/compat.c4
-rw-r--r--fs/exec.c12
-rw-r--r--fs/file.c152
-rw-r--r--fs/namei.c12
5 files changed, 173 insertions, 16 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index b25707fee2c..0fa95b198e6 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -256,7 +256,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
- return 0;
+ return -EINVAL;
p += len;
}
if (__put_user(0, argv))
@@ -268,7 +268,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
- return 0;
+ return -EINVAL;
p += len;
}
if (__put_user(0, envp))
@@ -1900,7 +1900,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
/* alloc memory for large data structures: too large to be on stack */
elf = kmalloc(sizeof(*elf), GFP_KERNEL);
if (!elf)
- goto cleanup;
+ goto out;
segs = current->mm->map_count;
#ifdef ELF_CORE_EXTRA_PHDRS
@@ -2034,8 +2034,9 @@ end_coredump:
set_fs(fs);
cleanup:
- kfree(elf);
free_note_info(&info);
+ kfree(elf);
+out:
return has_dumped;
}
diff --git a/fs/compat.c b/fs/compat.c
index 332a869d2c5..ed43e17a5dc 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1405,7 +1405,7 @@ int compat_do_execve(char * filename,
/* execve success */
security_bprm_free(bprm);
acct_update_integrals(current);
- kfree(bprm);
+ free_bprm(bprm);
return retval;
}
@@ -1424,7 +1424,7 @@ out_file:
}
out_kfree:
- kfree(bprm);
+ free_bprm(bprm);
out_ret:
return retval;
diff --git a/fs/exec.c b/fs/exec.c
index 1f8a24aa1f8..3c2ba7ce11d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1251,6 +1251,12 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
EXPORT_SYMBOL(search_binary_handler);
+void free_bprm(struct linux_binprm *bprm)
+{
+ free_arg_pages(bprm);
+ kfree(bprm);
+}
+
/*
* sys_execve() executes a new program.
*/
@@ -1320,17 +1326,15 @@ int do_execve(char * filename,
retval = search_binary_handler(bprm,regs);
if (retval >= 0) {
/* execve success */
- free_arg_pages(bprm);
security_bprm_free(bprm);
acct_update_integrals(current);
- kfree(bprm);
+ free_bprm(bprm);
if (displaced)
put_files_struct(displaced);
return retval;
}
out:
- free_arg_pages(bprm);
if (bprm->security)
security_bprm_free(bprm);
@@ -1344,7 +1348,7 @@ out_file:
fput(bprm->file);
}
out_kfree:
- kfree(bprm);
+ free_bprm(bprm);
out_files:
if (displaced)
diff --git a/fs/file.c b/fs/file.c
index 4c6f0ea12c4..7b3887e054d 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -26,6 +26,8 @@ struct fdtable_defer {
};
int sysctl_nr_open __read_mostly = 1024*1024;
+int sysctl_nr_open_min = BITS_PER_LONG;
+int sysctl_nr_open_max = 1024 * 1024; /* raised later */
/*
* We use this list to defer free fdtables that have vmalloced
@@ -119,8 +121,6 @@ static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt)
unsigned int cpy, set;
BUG_ON(nfdt->max_fds < ofdt->max_fds);
- if (ofdt->max_fds == 0)
- return;
cpy = ofdt->max_fds * sizeof(struct file *);
set = (nfdt->max_fds - ofdt->max_fds) * sizeof(struct file *);
@@ -261,6 +261,139 @@ int expand_files(struct files_struct *files, int nr)
return expand_fdtable(files, nr);
}
+static int count_open_files(struct fdtable *fdt)
+{
+ int size = fdt->max_fds;
+ int i;
+
+ /* Find the last open fd */
+ for (i = size/(8*sizeof(long)); i > 0; ) {
+ if (fdt->open_fds->fds_bits[--i])
+ break;
+ }
+ i = (i+1) * 8 * sizeof(long);
+ return i;
+}
+
+/*
+ * Allocate a new files structure and copy contents from the
+ * passed in files structure.
+ * errorp will be valid only when the returned files_struct is NULL.
+ */
+struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
+{
+ struct files_struct *newf;
+ struct file **old_fds, **new_fds;
+ int open_files, size, i;
+ struct fdtable *old_fdt, *new_fdt;
+
+ *errorp = -ENOMEM;
+ newf = kmem_cache_alloc(files_cachep, GFP_KERNEL);
+ if (!newf)
+ goto out;
+
+ atomic_set(&newf->count, 1);
+
+ spin_lock_init(&newf->file_lock);
+ newf->next_fd = 0;
+ new_fdt = &newf->fdtab;
+ new_fdt->max_fds = NR_OPEN_DEFAULT;
+ new_fdt->close_on_exec = (fd_set *)&newf->close_on_exec_init;
+ new_fdt->open_fds = (fd_set *)&newf->open_fds_init;
+ new_fdt->fd = &newf->fd_array[0];
+ INIT_RCU_HEAD(&new_fdt->rcu);
+ new_fdt->next = NULL;
+
+ spin_lock(&oldf->file_lock);
+ old_fdt = files_fdtable(oldf);
+ open_files = count_open_files(old_fdt);
+
+ /*
+ * Check whether we need to allocate a larger fd array and fd set.
+ */
+ while (unlikely(open_files > new_fdt->max_fds)) {
+ spin_unlock(&oldf->file_lock);
+
+ if (new_fdt != &newf->fdtab) {
+ free_fdarr(new_fdt);
+ free_fdset(new_fdt);
+ kfree(new_fdt);
+ }
+
+ new_fdt = alloc_fdtable(open_files - 1);
+ if (!new_fdt) {
+ *errorp = -ENOMEM;
+ goto out_release;
+ }
+
+ /* beyond sysctl_nr_open; nothing to do */
+ if (unlikely(new_fdt->max_fds < open_files)) {
+ free_fdarr(new_fdt);
+ free_fdset(new_fdt);
+ kfree(new_fdt);
+ *errorp = -EMFILE;
+ goto out_release;
+ }
+
+ /*
+ * Reacquire the oldf lock and a pointer to its fd table
+ * who knows it may have a new bigger fd table. We need
+ * the latest pointer.
+ */
+ spin_lock(&oldf->file_lock);
+ old_fdt = files_fdtable(oldf);
+ open_files = count_open_files(old_fdt);
+ }
+
+ old_fds = old_fdt->fd;
+ new_fds = new_fdt->fd;
+
+ memcpy(new_fdt->open_fds->fds_bits,
+ old_fdt->open_fds->fds_bits, open_files/8);
+ memcpy(new_fdt->close_on_exec->fds_bits,
+ old_fdt->close_on_exec->fds_bits, open_files/8);
+
+ for (i = open_files; i != 0; i--) {
+ struct file *f = *old_fds++;
+ if (f) {
+ get_file(f);
+ } else {
+ /*
+ * The fd may be claimed in the fd bitmap but not yet
+ * instantiated in the files array if a sibling thread
+ * is partway through open(). So make sure that this
+ * fd is available to the new process.
+ */
+ FD_CLR(open_files - i, new_fdt->open_fds);
+ }
+ rcu_assign_pointer(*new_fds++, f);
+ }
+ spin_unlock(&oldf->file_lock);
+
+ /* compute the remainder to be cleared */
+ size = (new_fdt->max_fds - open_files) * sizeof(struct file *);
+
+ /* This is long word aligned thus could use a optimized version */
+ memset(new_fds, 0, size);
+
+ if (new_fdt->max_fds > open_files) {
+ int left = (new_fdt->max_fds-open_files)/8;
+ int start = open_files / (8 * sizeof(unsigned long));
+
+ memset(&new_fdt->open_fds->fds_bits[start], 0, left);
+ memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
+ }
+
+ rcu_assign_pointer(newf->fdt, new_fdt);
+
+ return newf;
+
+out_release:
+ kmem_cache_free(files_cachep, newf);
+out:
+ return NULL;
+}
+
static void __devinit fdtable_defer_list_init(int cpu)
{
struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
@@ -274,4 +407,19 @@ void __init files_defer_init(void)
int i;
for_each_possible_cpu(i)
fdtable_defer_list_init(i);
+ sysctl_nr_open_max = min((size_t)INT_MAX, ~(size_t)0/sizeof(void *)) &
+ -BITS_PER_LONG;
}
+
+struct files_struct init_files = {
+ .count = ATOMIC_INIT(1),
+ .fdt = &init_files.fdtab,
+ .fdtab = {
+ .max_fds = NR_OPEN_DEFAULT,
+ .fd = &init_files.fd_array[0],
+ .close_on_exec = (fd_set *)&init_files.close_on_exec_init,
+ .open_fds = (fd_set *)&init_files.open_fds_init,
+ .rcu = RCU_HEAD_INIT,
+ },
+ .file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock),
+};
diff --git a/fs/namei.c b/fs/namei.c
index 32fd9655485..c7e43536c49 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2003,18 +2003,22 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
if (IS_ERR(dentry))
goto fail;
+ if (dentry->d_inode)
+ goto eexist;
/*
* Special case - lookup gave negative, but... we had foo/bar/
* From the vfs_mknod() POV we just have a negative dentry -
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
- if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
- goto enoent;
+ if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
+ dput(dentry);
+ dentry = ERR_PTR(-ENOENT);
+ }
return dentry;
-enoent:
+eexist:
dput(dentry);
- dentry = ERR_PTR(-ENOENT);
+ dentry = ERR_PTR(-EEXIST);
fail:
return dentry;
}