[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] Fix error checking and cleaning in path.c
From: |
Kirill A. Shutemov |
Subject: |
Re: [Qemu-devel] [PATCH] Fix error checking and cleaning in path.c |
Date: |
Thu, 3 Sep 2009 10:19:19 +0300 |
On Thu, Sep 3, 2009 at 3:32 AM, Jean-Christophe
DUBOIS<address@hidden> wrote:
> Very little error checking was done in path.c and we were
> leaking some memories in case of error.
Nak.
Do you really think you can do something useful after memory allocation fail?
I think you can only do is call abort().
>
> Signed-off-by: Jean-Christophe Dubois <address@hidden>
> ---
> path.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++----------
> 1 files changed, 64 insertions(+), 12 deletions(-)
>
> diff --git a/path.c b/path.c
> index cc9e007..24e8fdd 100644
> --- a/path.c
> +++ b/path.c
> @@ -40,15 +40,50 @@ static int strneq(const char *s1, unsigned int n, const
> char *s2)
>
> static struct pathelem *add_entry(struct pathelem *root, const char *name);
>
> +static void free_entry(struct pathelem *ptr)
> +{
> + if(ptr)
> + {
> + while(ptr->num_entries) {
> + if (ptr->entries[ptr->num_entries -1]) {
> + free_entry(ptr->entries[ptr->num_entries -1]);
> + qemu_free(ptr->entries[ptr->num_entries -1]);
> + ptr->entries[ptr->num_entries -1] = NULL;
> + }
> + ptr->num_entries--;
> + }
> +
> + if (ptr->name) {
> + qemu_free(ptr->name);
> + ptr->name = NULL;
> + }
> +
> + if (ptr->pathname) {
> + free(ptr->pathname);
> + ptr->pathname = NULL;
> + }
> + }
> +}
> +
> static struct pathelem *new_entry(const char *root,
> struct pathelem *parent,
> const char *name)
> {
> - struct pathelem *new = malloc(sizeof(*new));
> - new->name = strdup(name);
> - asprintf(&new->pathname, "%s/%s", root, name);
> - new->num_entries = 0;
> + struct pathelem *new = qemu_mallocz(sizeof(*new));
> +
> + if (new) {
> + if (!(new->name = qemu_strdup(name)))
> + goto fail;
> + if (asprintf(&new->pathname, "%s/%s", root, name) < 0)
> + goto fail;
> + new->num_entries = 0;
> + }
> return new;
> +
> +fail:
> + free_entry(new);
> + qemu_free(new);
> + return NULL;
> }
>
> #define streq(a,b) (strcmp((a), (b)) == 0)
> @@ -57,7 +92,7 @@ static struct pathelem *add_dir_maybe(struct pathelem *path)
> {
> DIR *dir;
>
> - if ((dir = opendir(path->pathname)) != NULL) {
> + if (path && ((dir = opendir(path->pathname)) != NULL)) {
> struct dirent *dirent;
>
> while ((dirent = readdir(dir)) != NULL) {
> @@ -67,6 +102,7 @@ static struct pathelem *add_dir_maybe(struct pathelem
> *path)
> }
> closedir(dir);
> }
> +
> return path;
> }
>
> @@ -74,13 +110,25 @@ static struct pathelem *add_entry(struct pathelem *root,
> const char *name)
> {
> root->num_entries++;
>
> - root = realloc(root, sizeof(*root)
> + root = qemu_realloc(root, sizeof(*root)
> + sizeof(root->entries[0])*root->num_entries);
>
> - root->entries[root->num_entries-1] = new_entry(root->pathname, root,
> name);
> - root->entries[root->num_entries-1]
> - = add_dir_maybe(root->entries[root->num_entries-1]);
> + if (root) {
> + root->entries[root->num_entries-1]
> + = add_dir_maybe(new_entry(root->pathname, root, name));
> +
> + if (!root->entries[root->num_entries-1])
> + goto fail;
> + } else {
> + /* if realloc failed, we have leaked some memory and we can't
> recover it */
> + }
> +
> return root;
> +
> +fail:
> + free_entry(root);
> + qemu_free(root);
> + return NULL;
> }
>
> /* This needs to be done after tree is stabilized (ie. no more reallocs!). */
> @@ -140,10 +188,14 @@ void init_paths(const char *prefix)
> } else
> pstrcpy(pref_buf, sizeof(pref_buf), prefix + 1);
>
> - base = new_entry("", NULL, pref_buf);
> - base = add_dir_maybe(base);
> + base = add_dir_maybe(new_entry("", NULL, pref_buf));
> +
> + if (!base)
> + abort();
> +
> if (base->num_entries == 0) {
> - free (base);
> + free_entry(base);
> + qemu_free (base);
> base = NULL;
> } else {
> set_parents(base, base);
> --
> 1.6.0.4
>
>
>
>