On Wed, Nov 20, 2024 at 8:57 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> The generic ->do_entry() handler is currently limited to returning
> a single alias string.
>
> However, this is not flexible enough for several subsystems, which
> currently require their own implementations:
>
> - do_usb_table()
> - do_of_table()
> - do_pnp_device_entry()
> - do_pnp_card_entries()
>
> This commit introduces a helper function so that these special cases can
> add multiple MODULE_ALIAS() and then migrate to the generic framework.
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> scripts/mod/file2alias.c | 89 +++++++++++++++++++++++++++++-----------
> scripts/mod/modpost.c | 11 ++++-
> scripts/mod/modpost.h | 19 ++++++++-
> 3 files changed, 91 insertions(+), 28 deletions(-)
>
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> index 34678ed40fdb..e31619cee05e 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -10,6 +10,12 @@
> * of the GNU General Public License, incorporated herein by reference.
> */
>
> +#include <stdarg.h>
> +#include <stdio.h>
> +
> +#include "list.h"
> +#include "xalloc.h"
> +
> #include "modpost.h"
> #include "devicetable-offsets.h"
>
> @@ -31,6 +37,56 @@ typedef Elf64_Addr kernel_ulong_t;
> #include <ctype.h>
> #include <stdbool.h>
>
> +/**
> + * module_alias_printf - add auto-generated MODULE_ALIAS()
> + *
> + * @mod: module
> + * @append_wildcard: append '*' for future extension if not exist yet
> + * @fmt: printf(3)-like format
> + */
> +static void __attribute__((format (printf, 3, 4)))
> +module_alias_printf(struct module *mod, bool append_wildcard,
> + const char *fmt, ...)
> +{
> + struct module_alias *new;
> + size_t len, n;
> + va_list ap;
> +
> + /* Determine required size. */
> + va_start(ap, fmt);
> + n = vsnprintf(NULL, 0, fmt, ap);
> + va_end(ap);
> +
> + if (n < 0) {
> + error("vsnprintf failed\n");
> + return;
> + }
> +
> + len = n + 1; /* extra byte for '\0' */
> +
> + if (append_wildcard)
> + len++; /* extra byte for '*' */
> +
> + new = xmalloc(sizeof(*new) + len);
> +
> + /* Now, really print it to the allocated buffer */
> + va_start(ap, fmt);
> + n = vsnprintf(new->str, len, fmt, ap);
> + va_end(ap);
> +
> + if (n < 0) {
> + error("vsnprintf failed\n");
> + return;
This is a memory leak bug.
I will add free() here.
if (n < 0) {
error("vsnprintf failed\n");
+ free(new);
return;
}
--
Best Regards
Masahiro Yamada
