Hi,
On 10/28/25 1:18 PM, Fabian Pflug wrote:
> Without the SCONFIG_FS_EXTERNAL, the bus of the driver for pstore will
> not load, resulting in a missing driver for pstore and an error during
> bootup.
> Only mount the /pstore if FS_EXTERNAL is allowed by the security policy.
> > Signed-off-by: Fabian Pflug <[email protected]>
> ---
> common/startup.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/common/startup.c b/common/startup.c
> index ea5436afa6..f16a99f7e4 100644
> --- a/common/startup.c
> +++ b/common/startup.c
> @@ -55,6 +55,19 @@ extern exitcall_t __barebox_exitcalls_start[],
> __barebox_exitcalls_end[];
> enum system_states barebox_system_state;
>
> #if defined CONFIG_FS_RAMFS && defined CONFIG_FS_DEVFS
> +static struct sconfig_notifier_block sconfig_notifier;
> +static void u_mount_pstore(struct sconfig_notifier_block *nb,
> + enum security_config_option opt, bool allowed)
> +{
> + if (allowed) {
> + mkdir("/pstore", 0);
I think we should create the directory unconditionally without paying
respect to whether we can mount or not.
> + mount("none", "pstore", "/pstore", NULL);
> + } else {
> + umount("/pstore");
The harm is already done when loosening security mode, so I don't think
we want to start unmounting things.
As mentioned, I'd prefer replacing SCONFIG_FS_EXTERNAL altogether with a
whitelist of mounts, so common code calls:
allow_mount("none", "ramfs", "/", NULL);
allow_mount("none", "devfs", "/dev", NULL);
and board code can call:
allow_mount("non", "pstore", "/pstore", NULL);
and we won't need any special handling here. Waiting to see what Sascha
thinks.
Cheers,
Ahmad
> + rmdir("/pstore");
> + }
> +}
> +
> static int mount_root(void)
> {
> mount("none", "ramfs", "/", NULL);
> @@ -69,8 +82,13 @@ static int mount_root(void)
> }
>
> if (IS_ENABLED(CONFIG_FS_PSTORE)) {
> - mkdir("/pstore", 0);
> - mount("none", "pstore", "/pstore", NULL);
> + if (IS_ALLOWED(SCONFIG_FS_EXTERNAL)) {
> + mkdir("/pstore", 0);
> + mount("none", "pstore", "/pstore", NULL);
> + }
> + sconfig_register_handler_filtered(&sconfig_notifier,
> + u_mount_pstore,
> + SCONFIG_FS_EXTERNAL);
> }
>
> if (IS_ENABLED(CONFIG_9P_FS))
--
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