leandrof/u-boot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

dm: core: Don't allow uclass use before ready

Browse Source 
At present it is possible to call uclass_get() before driver model is
inited. In fact this happens on x86 boards which use Intel FSPv1, since
mrccache_get_region() tries to get the SPI flash device very early
during init.

This has always been undefined behaviour. Previously it generally worked,
i.e. returned an error code without crashing, because gd->uclass_root_s
is zeroed and the uclass can be added despite driver model not being
ready, due to the way lists are implemented. With the change to use a
gd->uclass_root pointer, this no-longer works. For example, it causes a
hang on minnowmax.

Fix this by adding a check that driver model is ready when uclass_get() is
called. This function is called in the process of locating any device, so
it is a good place to add the check.

This fixes booting on minnowmax.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 8a715530bb ("dm: core: Allow the uclass list to move")
This commit is contained in:
Simon Glass 2021-08-01 12:05:23 -06:00
parent b18b38f2ae
commit 1e9ced28f1
3 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/core/uclass.c
View File

@ -146,6 +146,9 @@ int uclass_get(enum uclass_id id, struct uclass **ucp)
{
struct uclass *uc;
/* Immediately fail if driver model is not set up */
if (!gd->uclass_root)
return -EDEADLK;
*ucp = NULL;
uc = uclass_find(id);
if (!uc) {

3
include/dm/uclass.h
View File

@ -159,7 +159,8 @@ void *uclass_get_priv(const struct uclass *uc);
*
* @key: ID to look up
* @ucp: Returns pointer to uclass (there is only one per ID)
* @return 0 if OK, -ve on error
* @return 0 if OK, -EDEADLK if driver model is not yet inited, other -ve on
* other error
*/
int uclass_get(enum uclass_id key, struct uclass **ucp);

1
test/dm/core.c
View File

@ -994,6 +994,7 @@ static int dm_test_uclass_before_ready(struct unit_test_state *uts)
memset(&gd->uclass_root, '\0', sizeof(gd->uclass_root));
ut_asserteq_ptr(NULL, uclass_find(UCLASS_TEST));
ut_asserteq(-EDEADLK, uclass_get(UCLASS_TEST, &uc));
return 0;
}