In case there are two variables which each implement env callback that performs env_set() on the other variable, the callbacks will call each other recursively until the stack runs out. Prevent such a recursion from happening.
Example which triggers this behavior: static int on_foo(...) { env_set("bar", 0); ... } static int on_bar(...) { env_set("foo", 0); ... } U_BOOT_ENV_CALLBACK(foo, on_foo); U_BOOT_ENV_CALLBACK(bar, on_bar);
Signed-off-by: Christoph Niedermaier cniedermaier@dh-electronics.com Suggested-by: Marek Vasut marex@denx.de --- Cc: Tom Rini trini@konsulko.com Cc: Simon Glass sjg@chromium.org Cc: Marek Vasut marex@denx.de Cc: u-boot@dh-electronics.com --- V4: - Add this patch to the series v5: - No functional changes, but changed the order of the patches --- lib/hashtable.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/lib/hashtable.c b/lib/hashtable.c index e8a59e2dca..75c263b505 100644 --- a/lib/hashtable.c +++ b/lib/hashtable.c @@ -221,11 +221,32 @@ static int do_callback(const struct env_entry *e, const char *name, const char *value, enum env_op op, int flags) { + int ret = 0; + #ifndef CONFIG_XPL_BUILD - if (e->callback) - return e->callback(name, value, op, flags); + static bool in_callback; + + if (!e->callback || in_callback) + return 0; + + /* + * In case there are two variables which each implement env callback + * that performs env_set() on the other variable, the callbacks will + * call each other recursively until the stack runs out. Prevent such + * a recursion from happening. + * + * Example which triggers this behavior: + * static int on_foo(...) { env_set("bar", 0); ... } + * static int on_bar(...) { env_set("foo", 0); ... } + * U_BOOT_ENV_CALLBACK(foo, on_foo); + * U_BOOT_ENV_CALLBACK(bar, on_bar); + */ + in_callback = true; + ret = e->callback(name, value, op, flags); + in_callback = false; #endif - return 0; + + return ret; }
/*