Static analysis tools may detect a possible null pointer dereference of 'config'. This ASSERT helps them in detecting that such a condition is not possible given that only real domains can enter this branch, which are guaranteeed to have a non-NULL config at this point, but this information is not inferred by the tool.
Checking that the condition given in the assertion holds via testing is the means to protect release builds, where the assertion expands to effectively nothing. Suggested-by: Julien Grall <jul...@xen.org> Signed-off-by: Nicola Vetrini <nicola.vetr...@bugseng.com> Acked-by: Stefano Stabellini <sstabell...@kernel.org> --- Changes in v2: - Clarified the context in which the assertion is useful. The check may be later improved by proper error checking instead of relying on the semantics explained here: https://lore.kernel.org/xen-devel/61f04d4b-34d9-4fd1-a989-56b042b4f...@citrix.com/ --- xen/common/domain.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/xen/common/domain.c b/xen/common/domain.c index 8f9ab01c0cb7..924099db1098 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -700,6 +700,13 @@ struct domain *domain_create(domid_t domid, if ( !is_idle_domain(d) ) { + /* + * The assertion helps static analysis tools infer that config cannot + * be NULL in this branch, which in turn means that it can be safely + * dereferenced. Therefore, this assertion is not redundant. + */ + ASSERT(config); + watchdog_domain_init(d); init_status |= INIT_watchdog; -- 2.34.1
