[xen master] domain: add ASSERT to help static analysis tools

[patchbot@xxxxxxx]

commit caa221791d4214445f2913f51a3230cc5644ab8d
Author:     Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
AuthorDate: Fri Nov 17 10:21:52 2023 +0100
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxx>
CommitDate: Tue Nov 28 19:12:53 2023 -0800

    domain: add ASSERT to help static analysis tools
    
    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 <julien@xxxxxxx>
    Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
    Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/common/domain.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/xen/common/domain.c b/xen/common/domain.c
index f15c2f1e95..cd2ca6d49a 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;
 
--
generated by git-patchbot for /home/xen/git/xen.git#master