On 16.11.24 11:46, Julien Grall wrote:
Hi,On 23/10/2024 14:10, Juergen Gross wrote:Xenstore is referencing domains by their domid, but reuse of a domid can lead to the situation that Xenstore can't tell whether a domain with that domid has been deleted and created again without Xenstore noticing the domain is a new one now. Add a global domain creation unique id which is updated when creating a new domain, and store that value in struct domain of the new domain. The global unique id is initialized with the system time and updates are done via the xorshift algorithm which is used for pseudo random number generation, too (see https://en.wikipedia.org/wiki/Xorshift). Signed-off-by: Juergen Gross <jgr...@suse.com> Reviewed-by: Jan Beulich <jbeul...@suse.com> --- V1: - make unique_id local to function (Jan Beulich) - add lock (Julien Grall) - add comment (Julien Grall) --- xen/common/domain.c | 20 ++++++++++++++++++++ xen/include/xen/sched.h | 3 +++ 2 files changed, 23 insertions(+) diff --git a/xen/common/domain.c b/xen/common/domain.c index 92263a4fbd..3948640fb0 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -562,6 +562,25 @@ static void _domain_destroy(struct domain *d) free_domain_struct(d); } +static uint64_t get_unique_id(void) +{ + static uint64_t unique_id; + static DEFINE_SPINLOCK(lock); + uint64_t x = unique_id ? : NOW();I think unique_id needs to be read within the critical section. Otherwise, get_unique_id() could return the same ID twice.
Yes, you are right. Juergen
OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key
OpenPGP_signature.asc
Description: OpenPGP digital signature
