From: Reinette Chatre <reinette.chatre@xxxxxxxxx> commit 8795359e35bc33bf86b6d0765aa7f37431db3b9c upstream. Vijay reported that the "unclobbered_vdso_oversubscribed" selftest triggers the softlockup detector. Actual SGX systems have 128GB of enclave memory or more. The "unclobbered_vdso_oversubscribed" selftest creates one enclave which consumes all of the enclave memory on the system. Tearing down such a large enclave takes around a minute, most of it in the loop where the EREMOVE instruction is applied to each individual 4k enclave page. Spending one minute in a loop triggers the softlockup detector. Add a cond_resched() to give other tasks a chance to run and placate the softlockup detector. Cc: stable@xxxxxxxxxxxxxxx Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer") Reported-by: Vijay Dhanraj <vijay.dhanraj@xxxxxxxxx> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Tested-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> (kselftest as sanity check) Link: https://lkml.kernel.org/r/ced01cac1e75f900251b0a4ae1150aa8ebd295ec.1644345232.git.reinette.chatre@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/sgx/encl.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -410,6 +410,8 @@ void sgx_encl_release(struct kref *ref) } kfree(entry); + /* Invoke scheduler to prevent soft lockups. */ + cond_resched(); } xa_destroy(&encl->page_array); Patches currently in stable-queue which might be from reinette.chatre@xxxxxxxxx are queue-5.16/x86-sgx-silence-softlockup-detection-when-releasing-large-enclaves.patch