From: Reinette Chatre reinette.chatre@intel.com
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@vger.kernel.org Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer") Reported-by: Vijay Dhanraj vijay.dhanraj@intel.com Signed-off-by: Reinette Chatre reinette.chatre@intel.com Signed-off-by: Dave Hansen dave.hansen@linux.intel.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Acked-by: Dave Hansen dave.hansen@linux.intel.com Tested-by: Jarkko Sakkinen jarkko@kernel.org (kselftest as sanity check) Link: https://lkml.kernel.org/r/ced01cac1e75f900251b0a4ae1150aa8ebd295ec.164434523... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);