From: Reinette Chatre Date: Tue, 8 Feb 2022 18:48:07 +0000 (-0800) Subject: x86/sgx: Silence softlockup detection when releasing large enclaves X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8795359e35bc33bf86b6d0765aa7f37431db3b9c;p=linux.git x86/sgx: Silence softlockup detection when releasing large enclaves 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 Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Reviewed-by: Jarkko Sakkinen Acked-by: Dave Hansen Tested-by: Jarkko Sakkinen (kselftest as sanity check) Link: https://lkml.kernel.org/r/ced01cac1e75f900251b0a4ae1150aa8ebd295ec.1644345232.git.reinette.chatre@intel.com --- diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 001808e3901cc..48afe96ae0f0f 100644 --- 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);