On Wed, Oct 23, 2019 at 03:43:40PM +0300, Jarkko Sakkinen wrote: > On Tue, Oct 22, 2019 at 03:49:21PM -0700, Sean Christopherson wrote: > > Don't add an EPC page to the free page list of EREMOVE fails, as doing > > so will cause any future attempt to use the EPC page to fail, and likely > > WARN as well. > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > --- > > arch/x86/kernel/cpu/sgx/main.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > > index d45bf6fca0c8..8e7557d3ff03 100644 > > --- a/arch/x86/kernel/cpu/sgx/main.c > > +++ b/arch/x86/kernel/cpu/sgx/main.c > > @@ -138,7 +138,8 @@ int sgx_free_page(struct sgx_epc_page *page) > > spin_unlock(&sgx_active_page_list_lock); > > > > ret = __eremove(sgx_epc_addr(page)); > > - WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret); > > + if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret)) > > + return -EIO; > > How did you end up choosing -EIO? Don't immediately have any better > suggestion but neither sure if that is the best choice. That is why I'm > asking. sgx_edbgrd() and sgx_edbgwr() return -EIO on failure, and they're the only other case I can think of where an ENCLS instruction failure is reported to userspace *and* may or may not be due to a fault. I honestly didn't spend much time thinking about it as the code is dropped in the next path.
