On Sun, Oct 04, 2020 at 10:27:43PM -0500, Haitao Huang wrote: > On Sun, 04 Oct 2020 19:41:20 -0500, Jarkko Sakkinen > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > Fix the issue further discussed in: > > > > 1. https://lore.kernel.org/linux-sgx/op.0rwbv916wjvjmi@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > 2. https://lore.kernel.org/linux-sgx/20201003195440.GD20115@xxxxxxxxxxxxxxxxxxxx/ > > > > Reported-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx> > > Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > Cc: Jethro Beekman <jethro@xxxxxxxxxxxx> > > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > --- > > arch/x86/kernel/cpu/sgx/encl.c | 14 +++++++++----- > > 1 file changed, 9 insertions(+), 5 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/sgx/encl.c > > b/arch/x86/kernel/cpu/sgx/encl.c > > index ae45f8f0951e..a225e96c7a39 100644 > > --- a/arch/x86/kernel/cpu/sgx/encl.c > > +++ b/arch/x86/kernel/cpu/sgx/encl.c > > @@ -304,11 +304,10 @@ int sgx_encl_may_map(struct sgx_encl *encl, > > unsigned long start, > > unsigned long end, unsigned long vm_flags) > > { > > unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC); > > - unsigned long idx_start = PFN_DOWN(start); > > - unsigned long idx_end = PFN_DOWN(end - 1); > > + unsigned long start_i = PFN_DOWN(start); > > + unsigned long end_i = PFN_DOWN(end - 1); > > struct sgx_encl_page *page; > > - > > - XA_STATE(xas, &encl->page_array, idx_start); > > + int i; > > /* > > * Disallow READ_IMPLIES_EXEC tasks as their VMA permissions might > > @@ -317,9 +316,14 @@ int sgx_encl_may_map(struct sgx_encl *encl, > > unsigned long start, > > if (current->personality & READ_IMPLIES_EXEC) > > return -EACCES; > > - xas_for_each(&xas, page, idx_end) > > + for (i = start_i; i <= end_i; i++) { > > + mutex_lock(&encl->lock); > > + page = xa_load(&encl->page_array, i); > > + mutex_unlock(&encl->lock); > > + > > if (!page || (~page->vm_max_prot_bits & vm_prot_bits)) > > return -EACCES; > > + } > > return 0; > > } > > Works with no PROVE_LOCKING complaints. > Haitao Great. That is a good reference point. Thank you. v2 should work too but needs to be checked. /Jarkko
