diff options
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/fault.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 8ae3dc5783fd..18b6212bd449 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -792,6 +792,32 @@ void do_secure_storage_access(struct pt_regs *regs) struct page *page; int rc; + /* + * bit 61 tells us if the address is valid, if it's not we + * have a major problem and should stop the kernel or send a + * SIGSEGV to the process. Unfortunately bit 61 is not + * reliable without the misc UV feature so we need to check + * for that as well. + */ + if (test_bit_inv(BIT_UV_FEAT_MISC, &uv_info.uv_feature_indications) && + !test_bit_inv(61, ®s->int_parm_long)) { + /* + * When this happens, userspace did something that it + * was not supposed to do, e.g. branching into secure + * memory. Trigger a segmentation fault. + */ + if (user_mode(regs)) { + send_sig(SIGSEGV, current, 0); + return; + } + + /* + * The kernel should never run into this case and we + * have no way out of this situation. + */ + panic("Unexpected PGM 0x3d with TEID bit 61=0"); + } + switch (get_fault_type(regs)) { case USER_FAULT: mm = current->mm; |