On Wed, Apr 05, 2017 at 07:36:17AM -0700, Thomas Garnier wrote: > On Wed, Apr 5, 2017 at 7:22 AM, Catalin Marinas <catalin.marinas@xxxxxxx> wrote: > > On Tue, Apr 04, 2017 at 10:47:27AM -0700, Thomas Garnier wrote: > >> + > >> ldr x1, [tsk, #TSK_TI_FLAGS] > >> and x2, x1, #_TIF_WORK_MASK > >> cbnz x2, work_pending > >> @@ -779,6 +788,12 @@ finish_ret_to_user: > >> kernel_exit 0 > >> ENDPROC(ret_to_user) > >> > >> +addr_limit_fail: > >> + stp x0, lr, [sp,#-16]! > >> + bl asm_verify_pre_usermode_state > >> + ldp x0, lr, [sp],#16 > >> + ret lr > > > > Where is this supposed to return? What is the value of lr when branching > > to addr_limit_fail? > > It is not supposed to return. Do you think I should remove stp, ldp, > ret and jut add a brk 0x100 or jmp/call a break/bug function? Can you not just make addr_limit_fail a C function which never returns (similar to what we to with bad_mode() on arm64)? Since addr_limit_fail is only called when the segment is not the right one, I don't really see why you need another call to asm_verify_pre_usermode_state() to do a similar check again. Just panic in addr_limit_fail (unless I misunderstood what you are trying to achieve). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
