On 12/5/18 3:20 PM, Sean Christopherson wrote: > @@ -223,6 +224,10 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, > const char *str, > tsk->thread.error_code = error_code; > tsk->thread.trap_nr = trapnr; > > + if (user_mode(regs) && > + fixup_vdso_exception(regs, trapnr, error_code, 0)) > + return 0; > + > return -1; > } > > @@ -563,6 +568,9 @@ do_general_protection(struct pt_regs *regs, long > error_code) > tsk->thread.error_code = error_code; > tsk->thread.trap_nr = X86_TRAP_GP; > > + if (fixup_vdso_exception(regs, X86_TRAP_GP, error_code, 0)) > + return; > + > show_signal(tsk, SIGSEGV, "", desc, regs, error_code); > > force_sig(SIGSEGV, tsk); > @@ -854,6 +862,9 @@ static void math_error(struct pt_regs *regs, int > error_code, int trapnr) > if (!si_code) > return; > > + if (fixup_vdso_exception(regs, trapnr, error_code, 0)) > + return; > + > force_sig_fault(SIGFPE, si_code, > (void __user *)uprobe_get_trap_addr(regs), task); > } > --
Needs commenting, please. But, also, this seems really ad-hoc. Probably, that's a result of our signal generation being really ad-hoc itself. But, if this claims "Attempt to fixup exceptions in vDSO before signaling", how do we assure ourselves that we hit all the ad-hoc signal generation cases? How do we know we didn't miss one or ten? I want to hear more of the story of how you picked these sites and also decided that this is a comprehensive-enough set of sites to patch.
