On Thu, 2021-09-02 at 13:25 +0200, Ingo Schwarze wrote:
> Hi Tim,
>
> trondd wrote on Wed, Sep 01, 2021 at 08:46:28PM -0400:
> > Ingo Schwarze <[email protected]> wrote:
> > > Ingo Schwarze wrote on Wed, Sep 01, 2021 at 04:38:51PM +0200:
>
> > > > Note that the h_hup() and h_term() signal handlers are still unsafe
> > > > after this commit because they also set the "killersig" (how fitting!)
> > > > field in a global struct.
>
> > > I like it when fixing two bugs only amounts to minus: minus 14 LOC,
> > > 1 function, 1 global variable, 2 automatic variables, 1 struct member,
> > > 9 pointer dereferences, 1 #define, and minus 1 #undef.
> > >
> > > The argument that only one single GS exists applies unchanged.
>
> > Great. This is the direction I was going to go in with it. I hadn't
> > thought of collapsing h_hup an h_term, though.
> >
> > This makes sense as I understand the signal/event handling and a quick
> > test through the signals shows no difference in behavior.
>
> Thank you (and martijn@) for reviewing and testing.
> This is now committed.
>
> > Should h_term() and cl_sigterm be named something more general to
> > indicate that they also handle SIGHUP? Or is it good enough since it
> > includes all the signals that 'term'inate vi? It's not hard to follow
> > as-is.
>
> That is what i was thinking: why re-paint a bike shed if the existing
> paint is already pretty and not yet falling off?
Luckily the paint is pretty. :-)
>
> Yours,
> Ingo
>
>
> > > Index: cl/cl.h
> > > ===================================================================
> > > RCS file: /cvs/src/usr.bin/vi/cl/cl.h,v
> > > retrieving revision 1.11
> > > diff -u -p -r1.11 cl.h
> > > --- cl/cl.h 1 Sep 2021 14:28:15 -0000 1.11
> > > +++ cl/cl.h 1 Sep 2021 17:15:34 -0000
> > > @@ -11,7 +11,6 @@
> > > * @(#)cl.h 10.19 (Berkeley) 9/24/96
> > > */
> > >
> > > -extern volatile sig_atomic_t cl_sighup;
> > > extern volatile sig_atomic_t cl_sigint;
> > > extern volatile sig_atomic_t cl_sigterm;
> > > extern volatile sig_atomic_t cl_sigwinch;
> > > @@ -31,7 +30,6 @@ typedef struct _cl_private {
> > > char *rmso, *smso; /* Inverse video terminal strings. */
> > > char *smcup, *rmcup; /* Terminal start/stop strings. */
> > >
> > > - int killersig; /* Killer signal. */
> > > #define INDX_HUP 0
> > > #define INDX_INT 1
> > > #define INDX_TERM 2
> > > Index: cl/cl_funcs.c
> > > ===================================================================
> > > RCS file: /cvs/src/usr.bin/vi/cl/cl_funcs.c,v
> > > retrieving revision 1.21
> > > diff -u -p -r1.21 cl_funcs.c
> > > --- cl/cl_funcs.c 1 Sep 2021 14:28:15 -0000 1.21
> > > +++ cl/cl_funcs.c 1 Sep 2021 17:15:34 -0000
> > > @@ -437,7 +437,7 @@ cl_refresh(SCR *sp, int repaint)
> > > * If we received a killer signal, we're done, there's no point
> > > * in refreshing the screen.
> > > */
> > > - if (clp->killersig)
> > > + if (cl_sigterm)
> > > return (0);
> > >
> > > /*
> > > @@ -582,7 +582,7 @@ cl_suspend(SCR *sp, int *allowedp)
> > > * unchanged. In addition, the terminal has already been reset
> > > * correctly, so leave it alone.
> > > */
> > > - if (clp->killersig) {
> > > + if (cl_sigterm) {
> > > F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
> > > return (0);
> > > }
> > > Index: cl/cl_main.c
> > > ===================================================================
> > > RCS file: /cvs/src/usr.bin/vi/cl/cl_main.c,v
> > > retrieving revision 1.34
> > > diff -u -p -r1.34 cl_main.c
> > > --- cl/cl_main.c 1 Sep 2021 14:28:15 -0000 1.34
> > > +++ cl/cl_main.c 1 Sep 2021 17:15:34 -0000
> > > @@ -33,7 +33,6 @@
> > >
> > > GS *__global_list; /* GLOBAL: List of
> > > screens. */
> > >
> > > -volatile sig_atomic_t cl_sighup;
> > > volatile sig_atomic_t cl_sigint;
> > > volatile sig_atomic_t cl_sigterm;
> > > volatile sig_atomic_t cl_sigwinch;
> > > @@ -120,9 +119,9 @@ main(int argc, char *argv[])
> > > }
> > >
> > > /* If a killer signal arrived, pretend we just got it. */
> > > - if (clp->killersig) {
> > > - (void)signal(clp->killersig, SIG_DFL);
> > > - (void)kill(getpid(), clp->killersig);
> > > + if (cl_sigterm) {
> > > + (void)signal(cl_sigterm, SIG_DFL);
> > > + (void)kill(getpid(), cl_sigterm);
> > > /* NOTREACHED */
> > > }
> > >
> > > @@ -215,17 +214,6 @@ term_init(char *ttype)
> > > }
> > > }
> > >
> > > -#define GLOBAL_CLP \
> > > - CL_PRIVATE *clp = GCLP(__global_list);
> > > -static void
> > > -h_hup(int signo)
> > > -{
> > > - GLOBAL_CLP;
> > > -
> > > - cl_sighup = 1;
> > > - clp->killersig = SIGHUP;
> > > -}
> > > -
> > > static void
> > > h_int(int signo)
> > > {
> > > @@ -235,10 +223,7 @@ h_int(int signo)
> > > static void
> > > h_term(int signo)
> > > {
> > > - GLOBAL_CLP;
> > > -
> > > - cl_sigterm = 1;
> > > - clp->killersig = SIGTERM;
> > > + cl_sigterm = signo;
> > > }
> > >
> > > static void
> > > @@ -246,7 +231,6 @@ h_winch(int signo)
> > > {
> > > cl_sigwinch = 1;
> > > }
> > > -#undef GLOBAL_CLP
> > >
> > > /*
> > > * sig_init --
> > > @@ -261,20 +245,19 @@ sig_init(GS *gp, SCR *sp)
> > >
> > > clp = GCLP(gp);
> > >
> > > - cl_sighup = 0;
> > > cl_sigint = 0;
> > > cl_sigterm = 0;
> > > cl_sigwinch = 0;
> > >
> > > if (sp == NULL) {
> > > - if (setsig(SIGHUP, &clp->oact[INDX_HUP], h_hup) ||
> > > + if (setsig(SIGHUP, &clp->oact[INDX_HUP], h_term) ||
> > > setsig(SIGINT, &clp->oact[INDX_INT], h_int) ||
> > > setsig(SIGTERM, &clp->oact[INDX_TERM], h_term) ||
> > > setsig(SIGWINCH, &clp->oact[INDX_WINCH], h_winch)
> > > )
> > > err(1, NULL);
> > > } else
> > > - if (setsig(SIGHUP, NULL, h_hup) ||
> > > + if (setsig(SIGHUP, NULL, h_term) ||
> > > setsig(SIGINT, NULL, h_int) ||
> > > setsig(SIGTERM, NULL, h_term) ||
> > > setsig(SIGWINCH, NULL, h_winch)
> > > Index: cl/cl_read.c
> > > ===================================================================
> > > RCS file: /cvs/src/usr.bin/vi/cl/cl_read.c,v
> > > retrieving revision 1.22
> > > diff -u -p -r1.22 cl_read.c
> > > --- cl/cl_read.c 1 Sep 2021 14:28:15 -0000 1.22
> > > +++ cl/cl_read.c 1 Sep 2021 17:15:34 -0000
> > > @@ -62,13 +62,15 @@ retest: if (LF_ISSET(EC_INTERRUPT) || cl
> > > evp->e_event = E_TIMEOUT;
> > > return (0);
> > > }
> > > - if (cl_sighup) {
> > > + switch (cl_sigterm) {
> > > + case SIGHUP:
> > > evp->e_event = E_SIGHUP;
> > > return (0);
> > > - }
> > > - if (cl_sigterm) {
> > > + case SIGTERM:
> > > evp->e_event = E_SIGTERM;
> > > return (0);
> > > + default:
> > > + break;
> > > }
> > > if (cl_sigwinch) {
> > > cl_sigwinch = 0;
>
