Fix I/O redirection in -c script (Solaris patch 280-23332860)

McDutchie · McDutchie · commit 17ebfbf6a345 · 2021-01-08T15:15:53.000Z
This change is pulled from here: https://github.com/oracle/solaris-userland/blob/master/components/ksh93/patches/280-23332860.patch Info and reproducers: att#36 In a -c script (like ksh -c 'commands'), the last command misredirects standard output if an EXIT or ERR trap is set. This appears to be a side effect of the optimisation that runs the last command without forking. This applies a patch by George Lijo that flags these specific cases and disables the optimisation. src/cmd/ksh93/include/defs.h, src/cmd/ksh93/bltins/trap.c, src/cmd/ksh93/sh/init.c, src/cmd/ksh93/sh/main.c, src/cmd/ksh93/sh/xec.c: - Apply patch as above. src/cmd/ksh93/tests/io.sh: - Add the reproducers from the bug report as regression tests.
diff --git a/src/cmd/ksh93/bltins/trap.c b/src/cmd/ksh93/bltins/trap.c
@@ -127,6 +127,14 @@ int	b_trap(int argc,char *argv[],Shbltin_t *context)
 						shp->trapnote |= SH_SIGTRAP;
 					else
 						shp->trapnote = 0;
+
+				}
+				if(sig == SH_ERRTRAP)
+				{
+					if(clear)
+						shp->errtrap = 0;
+					else if(!shp->fn_depth || shp->end_fn)
+						shp->errtrap = 1;
 				}
 				continue;
 			}
@@ -144,6 +152,8 @@ int	b_trap(int argc,char *argv[],Shbltin_t *context)
 			else if(clear)
 			{
 				sh_sigclear(sig);
+				if(sig == 0)
+					shp->exittrap = 0;
 				if(dflag)
 					signal(sig,SIG_DFL);
 			}
@@ -156,6 +166,8 @@ int	b_trap(int argc,char *argv[],Shbltin_t *context)
 				shp->st.trapcom[sig] = (shp->sigflag[sig]&SH_SIGOFF) ? Empty : strdup(action);
 				if(arg && arg != Empty)
 					free(arg);
+				if(sig == 0 && (!shp->fn_depth || shp->end_fn))
+					shp->exittrap = 1;
 			}
 		}
 	}
diff --git a/src/cmd/ksh93/include/defs.h b/src/cmd/ksh93/include/defs.h
@@ -272,7 +272,10 @@ struct shared
 	Namfun_t	nvfun; \
 	char		*mathnodes; \
 	char		*bltin_dir; \
-	struct Regress_s*regress;
+	struct Regress_s*regress; \
+	char 		exittrap; \
+	char 		errtrap; \
+	char 		end_fn;
 
 #include	<shell.h>
 
diff --git a/src/cmd/ksh93/sh/init.c b/src/cmd/ksh93/sh/init.c
@@ -1479,6 +1479,9 @@ Shell_t *sh_init(register int argc,register char *argv[], Shinit_f userinit)
 #endif
 	if(shp->userinit=userinit)
 		(*userinit)(shp, 0);
+	shp->exittrap = 0;
+	shp->errtrap = 0;
+	shp->end_fn = 0;
 	return(shp);
 }
 
@@ -1580,6 +1583,9 @@ int sh_reinit(char *argv[])
 	shp->inpipe = shp->outpipe = 0;
 	job_clear();
 	job.in_critical = 0;
+	shp->exittrap = 0;
+	shp->errtrap = 0;
+	shp->end_fn = 0;
 	/* update ${.sh.pid}, $$, $PPID */
 	shgd->current_pid = shgd->pid = getpid();
 	shgd->ppid = getppid();
diff --git a/src/cmd/ksh93/sh/main.c b/src/cmd/ksh93/sh/main.c
@@ -455,6 +455,9 @@ static void	exfile(register Shell_t *shp, register Sfio_t *iop,register int fno)
 	error_info.line = 1;
 	shp->inlineno = 1;
 	shp->binscript = 0;
+	shp->exittrap = 0;
+	shp->errtrap = 0;
+	shp->end_fn = 0;
 	if(sfeof(iop))
 		goto eof_or_error;
 	/* command loop */
diff --git a/src/cmd/ksh93/sh/xec.c b/src/cmd/ksh93/sh/xec.c
@@ -987,6 +987,8 @@ int sh_exec(register const Shnode_t *t, int flags)
 		shp->exitval=0;
 		shp->lastsig = 0;
 		shp->lastpath = 0;
+		if(shp->exittrap || shp->errtrap)
+			execflg = 0;
 		switch(type&COMMSK)
 		{
 		    case TCOM:
@@ -3119,6 +3121,8 @@ int sh_funscope(int argn, char *argv[],int(*fun)(void*),void *arg,int execflg)
 		nv_putval(SH_PATHNAMENOD,shp->st.filename,NV_NOFREE);
 		nv_putval(SH_FUNNAMENOD,shp->st.funname,NV_NOFREE);
 	}
+	if((execflg & sh_state(SH_NOFORK)))
+		shp->end_fn = 1;
 	jmpval = sigsetjmp(buffp->buff,0);
 	if(jmpval == 0)
 	{
@@ -3166,6 +3170,7 @@ int sh_funscope(int argn, char *argv[],int(*fun)(void*),void *arg,int execflg)
 	shp->st = *prevscope;
 	shp->topscope = (Shscope_t*)prevscope;
 	nv_getval(sh_scoped(shp,IFSNOD));
+	shp->end_fn = 0;
 	if(nsig)
 	{
 		for (isig = 0; isig < nsig; ++isig)
diff --git a/src/cmd/ksh93/tests/io.sh b/src/cmd/ksh93/tests/io.sh
@@ -649,5 +649,53 @@ err=$(
 ((!(e = $?))) || err_exit 'crash on null-command redirection with DEBUG trap' \
 	"(got status $e$( ((e>128)) && print -n / && kill -l "$e"), $(printf %q "$got"))"
 
+# ======
+# stdout was misdirected if an EXIT/ERR trap handler was defined in a -c script
+# https://github.com/att/ast/issues/36
+exp=$'exit to stdout\ntrap to stdout'
+exp2=$'exit to file\ntrap to file'
+got=$(export tmp; "$SHELL" -ec \
+'	function log
+	{
+		echo "$* to stdout"
+		echo "$* to file" >> $tmp/ast36_a.test.log
+	}
+	function test_exit
+	{
+		log trap
+	}
+	trap test_exit EXIT
+	log exit
+')
+[[ $got == "$exp" ]] || err_exit 'stdout misdirected to file with EXIT/ERR trap defined (1)' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+[[ $(< $tmp/ast36_a.test.log) == "$exp2" ]] || err_exit 'stdout not correctly redirected to file with EXIT/ERR trap defined (1)' \
+	"(expected $(printf %q "$exp2"), wrote $(printf %q "$(< $tmp/ast36_a.test.log)"))"
+
+exp=$'trap to stdout\nexit to stdout'
+exp2=$'trap to file\nexit to file'
+got=$(export tmp; "$SHELL" -ec \
+'	function log
+	{
+		echo "$* to stdout"
+		echo "$* to file" >> $tmp/ast36_b.test.log
+	}
+	function test_exit
+	{
+		trap test_exittrap EXIT
+		log trap
+	}
+	function test_exittrap
+	{
+		log exit
+	}
+	test_exit
+')
+[[ $got == "$exp" ]] || err_exit 'stdout misdirected to file with EXIT/ERR trap defined (2)' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+[[ $(< $tmp/ast36_b.test.log) == "$exp2" ]] || err_exit 'stdout not correctly redirected to file with EXIT/ERR trap defined (2)' \
+	"(expected $(printf %q "$exp2"), wrote $(printf %q "$(< $tmp/ast36_b.test.log)"))"
+
+
 # ======
 exit $((Errors<125?Errors:125))

Original file line number	Diff line number	Diff line change
`@@ -127,6 +127,14 @@ int b_trap(int argc,char argv[],Shbltin_t context)`
`127`	`127`	`shp->trapnote \|= SH_SIGTRAP;`
`128`	`128`	`else`
`129`	`129`	`shp->trapnote = 0;`
	`130`	`+`
	`131`	`+ }`
	`132`	`+ if(sig == SH_ERRTRAP)`
	`133`	`+ {`
	`134`	`+ if(clear)`
	`135`	`+ shp->errtrap = 0;`
	`136`	`+ else if(!shp->fn_depth \|\| shp->end_fn)`
	`137`	`+ shp->errtrap = 1;`
`130`	`138`	`}`
`131`	`139`	`continue;`
`132`	`140`	`}`
`@@ -144,6 +152,8 @@ int b_trap(int argc,char argv[],Shbltin_t context)`
`144`	`152`	`else if(clear)`
`145`	`153`	`{`
`146`	`154`	`sh_sigclear(sig);`
	`155`	`+ if(sig == 0)`
	`156`	`+ shp->exittrap = 0;`
`147`	`157`	`if(dflag)`
`148`	`158`	`signal(sig,SIG_DFL);`
`149`	`159`	`}`
`@@ -156,6 +166,8 @@ int b_trap(int argc,char argv[],Shbltin_t context)`
`156`	`166`	`shp->st.trapcom[sig] = (shp->sigflag[sig]&SH_SIGOFF) ? Empty : strdup(action);`
`157`	`167`	`if(arg && arg != Empty)`
`158`	`168`	`free(arg);`
	`169`	`+ if(sig == 0 && (!shp->fn_depth \|\| shp->end_fn))`
	`170`	`+ shp->exittrap = 1;`
`159`	`171`	`}`
`160`	`172`	`}`
`161`	`173`	`}`
Original file line number	Diff line number	Diff line change
`@@ -987,6 +987,8 @@ int sh_exec(register const Shnode_t *t, int flags)`
`987`	`987`	`shp->exitval=0;`
`988`	`988`	`shp->lastsig = 0;`
`989`	`989`	`shp->lastpath = 0;`
	`990`	`+ if(shp->exittrap \|\| shp->errtrap)`
	`991`	`+ execflg = 0;`
`990`	`992`	`switch(type&COMMSK)`
`991`	`993`	`{`
`992`	`994`	`case TCOM:`
`@@ -3119,6 +3121,8 @@ int sh_funscope(int argn, char argv[],int(fun)(void),void arg,int execflg)`
`3119`	`3121`	`nv_putval(SH_PATHNAMENOD,shp->st.filename,NV_NOFREE);`
`3120`	`3122`	`nv_putval(SH_FUNNAMENOD,shp->st.funname,NV_NOFREE);`
`3121`	`3123`	`}`
	`3124`	`+ if((execflg & sh_state(SH_NOFORK)))`
	`3125`	`+ shp->end_fn = 1;`
`3122`	`3126`	`jmpval = sigsetjmp(buffp->buff,0);`
`3123`	`3127`	`if(jmpval == 0)`
`3124`	`3128`	`{`
`@@ -3166,6 +3170,7 @@ int sh_funscope(int argn, char argv[],int(fun)(void),void arg,int execflg)`
`3166`	`3170`	`shp->st = *prevscope;`
`3167`	`3171`	`shp->topscope = (Shscope_t*)prevscope;`
`3168`	`3172`	`nv_getval(sh_scoped(shp,IFSNOD));`
	`3173`	`+ shp->end_fn = 0;`
`3169`	`3174`	`if(nsig)`
`3170`	`3175`	`{`
`3171`	`3176`	`for (isig = 0; isig < nsig; ++isig)`