[ast-developers] [patch] Fix |shgd->sigmax| handling...

[Roland Mainz]

Hi!

----

Attached (as "astksh20130807_sigmax001.diff.txt") is a patch which
fixes some issues related to |shgd->sigmax| handling.
Originally |shgd->sigmax| counted the signals from "|0| -
|shgd->sigmax|" but later this was changed incrementally over months
to "|0| - |shgd->sigmax-1|". The patch unifies&&fixes the logic (and
fixes SIGRTMAX users; but note that "valgrind" uses some realtime
signals for it's own usage... see
http://article.gmane.org/gmane.comp.debugging.valgrind.devel/23869).

* Fixed bugs:
1. The following valgrind hit on SuSE 12.3/AMD64/64bitis fixed:
-- snip --
==44984== Warning: ignored attempt to set SIGRT32 handler in sigaction();
==44984== the SIGRT32 signal is used internally by Valgrind
==44984== Conditional jump or move depends on uninitialised value(s)
==44984== at 0x414910: sh_sigtrap (fault.c:318)
==44984== by 0x48BB46: b_trap (trap.c:170)
==44984== by 0x468E00: sh_exec (xec.c:1360)
==44984== by 0x46BEA6: sh_exec (xec.c:2223)
==44984== by 0x40F502: exfile (main.c:603)
==44984== by 0x40E74D: sh_main (main.c:375)
==44984== by 0x40D920: main (pmain.c:45)
-- snip --

2. SIGRTMAX traps now work stable and no longer have weired "works,
works not, works, works not" issues between runs (this is likely
related to signal storms and [3] below)

3. |shp->siginfo| is no longer allocated on demand in the signal
handler, removing a possible race condition (see [2] above) and other
related mess (yes... I know... consumes more memory by default... but
better "safe than sorry" in the case of signals... we can re-optimise
it later again when signals are stable...)

4. The mysterious signal SIG65 (SIGRTMAX+1) on Linux is now gone

----

Bye,
Roland
--
__ . . __
(o.\ \/ /.o) roland.mainz at nrubsig.org
\__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer
/O /==\ O\ TEL [phone]
(;O/ \/ \O;)
-------------- next part --------------
diff -r -u original/src/cmd/ksh93/bltins/cflow.c build_sigmax/src/cmd/ksh93/bltins/cflow.c
--- src/cmd/ksh93/bltins/cflow.c 2012-08-03 20:41:32.000000000 +0200
+++ src/cmd/ksh93/bltins/cflow.c 2013-08-09 18:03:51.538495834 +0200
@@ -65,7 +65,7 @@
pp->mode = (**argv=='e'?SH_JMPEXIT:SH_JMPFUN);
argv += opt_info.index;
n = (((arg= *argv)?(int)strtol(arg, (char**)0, 10):shp->oldexit));
- if(n<0 || n==256 || n > SH_EXITMASK+shp->gd->sigmax+1)
+ if(n<0 || n==256 || n > (SH_EXITMASK+shp->gd->sigmax))
n &= ((unsigned int)n)&SH_EXITMASK;
/* return outside of function, dotscript and profile is exit */
if(shp->fn_depth==0 && shp->dot_depth==0 && !sh_isstate(shp,SH_PROFILE))
diff -r -u original/src/cmd/ksh93/bltins/trap.c build_sigmax/src/cmd/ksh93/bltins/trap.c
--- src/cmd/ksh93/bltins/trap.c 2013-08-02 20:50:23.000000000 +0200
+++ src/cmd/ksh93/bltins/trap.c 2013-08-09 18:06:25.956814669 +0200
@@ -144,7 +144,7 @@
free(arg);
continue;
}
- if(sig>shp->gd->sigmax)
+ if(sig>=shp->gd->sigmax)
{
errormsg(SH_DICT,2,e_trap,arg);
return(1);
@@ -261,7 +261,7 @@
}
if(flag&S_FLAG)
{
- if((sig=sig_number(shp,signame)) < 0 || sig > shp->gd->sigmax)
+ if(((sig=sig_number(shp,signame)) < 0) || (sig >= shp->gd->sigmax))
{
shp->exitval = 2;
errormsg(SH_DICT,ERROR_exit(1),e_nosignal,signame);
diff -r -u original/src/cmd/ksh93/sh/fault.c build_sigmax/src/cmd/ksh93/sh/fault.c
--- src/cmd/ksh93/sh/fault.c 2013-08-02 19:21:24.000000000 +0200
+++ src/cmd/ksh93/sh/fault.c 2013-08-09 18:18:13.520584040 +0200
@@ -182,7 +182,7 @@
}
/* mark signal and continue */
shp->trapnote |= SH_SIGSET;
- if(sig <= shp->gd->sigmax)
+ if(sig < shp->gd->sigmax)
shp->sigflag[sig] |= SH_SIGSET;
#if defined(VMFL) && (VMALLOC_VERSION>=20031205L)
if(abortsig(sig))
@@ -238,7 +238,7 @@
if(flag&(SH_SIGSET|SH_SIGTRAP))
astserial(AST_SERIAL_RESTART, AST_SERIAL_except);
#endif
- if(sig <= shp->gd->sigmax)
+ if(sig < shp->gd->sigmax)
shp->sigflag[sig] |= flag;
if(pp->mode==SH_JMPCMD && sh_isstate(shp,SH_STOPOK))
{
@@ -283,10 +283,12 @@
shp->st.trapcom = (char**)calloc(n,sizeof(char*));
shp->sigflag = (unsigned char*)calloc(n,sizeof(char));
shp->gd->sigmsg = (char**)calloc(n,sizeof(char*));
+ shp->siginfo = (void**)calloc(sizeof(void*),shp->gd->sigmax);
+
for(tp=shtab_signals; sig=tp->sh_number; tp++)
{
n = (sig>>SH_SIGBITS);
- if((sig &= ((1<<SH_SIGBITS)-1)) > (shp->gd->sigmax+1))
+ if((sig &= ((1<<SH_SIGBITS)-1)) >= shp->gd->sigmax)
continue;
sig--;
if(n&SH_SIGRUNTIME)
@@ -320,8 +322,6 @@
}
else
{
- if(!shp->siginfo)
- shp->siginfo = (void**)calloc(sizeof(void*),shp->gd->sigmax);
flag |= SH_SIGFAULT;
if(sig==SIGALRM && fun!=SIG_DFL && fun!=(sh_sigfun_t)sh_fault)
signal(sig,fun);
@@ -336,9 +336,10 @@
*/
void sh_sigdone(Shell_t *shp)
{
- register int flag, sig = shgd->sigmax;
+ unsigned char flag;
+ int sig;
shp->sigflag[0] |= SH_SIGFAULT;
- for(sig=shgd->sigmax; sig>0; sig--)
+ for(sig=shgd->sigmax-1 ; sig>=0 ; sig--)
{
flag = shp->sigflag[sig];
if((flag&(SH_SIGDONE|SH_SIGIGNORE|SH_SIGINTERACTIVE)) && !(flag&(SH_SIGFAULT|SH_SIGOFF)))
@@ -758,7 +759,7 @@
if(flag<=0)
{
/* not all signals may be defined, so initialize */
- for(sig=shp->gd->sigmax; sig>=0; sig--)
+ for(sig=shp->gd->sigmax-1; sig>=0; sig--)
names[sig] = 0;
for(sig=SH_DEBUGTRAP; sig>=0; sig--)
traps[sig] = 0;
@@ -791,7 +792,7 @@
{
if(!(trap=trapcom[sig]))
continue;
- if(sig > shp->gd->sigmax || !(sname=(char*)names[sig]))
+ if(sig >= shp->gd->sigmax || !(sname=(char*)names[sig]))
sname = sig_name(shp,sig,name,1);
sfprintf(iop,trapfmt,sh_fmtq(trap),sname);
}
@@ -805,7 +806,7 @@
else
{
/* print all the signal names */
- for(sig=1; sig <= shp->gd->sigmax; sig++)
+ for(sig=1; sig < shp->gd->sigmax; sig++)
{
if(!(sname=(char*)names[sig]))
{
diff -r -u original/src/cmd/ksh93/sh/jobs.c build_sigmax/src/cmd/ksh93/sh/jobs.c
--- src/cmd/ksh93/sh/jobs.c 2013-07-17 18:22:06.000000000 +0200
+++ src/cmd/ksh93/sh/jobs.c 2013-08-09 18:04:27.976348098 +0200
@@ -1996,7 +1996,7 @@
static char *job_sigmsg(Shell_t *shp,int sig)
{
static char signo[40];
- if(sig<=shgd->sigmax && shgd->sigmsg[sig])
+ if(sig<shgd->sigmax && shgd->sigmsg[sig])
return(shgd->sigmsg[sig]);
#if defined(SIGRTMIN) && defined(SIGRTMAX)
if(sig>=shp->gd->sigruntime[SH_SIGRTMIN] && sig<=shp->gd->sigruntime[SH_SIGRTMAX])
diff -r -u original/src/cmd/ksh93/sh/timers.c build_sigmax/src/cmd/ksh93/sh/timers.c
--- src/cmd/ksh93/sh/timers.c 2012-08-08 18:57:52.000000000 +0200
+++ src/cmd/ksh93/sh/timers.c 2013-08-09 18:04:51.724857872 +0200
@@ -97,8 +97,6 @@
Shell_t *shp = sh_getinterp();
if(shp->st.trapcom[SIGALRM] && *shp->st.trapcom[SIGALRM])
{
- if(!shp->siginfo)
- shp->siginfo = (void**)calloc(sizeof(void*),shp->gd->sigmax);
shp->siginfo[SIGALRM] = malloc(sizeof(siginfo_t));
memcpy(shp->siginfo[SIGALRM],context,sizeof(siginfo_t));
}