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cde/src/cmd/ksh93/bltins/misc.c
Martijn Dekker 56805b25af Fix leak and crash upon defining functions in subshells
A memory leak occurred upon leaving a virtual subshell if a
function was defined within it. If this was done more than 32766
(= 2^15-2 = the 'short' max value - 1) times, the shell crashed.
Discussion and reproducer: https://github.com/ksh93/ksh/issues/114

src/cmd/ksh93/sh/subshell.c: table_unset():
- A subshell-defined function was never freed because a broken
  check for autoloaded functions (which must not be freed[*]). It
  looked for an initial '/' in the canonical path of the script
  file that defined the function, but that path is also stored for
  regular functions. Now use a check that executes nv_search() in
  fpathdict, the same method used in _nv_unset() in name.c for a
  regular function unset.

src/cmd/ksh93/bltins/misc.c: b_dot_cmd():
- Fix an additional memory leak introduced in bd88cc7f, that caused
  POSIX functions (which are run with b_dot_cmd() like dot scripts)
  to leak extra. This fix avoids both the crash fixed there and the
  memory leak by introducing a 'tofree' variable remembering the
  filename to free. Thanks to Johnothan King for the patch.

src/lib/libast/include/stk.h,
src/lib/libast/misc/stk.c,
src/lib/libast/man/stk.3,
src/lib/libast/man/stak.3:
- Make the stack more resilient by extending the stack reference
  counter 'stkref' from (signed) short to unsigned int. On modern
  systems with 32-bit ints, this extends the maximum number of
  elements on a stack from 2^15-1==32767 to 2^32-1==4294967295.
  The ref counter can never be negative, so there is no reason for
  signedness. sizeof(int) is defined as the size of a single CPU
  word, so this should not affect performance at all.
     On a 16-bit system (not that ksh still compiles there), this
  doubles the max number of entries to 2^16-1=65535.

src/cmd/ksh93/tests/leaks.sh:
- Add leak regression tests for ksh functions, POSIX functions, dot
  scripts run with '.', and dot scripts run with 'source'.

src/cmd/ksh93/tests/path.sh:
- Add an output builtin with a redirect to an autoloaded function
  so that a crash[*] is triggered if the check for an autoloaded
  function is ever removed from table_unset(), as was done in ksh
  93v- (which crashed).

[*] Freeing autoloaded functions after leaving a virtual subshell
    causes a crashing bug: https://github.com/att/ast/issues/803

Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Fixes: https://github.com/ksh93/ksh/issues/114
2020-08-14 00:25:31 +01:00

582 lines
15 KiB
C

/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1982-2012 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* David Korn <dgk@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* exec [arg...]
* eval [arg...]
* jobs [-lnp] [job...]
* login [arg...]
* let expr...
* . file [arg...]
* :, true, false
* wait [job...]
* shift [n]
*
* David Korn
* AT&T Labs
*
*/
#include "defs.h"
#include "variables.h"
#include "shnodes.h"
#include "path.h"
#include "io.h"
#include "name.h"
#include "history.h"
#include "builtins.h"
#include "jobs.h"
#include <math.h>
#include "FEATURE/locale"
#include "FEATURE/time"
#if _lib_getrusage
#include <sys/resource.h>
#else
#include <times.h>
#endif
#define DOTMAX MAXDEPTH /* maximum level of . nesting */
static void noexport(Namval_t*,void*);
struct login
{
Shell_t *sh;
int clear;
char *arg0;
};
/*
* Handler function for nv_scan() that unsets a variable's export attribute
*/
static void noexport(register Namval_t* np, void *data)
{
NOT_USED(data);
nv_offattr(np,NV_EXPORT);
}
/*
* 'exec' special builtin and 'redirect' builtin
*/
#if 0
/* for the dictionary generator */
int b_redirect(int argc,char *argv[],Shbltin_t *context){}
#endif
int b_exec(int argc,char *argv[], Shbltin_t *context)
{
struct login logdata;
register int n;
struct checkpt *pp;
const char *pname;
logdata.clear = 0;
logdata.arg0 = 0;
logdata.sh = context->shp;
logdata.sh->st.ioset = 0;
while (n = optget(argv, *argv[0]=='r' ? sh_optredirect : sh_optexec)) switch (n)
{
case 'a':
logdata.arg0 = opt_info.arg;
argc = 0;
break;
case 'c':
logdata.clear=1;
break;
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(0), "%s", opt_info.arg);
return(2);
}
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
if(*argv[0]=='r' && argv[opt_info.index]) /* 'redirect' supports no args */
errormsg(SH_DICT,ERROR_exit(2),e_badsyntax);
argv += opt_info.index;
if(!*argv)
return(0);
/* from here on, it's 'exec' with args, so we're replacing the shell */
if(sh_isoption(SH_RESTRICTED))
errormsg(SH_DICT,ERROR_exit(1),e_restricted,argv[0]);
else
{
register struct argnod *arg=logdata.sh->envlist;
register Namval_t* np;
register char *cp;
if(logdata.sh->subshell && !logdata.sh->subshare)
sh_subfork();
if(logdata.clear)
{
#ifdef _ENV_H
env_close(logdata.sh->env);
logdata.sh->env = env_open((char**)0,3);
#else
nv_scan(logdata.sh->var_tree,noexport,0,NV_EXPORT,NV_EXPORT);
#endif
}
while(arg)
{
if((cp=strchr(arg->argval,'=')) &&
(*cp=0,np=nv_search(arg->argval,logdata.sh->var_tree,0)))
{
nv_onattr(np,NV_EXPORT);
sh_envput(logdata.sh->env,np);
}
if(cp)
*cp = '=';
arg=arg->argnxt.ap;
}
pname = argv[0];
if(logdata.arg0)
argv[0] = logdata.arg0;
#ifdef JOBS
if(job_close(logdata.sh) < 0)
return(1);
#endif /* JOBS */
/* force bad exec to terminate shell */
pp = (struct checkpt*)logdata.sh->jmplist;
pp->mode = SH_JMPEXIT;
sh_sigreset(2);
sh_freeup(logdata.sh);
path_exec(logdata.sh,pname,argv,NIL(struct argnod*));
sh_done(logdata.sh,0);
}
return(1);
}
int b_let(int argc,char *argv[],Shbltin_t *context)
{
register int r;
register char *arg;
Shell_t *shp = context->shp;
NOT_USED(argc);
while (r = optget(argv,sh_optlet)) switch (r)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(2), "%s", opt_info.arg);
break;
}
argv += opt_info.index;
if(error_info.errors || !*argv)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
while(arg= *argv++)
r = !sh_arith(shp,arg);
return(r);
}
int b_eval(int argc,char *argv[], Shbltin_t *context)
{
register int r;
register Shell_t *shp = context->shp;
NOT_USED(argc);
while (r = optget(argv,sh_opteval)) switch (r)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(0), "%s",opt_info.arg);
return(2);
}
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
argv += opt_info.index;
if(*argv && **argv)
{
sh_offstate(SH_MONITOR);
sh_eval(sh_sfeval(argv),0);
}
return(shp->exitval);
}
int b_dot_cmd(register int n,char *argv[],Shbltin_t *context)
{
register char *script;
register Namval_t *np;
register int jmpval;
register Shell_t *shp = context->shp;
struct sh_scoped savst, *prevscope = shp->st.self;
char *filename=0, *buffer=0, *tofree;
int fd;
struct dolnod *saveargfor;
volatile struct dolnod *argsave=0;
struct checkpt buff;
Sfio_t *iop=0;
short level;
while (n = optget(argv,sh_optdot)) switch (n)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(0), "%s",opt_info.arg);
return(2);
}
argv += opt_info.index;
script = *argv;
if(error_info.errors || !script)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
if(shp->dot_depth+1 > DOTMAX)
errormsg(SH_DICT,ERROR_exit(1),e_toodeep,script);
if(!(np=shp->posix_fun))
{
/* check for KornShell style function first */
np = nv_search(script,shp->fun_tree,0);
if(np && is_afunction(np) && !nv_isattr(np,NV_FPOSIX))
{
if(!np->nvalue.ip)
{
path_search(shp,script,NIL(Pathcomp_t**),0);
if(np->nvalue.ip)
{
if(nv_isattr(np,NV_FPOSIX))
np = 0;
}
else
errormsg(SH_DICT,ERROR_exit(1),e_found,script);
}
}
else
np = 0;
if(!np)
{
if((fd=path_open(shp,script,path_get(shp,script))) < 0)
errormsg(SH_DICT,ERROR_system(1),e_open,script);
filename = path_fullname(shp,stkptr(shp->stk,PATH_OFFSET));
}
}
*prevscope = shp->st;
shp->st.lineno = np?((struct functnod*)nv_funtree(np))->functline:1;
shp->st.var_local = shp->st.save_tree = shp->var_tree;
if(filename)
{
shp->st.filename = filename;
shp->st.lineno = 1;
}
level = shp->fn_depth+shp->dot_depth+1;
nv_putval(SH_LEVELNOD,(char*)&level,NV_INT16);
shp->st.prevst = prevscope;
shp->st.self = &savst;
shp->topscope = (Shscope_t*)shp->st.self;
prevscope->save_tree = shp->var_tree;
tofree = shp->st.filename;
if(np)
shp->st.filename = np->nvalue.rp->fname;
nv_putval(SH_PATHNAMENOD, shp->st.filename ,NV_NOFREE);
shp->posix_fun = 0;
if(np || argv[1])
argsave = sh_argnew(shp,argv,&saveargfor);
sh_pushcontext(shp,&buff,SH_JMPDOT);
jmpval = sigsetjmp(buff.buff,0);
if(jmpval == 0)
{
shp->dot_depth++;
if(np)
sh_exec((Shnode_t*)(nv_funtree(np)),sh_isstate(SH_ERREXIT));
else
{
buffer = malloc(IOBSIZE+1);
iop = sfnew(NIL(Sfio_t*),buffer,IOBSIZE,fd,SF_READ);
sh_offstate(SH_NOFORK);
sh_eval(iop,sh_isstate(SH_PROFILE)?SH_FUNEVAL:0);
}
}
sh_popcontext(shp,&buff);
if(buffer)
free(buffer);
if(!np)
free(tofree);
shp->dot_depth--;
if((np || argv[1]) && jmpval!=SH_JMPSCRIPT)
sh_argreset(shp,(struct dolnod*)argsave,saveargfor);
else
{
prevscope->dolc = shp->st.dolc;
prevscope->dolv = shp->st.dolv;
}
if (shp->st.self != &savst)
*shp->st.self = shp->st;
/* only restore the top Shscope_t portion for posix functions */
memcpy((void*)&shp->st, (void*)prevscope, sizeof(Shscope_t));
shp->topscope = (Shscope_t*)prevscope;
nv_putval(SH_PATHNAMENOD, shp->st.filename ,NV_NOFREE);
if(jmpval && jmpval!=SH_JMPFUN)
siglongjmp(*shp->jmplist,jmpval);
return(shp->exitval);
}
/*
* null, true command
*/
int b_true(int argc,register char *argv[],Shbltin_t *context)
{
NOT_USED(argc);
NOT_USED(argv[0]);
NOT_USED(context);
return(0);
}
/*
* false command
*/
int b_false(int argc,register char *argv[], Shbltin_t *context)
{
NOT_USED(argc);
NOT_USED(argv[0]);
NOT_USED(context);
return(1);
}
int b_shift(register int n, register char *argv[], Shbltin_t *context)
{
register char *arg;
register Shell_t *shp = context->shp;
while((n = optget(argv,sh_optshift))) switch(n)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(0), "%s",opt_info.arg);
return(2);
}
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
argv += opt_info.index;
n = ((arg= *argv)?(int)sh_arith(shp,arg):1);
if(n<0 || shp->st.dolc<n)
errormsg(SH_DICT,ERROR_exit(1),e_number,arg);
else
{
shp->st.dolv += n;
shp->st.dolc -= n;
}
return(0);
}
int b_wait(int n,register char *argv[],Shbltin_t *context)
{
register Shell_t *shp = context->shp;
while((n = optget(argv,sh_optwait))) switch(n)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(2), "%s",opt_info.arg);
break;
}
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
argv += opt_info.index;
job_bwait(argv);
return(shp->exitval);
}
#ifdef JOBS
# if 0
/* for the dictionary generator */
int b_fg(int n,char *argv[],Shbltin_t *context){}
int b_disown(int n,char *argv[],Shbltin_t *context){}
# endif
int b_bg(register int n,register char *argv[],Shbltin_t *context)
{
register int flag = **argv;
register Shell_t *shp = context->shp;
register const char *optstr = sh_optbg;
if(*argv[0]=='f')
optstr = sh_optfg;
else if(*argv[0]=='d')
optstr = sh_optdisown;
while((n = optget(argv,optstr))) switch(n)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(2), "%s",opt_info.arg);
break;
}
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
argv += opt_info.index;
if(!sh_isoption(SH_MONITOR) || !job.jobcontrol)
{
if(sh_isstate(SH_INTERACTIVE))
errormsg(SH_DICT,ERROR_exit(1),e_no_jctl);
return(1);
}
if(flag=='d' && *argv==0)
argv = (char**)0;
if(job_walk(sfstdout,job_switch,flag,argv))
errormsg(SH_DICT,ERROR_exit(1),e_no_job);
return(shp->exitval);
}
int b_jobs(register int n,char *argv[],Shbltin_t *context)
{
register int flag = 0;
register Shell_t *shp = context->shp;
while((n = optget(argv,sh_optjobs))) switch(n)
{
case 'l':
flag = JOB_LFLAG;
break;
case 'n':
flag = JOB_NFLAG;
break;
case 'p':
flag = JOB_PFLAG;
break;
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(2), "%s",opt_info.arg);
break;
}
argv += opt_info.index;
if(error_info.errors)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
if(*argv==0)
argv = (char**)0;
if(job_walk(sfstdout,job_list,flag,argv))
errormsg(SH_DICT,ERROR_exit(1),e_no_job);
job_wait((pid_t)0);
return(shp->exitval);
}
#endif
/*
* times command
*/
static void print_times(struct timeval utime, struct timeval stime)
{
int ut_min = utime.tv_sec / 60;
int ut_sec = utime.tv_sec % 60;
int ut_ms = utime.tv_usec / 1000;
int st_min = stime.tv_sec / 60;
int st_sec = stime.tv_sec % 60;
int st_ms = stime.tv_usec / 1000;
char radix = GETDECIMAL(0);
sfprintf(sfstdout, "%dm%02d%c%03ds %dm%02d%c%03ds\n", ut_min, ut_sec, radix, ut_ms, st_min, st_sec, radix, st_ms);
}
#if _lib_getrusage
static void print_cpu_times()
{
struct rusage usage;
/* Print the time (user & system) consumed by the shell. */
getrusage(RUSAGE_SELF, &usage);
print_times(usage.ru_utime, usage.ru_stime);
/* Print the time (user & system) consumed by the child processes of the shell. */
getrusage(RUSAGE_CHILDREN, &usage);
print_times(usage.ru_utime, usage.ru_stime);
}
#else /* _lib_getrusage */
static void print_cpu_times()
{
struct timeval utime, stime;
double dtime;
int clk_tck = shgd->lim.clk_tck;
struct tms cpu_times;
times(&cpu_times);
/* Print the time (user & system) consumed by the shell. */
dtime = (double)cpu_times.tms_utime / clk_tck;
utime.tv_sec = dtime / 60;
utime.tv_usec = 1000000 * (dtime - utime.tv_sec);
dtime = (double)cpu_times.tms_stime / clk_tck;
stime.tv_sec = dtime / 60;
stime.tv_usec = 1000000 * (dtime - utime.tv_sec);
print_times(utime, stime);
/* Print the time (user & system) consumed by the child processes of the shell. */
dtime = (double)cpu_times.tms_cutime / clk_tck;
utime.tv_sec = dtime / 60;
utime.tv_usec = 1000000 * (dtime - utime.tv_sec);
dtime = (double)cpu_times.tms_cstime / clk_tck;
stime.tv_sec = dtime / 60;
stime.tv_usec = 1000000 * (dtime - utime.tv_sec);
print_times(utime, stime);
}
#endif /* _lib_getrusage */
int b_times(int argc, char *argv[], Shbltin_t *context)
{
NOT_USED(context);
/* No options or operands are supported, except --man, etc. */
if (argc = optget(argv, sh_opttimes)) switch (argc)
{
case ':':
errormsg(SH_DICT, 2, "%s", opt_info.arg);
errormsg(SH_DICT, ERROR_usage(2), "%s", optusage((char*)0));
default:
errormsg(SH_DICT, ERROR_usage(0), "%s", opt_info.arg);
return(2);
}
if (argv[opt_info.index])
errormsg(SH_DICT, ERROR_exit(2), e_toomanyops);
/* Get & print the times */
print_cpu_times();
return(0);
}
#ifdef _cmd_universe
/*
* There are several universe styles that are masked by the getuniv(),
* setuniv() calls.
*/
int b_universe(int argc, char *argv[],Shbltin_t *context)
{
register char *arg;
register int n;
NOT_USED(context);
while((n = optget(argv,sh_optuniverse))) switch(n)
{
case ':':
errormsg(SH_DICT,2, "%s", opt_info.arg);
break;
case '?':
errormsg(SH_DICT,ERROR_usage(2), "%s",opt_info.arg);
break;
}
argv += opt_info.index;
argc -= opt_info.index;
if(error_info.errors || argc>1)
errormsg(SH_DICT,ERROR_usage(2),"%s",optusage((char*)0));
if(arg = argv[0])
{
if(!astconf("UNIVERSE",0,arg))
errormsg(SH_DICT,ERROR_exit(1), e_badname,arg);
}
else
{
if(!(arg=astconf("UNIVERSE",0,0)))
errormsg(SH_DICT,ERROR_exit(1),e_nouniverse);
else
sfputr(sfstdout,arg,'\n');
}
return(0);
}
#endif /* cmd_universe */