jobs: change p_job variable type from short to int (#763)

This change addresses an issue where ksh has undefined behavior when the number of jobs exceeds `2^15 - 1` (32767), which is the maximum value for a `short`. The short integer overflow happened in jobs.c, line 1210.
ksh93 · Jul 13, 2024 · 685f18d · 685f18d
1 parent 53667fb
commit 685f18d
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Showing 4 changed files with 16 additions and 9 deletions.
diff --git a/NEWS b/NEWS
@@ -2,6 +2,11 @@ This documents significant changes in the 1.0 branch of ksh 93u+m.
 For full details, see the git log at: https://github.com/ksh93/ksh/tree/1.0
 Uppercase BUG_* IDs are shell bug IDs as used by the Modernish shell library.
 
+2024-07-13:
+
+- The shell is now capable of handling more than 32767 simultaneous
+  background jobs, subject to system limitations.
+
 2024-07-02:
 
 - Release 1.0.9.

diff --git a/src/cmd/ksh93/include/jobs.h b/src/cmd/ksh93/include/jobs.h
@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2011 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -14,6 +14,7 @@
 *                  Martijn Dekker <[email protected]>                   *
 *            Johnothan King <[email protected]>             *
 *               Anuradha Weeraman <[email protected]>                *
+*               Vincent Mihalkovic <[email protected]>               *
 *                                                                      *
 ***********************************************************************/
 #ifndef JOB_NFLAG
@@ -51,7 +52,7 @@ struct process
 	pid_t		p_pid;		/* process ID */
 	pid_t		p_pgrp;		/* process group */
 	pid_t		p_fgrp;		/* process group when stopped */
-	short		p_job;		/* job number of process */
+	int		p_job;		/* job number of process */
 	unsigned short	p_exit;		/* exit value or signal number */
 	unsigned short	p_exitmin;	/* minimum exit value for xargs */
 	unsigned short	p_flag;		/* flags - see below */

diff --git a/src/cmd/ksh93/include/version.h b/src/cmd/ksh93/include/version.h
@@ -17,8 +17,8 @@
 #include <releaseflags.h>
 
 #define SH_RELEASE_FORK	"93u+m"		/* only change if you develop a new ksh93 fork */
-#define SH_RELEASE_SVER	"1.0.9"		/* semantic version number: https://semver.org */
-#define SH_RELEASE_DATE	"2024-07-02"	/* must be in this format for $((.sh.version)) */
+#define SH_RELEASE_SVER	"1.0.10-beta"	/* semantic version number: https://semver.org */
+#define SH_RELEASE_DATE	"2024-07-13"	/* must be in this format for $((.sh.version)) */
 #define SH_RELEASE_CPYR	"(c) 2020-2024 Contributors to ksh " SH_RELEASE_FORK
 
 /* Scripts sometimes field-split ${.sh.version}, so don't change amount of whitespace. */

diff --git a/src/cmd/ksh93/sh/jobs.c b/src/cmd/ksh93/sh/jobs.c
@@ -13,6 +13,7 @@
 *                  David Korn <[email protected]>                   *
 *                  Martijn Dekker <[email protected]>                   *
 *            Johnothan King <[email protected]>             *
+*               Vincent Mihalkovic <[email protected]>               *
 *                                                                      *
 ***********************************************************************/
 /*
@@ -437,7 +438,7 @@ int job_reap(int sig)
 			pw->p_flag &= ~P_NOTIFY;
 		if(job.jobcontrol && pid==pw->p_fgrp && pid==tcgetpgrp(JOBTTY))
 		{
-			px = job_byjid((int)pw->p_job);
+			px = job_byjid(pw->p_job);
 			for(; px && (px->p_flag&P_DONE); px=px->p_nxtproc);
 			if(!px)
 				tcsetpgrp(JOBTTY,job.mypid);
@@ -1528,7 +1529,7 @@ int job_switch(struct process *pw,int bgflag)
 {
 	const char *msg;
 	job_lock();
-	if(!pw || !(pw=job_byjid((int)pw->p_job)))
+	if(!pw || !(pw=job_byjid(pw->p_job)))
 	{
 		job_unlock();
 		return 1;
@@ -1542,7 +1543,7 @@ int job_switch(struct process *pw,int bgflag)
 	}
 	if(bgflag=='b')
 	{
-		sfprintf(outfile,"[%d]\t",(int)pw->p_job);
+		sfprintf(outfile,"[%d]\t",pw->p_job);
 		sh.bckpid = pw->p_pid;
 		pw->p_flag |= P_BG;
 		msg = "&";
@@ -1623,7 +1624,7 @@ static struct process *job_unpost(struct process *pwtop,int notify)
 	sfprintf(sfstderr,"ksh: job line %4d: drop PID=%lld critical=%d PID=%d env=%u\n",__LINE__,(Sflong_t)sh.current_pid,job.in_critical,pwtop->p_pid,pwtop->p_env);
 	sfsync(sfstderr);
 #endif /* DEBUG */
-	pwtop = pw = job_byjid((int)pwtop->p_job);
+	pwtop = pw = job_byjid(pwtop->p_job);
 	if(!pw)
 		return NULL;
 #if SHOPT_BGX
@@ -1664,7 +1665,7 @@ static struct process *job_unpost(struct process *pwtop,int notify)
 	sfprintf(sfstderr,"ksh: job line %4d: free PID=%lld critical=%d job=%d\n",__LINE__,(Sflong_t)sh.current_pid,job.in_critical,pwtop->p_job);
 	sfsync(sfstderr);
 #endif /* DEBUG */
-	job_free((int)pwtop->p_job);
+	job_free(pwtop->p_job);
 	return NULL;
 }