OS-4474 lxbrand missing prctl(PR_SET_PDEATHSIG) support

OS-4476 lxbrand convert prctl to IKE
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

usr/src/common/brand/lx/lx_signum.c

@@ -271,6 +271,28 @@ lx_stol_signo(int signo, int defsig)
 	return (rval);
 }
 
+
+/*
+ * Convert a Linux signal number to an illumos signal number and return it.
+ * Error behavior is identical to lx_stol_signo.
+ */
+int
+lx_ltos_signo(int signo, int defsig)
+{
+#ifdef	_KERNEL
+	VERIFY3S(defsig, >=, 0);
+#endif
+
+	if (signo < 1 || signo >= NSIG) {
+#ifndef	_KERNEL
+		VERIFY3S(defsig, >=, 0);
+#endif
+		return (defsig);
+	}
+
+	return (ltos_signo[signo]);
+}
+
 /*
  * Convert the "status" field of a SIGCLD siginfo_t.  We need to extract the
  * illumos signal number and convert it to a Linux signal number while leaving

usr/src/common/brand/lx/lx_signum.h

@@ -75,6 +75,7 @@ extern const int ltos_signo[];
 extern const int stol_signo[];
 
 extern int lx_stol_signo(int, int);
+extern int lx_ltos_signo(int, int);
 extern int lx_stol_status(int, int);
 extern int lx_stol_sigcode(int);
 

usr/src/lib/brand/lx/lx_brand/common/lx_brand.c

@@ -1071,7 +1071,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	NULL,				/* 154: modify_ldt */
 	NULL,				/* 155: pivot_root */
 	lx_sysctl,			/* 156: sysctl */
-	lx_prctl,			/* 157: prctl */
+	NULL,				/* 157: prctl */
 	NULL,				/* 158: arch_prctl */
 	lx_adjtimex,			/* 159: adjtimex */
 	NULL,				/* 160: setrlimit */
@@ -1417,7 +1417,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	NULL,				/* 169: nfsservctl */
 	NULL,				/* 170: setresgid16 */
 	lx_getresgid16,			/* 171: getresgid16 */
-	lx_prctl,			/* 172: prctl */
+	NULL,				/* 172: prctl */
 	lx_rt_sigreturn,		/* 173: rt_sigreturn */
 	lx_rt_sigaction,		/* 174: rt_sigaction */
 	lx_rt_sigprocmask,		/* 175: rt_sigprocmask */

usr/src/lib/brand/lx/lx_brand/common/misc.c

@@ -602,106 +602,6 @@ lx_setgroups(uintptr_t p1, uintptr_t p2)
 	return ((r == -1) ? -errno : r);
 }
 
-/*
- * Linux currently defines 42 options for prctl (PR_CAPBSET_READ,
- * PR_CAPBSET_DROP, etc.). Most of these are not emulated.
- */
-long
-lx_prctl(int option, uintptr_t arg2, uintptr_t arg3,
-    uintptr_t arg4, uintptr_t arg5)
-{
-	psinfo_t psinfo;
-	size_t fnamelen = sizeof (psinfo.pr_fname);
-	size_t psargslen = sizeof (psinfo.pr_psargs);
-	int fd;
-
-	if (option == LX_PR_GET_DUMPABLE) {
-		/* Indicate that process is always dumpable */
-		return (1);
-	}
-
-	if (option == LX_PR_GET_SECUREBITS) {
-		/* Our bits are always 0 */
-		return (0);
-	}
-
-	if (option == LX_PR_SET_SECUREBITS) {
-		/* Ignore setting any bits from arg2 */
-		return (0);
-	}
-
-	if (option == LX_PR_SET_DUMPABLE) {
-		if (arg2 != 1 && arg2 != 0)
-			return (-EINVAL);
-		/* Lie about altering process dumpability */
-		return (0);
-	}
-
-	if (option == LX_PR_SET_KEEPCAPS) {
-		/*
-		 * The closest illumos analog to SET_KEEPCAPS is the PRIV_AWARE
-		 * flag.  There are probably some cases where it's not exactly
-		 * the same, but this will do for a first try.
-		 */
-		if (arg2 == 0) {
-			if (setpflags(PRIV_AWARE_RESET, 1) != 0)
-				return (-errno);
-		} else {
-			if (setpflags(PRIV_AWARE, 1) != 0)
-				return (-errno);
-		}
-		return (0);
-	}
-
-	if (option != LX_PR_SET_NAME) {
-		lx_unsupported("prctl option %d", option);
-		return (-ENOSYS);
-	}
-
-	/*
-	 * In Linux, PR_SET_NAME sets the name of the thread, not the process.
-	 * Due to the historical quirks of Linux's asinine thread model, this
-	 * name is effectively the name of the process (as visible via ps(1))
-	 * if the thread is the first of its task group.  The first thread is
-	 * therefore special, and to best mimic Linux semantics (and absent a
-	 * notion of per-LWP names), we do nothing (but return success) on LWPs
-	 * other than LWP 1.
-	 */
-	if (thr_self() != 1)
-		return (0);
-
-	if (uucopy((void *)arg2, psinfo.pr_fname,
-	    MIN(LX_PR_SET_NAME_NAMELEN, fnamelen)) != 0)
-		return (-errno);
-
-	psinfo.pr_fname[fnamelen - 1] = '\0';
-
-	if (uucopy((void *)arg2, psinfo.pr_psargs,
-	    MIN(LX_PR_SET_NAME_NAMELEN, psargslen)) != 0)
-		return (-errno);
-
-	psinfo.pr_psargs[psargslen - 1] = '\0';
-
-	if ((fd = open("/native/proc/self/psinfo", O_WRONLY)) < 0)
-		return (-errno);
-
-	if (pwrite(fd, psinfo.pr_fname, fnamelen,
-	    (uintptr_t)psinfo.pr_fname - (uintptr_t)&psinfo) != fnamelen) {
-		(void) close(fd);
-		return (-EIO);
-	}
-
-	if (pwrite(fd, psinfo.pr_psargs, psargslen,
-	    (uintptr_t)psinfo.pr_psargs - (uintptr_t)&psinfo) != psargslen) {
-		(void) close(fd);
-		return (-EIO);
-	}
-
-	(void) close(fd);
-
-	return (0);
-}
-
 /*
  * For syslog(), as there is no kernel and nothing to log, we simply emulate a
  * kernel cyclic buffer (LOG_BUF_LEN) of 0 bytes, only handling errors for bad

usr/src/lib/brand/lx/lx_brand/sys/lx_misc.h

@@ -102,19 +102,6 @@ extern pid_t zoneinit_pid;
 #define	LX_RUSAGE_BOTH		(-2)
 #define	LX_RUSAGE_THREAD	1
 
-/*
- * Constants for prctl().  We only include the ones here that we actually
- * support; everything else will be ENOSYS.
- */
-#define	LX_PR_GET_DUMPABLE	3
-#define	LX_PR_SET_DUMPABLE	4
-#define	LX_PR_SET_KEEPCAPS	8
-#define	LX_PR_SET_NAME		15
-#define	LX_PR_GET_SECUREBITS	27
-#define	LX_PR_SET_SECUREBITS	28
-
-#define	LX_PR_SET_NAME_NAMELEN	16
-
 /*
  * Based on code from brand_misc.h, but use of that is incompatible with the
  * lx brand.

usr/src/lib/brand/lx/lx_brand/sys/lx_syscall.h

@@ -276,8 +276,6 @@ extern long lx_shmget(key_t, size_t, int);
 extern long lx_shmat(int, void *, int);
 extern long lx_shmctl(int, int, void *);
 
-extern long lx_prctl(int, uintptr_t, uintptr_t, uintptr_t, uintptr_t);
-
 extern long lx_alarm(unsigned int);
 extern long lx_close(int);
 extern long lx_chdir(const char *);

usr/src/lib/brand/lx/testing/Readme_ltp

@@ -189,8 +189,6 @@ x open01	need PRIV_SYS_CONFIG to set sticky bit on reg file
 # open10	setgid on sgid subdir behavior
 x open11	makes device
 # ppoll01
-# prctl01	get/set deathsig    
-# prctl02	more deathsig
 # process_vm_readv01
 # process_vm_readv02
 # process_vm_readv03

usr/src/lib/brand/lx/testing/ltp_skiplist

@@ -177,8 +177,6 @@ open10
 perf_event_open01
 perf_event_open02
 ppoll01
-prctl01
-prctl02
 process_vm_readv01
 process_vm_readv02
 process_vm_readv03

usr/src/uts/common/brand/lx/os/lx_brand.c

@@ -310,8 +310,31 @@ static struct modlinkage modlinkage = {
 void
 lx_proc_exit(proc_t *p)
 {
-	VERIFY(p->p_brand == &lx_brand);
-	VERIFY(p->p_brand_data != NULL);
+	lx_proc_data_t *lxpd;
+	proc_t *cp;
+
+	mutex_enter(&p->p_lock);
+	VERIFY(lxpd = ptolxproc(p));
+	if ((lxpd->l_flags & LX_PROC_CHILD_DEATHSIG) == 0) {
+		mutex_exit(&p->p_lock);
+		return;
+	}
+	mutex_exit(&p->p_lock);
+
+	/* Check for children which desire notification of parental death. */
+	mutex_enter(&pidlock);
+	for (cp = p->p_child; cp != NULL; cp = cp->p_sibling) {
+		mutex_enter(&cp->p_lock);
+		if ((lxpd = ptolxproc(cp)) == NULL) {
+			mutex_exit(&cp->p_lock);
+			continue;
+		}
+		if (lxpd->l_parent_deathsig != 0) {
+			sigtoproc(p, NULL, lxpd->l_parent_deathsig);
+		}
+		mutex_exit(&cp->p_lock);
+	}
+	mutex_exit(&pidlock);
 }
 
 void
@@ -879,7 +902,7 @@ lx_brandsys(int cmd, int64_t *rval, uintptr_t arg1, uintptr_t arg2,
 		    (void *)&lx_brand, (void *)reg.lxbr_handler, (void *)p);
 		pd = p->p_brand_data;
 		pd->l_handler = (uintptr_t)reg.lxbr_handler;
-		pd->l_flags = reg.lxbr_flags;
+		pd->l_flags = reg.lxbr_flags & LX_PROC_ALL;
 
 		return (0);
 

usr/src/uts/common/brand/lx/os/lx_syscall.c

@@ -695,7 +695,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"nfsservctl",	NULL,			NOSYS_KERNEL,	0}, /* 169 */
 	{"setresgid16",	lx_setresgid16,		0,		3}, /* 170 */
 	{"getresgid16",	NULL,			0,		3}, /* 171 */
-	{"prctl",	NULL,			0,		5}, /* 172 */
+	{"prctl",	lx_prctl,		0,		5}, /* 172 */
 	{"rt_sigreturn", NULL,			0,		0}, /* 173 */
 	{"rt_sigaction", NULL,			0,		4}, /* 174 */
 	{"rt_sigprocmask", NULL,		0,		4}, /* 175 */
@@ -1051,7 +1051,7 @@ lx_sysent_t lx_sysent64[] = {
 	{"modify_ldt",	lx_modify_ldt,		0,		3}, /* 154 */
 	{"pivot_root",	NULL,			NOSYS_KERNEL,	0}, /* 155 */
 	{"sysctl",	NULL,			0,		1}, /* 156 */
-	{"prctl",	NULL,			0,		5}, /* 157 */
+	{"prctl",	lx_prctl,		0,		5}, /* 157 */
 	{"arch_prctl",	lx_arch_prctl,		0,		2}, /* 158 */
 	{"adjtimex",	NULL,			0,		1}, /* 159 */
 	{"setrlimit",	lx_setrlimit,		0,		2}, /* 160 */

usr/src/uts/common/brand/lx/sys/lx_brand.h

@@ -371,8 +371,11 @@ typedef lx_elf_data32_t lx_elf_data_t;
 #endif
 
 typedef enum lx_proc_flags {
-	LX_PROC_INSTALL_MODE = 0x01,
-	LX_PROC_STRICT_MODE = 0x02
+	/* flags configurable via brandsys() and members of LX_PROC_ALL */
+	LX_PROC_INSTALL_MODE	= 0x01,
+	LX_PROC_STRICT_MODE	= 0x02,
+	/* internal flags */
+	LX_PROC_CHILD_DEATHSIG	= 0x04
 } lx_proc_flags_t;
 
 #define	LX_PROC_ALL	(LX_PROC_INSTALL_MODE | LX_PROC_STRICT_MODE)
@@ -398,8 +401,10 @@ typedef struct lx_proc_data {
 	pid_t l_ppid;		/* pid of originating parent proc */
 	uint64_t l_ptrace;	/* process being observed with ptrace */
 	lx_elf_data_t l_elf_data; /* ELF data for linux executable */
-	int l_signal;		/* signal to deliver to parent when this */
-				/* thread group dies */
+	/* signal to deliver to parent when this thread group dies */
+	int l_signal;
+	/* native signal to deliver to process when parent dies */
+	int l_parent_deathsig;
 	lx_proc_flags_t l_flags;
 
 	lx_rlimit64_t l_fake_limits[LX_RLFAKE_NLIMITS];

usr/src/uts/common/brand/lx/sys/lx_syscalls.h

@@ -76,6 +76,7 @@ extern long lx_open();
 extern long lx_openat();
 extern long lx_pipe();
 extern long lx_pipe2();
+extern long lx_prctl();
 extern long lx_prlimit64();
 extern long lx_read();
 extern long lx_recv();