prctl.c - platform/external/strace - Git at Google

 /*
  * Copyright (c) 1994-1996 Rick Sladkey <[email protected]>
  * Copyright (c) 1996-2000 Wichert Akkerman <[email protected]>
  * Copyright (c) 2005-2007 Roland McGrath <[email protected]>
  * Copyright (c) 2008-2015 Dmitry V. Levin <[email protected]>
  * Copyright (c) 2014-2018 The strace developers.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "defs.h"

 #include <linux/prctl.h>

 #include "xstring.h"

 #include "xlat/prctl_options.h"
 #include "xlat/pr_cap_ambient.h"
 #include "xlat/pr_dumpable.h"
 #include "xlat/pr_fp_mode.h"
 #include "xlat/pr_mce_kill.h"
 #include "xlat/pr_mce_kill_policy.h"
 #include "xlat/pr_set_mm.h"
 #include "xlat/pr_spec_cmds.h"
 #include "xlat/pr_spec_get_store_bypass_flags.h"
 #include "xlat/pr_spec_set_store_bypass_flags.h"
 #include "xlat/pr_sve_vl_flags.h"
 #include "xlat/pr_tsc.h"
 #include "xlat/pr_unalign_flags.h"

 #ifndef TASK_COMM_LEN
 # define TASK_COMM_LEN 16
 #endif

 #ifdef HAVE_LINUX_SECCOMP_H
 # include <linux/seccomp.h>
 #endif
 #include "xlat/seccomp_mode.h"

 #ifdef HAVE_LINUX_SECUREBITS_H
 # include <linux/securebits.h>
 #endif
 #include "xlat/secbits.h"

 /* these constants are the same as in <linux/capability.h> */
 enum {
 #include "caps0.h"
 #include "caps1.h"
 };

 #include "xlat/cap.h"

 #ifndef PR_SVE_VL_LEN_MASK
 # define PR_SVE_VL_LEN_MASK 0xffff
 #endif


 static void
 print_prctl_args(struct tcb *tcp, const unsigned int first)
 {
 	unsigned int i;

 	for (i = first; i < tcp->s_ent->nargs; ++i)
 		tprintf(", %#" PRI_klx, tcp->u_arg[i]);
 }

 static char *
 sprint_sve_val(kernel_ulong_t arg)
 {
 	static char out[sizeof("PR_SVE_SET_VL_ONEXEC|PR_SVE_VL_INHERIT|0x") +
 			sizeof(kernel_ulong_t) * 2];

 	kernel_ulong_t vl = arg & PR_SVE_VL_LEN_MASK;
 	kernel_ulong_t flags = arg & ~PR_SVE_VL_LEN_MASK;
 	const char *flags_str = sprintflags("", pr_sve_vl_flags, flags);

 	xsprintf(out, "%s%s%#" PRI_klx,
 		 flags_str ?: "", flags_str ? "|" : "", vl);

 	return out;
 }

 SYS_FUNC(prctl)
 {
 	const unsigned int option = tcp->u_arg[0];
 	const kernel_ulong_t arg2 = tcp->u_arg[1];
 	const kernel_ulong_t arg3 = tcp->u_arg[2];
 	/*
 	 * PR_SET_VMA is the only command which actually uses these arguments
 	 * currently, and it is available only on Android for now.
 	 */
 #ifdef __ANDROID__
 	const kernel_ulong_t arg4 = tcp->u_arg[3];
 	const kernel_ulong_t arg5 = tcp->u_arg[4];
 #endif
 	unsigned int i;

 	if (entering(tcp))
 		printxval(prctl_options, option, "PR_???");

 	switch (option) {
 	case PR_GET_KEEPCAPS:
 	case PR_GET_SECCOMP:
 	case PR_GET_TIMERSLACK:
 	case PR_GET_TIMING:
 		return RVAL_DECODED;

 	case PR_GET_CHILD_SUBREAPER:
 	case PR_GET_ENDIAN:
 	case PR_GET_FPEMU:
 	case PR_GET_FPEXC:
 		if (entering(tcp))
 			tprints(", ");
 		else
 			printnum_int(tcp, arg2, "%u");
 		break;

 	case PR_GET_DUMPABLE:
 		if (entering(tcp))
 			break;
 		if (syserror(tcp))
 			return 0;
 		tcp->auxstr = xlookup(pr_dumpable, (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;

 	case PR_GET_NAME:
 		if (entering(tcp)) {
 			tprints(", ");
 		} else {
 			if (syserror(tcp))
 				printaddr(arg2);
 			else
 				printstr_ex(tcp, arg2, TASK_COMM_LEN,
 					    QUOTE_0_TERMINATED);
 		}
 		break;

 	case PR_GET_PDEATHSIG:
 		if (entering(tcp)) {
 			tprints(", ");
 		} else if (!umove_or_printaddr(tcp, arg2, &i)) {
 			tprints("[");
 			tprints(signame(i));
 			tprints("]");
 		}
 		break;

 	case PR_GET_SECUREBITS:
 		if (entering(tcp))
 			break;
 		if (syserror(tcp) || tcp->u_rval == 0)
 			return 0;
 		tcp->auxstr = sprintflags("", secbits,
 					  (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;

 	case PR_GET_TID_ADDRESS:
 		if (entering(tcp))
 			tprints(", ");
 		else
 			printnum_kptr(tcp, arg2);
 		break;

 	case PR_GET_TSC:
 		if (entering(tcp)) {
 			tprints(", ");
 		} else if (!umove_or_printaddr(tcp, arg2, &i)) {
 			tprints("[");
 			printxval(pr_tsc, i, "PR_TSC_???");
 			tprints("]");
 		}
 		break;

 	case PR_GET_UNALIGN:
 		if (entering(tcp)) {
 			tprints(", ");
 		} else if (!umove_or_printaddr(tcp, arg2, &i)) {
 			tprints("[");
 			printflags(pr_unalign_flags, i, "PR_UNALIGN_???");
 			tprints("]");
 		}
 		break;

 	case PR_GET_FP_MODE:
 		if (entering(tcp))
 			break;
 		if (syserror(tcp) || tcp->u_rval == 0)
 			return 0;
 		tcp->auxstr = sprintflags("", pr_fp_mode,
 					  (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;

 	case PR_SVE_SET_VL:
 		if (entering(tcp)) {
 			tprintf(", %s", sprint_sve_val(arg2));
 			return 0;
 		}
 		ATTRIBUTE_FALLTHROUGH;

 	case PR_SVE_GET_VL:
 		if (entering(tcp))
 			break;
 		if (syserror(tcp) || tcp->u_rval == 0)
 			return 0;

 		tcp->auxstr = sprint_sve_val(tcp->u_rval);

 		return RVAL_STR;

 	case PR_GET_SPECULATION_CTRL:
 		if (entering(tcp)) {
 			tprints(", ");
 			printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");

 			break;
 		}

 		if (syserror(tcp))
 			return 0;

 		switch (arg2) {
 		case PR_SPEC_STORE_BYPASS:
 			tcp->auxstr = sprintflags("",
 						  pr_spec_get_store_bypass_flags,
 						  (kernel_ulong_t) tcp->u_rval);
 			break;
 		}

 		return RVAL_STR;

 	/* PR_TASK_PERF_EVENTS_* take no arguments. */
 	case PR_TASK_PERF_EVENTS_DISABLE:
 	case PR_TASK_PERF_EVENTS_ENABLE:
 		return RVAL_DECODED;

 	case PR_SET_CHILD_SUBREAPER:
 	case PR_SET_ENDIAN:
 	case PR_SET_FPEMU:
 	case PR_SET_FPEXC:
 	case PR_SET_KEEPCAPS:
 	case PR_SET_TIMING:
 		tprintf(", %" PRI_klu, arg2);
 		return RVAL_DECODED;

 	case PR_SET_DUMPABLE:
 		tprints(", ");
 		printxval64(pr_dumpable, arg2, "SUID_DUMP_???");
 		return RVAL_DECODED;

 	case PR_CAPBSET_DROP:
 	case PR_CAPBSET_READ:
 		tprints(", ");
 		printxval64(cap, arg2, "CAP_???");
 		return RVAL_DECODED;

 	case PR_CAP_AMBIENT:
 		tprints(", ");
 		printxval64(pr_cap_ambient, arg2,
 			       "PR_CAP_AMBIENT_???");
 		switch (arg2) {
 		case PR_CAP_AMBIENT_RAISE:
 		case PR_CAP_AMBIENT_LOWER:
 		case PR_CAP_AMBIENT_IS_SET:
 			tprints(", ");
 			printxval64(cap, arg3, "CAP_???");
 			print_prctl_args(tcp, 3);
 			break;
 		default:
 			print_prctl_args(tcp, 2);
 			break;
 		}
 		return RVAL_DECODED;

 	case PR_MCE_KILL:
 		tprints(", ");
 		printxval64(pr_mce_kill, arg2, "PR_MCE_KILL_???");
 		tprints(", ");
 		if (PR_MCE_KILL_SET == arg2)
 			printxval64(pr_mce_kill_policy, arg3,
 				    "PR_MCE_KILL_???");
 		else
 			tprintf("%#" PRI_klx, arg3);
 		print_prctl_args(tcp, 3);
 		return RVAL_DECODED;

 	case PR_SET_NAME:
 		tprints(", ");
 		printstr_ex(tcp, arg2, TASK_COMM_LEN - 1,
 			    QUOTE_0_TERMINATED);
 		return RVAL_DECODED;

 #ifdef __ANDROID__
 # ifndef PR_SET_VMA_ANON_NAME
 #  define PR_SET_VMA_ANON_NAME    0
 # endif
 	case PR_SET_VMA:
 		if (arg2 == PR_SET_VMA_ANON_NAME) {
 			tprintf(", PR_SET_VMA_ANON_NAME, %#" PRI_klx, arg3);
 			tprintf(", %" PRI_klu ", ", arg4);
 			printstr(tcp, arg5);
 		} else {
 			/* There are no other sub-options now, but there
 			 * might be in future... */
 			print_prctl_args(tcp, 1);
 		}
 		return RVAL_DECODED;
 #endif

 	case PR_SET_MM:
 		tprints(", ");
 		printxval(pr_set_mm, arg2, "PR_SET_MM_???");
 		print_prctl_args(tcp, 2);
 		return RVAL_DECODED;

 	case PR_SET_PDEATHSIG:
 		tprints(", ");
 		if (arg2 > 128)
 			tprintf("%" PRI_klu, arg2);
 		else
 			tprints(signame(arg2));
 		return RVAL_DECODED;

 	case PR_SET_PTRACER:
 		tprints(", ");
 		if ((int) arg2 == -1) {
 			print_xlat_ex(arg2, "PR_SET_PTRACER_ANY",
 				      XLAT_STYLE_DEFAULT);
 		} else {
 			tprintf("%" PRI_klu, arg2);
 		}
 		return RVAL_DECODED;

 	case PR_SET_SECCOMP:
 		tprints(", ");
 		printxval64(seccomp_mode, arg2,
 			    "SECCOMP_MODE_???");
 		if (SECCOMP_MODE_STRICT == arg2)
 			return RVAL_DECODED;
 		if (SECCOMP_MODE_FILTER == arg2) {
 			tprints(", ");
 			decode_seccomp_fprog(tcp, arg3);
 			return RVAL_DECODED;
 		}
 		print_prctl_args(tcp, 2);
 		return RVAL_DECODED;

 	case PR_SET_SECUREBITS:
 		tprints(", ");
 		printflags64(secbits, arg2, "SECBIT_???");
 		return RVAL_DECODED;

 	case PR_SET_TIMERSLACK:
 		tprintf(", %" PRI_kld, arg2);
 		return RVAL_DECODED;

 	case PR_SET_TSC:
 		tprints(", ");
 		printxval(pr_tsc, arg2, "PR_TSC_???");
 		return RVAL_DECODED;

 	case PR_SET_UNALIGN:
 		tprints(", ");
 		printflags(pr_unalign_flags, arg2, "PR_UNALIGN_???");
 		return RVAL_DECODED;

 	case PR_SET_NO_NEW_PRIVS:
 	case PR_SET_THP_DISABLE:
 		tprintf(", %" PRI_klu, arg2);
 		print_prctl_args(tcp, 2);
 		return RVAL_DECODED;

 	case PR_MCE_KILL_GET:
 		if (entering(tcp)) {
 			print_prctl_args(tcp, 1);
 			return 0;
 		}
 		if (syserror(tcp))
 			return 0;
 		tcp->auxstr = xlookup(pr_mce_kill_policy,
 				      (kernel_ulong_t) tcp->u_rval);
 		return RVAL_STR;

 	case PR_SET_FP_MODE:
 		tprints(", ");
 		printflags(pr_fp_mode, arg2, "PR_FP_MODE_???");
 		return RVAL_DECODED;

 	case PR_SET_SPECULATION_CTRL:
 		tprints(", ");
 		printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");
 		tprints(", ");

 		switch (arg2) {
 		case PR_SPEC_STORE_BYPASS:
 			printxval64(pr_spec_set_store_bypass_flags, arg3,
 				    "PR_SPEC_???");
 			break;

 		default:
 			tprintf("%#" PRI_klx, arg3);
 		}

 		return RVAL_DECODED;

 	case PR_GET_NO_NEW_PRIVS:
 	case PR_GET_THP_DISABLE:
 	case PR_MPX_DISABLE_MANAGEMENT:
 	case PR_MPX_ENABLE_MANAGEMENT:
 	default:
 		print_prctl_args(tcp, 1);
 		return RVAL_DECODED;
 	}
 	return 0;
 }

 #if defined X86_64 || defined X32 || defined I386
 # include "xlat/archvals.h"

 SYS_FUNC(arch_prctl)
 {
 	const unsigned int option = tcp->u_arg[0];
 	const kernel_ulong_t addr = tcp->u_arg[1];

 	if (entering(tcp))
 		printxval(archvals, option, "ARCH_???");

 	switch (option) {
 	case ARCH_GET_GS:
 	case ARCH_GET_FS:
 		if (entering(tcp))
 			tprints(", ");
 		else
 			printnum_ptr(tcp, addr);
 		return 0;
 	}

 	tprintf(", %#" PRI_klx, addr);
 	return RVAL_DECODED;
 }
 #endif /* X86_64 || X32 || I386 */
	/*
	* Copyright (c) 1994-1996 Rick Sladkey <[email protected]>
	* Copyright (c) 1996-2000 Wichert Akkerman <[email protected]>
	* Copyright (c) 2005-2007 Roland McGrath <[email protected]>
	* Copyright (c) 2008-2015 Dmitry V. Levin <[email protected]>
	* Copyright (c) 2014-2018 The strace developers.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "defs.h"

	#include <linux/prctl.h>

	#include "xstring.h"

	#include "xlat/prctl_options.h"
	#include "xlat/pr_cap_ambient.h"
	#include "xlat/pr_dumpable.h"
	#include "xlat/pr_fp_mode.h"
	#include "xlat/pr_mce_kill.h"
	#include "xlat/pr_mce_kill_policy.h"
	#include "xlat/pr_set_mm.h"
	#include "xlat/pr_spec_cmds.h"
	#include "xlat/pr_spec_get_store_bypass_flags.h"
	#include "xlat/pr_spec_set_store_bypass_flags.h"
	#include "xlat/pr_sve_vl_flags.h"
	#include "xlat/pr_tsc.h"
	#include "xlat/pr_unalign_flags.h"

	#ifndef TASK_COMM_LEN
	# define TASK_COMM_LEN 16
	#endif

	#ifdef HAVE_LINUX_SECCOMP_H
	# include <linux/seccomp.h>
	#endif
	#include "xlat/seccomp_mode.h"

	#ifdef HAVE_LINUX_SECUREBITS_H
	# include <linux/securebits.h>
	#endif
	#include "xlat/secbits.h"

	/* these constants are the same as in <linux/capability.h> */
	enum {
	#include "caps0.h"
	#include "caps1.h"
	};

	#include "xlat/cap.h"

	#ifndef PR_SVE_VL_LEN_MASK
	# define PR_SVE_VL_LEN_MASK 0xffff
	#endif


	static void
	print_prctl_args(struct tcb *tcp, const unsigned int first)
	{
	unsigned int i;

	for (i = first; i < tcp->s_ent->nargs; ++i)
	tprintf(", %#" PRI_klx, tcp->u_arg[i]);
	}

	static char *
	sprint_sve_val(kernel_ulong_t arg)
	{
	static char out[sizeof("PR_SVE_SET_VL_ONEXEC\|PR_SVE_VL_INHERIT\|0x") +
	sizeof(kernel_ulong_t) * 2];

	kernel_ulong_t vl = arg & PR_SVE_VL_LEN_MASK;
	kernel_ulong_t flags = arg & ~PR_SVE_VL_LEN_MASK;
	const char *flags_str = sprintflags("", pr_sve_vl_flags, flags);

	xsprintf(out, "%s%s%#" PRI_klx,
	flags_str ?: "", flags_str ? "\|" : "", vl);

	return out;
	}

	SYS_FUNC(prctl)
	{
	const unsigned int option = tcp->u_arg[0];
	const kernel_ulong_t arg2 = tcp->u_arg[1];
	const kernel_ulong_t arg3 = tcp->u_arg[2];
	/*
	* PR_SET_VMA is the only command which actually uses these arguments
	* currently, and it is available only on Android for now.
	*/
	#ifdef __ANDROID__
	const kernel_ulong_t arg4 = tcp->u_arg[3];
	const kernel_ulong_t arg5 = tcp->u_arg[4];
	#endif
	unsigned int i;

	if (entering(tcp))
	printxval(prctl_options, option, "PR_???");

	switch (option) {
	case PR_GET_KEEPCAPS:
	case PR_GET_SECCOMP:
	case PR_GET_TIMERSLACK:
	case PR_GET_TIMING:
	return RVAL_DECODED;

	case PR_GET_CHILD_SUBREAPER:
	case PR_GET_ENDIAN:
	case PR_GET_FPEMU:
	case PR_GET_FPEXC:
	if (entering(tcp))
	tprints(", ");
	else
	printnum_int(tcp, arg2, "%u");
	break;

	case PR_GET_DUMPABLE:
	if (entering(tcp))
	break;
	if (syserror(tcp))
	return 0;
	tcp->auxstr = xlookup(pr_dumpable, (kernel_ulong_t) tcp->u_rval);
	return RVAL_STR;

	case PR_GET_NAME:
	if (entering(tcp)) {
	tprints(", ");
	} else {
	if (syserror(tcp))
	printaddr(arg2);
	else
	printstr_ex(tcp, arg2, TASK_COMM_LEN,
	QUOTE_0_TERMINATED);
	}
	break;

	case PR_GET_PDEATHSIG:
	if (entering(tcp)) {
	tprints(", ");
	} else if (!umove_or_printaddr(tcp, arg2, &i)) {
	tprints("[");
	tprints(signame(i));
	tprints("]");
	}
	break;

	case PR_GET_SECUREBITS:
	if (entering(tcp))
	break;
	if (syserror(tcp) \|\| tcp->u_rval == 0)
	return 0;
	tcp->auxstr = sprintflags("", secbits,
	(kernel_ulong_t) tcp->u_rval);
	return RVAL_STR;

	case PR_GET_TID_ADDRESS:
	if (entering(tcp))
	tprints(", ");
	else
	printnum_kptr(tcp, arg2);
	break;

	case PR_GET_TSC:
	if (entering(tcp)) {
	tprints(", ");
	} else if (!umove_or_printaddr(tcp, arg2, &i)) {
	tprints("[");
	printxval(pr_tsc, i, "PR_TSC_???");
	tprints("]");
	}
	break;

	case PR_GET_UNALIGN:
	if (entering(tcp)) {
	tprints(", ");
	} else if (!umove_or_printaddr(tcp, arg2, &i)) {
	tprints("[");
	printflags(pr_unalign_flags, i, "PR_UNALIGN_???");
	tprints("]");
	}
	break;

	case PR_GET_FP_MODE:
	if (entering(tcp))
	break;
	if (syserror(tcp) \|\| tcp->u_rval == 0)
	return 0;
	tcp->auxstr = sprintflags("", pr_fp_mode,
	(kernel_ulong_t) tcp->u_rval);
	return RVAL_STR;

	case PR_SVE_SET_VL:
	if (entering(tcp)) {
	tprintf(", %s", sprint_sve_val(arg2));
	return 0;
	}
	ATTRIBUTE_FALLTHROUGH;

	case PR_SVE_GET_VL:
	if (entering(tcp))
	break;
	if (syserror(tcp) \|\| tcp->u_rval == 0)
	return 0;

	tcp->auxstr = sprint_sve_val(tcp->u_rval);

	return RVAL_STR;

	case PR_GET_SPECULATION_CTRL:
	if (entering(tcp)) {
	tprints(", ");
	printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");

	break;
	}

	if (syserror(tcp))
	return 0;

	switch (arg2) {
	case PR_SPEC_STORE_BYPASS:
	tcp->auxstr = sprintflags("",
	pr_spec_get_store_bypass_flags,
	(kernel_ulong_t) tcp->u_rval);
	break;
	}

	return RVAL_STR;

	/* PR_TASK_PERF_EVENTS_* take no arguments. */
	case PR_TASK_PERF_EVENTS_DISABLE:
	case PR_TASK_PERF_EVENTS_ENABLE:
	return RVAL_DECODED;

	case PR_SET_CHILD_SUBREAPER:
	case PR_SET_ENDIAN:
	case PR_SET_FPEMU:
	case PR_SET_FPEXC:
	case PR_SET_KEEPCAPS:
	case PR_SET_TIMING:
	tprintf(", %" PRI_klu, arg2);
	return RVAL_DECODED;

	case PR_SET_DUMPABLE:
	tprints(", ");
	printxval64(pr_dumpable, arg2, "SUID_DUMP_???");
	return RVAL_DECODED;

	case PR_CAPBSET_DROP:
	case PR_CAPBSET_READ:
	tprints(", ");
	printxval64(cap, arg2, "CAP_???");
	return RVAL_DECODED;

	case PR_CAP_AMBIENT:
	tprints(", ");
	printxval64(pr_cap_ambient, arg2,
	"PR_CAP_AMBIENT_???");
	switch (arg2) {
	case PR_CAP_AMBIENT_RAISE:
	case PR_CAP_AMBIENT_LOWER:
	case PR_CAP_AMBIENT_IS_SET:
	tprints(", ");
	printxval64(cap, arg3, "CAP_???");
	print_prctl_args(tcp, 3);
	break;
	default:
	print_prctl_args(tcp, 2);
	break;
	}
	return RVAL_DECODED;

	case PR_MCE_KILL:
	tprints(", ");
	printxval64(pr_mce_kill, arg2, "PR_MCE_KILL_???");
	tprints(", ");
	if (PR_MCE_KILL_SET == arg2)
	printxval64(pr_mce_kill_policy, arg3,
	"PR_MCE_KILL_???");
	else
	tprintf("%#" PRI_klx, arg3);
	print_prctl_args(tcp, 3);
	return RVAL_DECODED;

	case PR_SET_NAME:
	tprints(", ");
	printstr_ex(tcp, arg2, TASK_COMM_LEN - 1,
	QUOTE_0_TERMINATED);
	return RVAL_DECODED;

	#ifdef __ANDROID__
	# ifndef PR_SET_VMA_ANON_NAME
	# define PR_SET_VMA_ANON_NAME 0
	# endif
	case PR_SET_VMA:
	if (arg2 == PR_SET_VMA_ANON_NAME) {
	tprintf(", PR_SET_VMA_ANON_NAME, %#" PRI_klx, arg3);
	tprintf(", %" PRI_klu ", ", arg4);
	printstr(tcp, arg5);
	} else {
	/* There are no other sub-options now, but there
	* might be in future... */
	print_prctl_args(tcp, 1);
	}
	return RVAL_DECODED;
	#endif

	case PR_SET_MM:
	tprints(", ");
	printxval(pr_set_mm, arg2, "PR_SET_MM_???");
	print_prctl_args(tcp, 2);
	return RVAL_DECODED;

	case PR_SET_PDEATHSIG:
	tprints(", ");
	if (arg2 > 128)
	tprintf("%" PRI_klu, arg2);
	else
	tprints(signame(arg2));
	return RVAL_DECODED;

	case PR_SET_PTRACER:
	tprints(", ");
	if ((int) arg2 == -1) {
	print_xlat_ex(arg2, "PR_SET_PTRACER_ANY",
	XLAT_STYLE_DEFAULT);
	} else {
	tprintf("%" PRI_klu, arg2);
	}
	return RVAL_DECODED;

	case PR_SET_SECCOMP:
	tprints(", ");
	printxval64(seccomp_mode, arg2,
	"SECCOMP_MODE_???");
	if (SECCOMP_MODE_STRICT == arg2)
	return RVAL_DECODED;
	if (SECCOMP_MODE_FILTER == arg2) {
	tprints(", ");
	decode_seccomp_fprog(tcp, arg3);
	return RVAL_DECODED;
	}
	print_prctl_args(tcp, 2);
	return RVAL_DECODED;

	case PR_SET_SECUREBITS:
	tprints(", ");
	printflags64(secbits, arg2, "SECBIT_???");
	return RVAL_DECODED;

	case PR_SET_TIMERSLACK:
	tprintf(", %" PRI_kld, arg2);
	return RVAL_DECODED;

	case PR_SET_TSC:
	tprints(", ");
	printxval(pr_tsc, arg2, "PR_TSC_???");
	return RVAL_DECODED;

	case PR_SET_UNALIGN:
	tprints(", ");
	printflags(pr_unalign_flags, arg2, "PR_UNALIGN_???");
	return RVAL_DECODED;

	case PR_SET_NO_NEW_PRIVS:
	case PR_SET_THP_DISABLE:
	tprintf(", %" PRI_klu, arg2);
	print_prctl_args(tcp, 2);
	return RVAL_DECODED;

	case PR_MCE_KILL_GET:
	if (entering(tcp)) {
	print_prctl_args(tcp, 1);
	return 0;
	}
	if (syserror(tcp))
	return 0;
	tcp->auxstr = xlookup(pr_mce_kill_policy,
	(kernel_ulong_t) tcp->u_rval);
	return RVAL_STR;

	case PR_SET_FP_MODE:
	tprints(", ");
	printflags(pr_fp_mode, arg2, "PR_FP_MODE_???");
	return RVAL_DECODED;

	case PR_SET_SPECULATION_CTRL:
	tprints(", ");
	printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");
	tprints(", ");

	switch (arg2) {
	case PR_SPEC_STORE_BYPASS:
	printxval64(pr_spec_set_store_bypass_flags, arg3,
	"PR_SPEC_???");
	break;

	default:
	tprintf("%#" PRI_klx, arg3);
	}

	return RVAL_DECODED;

	case PR_GET_NO_NEW_PRIVS:
	case PR_GET_THP_DISABLE:
	case PR_MPX_DISABLE_MANAGEMENT:
	case PR_MPX_ENABLE_MANAGEMENT:
	default:
	print_prctl_args(tcp, 1);
	return RVAL_DECODED;
	}
	return 0;
	}

	#if defined X86_64 \|\| defined X32 \|\| defined I386
	# include "xlat/archvals.h"

	SYS_FUNC(arch_prctl)
	{
	const unsigned int option = tcp->u_arg[0];
	const kernel_ulong_t addr = tcp->u_arg[1];

	if (entering(tcp))
	printxval(archvals, option, "ARCH_???");

	switch (option) {
	case ARCH_GET_GS:
	case ARCH_GET_FS:
	if (entering(tcp))
	tprints(", ");
	else
	printnum_ptr(tcp, addr);
	return 0;
	}

	tprintf(", %#" PRI_klx, addr);
	return RVAL_DECODED;
	}
	#endif /* X86_64 \|\| X32 \|\| I386 */