Attachment #149614 for bug #217323





	  Take the default (1) unless you want more control or more info.

config ALPHA_UAC_SYSCTL
	bool "Configure UAC policy via sysctl"
	depends on SYSCTL
	default y
	---help---
	  Configuring the UAC (unaligned access control) policy on a Linux
	  system usually involves setting a compile time define. If you say
	  Y here, you will be able to modify the UAC policy at runtime using
	  the /proc interface.

	  The UAC policy defines the action Linux should take when an
	  unaligned memory access occurs. The action can include printing a
	  warning message (NOPRINT), sending a signal to the offending
	  program to help developers debug their applications (SIGBUS), or
	  disabling the transparent fixing (NOFIX).

	  The sysctls will be initialized to the compile-time defined UAC
	  policy. You can change these manually, or with the sysctl(8)
	  userspace utility.

	  To disable the warning messages at runtime, you would use

	    echo 1 > /proc/sys/kernel/uac/noprint

	  This is pretty harmless. Say Y if you're not sure.

source "drivers/pci/Kconfig"
source "drivers/eisa/Kconfig"





			   "t10", "t11", "ra", "pv", "at", "gp", "sp", "zero"};
#endif

#ifdef CONFIG_ALPHA_UAC_SYSCTL

#include <linux/sysctl.h>

static int enabled_noprint = 0;
static int enabled_sigbus = 0;
static int enabled_nofix = 0;

ctl_table uac_table[] = {
   	{
		.ctl_name 	= CTL_UNNUMBERED,
		.procname 	= "noprint", 
		.data 		= &enabled_noprint, 
		.maxlen 	= sizeof (int), 
		.mode 		= 0644, 
		.proc_handler = &proc_dointvec,
	},
   	{
		.ctl_name 	= CTL_UNNUMBERED,
		.procname 	= "sigbus", 
		.data 		= &enabled_sigbus, 
		.maxlen 	= sizeof (int), 
		.mode 		= 0644, 
		.proc_handler = &proc_dointvec,
	},
   	{
		.ctl_name 	= CTL_UNNUMBERED,
		.procname 	= "nofix", 
		.data 		= &enabled_nofix, 
		.maxlen 	= sizeof (int), 
		.mode 		= 0644, 
		.proc_handler = &proc_dointvec,
	},
	{ .ctl_name = 0 }
};

static int __init init_uac_sysctl(void)
{
   /* Initialize sysctls with the #defined UAC policy */
   enabled_noprint = (test_thread_flag (TIF_UAC_NOPRINT)) ? 1 : 0;
   enabled_sigbus = (test_thread_flag (TIF_UAC_SIGBUS)) ? 1 : 0;
   enabled_nofix = (test_thread_flag (TIF_UAC_NOFIX)) ? 1 : 0;
   return 0;
}
#endif

static void
dik_show_code(unsigned int *pc)
{

	/* Check the UAC bits to decide what the user wants us to do
	   with the unaliged access.  */

#ifndef CONFIG_ALPHA_UAC_SYSCTL
	if (!test_thread_flag (TIF_UAC_NOPRINT)) {
#else  /* CONFIG_ALPHA_UAC_SYSCTL */
   if (!(enabled_noprint)) {
#endif /* CONFIG_ALPHA_UAC_SYSCTL */
		if (cnt >= 5 && jiffies - last_time > 5*HZ) {
			cnt = 0;
		}

		}
		last_time = jiffies;
	}
#ifndef CONFIG_ALPHA_UAC_SYSCTL
	if (test_thread_flag (TIF_UAC_SIGBUS))
#else  /* CONFIG_ALPHA_UAC_SYSCTL */
   if (enabled_sigbus)
#endif /* CONFIG_ALPHA_UAC_SYSCTL */
		goto give_sigbus;
	/* Not sure why you'd want to use this, but... */
#ifndef CONFIG_ALPHA_UAC_SYSCTL
	if (test_thread_flag (TIF_UAC_NOFIX))
#else  /* CONFIG_ALPHA_UAC_SYSCTL */
   if (enabled_nofix)
#endif /* CONFIG_ALPHA_UAC_SYSCTL */
		return;

	/* Don't bother reading ds in the access check since we already

	wrent(entSys, 5);
	wrent(entDbg, 6);
}

#ifdef CONFIG_ALPHA_UAC_SYSCTL
	__initcall(init_uac_sysctl);
#endif

Lines 168-173 extern struct ctl_table random_table[]; Link Here

(-)src/kernel/sysctl.c.orig (+11 lines)
168	#ifdef CONFIG_INOTIFY_USER	168	#ifdef CONFIG_INOTIFY_USER
169	extern struct ctl_table inotify_table[];	169	extern struct ctl_table inotify_table[];
170	#endif	170	#endif
		171	#ifdef CONFIG_ALPHA_UAC_SYSCTL
		172	extern struct ctl_table uac_table[];
		173	#endif
171		174
172	#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT	175	#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
173	int sysctl_legacy_va_layout;	176	int sysctl_legacy_va_layout;
Lines 779-784 static struct ctl_table kern_table[] = { Link Here
779	* NOTE: do not add new entries to this table unless you have read	782	* NOTE: do not add new entries to this table unless you have read
780	* Documentation/sysctl/ctl_unnumbered.txt	783	* Documentation/sysctl/ctl_unnumbered.txt
781	*/	784	*/
		785	#ifdef CONFIG_ALPHA_UAC_SYSCTL
		786	{
		787	.ctl_name = CTL_UNNUMBERED,
		788	.procname = "uac",
		789	.mode = 0555,
		790	.child = uac_table,
		791	},
		792	#endif /* CONFIG_ALPHA_UAC_SYSCTL */
782	{ .ctl_name = 0 }	793	{ .ctl_name = 0 }
783	};	794	};
784		795

Return to bug 217323

Lines 616-621 config VERBOSE_MCHECK_ON Link Here

(-)src/arch/alpha/Kconfig.orig (+26 lines)
616		616
617	Take the default (1) unless you want more control or more info.	617	Take the default (1) unless you want more control or more info.
618		618
		619	config ALPHA_UAC_SYSCTL
		620	bool "Configure UAC policy via sysctl"
		621	depends on SYSCTL
		622	default y
		623	---help---
		624	Configuring the UAC (unaligned access control) policy on a Linux
		625	system usually involves setting a compile time define. If you say
		626	Y here, you will be able to modify the UAC policy at runtime using
		627	the /proc interface.
		628
		629	The UAC policy defines the action Linux should take when an
		630	unaligned memory access occurs. The action can include printing a
		631	warning message (NOPRINT), sending a signal to the offending
		632	program to help developers debug their applications (SIGBUS), or
		633	disabling the transparent fixing (NOFIX).
		634
		635	The sysctls will be initialized to the compile-time defined UAC
		636	policy. You can change these manually, or with the sysctl(8)
		637	userspace utility.
		638
		639	To disable the warning messages at runtime, you would use
		640
		641	echo 1 > /proc/sys/kernel/uac/noprint
		642
		643	This is pretty harmless. Say Y if you're not sure.
		644
619	source "drivers/pci/Kconfig"	645	source "drivers/pci/Kconfig"
620	source "drivers/eisa/Kconfig"	646	source "drivers/eisa/Kconfig"
621		647

Lines 102-107 static char * ireg_name[] = {"v0", "t0", Link Here

(-)src/arch/alpha/kernel/traps.c.orig (+62 lines)
102	"t10", "t11", "ra", "pv", "at", "gp", "sp", "zero"};	102	"t10", "t11", "ra", "pv", "at", "gp", "sp", "zero"};
103	#endif	103	#endif
104		104
		105	#ifdef CONFIG_ALPHA_UAC_SYSCTL
		106
		107	#include <linux/sysctl.h>
		108
		109	static int enabled_noprint = 0;
		110	static int enabled_sigbus = 0;
		111	static int enabled_nofix = 0;
		112
		113	ctl_table uac_table[] = {
		114	{
		115	.ctl_name = CTL_UNNUMBERED,
		116	.procname = "noprint",
		117	.data = &enabled_noprint,
		118	.maxlen = sizeof (int),
		119	.mode = 0644,
		120	.proc_handler = &proc_dointvec,
		121	},
		122	{
		123	.ctl_name = CTL_UNNUMBERED,
		124	.procname = "sigbus",
		125	.data = &enabled_sigbus,
		126	.maxlen = sizeof (int),
		127	.mode = 0644,
		128	.proc_handler = &proc_dointvec,
		129	},
		130	{
		131	.ctl_name = CTL_UNNUMBERED,
		132	.procname = "nofix",
		133	.data = &enabled_nofix,
		134	.maxlen = sizeof (int),
		135	.mode = 0644,
		136	.proc_handler = &proc_dointvec,
		137	},
		138	{ .ctl_name = 0 }
		139	};
		140
		141	static int __init init_uac_sysctl(void)
		142	{
		143	/* Initialize sysctls with the #defined UAC policy */
		144	enabled_noprint = (test_thread_flag (TIF_UAC_NOPRINT)) ? 1 : 0;
		145	enabled_sigbus = (test_thread_flag (TIF_UAC_SIGBUS)) ? 1 : 0;
		146	enabled_nofix = (test_thread_flag (TIF_UAC_NOFIX)) ? 1 : 0;
		147	return 0;
		148	}
		149	#endif
		150
105	static void	151	static void
106	dik_show_code(unsigned int *pc)	152	dik_show_code(unsigned int *pc)
107	{	153	{
Lines 780-786 do_entUnaUser(void __user * va, unsigned Link Here
780	/* Check the UAC bits to decide what the user wants us to do	826	/* Check the UAC bits to decide what the user wants us to do
781	with the unaliged access. */	827	with the unaliged access. */
782		828
		829	#ifndef CONFIG_ALPHA_UAC_SYSCTL
783	if (!test_thread_flag (TIF_UAC_NOPRINT)) {	830	if (!test_thread_flag (TIF_UAC_NOPRINT)) {
		831	#else /* CONFIG_ALPHA_UAC_SYSCTL */
		832	if (!(enabled_noprint)) {
		833	#endif /* CONFIG_ALPHA_UAC_SYSCTL */
784	if (cnt >= 5 && jiffies - last_time > 5*HZ) {	834	if (cnt >= 5 && jiffies - last_time > 5*HZ) {
785	cnt = 0;	835	cnt = 0;
786	}	836	}
Lines 791-800 do_entUnaUser(void __user * va, unsigned Link Here
791	}	841	}
792	last_time = jiffies;	842	last_time = jiffies;
793	}	843	}
		844	#ifndef CONFIG_ALPHA_UAC_SYSCTL
794	if (test_thread_flag (TIF_UAC_SIGBUS))	845	if (test_thread_flag (TIF_UAC_SIGBUS))
		846	#else /* CONFIG_ALPHA_UAC_SYSCTL */
		847	if (enabled_sigbus)
		848	#endif /* CONFIG_ALPHA_UAC_SYSCTL */
795	goto give_sigbus;	849	goto give_sigbus;
796	/* Not sure why you'd want to use this, but... */	850	/* Not sure why you'd want to use this, but... */
		851	#ifndef CONFIG_ALPHA_UAC_SYSCTL
797	if (test_thread_flag (TIF_UAC_NOFIX))	852	if (test_thread_flag (TIF_UAC_NOFIX))
		853	#else /* CONFIG_ALPHA_UAC_SYSCTL */
		854	if (enabled_nofix)
		855	#endif /* CONFIG_ALPHA_UAC_SYSCTL */
798	return;	856	return;
799		857
800	/* Don't bother reading ds in the access check since we already	858	/* Don't bother reading ds in the access check since we already
Lines 1089-1091 trap_init(void) Link Here
1089	wrent(entSys, 5);	1147	wrent(entSys, 5);
1090	wrent(entDbg, 6);	1148	wrent(entDbg, 6);
1091	}	1149	}
		1150
		1151	#ifdef CONFIG_ALPHA_UAC_SYSCTL
		1152	__initcall(init_uac_sysctl);
		1153	#endif