Skip to main content

Browse the archive

https://github.com/torvalds/linux
23 October 2021, 00:29:24 UTC
Revision 9cc6d9e5daaa147a9a3e31557efcb331989e77be authored by Nathan Lynch on 29 September 2014, 18:11:36 UTC, committed by Russell King on 30 September 2014, 15:55:23 UTC 
ARM: 8178/1: fix set_tls for !CONFIG_KUSER_HELPERS
 
Joachim Eastwood reports that commit fbfb872f5f41 "ARM: 8148/1: flush
TLS and thumbee register state during exec" causes a boot-time crash
on a Cortex-M4 nommu system:

Freeing unused kernel memory: 68K (281e5000 - 281f6000)
Unhandled exception: IPSR = 00000005 LR = fffffff1
CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191
task: 29834000 ti: 29832000 task.ti: 29832000
PC is at flush_thread+0x2e/0x40
LR is at flush_thread+0x21/0x40
pc : [<2800954a>] lr : [<2800953d>] psr: 4100000b
sp : 29833d60 ip : 00000000 fp : 00000001
r10: 00003cf8 r9 : 29b1f000 r8 : 00000000
r7 : 29b0bc00 r6 : 29834000 r5 : 29832000 r4 : 29832000
r3 : ffff0ff0 r2 : 29832000 r1 : 00000000 r0 : 282121f0
xPSR: 4100000b
CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-rc6-00313-gd2205fa30aa7 #191
[<2800afa5>] (unwind_backtrace) from [<2800a327>] (show_stack+0xb/0xc)
[<2800a327>] (show_stack) from [<2800a963>] (__invalid_entry+0x4b/0x4c)

The problem is that set_tls is attempting to clear the TLS location in
the kernel-user helper page, which isn't set up on V7M.

Fix this by guarding the write to the kuser helper page with
a CONFIG_KUSER_HELPERS ifdef.

Fixes: fbfb872f5f41 ARM: 8148/1: flush TLS and thumbee register state during exec

Reported-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1 parent ebc7725
Raw File
Tip revision: 9cc6d9e5daaa147a9a3e31557efcb331989e77be authored by Nathan Lynch on 29 September 2014, 18:11:36 UTC
ARM: 8178/1: fix set_tls for !CONFIG_KUSER_HELPERS
Tip revision: 9cc6d9e
video.h 
#ifndef __ACPI_VIDEO_H
#define __ACPI_VIDEO_H

#include <linux/errno.h> /* for ENODEV */

struct acpi_device;

#define ACPI_VIDEO_CLASS	"video"

#define ACPI_VIDEO_DISPLAY_CRT  1
#define ACPI_VIDEO_DISPLAY_TV   2
#define ACPI_VIDEO_DISPLAY_DVI  3
#define ACPI_VIDEO_DISPLAY_LCD  4

#define ACPI_VIDEO_DISPLAY_LEGACY_MONITOR 0x0100
#define ACPI_VIDEO_DISPLAY_LEGACY_PANEL   0x0110
#define ACPI_VIDEO_DISPLAY_LEGACY_TV      0x0200

#if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
extern int acpi_video_register(void);
extern void acpi_video_unregister(void);
extern void acpi_video_unregister_backlight(void);
extern int acpi_video_get_edid(struct acpi_device *device, int type,
			       int device_id, void **edid);
extern bool acpi_video_verify_backlight_support(void);
#else
static inline int acpi_video_register(void) { return 0; }
static inline void acpi_video_unregister(void) { return; }
static inline void acpi_video_unregister_backlight(void) { return; }
static inline int acpi_video_get_edid(struct acpi_device *device, int type,
				      int device_id, void **edid)
{
	return -ENODEV;
}
static inline bool acpi_video_verify_backlight_support(void) { return false; }
#endif

#endif
back to top