Revision 61f01dd941ba9e06d2bf05994450ecc3d61b6b8b authored by Andy Lutomirski on 26 April 2015, 23:47:59 UTC, committed by Linus Torvalds on 27 April 2015, 00:57:38 UTC
AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.

Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.

This was exposed by a recent vDSO cleanup.

Fixes: e7d6eefaaa44 x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1190944
Raw File
socfpga_defconfig
CONFIG_SYSVIPC=y
CONFIG_FHANDLE=y
CONFIG_HIGH_RES_TIMERS=y
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_LOG_BUF_SHIFT=14
CONFIG_CGROUPS=y
CONFIG_CPUSETS=y
CONFIG_NAMESPACES=y
CONFIG_EMBEDDED=y
CONFIG_PROFILING=y
CONFIG_OPROFILE=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_LBDAF is not set
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_IOSCHED_DEADLINE is not set
# CONFIG_IOSCHED_CFQ is not set
CONFIG_ARCH_SOCFPGA=y
CONFIG_ARM_THUMBEE=y
CONFIG_SMP=y
CONFIG_NR_CPUS=2
CONFIG_AEABI=y
CONFIG_ZBOOT_ROM_TEXT=0x0
CONFIG_ZBOOT_ROM_BSS=0x0
CONFIG_VFP=y
CONFIG_NEON=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_NET_KEY=y
CONFIG_NET_KEY_MIGRATE=y
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_RARP=y
CONFIG_IPV6=y
CONFIG_NETWORK_PHY_TIMESTAMPING=y
CONFIG_VLAN_8021Q=y
CONFIG_VLAN_8021Q_GVRP=y
CONFIG_CAN=y
CONFIG_CAN_C_CAN=y
CONFIG_CAN_C_CAN_PLATFORM=y
CONFIG_CAN_DEBUG_DEVICES=y
CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
CONFIG_DEVTMPFS=y
CONFIG_DEVTMPFS_MOUNT=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_COUNT=2
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_SRAM=y
CONFIG_SCSI=y
# CONFIG_SCSI_PROC_FS is not set
CONFIG_BLK_DEV_SD=y
# CONFIG_SCSI_LOWLEVEL is not set
CONFIG_NETDEVICES=y
CONFIG_STMMAC_ETH=y
CONFIG_DWMAC_SOCFPGA=y
CONFIG_MICREL_PHY=y
CONFIG_INPUT_EVDEV=y
# CONFIG_SERIO_SERPORT is not set
CONFIG_SERIO_AMBAKMI=y
CONFIG_LEGACY_PTY_COUNT=16
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_8250_NR_UARTS=2
CONFIG_SERIAL_8250_RUNTIME_UARTS=2
CONFIG_SERIAL_8250_DW=y
CONFIG_I2C=y
CONFIG_I2C_CHARDEV=y
CONFIG_I2C_DESIGNWARE_PLATFORM=y
CONFIG_GPIOLIB=y
CONFIG_GPIO_SYSFS=y
CONFIG_GPIO_DWAPB=y
CONFIG_PMBUS=y
CONFIG_SENSORS_LTC2978=y
CONFIG_SENSORS_LTC2978_REGULATOR=y
CONFIG_WATCHDOG=y
CONFIG_DW_WATCHDOG=y
CONFIG_REGULATOR=y
CONFIG_REGULATOR_FIXED_VOLTAGE=y
CONFIG_USB=y
CONFIG_USB_DWC2=y
CONFIG_USB_DWC2_HOST=y
CONFIG_MMC=y
CONFIG_MMC_DW=y
CONFIG_EXT2_FS=y
CONFIG_EXT2_FS_XATTR=y
CONFIG_EXT2_FS_POSIX_ACL=y
CONFIG_EXT3_FS=y
CONFIG_EXT4_FS=y
CONFIG_VFAT_FS=y
CONFIG_NTFS_FS=y
CONFIG_NTFS_RW=y
CONFIG_TMPFS=y
CONFIG_CONFIGFS_FS=y
CONFIG_NFS_FS=y
CONFIG_ROOT_NFS=y
CONFIG_NLS_CODEPAGE_437=y
CONFIG_NLS_ISO8859_1=y
CONFIG_PRINTK_TIME=y
CONFIG_DEBUG_INFO=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DETECT_HUNG_TASK=y
# CONFIG_SCHED_DEBUG is not set
CONFIG_ENABLE_DEFAULT_TRACERS=y
CONFIG_DEBUG_USER=y
CONFIG_XZ_DEC=y
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