linux_dsm_epyc7002/arch/arm/include/asm/system_misc.h
Russell King f5fe12b1ea ARM: spectre-v2: harden user aborts in kernel space
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:

Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.

If the IBE bit is not set, then there is little point to enabling the
workaround.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
2018-05-31 10:40:32 +01:00

49 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARM_SYSTEM_MISC_H
#define __ASM_ARM_SYSTEM_MISC_H
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/linkage.h>
#include <linux/irqflags.h>
#include <linux/reboot.h>
#include <linux/percpu.h>
extern void cpu_init(void);
void soft_restart(unsigned long);
extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
extern void (*arm_pm_idle)(void);
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
typedef void (*harden_branch_predictor_fn_t)(void);
DECLARE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
static inline void harden_branch_predictor(void)
{
harden_branch_predictor_fn_t fn = per_cpu(harden_branch_predictor_fn,
smp_processor_id());
if (fn)
fn();
}
#else
#define harden_branch_predictor() do { } while (0)
#endif
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)
#define UDBG_BADABORT (1 << 2)
#define UDBG_SEGV (1 << 3)
#define UDBG_BUS (1 << 4)
extern unsigned int user_debug;
static inline int handle_guest_sea(phys_addr_t addr, unsigned int esr)
{
return -1;
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_ARM_SYSTEM_MISC_H */