Viewing file:  kup-8xx.h (2.11 KB) -rw-r--r--
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_KUP_8XX_H_
#define _ASM_POWERPC_KUP_8XX_H_
#include <asm/bug.h>
#include <asm/mmu.h>
#ifdef CONFIG_PPC_KUAP
#ifndef __ASSEMBLY__
#include <linux/jump_label.h>
#include <asm/reg.h>
extern struct static_key_false disable_kuap_key;
static __always_inline bool kuap_is_disabled(void)
{
return static_branch_unlikely(&disable_kuap_key);
}
static inline void kuap_save_and_lock(struct pt_regs *regs)
{
if (kuap_is_disabled())
return;
regs->kuap = mfspr(SPRN_MD_AP);
mtspr(SPRN_MD_AP, MD_APG_KUAP);
}
static inline void kuap_user_restore(struct pt_regs *regs)
{
}
static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
{
if (kuap_is_disabled())
return;
mtspr(SPRN_MD_AP, regs->kuap);
}
static inline unsigned long kuap_get_and_assert_locked(void)
{
unsigned long kuap;
if (kuap_is_disabled())
return MD_APG_INIT;
kuap = mfspr(SPRN_MD_AP);
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
WARN_ON_ONCE(kuap >> 16 != MD_APG_KUAP >> 16);
return kuap;
}
static inline void kuap_assert_locked(void)
{
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && !kuap_is_disabled())
kuap_get_and_assert_locked();
}
static inline void allow_user_access(void __user *to, const void __user *from,
unsigned long size, unsigned long dir)
{
if (kuap_is_disabled())
return;
mtspr(SPRN_MD_AP, MD_APG_INIT);
}
static inline void prevent_user_access(unsigned long dir)
{
if (kuap_is_disabled())
return;
mtspr(SPRN_MD_AP, MD_APG_KUAP);
}
static inline unsigned long prevent_user_access_return(void)
{
unsigned long flags;
if (kuap_is_disabled())
return MD_APG_INIT;
flags = mfspr(SPRN_MD_AP);
mtspr(SPRN_MD_AP, MD_APG_KUAP);
return flags;
}
static inline void restore_user_access(unsigned long flags)
{
if (kuap_is_disabled())
return;
mtspr(SPRN_MD_AP, flags);
}
static inline bool
bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
{
if (kuap_is_disabled())
return false;
return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000);
}
#endif /* !__ASSEMBLY__ */
#endif /* CONFIG_PPC_KUAP */
#endif /* _ASM_POWERPC_KUP_8XX_H_ */
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