175 lines
3.7 KiB
C
175 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_POWERPC_BOOK3S_32_KUP_H
|
|
#define _ASM_POWERPC_BOOK3S_32_KUP_H
|
|
|
|
#include <asm/bug.h>
|
|
#include <asm/book3s/32/mmu-hash.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/synch.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#ifdef CONFIG_PPC_KUAP
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#define KUAP_NONE (~0UL)
|
|
|
|
static __always_inline void kuap_lock_one(unsigned long addr)
|
|
{
|
|
mtsr(mfsr(addr) | SR_KS, addr);
|
|
isync(); /* Context sync required after mtsr() */
|
|
}
|
|
|
|
static __always_inline void kuap_unlock_one(unsigned long addr)
|
|
{
|
|
mtsr(mfsr(addr) & ~SR_KS, addr);
|
|
isync(); /* Context sync required after mtsr() */
|
|
}
|
|
|
|
static __always_inline void uaccess_begin_32s(unsigned long addr)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
asm volatile(ASM_MMU_FTR_IFSET(
|
|
"mfsrin %0, %1;"
|
|
"rlwinm %0, %0, 0, %2;"
|
|
"mtsrin %0, %1;"
|
|
"isync", "", %3)
|
|
: "=&r"(tmp)
|
|
: "r"(addr), "i"(~SR_KS), "i"(MMU_FTR_KUAP)
|
|
: "memory");
|
|
}
|
|
|
|
static __always_inline void uaccess_end_32s(unsigned long addr)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
asm volatile(ASM_MMU_FTR_IFSET(
|
|
"mfsrin %0, %1;"
|
|
"oris %0, %0, %2;"
|
|
"mtsrin %0, %1;"
|
|
"isync", "", %3)
|
|
: "=&r"(tmp)
|
|
: "r"(addr), "i"(SR_KS >> 16), "i"(MMU_FTR_KUAP)
|
|
: "memory");
|
|
}
|
|
|
|
static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)
|
|
{
|
|
unsigned long kuap = current->thread.kuap;
|
|
|
|
regs->kuap = kuap;
|
|
if (unlikely(kuap == KUAP_NONE))
|
|
return;
|
|
|
|
current->thread.kuap = KUAP_NONE;
|
|
kuap_lock_one(kuap);
|
|
}
|
|
#define __kuap_save_and_lock __kuap_save_and_lock
|
|
|
|
static __always_inline void kuap_user_restore(struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
|
|
{
|
|
if (unlikely(kuap != KUAP_NONE)) {
|
|
current->thread.kuap = KUAP_NONE;
|
|
kuap_lock_one(kuap);
|
|
}
|
|
|
|
if (likely(regs->kuap == KUAP_NONE))
|
|
return;
|
|
|
|
current->thread.kuap = regs->kuap;
|
|
|
|
kuap_unlock_one(regs->kuap);
|
|
}
|
|
|
|
static __always_inline unsigned long __kuap_get_and_assert_locked(void)
|
|
{
|
|
unsigned long kuap = current->thread.kuap;
|
|
|
|
WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE);
|
|
|
|
return kuap;
|
|
}
|
|
#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked
|
|
|
|
static __always_inline void allow_user_access(void __user *to, const void __user *from,
|
|
u32 size, unsigned long dir)
|
|
{
|
|
BUILD_BUG_ON(!__builtin_constant_p(dir));
|
|
|
|
if (!(dir & KUAP_WRITE))
|
|
return;
|
|
|
|
current->thread.kuap = (__force u32)to;
|
|
uaccess_begin_32s((__force u32)to);
|
|
}
|
|
|
|
static __always_inline void prevent_user_access(unsigned long dir)
|
|
{
|
|
u32 kuap = current->thread.kuap;
|
|
|
|
BUILD_BUG_ON(!__builtin_constant_p(dir));
|
|
|
|
if (!(dir & KUAP_WRITE))
|
|
return;
|
|
|
|
current->thread.kuap = KUAP_NONE;
|
|
uaccess_end_32s(kuap);
|
|
}
|
|
|
|
static __always_inline unsigned long prevent_user_access_return(void)
|
|
{
|
|
unsigned long flags = current->thread.kuap;
|
|
|
|
if (flags != KUAP_NONE) {
|
|
current->thread.kuap = KUAP_NONE;
|
|
uaccess_end_32s(flags);
|
|
}
|
|
|
|
return flags;
|
|
}
|
|
|
|
static __always_inline void restore_user_access(unsigned long flags)
|
|
{
|
|
if (flags != KUAP_NONE) {
|
|
current->thread.kuap = flags;
|
|
uaccess_begin_32s(flags);
|
|
}
|
|
}
|
|
|
|
static __always_inline bool
|
|
__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
|
|
{
|
|
unsigned long kuap = regs->kuap;
|
|
|
|
if (!is_write)
|
|
return false;
|
|
if (kuap == KUAP_NONE)
|
|
return true;
|
|
|
|
/*
|
|
* If faulting address doesn't match unlocked segment, change segment.
|
|
* In case of unaligned store crossing two segments, emulate store.
|
|
*/
|
|
if ((kuap ^ address) & 0xf0000000) {
|
|
if (!(kuap & 0x0fffffff) && address > kuap - 4 && fix_alignment(regs)) {
|
|
regs_add_return_ip(regs, 4);
|
|
emulate_single_step(regs);
|
|
} else {
|
|
regs->kuap = address;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_KUAP */
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */
|