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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright 2020, Sandipan Das, IBM Corp.
*/
#ifndef _SELFTESTS_POWERPC_PKEYS_H
#define _SELFTESTS_POWERPC_PKEYS_H
#include <sys/mman.h>
#include "reg.h"
#include "utils.h"
/*
* Older versions of libc use the Intel-specific access rights.
* Hence, override the definitions as they might be incorrect.
*/
#undef PKEY_DISABLE_ACCESS
#define PKEY_DISABLE_ACCESS 0x3
#undef PKEY_DISABLE_WRITE
#define PKEY_DISABLE_WRITE 0x2
#undef PKEY_DISABLE_EXECUTE
#define PKEY_DISABLE_EXECUTE 0x4
/* Older versions of libc do not not define this */
#ifndef SEGV_PKUERR
#define SEGV_PKUERR 4
#endif
#define SI_PKEY_OFFSET 0x20
#define __NR_pkey_mprotect 386
#define __NR_pkey_alloc 384
#define __NR_pkey_free 385
#define PKEY_BITS_PER_PKEY 2
#define NR_PKEYS 32
#define PKEY_BITS_MASK ((1UL << PKEY_BITS_PER_PKEY) - 1)
inline unsigned long pkeyreg_get(void)
{
return mfspr(SPRN_AMR);
}
inline void pkeyreg_set(unsigned long amr)
{
set_amr(amr);
}
void pkey_set_rights(int pkey, unsigned long rights)
{
unsigned long amr, shift;
shift = (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY;
amr = pkeyreg_get();
amr &= ~(PKEY_BITS_MASK << shift);
amr |= (rights & PKEY_BITS_MASK) << shift;
pkeyreg_set(amr);
}
int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey)
{
return syscall(__NR_pkey_mprotect, addr, len, prot, pkey);
}
int sys_pkey_alloc(unsigned long flags, unsigned long rights)
{
return syscall(__NR_pkey_alloc, flags, rights);
}
int sys_pkey_free(int pkey)
{
return syscall(__NR_pkey_free, pkey);
}
int pkeys_unsupported(void)
{
bool hash_mmu = false;
int pkey;
/* Protection keys are currently supported on Hash MMU only */
FAIL_IF(using_hash_mmu(&hash_mmu));
SKIP_IF(!hash_mmu);
/* Check if the system call is supported */
pkey = sys_pkey_alloc(0, 0);
SKIP_IF(pkey < 0);
sys_pkey_free(pkey);
return 0;
}
int siginfo_pkey(siginfo_t *si)
{
/*
* In older versions of libc, siginfo_t does not have si_pkey as
* a member.
*/
#ifdef si_pkey
return si->si_pkey;
#else
return *((int *)(((char *) si) + SI_PKEY_OFFSET));
#endif
}
#define pkey_rights(r) ({ \
static char buf[4] = "rwx"; \
unsigned int amr_bits; \
if ((r) & PKEY_DISABLE_EXECUTE) \
buf[2] = '-'; \
amr_bits = (r) & PKEY_BITS_MASK; \
if (amr_bits & PKEY_DISABLE_WRITE) \
buf[1] = '-'; \
if (amr_bits & PKEY_DISABLE_ACCESS & ~PKEY_DISABLE_WRITE) \
buf[0] = '-'; \
buf; \
})
unsigned long next_pkey_rights(unsigned long rights)
{
if (rights == PKEY_DISABLE_ACCESS)
return PKEY_DISABLE_EXECUTE;
else if (rights == (PKEY_DISABLE_ACCESS | PKEY_DISABLE_EXECUTE))
return 0;
if ((rights & PKEY_BITS_MASK) == 0)
rights |= PKEY_DISABLE_WRITE;
else if ((rights & PKEY_BITS_MASK) == PKEY_DISABLE_WRITE)
rights |= PKEY_DISABLE_ACCESS;
return rights;
}
#endif /* _SELFTESTS_POWERPC_PKEYS_H */
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