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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PKEYS_POWERPC_H
#define _PKEYS_POWERPC_H
#ifndef SYS_pkey_alloc
# define SYS_pkey_alloc 384
# define SYS_pkey_free 385
#endif
#define REG_IP_IDX PT_NIP
#define MCONTEXT_IP(mc) mc.gp_regs[REG_IP_IDX]
#define MCONTEXT_TRAPNO(mc) mc.gp_regs[REG_TRAPNO]
#define REG_TRAPNO PT_TRAP
#define MCONTEXT_FPREGS
#define gregs gp_regs
#define fpregs fp_regs
#define si_pkey_offset 0x20
#undef PKEY_DISABLE_ACCESS
#define PKEY_DISABLE_ACCESS 0x3 /* disable read and write */
#undef PKEY_DISABLE_WRITE
#define PKEY_DISABLE_WRITE 0x2
#define NR_PKEYS 32
#define NR_RESERVED_PKEYS_4K 27 /* pkey-0, pkey-1, exec-only-pkey
and 24 other keys that cannot be
represented in the PTE */
#define NR_RESERVED_PKEYS_64K_3KEYS 3 /* PowerNV and KVM: pkey-0,
pkey-1 and exec-only key */
#define NR_RESERVED_PKEYS_64K_4KEYS 4 /* PowerVM: pkey-0, pkey-1,
pkey-31 and exec-only key */
#define PKEY_BITS_PER_PKEY 2
#define HPAGE_SIZE (1UL << 24)
#define PAGE_SIZE sysconf(_SC_PAGESIZE)
static inline u32 pkey_bit_position(int pkey)
{
return (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY;
}
static inline u64 __read_pkey_reg(void)
{
u64 pkey_reg;
asm volatile("mfspr %0, 0xd" : "=r" (pkey_reg));
return pkey_reg;
}
static inline void __write_pkey_reg(u64 pkey_reg)
{
u64 amr = pkey_reg;
dprintf4("%s() changing %016llx to %016llx\n",
__func__, __read_pkey_reg(), pkey_reg);
asm volatile("isync; mtspr 0xd, %0; isync"
: : "r" ((unsigned long)(amr)) : "memory");
dprintf4("%s() pkey register after changing %016llx to %016llx\n",
__func__, __read_pkey_reg(), pkey_reg);
}
static inline int cpu_has_pkeys(void)
{
/* No simple way to determine this */
return 1;
}
static inline bool arch_is_powervm()
{
struct stat buf;
if ((stat("/sys/firmware/devicetree/base/ibm,partition-name", &buf) == 0) &&
(stat("/sys/firmware/devicetree/base/hmc-managed?", &buf) == 0) &&
(stat("/sys/firmware/devicetree/base/chosen/qemu,graphic-width", &buf) == -1) )
return true;
return false;
}
static inline int get_arch_reserved_keys(void)
{
if (sysconf(_SC_PAGESIZE) == 4096)
return NR_RESERVED_PKEYS_4K;
else
if (arch_is_powervm())
return NR_RESERVED_PKEYS_64K_4KEYS;
else
return NR_RESERVED_PKEYS_64K_3KEYS;
}
void expect_fault_on_read_execonly_key(void *p1, int pkey)
{
/*
* powerpc does not allow userspace to change permissions of exec-only
* keys since those keys are not allocated by userspace. The signal
* handler wont be able to reset the permissions, which means the code
* will infinitely continue to segfault here.
*/
return;
}
/* 4-byte instructions * 16384 = 64K page */
#define __page_o_noops() asm(".rept 16384 ; nop; .endr")
void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
{
void *ptr;
int ret;
dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
size, prot, pkey);
pkey_assert(pkey < NR_PKEYS);
ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
pkey_assert(ptr != (void *)-1);
ret = syscall(__NR_subpage_prot, ptr, size, NULL);
if (ret) {
perror("subpage_perm");
return PTR_ERR_ENOTSUP;
}
ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
pkey_assert(!ret);
record_pkey_malloc(ptr, size, prot);
dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
return ptr;
}
#endif /* _PKEYS_POWERPC_H */
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