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Diffstat (limited to 'tools/testing/selftests/powerpc/include/pkeys.h')
-rw-r--r-- | tools/testing/selftests/powerpc/include/pkeys.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/include/pkeys.h b/tools/testing/selftests/powerpc/include/pkeys.h new file mode 100644 index 000000000..3312cb1b0 --- /dev/null +++ b/tools/testing/selftests/powerpc/include/pkeys.h @@ -0,0 +1,136 @@ +/* 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 */ |