[PATCH v15 13/23] selftests/vm/pkeys: Introduce powerpc support
Sandipan Das
sandipan at linux.ibm.com
Wed Dec 18 18:51:46 AEDT 2019
From: Ram Pai <linuxram at us.ibm.com>
This makes use of the abstractions added earlier and
introduces support for powerpc.
cc: Dave Hansen <dave.hansen at intel.com>
cc: Florian Weimer <fweimer at redhat.com>
Signed-off-by: Ram Pai <linuxram at us.ibm.com>
Signed-off-by: Sandipan Das <sandipan at linux.ibm.com>
---
tools/testing/selftests/vm/pkey-helpers.h | 2 +
tools/testing/selftests/vm/pkey-powerpc.h | 93 +++++++
tools/testing/selftests/vm/protection_keys.c | 269 ++++++++++---------
3 files changed, 236 insertions(+), 128 deletions(-)
create mode 100644 tools/testing/selftests/vm/pkey-powerpc.h
diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index c929cc09b3cc..5de06d3a81de 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -79,6 +79,8 @@ void expected_pkey_fault(int pkey);
#if defined(__i386__) || defined(__x86_64__) /* arch */
#include "pkey-x86.h"
+#elif defined(__powerpc64__) /* arch */
+#include "pkey-powerpc.h"
#else /* arch */
#error Architecture not supported
#endif /* arch */
diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h
new file mode 100644
index 000000000000..5ced9c58fa4a
--- /dev/null
+++ b/tools/testing/selftests/vm/pkey-powerpc.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _PKEYS_POWERPC_H
+#define _PKEYS_POWERPC_H
+
+#ifndef SYS_mprotect_key
+# define SYS_mprotect_key 386
+#endif
+#ifndef SYS_pkey_alloc
+# define SYS_pkey_alloc 384
+# define SYS_pkey_free 385
+#endif
+#define REG_IP_IDX PT_NIP
+#define REG_TRAPNO PT_TRAP
+#define gregs gp_regs
+#define fpregs fp_regs
+#define si_pkey_offset 0x20
+
+#ifndef PKEY_DISABLE_ACCESS
+# define PKEY_DISABLE_ACCESS 0x3 /* disable read and write */
+#endif
+
+#ifndef PKEY_DISABLE_WRITE
+# define PKEY_DISABLE_WRITE 0x2
+#endif
+
+#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 3 /* pkey-0, pkey-1 and exec-only-pkey */
+#define PKEY_BITS_PER_PKEY 2
+#define HPAGE_SIZE (1UL << 24)
+#define PAGE_SIZE (1UL << 16)
+#define pkey_reg_t u64
+#define PKEY_REG_FMT "%016lx"
+
+static inline u32 pkey_bit_position(int pkey)
+{
+ return (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY;
+}
+
+static inline pkey_reg_t __read_pkey_reg(void)
+{
+ pkey_reg_t pkey_reg;
+
+ asm volatile("mfspr %0, 0xd" : "=r" (pkey_reg));
+
+ return pkey_reg;
+}
+
+static inline void __write_pkey_reg(pkey_reg_t pkey_reg)
+{
+ pkey_reg_t eax = pkey_reg;
+
+ dprintf4("%s() changing "PKEY_REG_FMT" to "PKEY_REG_FMT"\n",
+ __func__, __read_pkey_reg(), pkey_reg);
+
+ asm volatile("mtspr 0xd, %0" : : "r" ((unsigned long)(eax)) : "memory");
+
+ dprintf4("%s() pkey register after changing "PKEY_REG_FMT" to "
+ PKEY_REG_FMT"\n", __func__, __read_pkey_reg(),
+ pkey_reg);
+}
+
+static inline int cpu_has_pku(void)
+{
+ return 1;
+}
+
+static inline int get_arch_reserved_keys(void)
+{
+ if (sysconf(_SC_PAGESIZE) == 4096)
+ return NR_RESERVED_PKEYS_4K;
+ else
+ return NR_RESERVED_PKEYS_64K;
+}
+
+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;
+}
+
+/* 8-bytes of instruction * 16384bytes = 1 page */
+#define __page_o_noops() asm(".rept 16384 ; nop; .endr")
+
+#endif /* _PKEYS_POWERPC_H */
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index dbc2918bec13..1920bca84def 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -168,6 +168,125 @@ void dump_mem(void *dumpme, int len_bytes)
}
}
+static u32 hw_pkey_get(int pkey, unsigned long flags)
+{
+ pkey_reg_t pkey_reg = __read_pkey_reg();
+
+ dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
+ __func__, pkey, flags, 0, 0);
+ dprintf2("%s() raw pkey_reg: "PKEY_REG_FMT"\n", __func__, pkey_reg);
+
+ return (u32) get_pkey_bits(pkey_reg, pkey);
+}
+
+static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
+{
+ u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
+ pkey_reg_t old_pkey_reg = __read_pkey_reg();
+ pkey_reg_t new_pkey_reg;
+
+ /* make sure that 'rights' only contains the bits we expect: */
+ assert(!(rights & ~mask));
+
+ /* modify bits accordingly in old pkey_reg and assign it */
+ new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);
+
+ __write_pkey_reg(new_pkey_reg);
+
+ dprintf3("%s(pkey=%d, rights=%lx, flags=%lx) = %x"
+ " pkey_reg now: "PKEY_REG_FMT" old_pkey_reg: "PKEY_REG_FMT"\n",
+ __func__, pkey, rights, flags, 0, __read_pkey_reg(),
+ old_pkey_reg);
+ return 0;
+}
+
+void pkey_disable_set(int pkey, int flags)
+{
+ unsigned long syscall_flags = 0;
+ int ret;
+ int pkey_rights;
+ pkey_reg_t orig_pkey_reg = read_pkey_reg();
+
+ dprintf1("START->%s(%d, 0x%x)\n", __func__,
+ pkey, flags);
+ pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
+
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
+
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
+ pkey, pkey, pkey_rights);
+
+ pkey_assert(pkey_rights >= 0);
+
+ pkey_rights |= flags;
+
+ ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
+ assert(!ret);
+ /* pkey_reg and flags have the same format */
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
+ dprintf1("%s(%d) shadow: 0x"PKEY_REG_FMT"\n",
+ __func__, pkey, shadow_pkey_reg);
+
+ pkey_assert(ret >= 0);
+
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
+ pkey, pkey, pkey_rights);
+
+ dprintf1("%s(%d) pkey_reg: 0x"PKEY_REG_FMT"\n",
+ __func__, pkey, read_pkey_reg());
+ if (flags)
+ pkey_assert(read_pkey_reg() >= orig_pkey_reg);
+ dprintf1("END<---%s(%d, 0x%x)\n", __func__,
+ pkey, flags);
+}
+
+void pkey_disable_clear(int pkey, int flags)
+{
+ unsigned long syscall_flags = 0;
+ int ret;
+ int pkey_rights = hw_pkey_get(pkey, syscall_flags);
+ pkey_reg_t orig_pkey_reg = read_pkey_reg();
+
+ pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
+
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
+ pkey, pkey, pkey_rights);
+ pkey_assert(pkey_rights >= 0);
+
+ pkey_rights &= ~flags;
+
+ ret = hw_pkey_set(pkey, pkey_rights, 0);
+ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
+ pkey_assert(ret >= 0);
+
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
+ pkey, pkey, pkey_rights);
+
+ dprintf1("%s(%d) pkey_reg: 0x"PKEY_REG_FMT"\n", __func__,
+ pkey, read_pkey_reg());
+ if (flags)
+ assert(read_pkey_reg() <= orig_pkey_reg);
+}
+
+void pkey_write_allow(int pkey)
+{
+ pkey_disable_clear(pkey, PKEY_DISABLE_WRITE);
+}
+void pkey_write_deny(int pkey)
+{
+ pkey_disable_set(pkey, PKEY_DISABLE_WRITE);
+}
+void pkey_access_allow(int pkey)
+{
+ pkey_disable_clear(pkey, PKEY_DISABLE_ACCESS);
+}
+void pkey_access_deny(int pkey)
+{
+ pkey_disable_set(pkey, PKEY_DISABLE_ACCESS);
+}
+
/* Failed address bound checks: */
#ifndef SEGV_BNDERR
# define SEGV_BNDERR 3
@@ -198,11 +317,12 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
int trapno;
unsigned long ip;
char *fpregs;
+#if defined(__i386__) || defined(__x86_64__) /* arch */
pkey_reg_t *pkey_reg_ptr;
+ int pkey_reg_offset;
+#endif /* arch */
u64 siginfo_pkey;
u32 *si_pkey_ptr;
- int pkey_reg_offset;
- fpregset_t fpregset;
dprint_in_signal = 1;
dprintf1(">>>>===============SIGSEGV============================\n");
@@ -212,12 +332,13 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO];
ip = uctxt->uc_mcontext.gregs[REG_IP_IDX];
- fpregset = uctxt->uc_mcontext.fpregs;
- fpregs = (void *)fpregset;
+ fpregs = (char *) uctxt->uc_mcontext.fpregs;
dprintf2("%s() trapno: %d ip: 0x%016lx info->si_code: %s/%d\n",
__func__, trapno, ip, si_code_str(si->si_code),
si->si_code);
+
+#if defined(__i386__) || defined(__x86_64__) /* arch */
#ifdef __i386__
/*
* 32-bit has some extra padding so that userspace can tell whether
@@ -225,12 +346,10 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
* state. We just assume that it is here.
*/
fpregs += 0x70;
-#endif
+#endif /* i386 */
pkey_reg_offset = pkey_reg_xstate_offset();
pkey_reg_ptr = (void *)(&fpregs[pkey_reg_offset]);
- dprintf1("siginfo: %p\n", si);
- dprintf1(" fpregs: %p\n", fpregs);
/*
* If we got a PKEY fault, we *HAVE* to have at least one bit set in
* here.
@@ -239,6 +358,10 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
if (DEBUG_LEVEL > 4)
dump_mem(pkey_reg_ptr - 128, 256);
pkey_assert(*pkey_reg_ptr);
+#endif /* arch */
+
+ dprintf1("siginfo: %p\n", si);
+ dprintf1(" fpregs: %p\n", fpregs);
if ((si->si_code == SEGV_MAPERR) ||
(si->si_code == SEGV_ACCERR) ||
@@ -247,14 +370,13 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
exit(4);
}
- si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset);
+ si_pkey_ptr = siginfo_get_pkey_ptr(si);
dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
dump_mem((u8 *)si_pkey_ptr - 8, 24);
siginfo_pkey = *si_pkey_ptr;
pkey_assert(siginfo_pkey < NR_PKEYS);
last_si_pkey = siginfo_pkey;
- dprintf1("signal pkey_reg from xsave: "PKEY_REG_FMT"\n", *pkey_reg_ptr);
/*
* need __read_pkey_reg() version so we do not do shadow_pkey_reg
* checking
@@ -262,8 +384,14 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
dprintf1("signal pkey_reg from pkey_reg: "PKEY_REG_FMT"\n",
__read_pkey_reg());
dprintf1("pkey from siginfo: %jx\n", siginfo_pkey);
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+ dprintf1("signal pkey_reg from xsave: "PKEY_REG_FMT"\n", *pkey_reg_ptr);
*(u64 *)pkey_reg_ptr = 0x00000000;
dprintf1("WARNING: set PKEY_REG=0 to allow faulting instruction to continue\n");
+#elif defined(__powerpc64__) /* arch */
+ /* restore access and let the faulting instruction continue */
+ pkey_access_allow(siginfo_pkey);
+#endif /* arch */
pkey_faults++;
dprintf1("<<<<==================================================\n");
dprint_in_signal = 0;
@@ -332,125 +460,6 @@ pid_t fork_lazy_child(void)
return forkret;
}
-static u32 hw_pkey_get(int pkey, unsigned long flags)
-{
- pkey_reg_t pkey_reg = __read_pkey_reg();
-
- dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
- __func__, pkey, flags, 0, 0);
- dprintf2("%s() raw pkey_reg: "PKEY_REG_FMT"\n", __func__, pkey_reg);
-
- return (u32) get_pkey_bits(pkey_reg, pkey);
-}
-
-static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
-{
- u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
- pkey_reg_t old_pkey_reg = __read_pkey_reg();
- pkey_reg_t new_pkey_reg;
-
- /* make sure that 'rights' only contains the bits we expect: */
- assert(!(rights & ~mask));
-
- /* modify bits accordingly in old pkey_reg and assign it */
- new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);
-
- __write_pkey_reg(new_pkey_reg);
-
- dprintf3("%s(pkey=%d, rights=%lx, flags=%lx) = %x"
- " pkey_reg now: "PKEY_REG_FMT" old_pkey_reg: "PKEY_REG_FMT"\n",
- __func__, pkey, rights, flags, 0, __read_pkey_reg(),
- old_pkey_reg);
- return 0;
-}
-
-void pkey_disable_set(int pkey, int flags)
-{
- unsigned long syscall_flags = 0;
- int ret;
- int pkey_rights;
- pkey_reg_t orig_pkey_reg = read_pkey_reg();
-
- dprintf1("START->%s(%d, 0x%x)\n", __func__,
- pkey, flags);
- pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
-
- pkey_rights = hw_pkey_get(pkey, syscall_flags);
-
- dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
- pkey, pkey, pkey_rights);
-
- pkey_assert(pkey_rights >= 0);
-
- pkey_rights |= flags;
-
- ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
- assert(!ret);
- /* pkey_reg and flags have the same format */
- shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
- dprintf1("%s(%d) shadow: 0x"PKEY_REG_FMT"\n",
- __func__, pkey, shadow_pkey_reg);
-
- pkey_assert(ret >= 0);
-
- pkey_rights = hw_pkey_get(pkey, syscall_flags);
- dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
- pkey, pkey, pkey_rights);
-
- dprintf1("%s(%d) pkey_reg: 0x"PKEY_REG_FMT"\n",
- __func__, pkey, read_pkey_reg());
- if (flags)
- pkey_assert(read_pkey_reg() >= orig_pkey_reg);
- dprintf1("END<---%s(%d, 0x%x)\n", __func__,
- pkey, flags);
-}
-
-void pkey_disable_clear(int pkey, int flags)
-{
- unsigned long syscall_flags = 0;
- int ret;
- int pkey_rights = hw_pkey_get(pkey, syscall_flags);
- pkey_reg_t orig_pkey_reg = read_pkey_reg();
-
- pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
-
- dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
- pkey, pkey, pkey_rights);
- pkey_assert(pkey_rights >= 0);
-
- pkey_rights &= ~flags;
-
- ret = hw_pkey_set(pkey, pkey_rights, 0);
- shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
- pkey_assert(ret >= 0);
-
- pkey_rights = hw_pkey_get(pkey, syscall_flags);
- dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
- pkey, pkey, pkey_rights);
-
- dprintf1("%s(%d) pkey_reg: 0x"PKEY_REG_FMT"\n", __func__,
- pkey, read_pkey_reg());
- if (flags)
- assert(read_pkey_reg() <= orig_pkey_reg);
-}
-
-void pkey_write_allow(int pkey)
-{
- pkey_disable_clear(pkey, PKEY_DISABLE_WRITE);
-}
-void pkey_write_deny(int pkey)
-{
- pkey_disable_set(pkey, PKEY_DISABLE_WRITE);
-}
-void pkey_access_allow(int pkey)
-{
- pkey_disable_clear(pkey, PKEY_DISABLE_ACCESS);
-}
-void pkey_access_deny(int pkey)
-{
- pkey_disable_set(pkey, PKEY_DISABLE_ACCESS);
-}
-
int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
unsigned long pkey)
{
@@ -889,11 +898,15 @@ void expected_pkey_fault(int pkey)
if (pkey != UNKNOWN_PKEY)
pkey_assert(last_si_pkey == pkey);
+#if defined(__i386__) || defined(__x86_64__) /* arch */
/*
* The signal handler shold have cleared out PKEY register to let the
* test program continue. We now have to restore it.
*/
if (__read_pkey_reg() != 0)
+#else /* arch */
+ if (__read_pkey_reg() != shadow_pkey_reg)
+#endif /* arch */
pkey_assert(0);
__write_pkey_reg(shadow_pkey_reg);
--
2.17.1
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