* [PATCH v3 1/3] selftests: powerpc: Fix pkey access right updates
2020-06-04 12:56 [PATCH v3 0/3] selftests: powerpc: Fixes and execute-disable test for pkeys Sandipan Das
@ 2020-06-04 12:56 ` Sandipan Das
2020-06-04 12:56 ` [PATCH v3 2/3] selftests: powerpc: Move Hash MMU check to utilities Sandipan Das
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Sandipan Das @ 2020-06-04 12:56 UTC (permalink / raw)
To: mpe
Cc: linux-kselftest, linuxppc-dev, linux-mm, linuxram, aneesh.kumar,
bauerman, fweimer, ruscur
The Power ISA mandates that all writes to the Authority
Mask Register (AMR) must always be preceded as well as
succeeded by a context synchronizing instruction.
This makes sure that the tests follow this requirement
when attempting to update a pkey's access rights.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/powerpc/include/reg.h | 6 ++++++
tools/testing/selftests/powerpc/ptrace/core-pkey.c | 2 +-
tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/powerpc/include/reg.h b/tools/testing/selftests/powerpc/include/reg.h
index 022c5076b2c5..c0f2742a3a59 100644
--- a/tools/testing/selftests/powerpc/include/reg.h
+++ b/tools/testing/selftests/powerpc/include/reg.h
@@ -57,6 +57,12 @@
#define SPRN_PPR 896 /* Program Priority Register */
#define SPRN_AMR 13 /* Authority Mask Register - problem state */
+#define set_amr(v) asm volatile("isync;" \
+ "mtspr " __stringify(SPRN_AMR) ",%0;" \
+ "isync" : \
+ : "r" ((unsigned long)(v)) \
+ : "memory")
+
/* TEXASR register bits */
#define TEXASR_FC 0xFE00000000000000
#define TEXASR_FP 0x0100000000000000
diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index d5c64fee032d..bbc05ffc5860 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -150,7 +150,7 @@ static int child(struct shared_info *info)
printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
user_write, info->amr, pkey1, pkey2, pkey3);
- mtspr(SPRN_AMR, info->amr);
+ set_amr(info->amr);
/*
* We won't use pkey3. This tests whether the kernel restores the UAMOR
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index bdbbbe8431e0..904c04f8c919 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -126,7 +126,7 @@ static int child(struct shared_info *info)
printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
user_write, info->amr1, pkey1, pkey2, pkey3);
- mtspr(SPRN_AMR, info->amr1);
+ set_amr(info->amr1);
/* Wait for parent to read our AMR value and write a new one. */
ret = prod_parent(&info->child_sync);
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v3 2/3] selftests: powerpc: Move Hash MMU check to utilities
2020-06-04 12:56 [PATCH v3 0/3] selftests: powerpc: Fixes and execute-disable test for pkeys Sandipan Das
2020-06-04 12:56 ` [PATCH v3 1/3] selftests: powerpc: Fix pkey access right updates Sandipan Das
@ 2020-06-04 12:56 ` Sandipan Das
2020-06-04 12:56 ` [PATCH v3 3/3] selftests: powerpc: Add test for execute-disabled pkeys Sandipan Das
2020-07-16 12:56 ` [PATCH v3 0/3] selftests: powerpc: Fixes and execute-disable test for pkeys Michael Ellerman
3 siblings, 0 replies; 5+ messages in thread
From: Sandipan Das @ 2020-06-04 12:56 UTC (permalink / raw)
To: mpe
Cc: linux-kselftest, linuxppc-dev, linux-mm, linuxram, aneesh.kumar,
bauerman, fweimer, ruscur
This moves a function to test if the MMU is in Hash mode
under the generic test utilities.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
.../testing/selftests/powerpc/include/utils.h | 1 +
tools/testing/selftests/powerpc/mm/Makefile | 2 +-
.../selftests/powerpc/mm/bad_accesses.c | 28 -------------------
tools/testing/selftests/powerpc/utils.c | 28 +++++++++++++++++++
4 files changed, 30 insertions(+), 29 deletions(-)
diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index e089a0c30d9a..ad2728736ae5 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -60,6 +60,7 @@ static inline bool have_hwcap2(unsigned long ftr2)
#endif
bool is_ppc64le(void);
+int using_hash_mmu(bool *using_hash);
/* Yes, this is evil */
#define FAIL_IF(x) \
diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile
index b9103c4bb414..2389bf791fd6 100644
--- a/tools/testing/selftests/powerpc/mm/Makefile
+++ b/tools/testing/selftests/powerpc/mm/Makefile
@@ -10,7 +10,7 @@ TEST_GEN_FILES := tempfile
top_srcdir = ../../../../..
include ../../lib.mk
-$(TEST_GEN_PROGS): ../harness.c
+$(TEST_GEN_PROGS): ../harness.c ../utils.c
$(OUTPUT)/prot_sao: ../utils.c
diff --git a/tools/testing/selftests/powerpc/mm/bad_accesses.c b/tools/testing/selftests/powerpc/mm/bad_accesses.c
index adc465f499ef..a864ed7e2008 100644
--- a/tools/testing/selftests/powerpc/mm/bad_accesses.c
+++ b/tools/testing/selftests/powerpc/mm/bad_accesses.c
@@ -64,34 +64,6 @@ int bad_access(char *p, bool write)
return 0;
}
-static int using_hash_mmu(bool *using_hash)
-{
- char line[128];
- FILE *f;
- int rc;
-
- f = fopen("/proc/cpuinfo", "r");
- FAIL_IF(!f);
-
- rc = 0;
- while (fgets(line, sizeof(line), f) != NULL) {
- if (strcmp(line, "MMU : Hash\n") == 0) {
- *using_hash = true;
- goto out;
- }
-
- if (strcmp(line, "MMU : Radix\n") == 0) {
- *using_hash = false;
- goto out;
- }
- }
-
- rc = -1;
-out:
- fclose(f);
- return rc;
-}
-
static int test(void)
{
unsigned long i, j, addr, region_shift, page_shift, page_size;
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 5ee0e98c4896..933678f1ed0a 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -293,3 +293,31 @@ void set_dscr(unsigned long val)
asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
}
+
+int using_hash_mmu(bool *using_hash)
+{
+ char line[128];
+ FILE *f;
+ int rc;
+
+ f = fopen("/proc/cpuinfo", "r");
+ FAIL_IF(!f);
+
+ rc = 0;
+ while (fgets(line, sizeof(line), f) != NULL) {
+ if (strcmp(line, "MMU : Hash\n") == 0) {
+ *using_hash = true;
+ goto out;
+ }
+
+ if (strcmp(line, "MMU : Radix\n") == 0) {
+ *using_hash = false;
+ goto out;
+ }
+ }
+
+ rc = -1;
+out:
+ fclose(f);
+ return rc;
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v3 3/3] selftests: powerpc: Add test for execute-disabled pkeys
2020-06-04 12:56 [PATCH v3 0/3] selftests: powerpc: Fixes and execute-disable test for pkeys Sandipan Das
2020-06-04 12:56 ` [PATCH v3 1/3] selftests: powerpc: Fix pkey access right updates Sandipan Das
2020-06-04 12:56 ` [PATCH v3 2/3] selftests: powerpc: Move Hash MMU check to utilities Sandipan Das
@ 2020-06-04 12:56 ` Sandipan Das
2020-07-16 12:56 ` [PATCH v3 0/3] selftests: powerpc: Fixes and execute-disable test for pkeys Michael Ellerman
3 siblings, 0 replies; 5+ messages in thread
From: Sandipan Das @ 2020-06-04 12:56 UTC (permalink / raw)
To: mpe
Cc: linux-kselftest, linuxppc-dev, linux-mm, linuxram, aneesh.kumar,
bauerman, fweimer, ruscur
Apart from read and write access, memory protection keys can
also be used for restricting execute permission of pages on
powerpc. This adds a test to verify if the feature works as
expected.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/powerpc/mm/.gitignore | 1 +
tools/testing/selftests/powerpc/mm/Makefile | 3 +-
.../selftests/powerpc/mm/pkey_exec_prot.c | 388 ++++++++++++++++++
3 files changed, 391 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore
index 2ca523255b1b..8f841f925baa 100644
--- a/tools/testing/selftests/powerpc/mm/.gitignore
+++ b/tools/testing/selftests/powerpc/mm/.gitignore
@@ -8,3 +8,4 @@ wild_bctr
large_vm_fork_separation
bad_accesses
tlbie_test
+pkey_exec_prot
diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile
index 2389bf791fd6..f9fa0ba7435c 100644
--- a/tools/testing/selftests/powerpc/mm/Makefile
+++ b/tools/testing/selftests/powerpc/mm/Makefile
@@ -3,7 +3,7 @@ noarg:
$(MAKE) -C ../
TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors wild_bctr \
- large_vm_fork_separation bad_accesses
+ large_vm_fork_separation bad_accesses pkey_exec_prot
TEST_GEN_PROGS_EXTENDED := tlbie_test
TEST_GEN_FILES := tempfile
@@ -17,6 +17,7 @@ $(OUTPUT)/prot_sao: ../utils.c
$(OUTPUT)/wild_bctr: CFLAGS += -m64
$(OUTPUT)/large_vm_fork_separation: CFLAGS += -m64
$(OUTPUT)/bad_accesses: CFLAGS += -m64
+$(OUTPUT)/pkey_exec_prot: CFLAGS += -m64
$(OUTPUT)/tempfile:
dd if=/dev/zero of=$@ bs=64k count=1
diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
new file mode 100644
index 000000000000..7c7c93425c5e
--- /dev/null
+++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2020, Sandipan Das, IBM Corp.
+ *
+ * Test if applying execute protection on pages using memory
+ * protection keys works as expected.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+
+#include <unistd.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 SYS_pkey_mprotect 386
+#define SYS_pkey_alloc 384
+#define SYS_pkey_free 385
+
+#define PKEY_BITS_PER_PKEY 2
+#define NR_PKEYS 32
+#define PKEY_BITS_MASK ((1UL << PKEY_BITS_PER_PKEY) - 1)
+
+#define PPC_INST_NOP 0x60000000
+#define PPC_INST_TRAP 0x7fe00008
+#define PPC_INST_BLR 0x4e800020
+
+#define sigsafe_err(msg) ({ \
+ ssize_t nbytes __attribute__((unused)); \
+ nbytes = write(STDERR_FILENO, msg, strlen(msg)); })
+
+static inline unsigned long pkeyreg_get(void)
+{
+ return mfspr(SPRN_AMR);
+}
+
+static inline void pkeyreg_set(unsigned long amr)
+{
+ set_amr(amr);
+}
+
+static 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);
+}
+
+static int sys_pkey_mprotect(void *addr, size_t len, int prot, int pkey)
+{
+ return syscall(SYS_pkey_mprotect, addr, len, prot, pkey);
+}
+
+static int sys_pkey_alloc(unsigned long flags, unsigned long rights)
+{
+ return syscall(SYS_pkey_alloc, flags, rights);
+}
+
+static int sys_pkey_free(int pkey)
+{
+ return syscall(SYS_pkey_free, pkey);
+}
+
+static volatile sig_atomic_t fault_pkey, fault_code, fault_type;
+static volatile sig_atomic_t remaining_faults;
+static volatile unsigned int *fault_addr;
+static unsigned long pgsize, numinsns;
+static unsigned int *insns;
+
+static void trap_handler(int signum, siginfo_t *sinfo, void *ctx)
+{
+ /* Check if this fault originated from the expected address */
+ if (sinfo->si_addr != (void *) fault_addr)
+ sigsafe_err("got a fault for an unexpected address\n");
+
+ _exit(1);
+}
+
+static void segv_handler(int signum, siginfo_t *sinfo, void *ctx)
+{
+ int signal_pkey;
+
+ /*
+ * In older versions of libc, siginfo_t does not have si_pkey as
+ * a member.
+ */
+#ifdef si_pkey
+ signal_pkey = sinfo->si_pkey;
+#else
+ signal_pkey = *((int *)(((char *) sinfo) + SI_PKEY_OFFSET));
+#endif
+
+ fault_code = sinfo->si_code;
+
+ /* Check if this fault originated from the expected address */
+ if (sinfo->si_addr != (void *) fault_addr) {
+ sigsafe_err("got a fault for an unexpected address\n");
+ _exit(1);
+ }
+
+ /* Check if too many faults have occurred for a single test case */
+ if (!remaining_faults) {
+ sigsafe_err("got too many faults for the same address\n");
+ _exit(1);
+ }
+
+
+ /* Restore permissions in order to continue */
+ switch (fault_code) {
+ case SEGV_ACCERR:
+ if (mprotect(insns, pgsize, PROT_READ | PROT_WRITE)) {
+ sigsafe_err("failed to set access permissions\n");
+ _exit(1);
+ }
+ break;
+ case SEGV_PKUERR:
+ if (signal_pkey != fault_pkey) {
+ sigsafe_err("got a fault for an unexpected pkey\n");
+ _exit(1);
+ }
+
+ switch (fault_type) {
+ case PKEY_DISABLE_ACCESS:
+ pkey_set_rights(fault_pkey, 0);
+ break;
+ case PKEY_DISABLE_EXECUTE:
+ /*
+ * Reassociate the exec-only pkey with the region
+ * to be able to continue. Unlike AMR, we cannot
+ * set IAMR directly from userspace to restore the
+ * permissions.
+ */
+ if (mprotect(insns, pgsize, PROT_EXEC)) {
+ sigsafe_err("failed to set execute permissions\n");
+ _exit(1);
+ }
+ break;
+ default:
+ sigsafe_err("got a fault with an unexpected type\n");
+ _exit(1);
+ }
+ break;
+ default:
+ sigsafe_err("got a fault with an unexpected code\n");
+ _exit(1);
+ }
+
+ remaining_faults--;
+}
+
+static 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;
+}
+
+static int test(void)
+{
+ struct sigaction segv_act, trap_act;
+ int pkey, ret, i;
+
+ ret = pkeys_unsupported();
+ if (ret)
+ return ret;
+
+ /* Setup SIGSEGV handler */
+ segv_act.sa_handler = 0;
+ segv_act.sa_sigaction = segv_handler;
+ FAIL_IF(sigprocmask(SIG_SETMASK, 0, &segv_act.sa_mask) != 0);
+ segv_act.sa_flags = SA_SIGINFO;
+ segv_act.sa_restorer = 0;
+ FAIL_IF(sigaction(SIGSEGV, &segv_act, NULL) != 0);
+
+ /* Setup SIGTRAP handler */
+ trap_act.sa_handler = 0;
+ trap_act.sa_sigaction = trap_handler;
+ FAIL_IF(sigprocmask(SIG_SETMASK, 0, &trap_act.sa_mask) != 0);
+ trap_act.sa_flags = SA_SIGINFO;
+ trap_act.sa_restorer = 0;
+ FAIL_IF(sigaction(SIGTRAP, &trap_act, NULL) != 0);
+
+ /* Setup executable region */
+ pgsize = getpagesize();
+ numinsns = pgsize / sizeof(unsigned int);
+ insns = (unsigned int *) mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ FAIL_IF(insns == MAP_FAILED);
+
+ /* Write the instruction words */
+ for (i = 1; i < numinsns - 1; i++)
+ insns[i] = PPC_INST_NOP;
+
+ /*
+ * Set the first instruction as an unconditional trap. If
+ * the last write to this address succeeds, this should
+ * get overwritten by a no-op.
+ */
+ insns[0] = PPC_INST_TRAP;
+
+ /*
+ * Later, to jump to the executable region, we use a branch
+ * and link instruction (bctrl) which sets the return address
+ * automatically in LR. Use that to return back.
+ */
+ insns[numinsns - 1] = PPC_INST_BLR;
+
+ /* Allocate a pkey that restricts execution */
+ pkey = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
+ FAIL_IF(pkey < 0);
+
+ /*
+ * Pick the first instruction's address from the executable
+ * region.
+ */
+ fault_addr = insns;
+
+ /* The following two cases will avoid SEGV_PKUERR */
+ fault_type = -1;
+ fault_pkey = -1;
+
+ /*
+ * Read an instruction word from the address when AMR bits
+ * are not set i.e. the pkey permits both read and write
+ * access.
+ *
+ * This should not generate a fault as having PROT_EXEC
+ * implies PROT_READ on GNU systems. The pkey currently
+ * restricts execution only based on the IAMR bits. The
+ * AMR bits are cleared.
+ */
+ remaining_faults = 0;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ printf("read from %p, pkey is execute-disabled, access-enabled\n",
+ (void *) fault_addr);
+ i = *fault_addr;
+ FAIL_IF(remaining_faults != 0);
+
+ /*
+ * Write an instruction word to the address when AMR bits
+ * are not set i.e. the pkey permits both read and write
+ * access.
+ *
+ * This should generate an access fault as having just
+ * PROT_EXEC also restricts writes. The pkey currently
+ * restricts execution only based on the IAMR bits. The
+ * AMR bits are cleared.
+ */
+ remaining_faults = 1;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ printf("write to %p, pkey is execute-disabled, access-enabled\n",
+ (void *) fault_addr);
+ *fault_addr = PPC_INST_TRAP;
+ FAIL_IF(remaining_faults != 0 || fault_code != SEGV_ACCERR);
+
+ /* The following three cases will generate SEGV_PKUERR */
+ fault_type = PKEY_DISABLE_ACCESS;
+ fault_pkey = pkey;
+
+ /*
+ * Read an instruction word from the address when AMR bits
+ * are set i.e. the pkey permits neither read nor write
+ * access.
+ *
+ * This should generate a pkey fault based on AMR bits only
+ * as having PROT_EXEC implicitly allows reads.
+ */
+ remaining_faults = 1;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ printf("read from %p, pkey is execute-disabled, access-disabled\n",
+ (void *) fault_addr);
+ pkey_set_rights(pkey, PKEY_DISABLE_ACCESS);
+ i = *fault_addr;
+ FAIL_IF(remaining_faults != 0 || fault_code != SEGV_PKUERR);
+
+ /*
+ * Write an instruction word to the address when AMR bits
+ * are set i.e. the pkey permits neither read nor write
+ * access.
+ *
+ * This should generate two faults. First, a pkey fault
+ * based on AMR bits and then an access fault since
+ * PROT_EXEC does not allow writes.
+ */
+ remaining_faults = 2;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ printf("write to %p, pkey is execute-disabled, access-disabled\n",
+ (void *) fault_addr);
+ pkey_set_rights(pkey, PKEY_DISABLE_ACCESS);
+ *fault_addr = PPC_INST_NOP;
+ FAIL_IF(remaining_faults != 0 || fault_code != SEGV_ACCERR);
+
+ /*
+ * Jump to the executable region when AMR bits are set i.e.
+ * the pkey permits neither read nor write access.
+ *
+ * This should generate a pkey fault based on IAMR bits which
+ * are set to not permit execution. AMR bits should not affect
+ * execution.
+ *
+ * This also checks if the overwrite of the first instruction
+ * word from a trap to a no-op succeeded.
+ */
+ fault_addr = insns;
+ fault_type = PKEY_DISABLE_EXECUTE;
+ fault_pkey = pkey;
+ remaining_faults = 1;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ pkey_set_rights(pkey, PKEY_DISABLE_ACCESS);
+ printf("execute at %p, pkey is execute-disabled, access-disabled\n",
+ (void *) fault_addr);
+ asm volatile("mtctr %0; bctrl" : : "r"(insns));
+ FAIL_IF(remaining_faults != 0 || fault_code != SEGV_PKUERR);
+
+ /*
+ * Free the current pkey and allocate a new one that is
+ * fully permissive.
+ */
+ sys_pkey_free(pkey);
+ pkey = sys_pkey_alloc(0, 0);
+
+ /*
+ * Jump to the executable region when AMR bits are not set
+ * i.e. the pkey permits read and write access.
+ *
+ * This should not generate any faults as the IAMR bits are
+ * also not set and hence will the pkey will not restrict
+ * execution.
+ */
+ fault_pkey = pkey;
+ remaining_faults = 0;
+ FAIL_IF(sys_pkey_mprotect(insns, pgsize, PROT_EXEC, pkey) != 0);
+ printf("execute at %p, pkey is execute-enabled, access-enabled\n",
+ (void *) fault_addr);
+ asm volatile("mtctr %0; bctrl" : : "r"(insns));
+ FAIL_IF(remaining_faults != 0);
+
+ /* Cleanup */
+ munmap((void *) insns, pgsize);
+ sys_pkey_free(pkey);
+
+ return 0;
+}
+
+int main(void)
+{
+ test_harness(test, "pkey_exec_prot");
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread