selftests/powerpc: Add pkey helpers for rights

This adds some new pkey-related helper to print
access rights of a pkey in the "rwx" format and
to generate different valid combinations of pkey
rights starting from a given combination.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6cc1c7d1f686618668a3e090f1d0c2a4cd9dea3f.1595821792.git.sandipan@linux.ibm.com

diff --git a/tools/testing/selftests/powerpc/include/pkeys.h b/tools/testing/selftests/powerpc/include/pkeys.h
index 9b53a97..6ba9503 100644 (file)
--- a/tools/testing/selftests/powerpc/include/pkeys.h
+++ b/tools/testing/selftests/powerpc/include/pkeys.h
@@ -105,4 +105,32 @@ int siginfo_pkey(siginfo_t *si)
 #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 */

diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
index 1253ad6..18ebfe6 100644 (file)
--- a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
+++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c
@@ -102,6 +102,7 @@ static void segv_handler(int signum, siginfo_t *sinfo, void *ctx)
 static int test(void)
 {
        struct sigaction segv_act, trap_act;
+       unsigned long rights;
        int pkey, ret, i;
 
        ret = pkeys_unsupported();
@@ -150,7 +151,8 @@ static int test(void)
        insns[numinsns - 1] = PPC_INST_BLR;
 
        /* Allocate a pkey that restricts execution */
-       pkey = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
+       rights = PKEY_DISABLE_EXECUTE;
+       pkey = sys_pkey_alloc(0, rights);
        FAIL_IF(pkey < 0);
 
        /*
@@ -175,8 +177,8 @@ static int test(void)
         */
        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);
+       printf("read from %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        i = *fault_addr;
        FAIL_IF(remaining_faults != 0);
 
@@ -192,12 +194,13 @@ static int test(void)
         */
        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);
+       printf("write to %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        *fault_addr = PPC_INST_TRAP;
        FAIL_IF(remaining_faults != 0 || fault_code != SEGV_ACCERR);
 
        /* The following three cases will generate SEGV_PKUERR */
+       rights |= PKEY_DISABLE_ACCESS;
        fault_type = PKEY_DISABLE_ACCESS;
        fault_pkey = pkey;
 
@@ -211,9 +214,9 @@ static int test(void)
         */
        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);
+       pkey_set_rights(pkey, rights);
+       printf("read from %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        i = *fault_addr;
        FAIL_IF(remaining_faults != 0 || fault_code != SEGV_PKUERR);
 
@@ -228,9 +231,9 @@ static int test(void)
         */
        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);
+       pkey_set_rights(pkey, rights);
+       printf("write to %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        *fault_addr = PPC_INST_NOP;
        FAIL_IF(remaining_faults != 0 || fault_code != SEGV_ACCERR);
 
@@ -251,8 +254,8 @@ static int test(void)
        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);
+       printf("execute at %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        asm volatile("mtctr     %0; bctrl" : : "r"(insns));
        FAIL_IF(remaining_faults != 0 || fault_code != SEGV_PKUERR);
 
@@ -261,7 +264,8 @@ static int test(void)
         * fully permissive.
         */
        sys_pkey_free(pkey);
-       pkey = sys_pkey_alloc(0, 0);
+       rights = 0;
+       pkey = sys_pkey_alloc(0, rights);
 
        /*
         * Jump to the executable region when AMR bits are not set
@@ -274,8 +278,8 @@ static int test(void)
        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);
+       printf("execute at %p, pkey permissions are %s\n", fault_addr,
+              pkey_rights(rights));
        asm volatile("mtctr     %0; bctrl" : : "r"(insns));
        FAIL_IF(remaining_faults != 0);