From 264d7fccc4711328a19f07e6bd57aee4c68803aa Mon Sep 17 00:00:00 2001 From: Sandipan Das Date: Mon, 27 Jul 2020 09:30:36 +0530 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/6cc1c7d1f686618668a3e090f1d0c2a4cd9dea3f.1595821792.git.sandipan@linux.ibm.com --- tools/testing/selftests/powerpc/include/pkeys.h | 28 +++++++++++++++++ .../testing/selftests/powerpc/mm/pkey_exec_prot.c | 36 ++++++++++++---------- 2 files changed, 48 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/powerpc/include/pkeys.h b/tools/testing/selftests/powerpc/include/pkeys.h index 9b53a97..6ba9503 100644 --- 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 --- 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); -- 2.7.4