Commit 264d7fcc authored by Sandipan Das's avatar Sandipan Das Committed by Michael Ellerman
Browse files

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: default avatarSandipan Das <sandipan@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6cc1c7d1f686618668a3e090f1d0c2a4cd9dea3f.1595821792.git.sandipan@linux.ibm.com
parent 128d3d02

tools/testing/selftests/powerpc/include/pkeys.h

+28 −0
Original line number Diff line number Diff line
@@ -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 */

tools/testing/selftests/powerpc/mm/pkey_exec_prot.c

+20 −16
Original line number Diff line number Diff line
@@ -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);

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