Commit 2ddadec2 authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface 



Extend the ptrace test support for NT_ARM_TLS to cover TPIDR2_EL0 - on
systems that support SME the NT_ARM_TLS regset can be up to 2 elements
long with the second element containing TPIDR2_EL0. On systems
supporting SME we verify that this value can be read and written while
on systems that do not support SME we verify correct truncation of reads
and writes.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829154921.837871-5-broonie@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 0027d9c6

tools/testing/selftests/arm64/abi/ptrace.c

+79 −3
Original line number Diff line number Diff line
@@ -20,9 +20,9 @@ 


#include "../../kselftest.h"



#define EXPECTED_TESTS 3

#define EXPECTED_TESTS 7



#define MAX_TPIDRS 1

#define MAX_TPIDRS 2



static bool have_sme(void)

{
@@ -34,7 +34,8 @@ static void test_tpidr(pid_t child) 
	uint64_t read_val[MAX_TPIDRS];

	uint64_t write_val[MAX_TPIDRS];

	struct iovec read_iov, write_iov;

	int ret;

	bool test_tpidr2 = false;

	int ret, i;



	read_iov.iov_base = read_val;

	write_iov.iov_base = write_val;
@@ -54,6 +55,81 @@ static void test_tpidr(pid_t child) 
	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);

	ksft_test_result(ret == 0 && write_val[0] == read_val[0],

			 "verify_tpidr_one\n");



	/* If we have TPIDR2 we should be able to read it */

	read_iov.iov_len = sizeof(read_val);

	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);

	if (ret == 0) {

		/* If we have SME there should be two TPIDRs */

		if (read_iov.iov_len >= sizeof(read_val))

			test_tpidr2 = true;



		if (have_sme() && test_tpidr2) {

			ksft_test_result(test_tpidr2, "count_tpidrs\n");

		} else {

			ksft_test_result(read_iov.iov_len % sizeof(uint64_t) == 0,

					 "count_tpidrs\n");

		}

	} else {

		ksft_test_result_fail("count_tpidrs\n");

	}



	if (test_tpidr2) {

		/* Try to write new values to all known TPIDRs... */

		write_iov.iov_len = sizeof(write_val);

		for (i = 0; i < MAX_TPIDRS; i++)

			write_val[i] = read_val[i] + 1;

		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);



		ksft_test_result(ret == 0 &&

				 write_iov.iov_len == sizeof(write_val),

				 "tpidr2_write\n");



		/* ...then read them back */

		read_iov.iov_len = sizeof(read_val);

		ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);



		if (have_sme()) {

			/* Should read back the written value */

			ksft_test_result(ret == 0 &&

					 read_iov.iov_len >= sizeof(read_val) &&

					 memcmp(read_val, write_val,

						sizeof(read_val)) == 0,

					 "tpidr2_read\n");

		} else {

			/* TPIDR2 should read as zero */

			ksft_test_result(ret == 0 &&

					 read_iov.iov_len >= sizeof(read_val) &&

					 read_val[0] == write_val[0] &&

					 read_val[1] == 0,

					 "tpidr2_read\n");

		}



		/* Writing only TPIDR... */

		write_iov.iov_len = sizeof(uint64_t);

		memcpy(write_val, read_val, sizeof(read_val));

		write_val[0] += 1;

		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);



		if (ret == 0) {

			/* ...should leave TPIDR2 untouched */

			read_iov.iov_len = sizeof(read_val);

			ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS,

				     &read_iov);



			ksft_test_result(ret == 0 &&

					 read_iov.iov_len >= sizeof(read_val) &&

					 memcmp(read_val, write_val,

						sizeof(read_val)) == 0,

					 "write_tpidr_only\n");

		} else {

			ksft_test_result_fail("write_tpidr_only\n");

		}

	} else {

		ksft_test_result_skip("tpidr2_write\n");

		ksft_test_result_skip("tpidr2_read\n");

		ksft_test_result_skip("write_tpidr_only\n");

	}

}



static int do_child(void)