From 2ddadec2206ca47a30995d22fa83be575e78f2a2 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 29 Aug 2022 16:49:21 +0100 Subject: [PATCH] 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: Mark Brown Link: https://lore.kernel.org/r/20220829154921.837871-5-broonie@kernel.org Signed-off-by: Catalin Marinas --- tools/testing/selftests/arm64/abi/ptrace.c | 82 ++++++++++++++++++++++++++++-- 1 file changed, 79 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c index a74157d..be95251 100644 --- a/tools/testing/selftests/arm64/abi/ptrace.c +++ b/tools/testing/selftests/arm64/abi/ptrace.c @@ -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) -- 2.7.4