The NT_ARM_SVE register set supports two data formats, the native SVE one and an alternative format where we embed a copy of user_fpsimd_data as used for NT_PRFPREG in the SVE register set. The register data is set as for a write to NT_PRFPREG and changes in vector length and streaming mode are handled as for any NT_ARM_SVE write. This has not previously been tested by fp-ptrace, add coverage of it.

We do not support writes in FPSIMD format for NT_ARM_SSVE so we skip the test for anything that would leave us in streaming mode.

Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/arm64/fp/fp-ptrace.c | 66 +++++++++++++++++++++++++++- 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/fp/fp-ptrace.c b/tools/testing/selftests/arm64/fp/fp-ptrace.c index 191c47ca0ed8..c479c97dea1a 100644 --- a/tools/testing/selftests/arm64/fp/fp-ptrace.c +++ b/tools/testing/selftests/arm64/fp/fp-ptrace.c @@ -1066,6 +1066,23 @@ static bool sve_write_supported(struct test_config *config) return true; }

+static bool sve_write_fpsimd_supported(struct test_config *config) +{ + if (!sve_supported()) + return false; + + if ((config->svcr_in & SVCR_ZA) != (config->svcr_expected & SVCR_ZA)) + return false; + + if (config->svcr_expected & SVCR_SM) + return false; + + if (config->sme_vl_in != config->sme_vl_expected) + return false; + + return true; +} + static void fpsimd_write_expected(struct test_config *config) { int vl; @@ -1152,7 +1169,7 @@ static void sve_write_expected(struct test_config *config) } }

-static void sve_write(pid_t child, struct test_config *config) +static void sve_write_sve(pid_t child, struct test_config *config) { struct user_sve_header *sve; struct iovec iov; @@ -1195,6 +1212,45 @@ static void sve_write(pid_t child, struct test_config *config) free(iov.iov_base); }

+static void sve_write_fpsimd(pid_t child, struct test_config *config) +{ + struct user_sve_header *sve; + struct user_fpsimd_state *fpsimd; + struct iovec iov; + int ret, vl, vq; + + vl = vl_expected(config); + vq = __sve_vq_from_vl(vl); + + if (!vl) + return; + + iov.iov_len = SVE_PT_SVE_OFFSET + SVE_PT_SVE_SIZE(vq, + SVE_PT_REGS_FPSIMD); + iov.iov_base = malloc(iov.iov_len); + if (!iov.iov_base) { + ksft_print_msg("Failed allocating %lu byte SVE write buffer\n", + iov.iov_len); + return; + } + memset(iov.iov_base, 0, iov.iov_len); + + sve = iov.iov_base; + sve->size = iov.iov_len; + sve->flags = SVE_PT_REGS_FPSIMD; + sve->vl = vl; + + fpsimd = iov.iov_base + SVE_PT_REGS_OFFSET; + memcpy(&fpsimd->vregs, v_expected, sizeof(v_expected)); + + ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_SVE, &iov); + if (ret != 0) + ksft_print_msg("Failed to write SVE: %s (%d)\n", + strerror(errno), errno); + + free(iov.iov_base); +} + static bool za_write_supported(struct test_config *config) { if ((config->svcr_in & SVCR_SM) != (config->svcr_expected & SVCR_SM)) @@ -1386,7 +1442,13 @@ static struct test_definition sve_test_defs[] = { .name = "SVE write", .supported = sve_write_supported, .set_expected_values = sve_write_expected, - .modify_values = sve_write, + .modify_values = sve_write_sve, + }, + { + .name = "SVE write FPSIMD format", + .supported = sve_write_fpsimd_supported, + .set_expected_values = fpsimd_write_expected, + .modify_values = sve_write_fpsimd, }, };

--- base-commit: 86731a2a651e58953fc949573895f2fa6d456841 change-id: 20250718-arm64-fp-ptrace-sve-fpsimd-ea20bdd9138b

Best regards, -- Mark Brown broonie@kernel.org