The ars_cap command indicates the buffer size we need to prepare for ars_status commands. The kernel reads the ars_status.out_length field to validate how much output buffer space is available. The ndctl_bus_cmd_new_ars_status() helper was neglecting to set that size. It was also misinterpreting the value of ars_cap.max_ars_out. That value is the total output data size of an ars_status command, not incremental to the base size of a ars_status command. Cc: Vishal Verma <vishal.l.verma(a)intel.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- lib/libndctl-ars.c | 4 ++-- test/libndctl.c | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/lib/libndctl-ars.c b/lib/libndctl-ars.c index ea3af82ca647..863217dd09aa 100644 --- a/lib/libndctl-ars.c +++ b/lib/libndctl-ars.c @@ -111,8 +111,7 @@ NDCTL_EXPORT struct ndctl_cmd *ndctl_bus_cmd_new_ars_status(struct ndctl_cmd *ar return NULL; } - size = sizeof(*cmd) + sizeof(struct nd_cmd_ars_status) + - ars_cap_cmd->max_ars_out; + size = sizeof(*cmd) + ars_cap_cmd->max_ars_out; cmd = calloc(1, size); if (!cmd) return NULL; @@ -123,6 +122,7 @@ NDCTL_EXPORT struct ndctl_cmd *ndctl_bus_cmd_new_ars_status(struct ndctl_cmd *ar cmd->size = size; cmd->status = 1; cmd->firmware_status = &cmd->ars_status->status; + cmd->ars_status->out_length = ars_cap_cmd->max_ars_out; return cmd; } diff --git a/test/libndctl.c b/test/libndctl.c index 5c26b5fdffc3..b4539b996d6a 100644 --- a/test/libndctl.c +++ b/test/libndctl.c @@ -1607,9 +1607,10 @@ static int check_ars_cap(struct ndctl_bus *bus, struct ndctl_dimm *dimm, return rc; } - if (ndctl_cmd_ars_cap_get_size(cmd) != 256) { - fprintf(stderr, "%s: bus: %s expect size: %d got: %d\n", - __func__, ndctl_bus_get_provider(bus), 256, + if (ndctl_cmd_ars_cap_get_size(cmd) < sizeof(struct nd_cmd_ars_status)) { + fprintf(stderr, "%s: bus: %s expect size >= %zd got: %d\n", + __func__, ndctl_bus_get_provider(bus), + sizeof(struct nd_cmd_ars_status), ndctl_cmd_ars_cap_get_size(cmd)); ndctl_cmd_unref(cmd); return -ENXIO;