From be608583d9c4910877d7553d4240e998818c2d70 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 22 Apr 2019 16:08:26 -0700 Subject: [PATCH] nfit/ars: Avoid stale ARS results commit 78153dd45e7e0596ba32b15d02bda08e1513111e upstream. Gate ARS result consumption on whether the OS issued start-ARS since the previous consumption. The BIOS may only clear its result buffers after a successful start-ARS. Fixes: 0caeef63e6d2 ("libnvdimm: Add a poison list and export badblocks") Cc: Reported-by: Krzysztof Rusocki Reported-by: Vishal Verma Reviewed-by: Toshi Kani Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- drivers/acpi/nfit/core.c | 17 ++++++++++++++++- drivers/acpi/nfit/nfit.h | 1 + 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 4b489d1..925dbc7 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -2540,7 +2540,10 @@ static int ars_start(struct acpi_nfit_desc *acpi_desc, if (rc < 0) return rc; - return cmd_rc; + if (cmd_rc < 0) + return cmd_rc; + set_bit(ARS_VALID, &acpi_desc->scrub_flags); + return 0; } static int ars_continue(struct acpi_nfit_desc *acpi_desc) @@ -2633,6 +2636,17 @@ static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc) */ if (ars_status->out_length < 44) return 0; + + /* + * Ignore potentially stale results that are only refreshed + * after a start-ARS event. + */ + if (!test_and_clear_bit(ARS_VALID, &acpi_desc->scrub_flags)) { + dev_dbg(acpi_desc->dev, "skip %d stale records\n", + ars_status->num_records); + return 0; + } + for (i = 0; i < ars_status->num_records; i++) { /* only process full records */ if (ars_status->out_length @@ -3117,6 +3131,7 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc) struct nfit_spa *nfit_spa; int rc; + set_bit(ARS_VALID, &acpi_desc->scrub_flags); list_for_each_entry(nfit_spa, &acpi_desc->spas, list) { switch (nfit_spa_type(nfit_spa->spa)) { case NFIT_SPA_VOLATILE: diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index b5fd352..68848fc 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -184,6 +184,7 @@ struct nfit_mem { enum scrub_flags { ARS_BUSY, ARS_CANCEL, + ARS_VALID, ARS_POLL, }; -- 2.7.4