[src/jdolecek-ncq]: src/sys/dev/ata add checksum verification for data return...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/19f34186078d
branches:  jdolecek-ncq
changeset: 822967:19f34186078d
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Fri Jul 21 18:12:37 2017 +0000

description:
add checksum verification for data returned by READ LOG EXT; this is mostly
just paranoia for eventual driver/hw DMA bugs

this doesn't make difference for QEMU, as there the command actually always
just fails (it's not implemented)

diffstat:

 sys/dev/ata/ata.c |  23 ++++++++++++++++-------
 1 files changed, 16 insertions(+), 7 deletions(-)

diffs (64 lines):

diff -r eb7bbe7f43bf -r 19f34186078d sys/dev/ata/ata.c
--- a/sys/dev/ata/ata.c Fri Jul 21 17:32:27 2017 +0000
+++ b/sys/dev/ata/ata.c Fri Jul 21 18:12:37 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ata.c,v 1.132.8.19 2017/07/19 19:39:28 jdolecek Exp $  */
+/*     $NetBSD: ata.c,v 1.132.8.20 2017/07/21 18:12:37 jdolecek Exp $  */
 
 /*
  * Copyright (c) 1998, 2001 Manuel Bouyer.  All rights reserved.
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ata.c,v 1.132.8.19 2017/07/19 19:39:28 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ata.c,v 1.132.8.20 2017/07/21 18:12:37 jdolecek Exp $");
 
 #include "opt_ata.h"
 
@@ -1039,7 +1039,7 @@
        int rv;
        struct ata_channel *chp = drvp->chnl_softc;
        struct atac_softc *atac = chp->ch_atac;
-       uint8_t *tb;
+       uint8_t *tb, cksum, page;
 
        ATADEBUG_PRINT(("%s\n", __func__), DEBUG_FUNCS);
 
@@ -1072,12 +1072,12 @@
         */
        xfer->c_flags |= C_IMMEDIATE;
        xfer->c_ata_c.r_command = WDCC_READ_LOG_EXT;
-       xfer->c_ata_c.r_lba = WDCC_LOG_PAGE_NCQ;
+       xfer->c_ata_c.r_lba = page = WDCC_LOG_PAGE_NCQ;
        xfer->c_ata_c.r_st_bmask = WDCS_DRDY;
        xfer->c_ata_c.r_st_pmask = WDCS_DRDY;
        xfer->c_ata_c.r_count = 1;
        xfer->c_ata_c.r_device = WDSD_LBA;
-       xfer->c_ata_c.flags = AT_READ | AT_LBA | flags;
+       xfer->c_ata_c.flags = AT_READ | AT_LBA | AT_LBA48 | flags;
        xfer->c_ata_c.timeout = 1000; /* 1s */
        xfer->c_ata_c.data = tb;
        xfer->c_ata_c.bcount = DEV_BSIZE;
@@ -1092,10 +1092,19 @@
                goto out2;
        }
 
-       /* XXX verify checksum and refuse if not correct (QEMU) */
+       cksum = 0;
+       for (int i = 0; i < DEV_BSIZE; i++)
+               cksum += tb[i];
+       if (cksum != 0) {
+               aprint_error_dev(drvp->drv_softc,
+                   "invalid checksum %x for READ LOG EXT page %x\n",
+                   cksum, page);
+               rv = EINVAL;
+               goto out2;
+       }
 
        if (tb[0] & WDCC_LOG_NQ) {
-               /* not a NCQ command */
+               /* not queued command */
                rv = EOPNOTSUPP;
                goto out2;
        }