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authorAndrew Gallatin <gallatin@myri.com>2008-08-13 15:16:00 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-13 15:16:00 -0700
commit64c00d81b5c2491bd140b3c8eb2e8c351513f971 (patch)
tree28f2122cab0dc9d1e228a96aedd178ed53f12456 /net
parent3e8a0a559c66ee9e7468195691a56fefc3589740 (diff)
pktgen: prevent pktgen from using bad tx queue
With the new multi-queue transmit code, it is possible to accidentally make pktgen pick a non-existing tx queue simply by using a stale script to drive pktgen. Access to this non-existing tx queue will then trigger a bad memory access and kill the machine. For example, setting "queue_map_max 2" will cause my machine to die when accessing a garbage spinlock in the non-existing tx queue: BUG: spinlock bad magic on CPU#0, kpktgend_0/564 lock: ffff88001ddf6718, .magic: ffffffff, .owner: /-1, .owner_cpu: 0 Pid: 564, comm: kpktgend_0 Not tainted 2.6.27-rc3 #35 Call Trace: [<ffffffff803a1228>] spin_bug+0xa4/0xac [<ffffffff803a1253>] _raw_spin_lock+0x23/0x123 [<ffffffff8055b06f>] _spin_lock_bh+0x17/0x1b [<ffffffff804cb57d>] pktgen_thread_worker+0xa97/0x1002 [<ffffffff8022874d>] ? finish_task_switch+0x38/0x97 [<ffffffff80242077>] ? autoremove_wake_function+0x0/0x36 [<ffffffff80242077>] ? autoremove_wake_function+0x0/0x36 [<ffffffff804caae6>] ? pktgen_thread_worker+0x0/0x1002 [<ffffffff80241a40>] kthread+0x44/0x6d [<ffffffff8020c399>] child_rip+0xa/0x11 [<ffffffff802419fc>] ? kthread+0x0/0x6d [<ffffffff8020c38f>] ? child_rip+0x0/0x11 The attached patch adds some sanity checking to prevent these sorts of configuration errors. Signed-off-by: Andrew Gallatin <gallatin@myri.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/pktgen.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 526236453908..a756847e3814 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1961,6 +1961,8 @@ static int pktgen_setup_dev(struct pktgen_dev *pkt_dev, const char *ifname)
*/
static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
{
+ int ntxq;
+
if (!pkt_dev->odev) {
printk(KERN_ERR "pktgen: ERROR: pkt_dev->odev == NULL in "
"setup_inject.\n");
@@ -1969,6 +1971,33 @@ static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
return;
}
+ /* make sure that we don't pick a non-existing transmit queue */
+ ntxq = pkt_dev->odev->real_num_tx_queues;
+ if (ntxq <= num_online_cpus() && (pkt_dev->flags & F_QUEUE_MAP_CPU)) {
+ printk(KERN_WARNING "pktgen: WARNING: QUEUE_MAP_CPU "
+ "disabled because CPU count (%d) exceeds number ",
+ num_online_cpus());
+ printk(KERN_WARNING "pktgen: WARNING: of tx queues "
+ "(%d) on %s \n", ntxq, pkt_dev->odev->name);
+ pkt_dev->flags &= ~F_QUEUE_MAP_CPU;
+ }
+ if (ntxq <= pkt_dev->queue_map_min) {
+ printk(KERN_WARNING "pktgen: WARNING: Requested "
+ "queue_map_min (%d) exceeds number of tx\n",
+ pkt_dev->queue_map_min);
+ printk(KERN_WARNING "pktgen: WARNING: queues (%d) on "
+ "%s, resetting\n", ntxq, pkt_dev->odev->name);
+ pkt_dev->queue_map_min = ntxq - 1;
+ }
+ if (ntxq <= pkt_dev->queue_map_max) {
+ printk(KERN_WARNING "pktgen: WARNING: Requested "
+ "queue_map_max (%d) exceeds number of tx\n",
+ pkt_dev->queue_map_max);
+ printk(KERN_WARNING "pktgen: WARNING: queues (%d) on "
+ "%s, resetting\n", ntxq, pkt_dev->odev->name);
+ pkt_dev->queue_map_max = ntxq - 1;
+ }
+
/* Default to the interface's mac if not explicitly set. */
if (is_zero_ether_addr(pkt_dev->src_mac))

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