This adds a fast path for 64-bit syscall entry and exit when
TIF_SYSCALL_AUDIT is set, but no other kind of syscall tracing.
This path does not need to save and restore all registers as
the general case of tracing does. Avoiding the iret return path
when syscall audit is enabled helps performance a lot.
Signed-off-by: Roland McGrath <roland@redhat.com>
This short-circuit path in sysret_signal looks wrong to me.
AFAICT, in practice the branch is never taken--and if it were,
it would go wrong. To wit, try loading a module whose init
function does set_thread_flag(TIF_IRET), and see insmod crash
(presumably with a wrong user stack pointer).
This is because the FIXUP_TOP_OF_STACK work hasn't been done yet
when we jump around the call to ptregscall_common and get to
int_with_check--where it expects the user RSP,SS,CS and EFLAGS to
have been stored by FIXUP_TOP_OF_STACK.
I don't think it's normally possible to get to sysret_signal with no
_TIF_DO_NOTIFY_MASK bits set anyway, so these two instructions are
already superfluous. If it ever did happen, it is harmless to call
do_notify_resume with nothing for it to do.
Signed-off-by: Roland McGrath <roland@redhat.com>
This is based upon an excellent bug report from Eric Dumazet.
tcp_ack() should clear ->icsk_probes_out even if there are packets
outstanding. Otherwise if we get a sequence of ACKs while we do have
packets outstanding over and over again, we'll never clear the
probes_out value and eventually think the connection is too sick and
we'll reset it.
This appears to be some "optimization" added to tcp_ack() in the 2.4.x
timeframe. In 2.2.x, probes_out is pretty much always cleared by
tcp_ack().
Here is Eric's original report:
----------------------------------------
Apparently, we can in some situations reset TCP connections in a couple of seconds when some frames are lost.
In order to reproduce the problem, please try the following program on linux-2.6.25.*
Setup some iptables rules to allow two frames per second sent on loopback interface to tcp destination port 12000
iptables -N SLOWLO
iptables -A SLOWLO -m hashlimit --hashlimit 2 --hashlimit-burst 1 --hashlimit-mode dstip --hashlimit-name slow2 -j ACCEPT
iptables -A SLOWLO -j DROP
iptables -A OUTPUT -o lo -p tcp --dport 12000 -j SLOWLO
Then run the attached program and see the output :
# ./loop
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,1)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,3)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,5)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,7)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,9)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,200ms,11)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,201ms,13)
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 40 127.0.0.1:54455 127.0.0.1:12000 timer:(persist,188ms,15)
write(): Connection timed out
wrote 890 bytes but was interrupted after 9 seconds
ESTAB 0 0 127.0.0.1:12000 127.0.0.1:54455
Exiting read() because no data available (4000 ms timeout).
read 860 bytes
While this tcp session makes progress (sending frames with 50 bytes of payload, every 500ms), linux tcp stack decides to reset it, when tcp_retries 2 is reached (default value : 15)
tcpdump :
15:30:28.856695 IP 127.0.0.1.56554 > 127.0.0.1.12000: S 33788768:33788768(0) win 32792 <mss 16396,nop,nop,sackOK,nop,wscale 7>
15:30:28.856711 IP 127.0.0.1.12000 > 127.0.0.1.56554: S 33899253:33899253(0) ack 33788769 win 32792 <mss 16396,nop,nop,sackOK,nop,wscale 7>
15:30:29.356947 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 1:61(60) ack 1 win 257
15:30:29.356966 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 61 win 257
15:30:29.866415 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 61:111(50) ack 1 win 257
15:30:29.866427 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 111 win 257
15:30:30.366516 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 111:161(50) ack 1 win 257
15:30:30.366527 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 161 win 257
15:30:30.876196 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 161:211(50) ack 1 win 257
15:30:30.876207 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 211 win 257
15:30:31.376282 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 211:261(50) ack 1 win 257
15:30:31.376290 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 261 win 257
15:30:31.885619 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 261:311(50) ack 1 win 257
15:30:31.885631 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 311 win 257
15:30:32.385705 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 311:361(50) ack 1 win 257
15:30:32.385715 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 361 win 257
15:30:32.895249 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 361:411(50) ack 1 win 257
15:30:32.895266 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 411 win 257
15:30:33.395341 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 411:461(50) ack 1 win 257
15:30:33.395351 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 461 win 257
15:30:33.918085 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 461:511(50) ack 1 win 257
15:30:33.918096 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 511 win 257
15:30:34.418163 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 511:561(50) ack 1 win 257
15:30:34.418172 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 561 win 257
15:30:34.927685 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 561:611(50) ack 1 win 257
15:30:34.927698 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 611 win 257
15:30:35.427757 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 611:661(50) ack 1 win 257
15:30:35.427766 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 661 win 257
15:30:35.937359 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 661:711(50) ack 1 win 257
15:30:35.937376 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 711 win 257
15:30:36.437451 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 711:761(50) ack 1 win 257
15:30:36.437464 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 761 win 257
15:30:36.947022 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 761:811(50) ack 1 win 257
15:30:36.947039 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 811 win 257
15:30:37.447135 IP 127.0.0.1.56554 > 127.0.0.1.12000: P 811:861(50) ack 1 win 257
15:30:37.447203 IP 127.0.0.1.12000 > 127.0.0.1.56554: . ack 861 win 257
15:30:41.448171 IP 127.0.0.1.12000 > 127.0.0.1.56554: F 1:1(0) ack 861 win 257
15:30:41.448189 IP 127.0.0.1.56554 > 127.0.0.1.12000: R 33789629:33789629(0) win 0
Source of program :
/*
* small producer/consumer program.
* setup a listener on 127.0.0.1:12000
* Forks a child
* child connect to 127.0.0.1, and sends 10 bytes on this tcp socket every 100 ms
* Father accepts connection, and read all data
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <sys/poll.h>
int port = 12000;
char buffer[4096];
int main(int argc, char *argv[])
{
int lfd = socket(AF_INET, SOCK_STREAM, 0);
struct sockaddr_in socket_address;
time_t t0, t1;
int on = 1, sfd, res;
unsigned long total = 0;
socklen_t alen = sizeof(socket_address);
pid_t pid;
time(&t0);
socket_address.sin_family = AF_INET;
socket_address.sin_port = htons(port);
socket_address.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
if (lfd == -1) {
perror("socket()");
return 1;
}
setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int));
if (bind(lfd, (struct sockaddr *)&socket_address, sizeof(socket_address)) == -1) {
perror("bind");
close(lfd);
return 1;
}
if (listen(lfd, 1) == -1) {
perror("listen()");
close(lfd);
return 1;
}
pid = fork();
if (pid == 0) {
int i, cfd = socket(AF_INET, SOCK_STREAM, 0);
close(lfd);
if (connect(cfd, (struct sockaddr *)&socket_address, sizeof(socket_address)) == -1) {
perror("connect()");
return 1;
}
for (i = 0 ; ;) {
res = write(cfd, "blablabla\n", 10);
if (res > 0) total += res;
else if (res == -1) {
perror("write()");
break;
} else break;
usleep(100000);
if (++i == 10) {
system("ss -on dst 127.0.0.1:12000");
i = 0;
}
}
time(&t1);
fprintf(stderr, "wrote %lu bytes but was interrupted after %g seconds\n", total, difftime(t1, t0));
system("ss -on | grep 127.0.0.1:12000");
close(cfd);
return 0;
}
sfd = accept(lfd, (struct sockaddr *)&socket_address, &alen);
if (sfd == -1) {
perror("accept");
return 1;
}
close(lfd);
while (1) {
struct pollfd pfd[1];
pfd[0].fd = sfd;
pfd[0].events = POLLIN;
if (poll(pfd, 1, 4000) == 0) {
fprintf(stderr, "Exiting read() because no data available (4000 ms timeout).\n");
break;
}
res = read(sfd, buffer, sizeof(buffer));
if (res > 0) total += res;
else if (res == 0) break;
else perror("read()");
}
fprintf(stderr, "read %lu bytes\n", total);
close(sfd);
return 0;
}
----------------------------------------
Signed-off-by: David S. Miller <davem@davemloft.net>
The original intention was to write a zero byte to mmc to force spi
signals to low when doing power off. Somehow the spi_w8r8 call got there
so a read followed the write of single zero byte. This patch changes
that to simple write of zero byte without the following read.
This way the power off is more reliable and completely sufficient.
Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The bug was reported and analysed by Mark McLoughlin <markmc@redhat.com>,
the patch is based on his and Roland's suggestions.
posix_timer_event() always rewrites the pre-allocated siginfo before sending
the signal. Most of the written info is the same all the time, but memset(0)
is very wrong. If ->sigq is queued we can race with collect_signal() which
can fail to find this siginfo looking at .si_signo, or copy_siginfo() can
copy the wrong .si_code/si_tid/etc.
In short, sys_timer_settime() can in fact stop the active timer, or the user
can receive the siginfo with the wrong .si_xxx values.
Move "memset(->info, 0)" from posix_timer_event() to alloc_posix_timer(),
change send_sigqueue() to set .si_overrun = 0 when ->sigq is not queued.
It would be nice to move the whole sigq->info initialization from send to
create path, but this is not easy to do without uglifying timer_create()
further.
As Roland rightly pointed out, we need more cleanups/fixes here, see the
"FIXME" comment in the patch. Hopefully this patch makes sense anyway, and
it can mask the most bad implications.
Reported-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Oliver Pinter <oliver.pntr@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kernel/posix-timers.c | 17 +++++++++++++----
kernel/signal.c | 1 +
2 files changed, 14 insertions(+), 4 deletions(-)
Based upon a report by Daniel Smolik.
We do it too early, which triggers a BUG in
cpufreq_register_notifier().
Signed-off-by: David S. Miller <davem@davemloft.net>
Evgeniy Polyakov noticed that drivers/net/e1000e/netdev.c:e1000_netpoll()
was calling e1000_clean_tx_irq() without taking the TX lock.
David Miller suggested to remove the call altogether: since in this
callpah there's periodic calls to ->poll() anyway which will do
e1000_clean_tx_irq() and will garbage-collect any finished TX ring
descriptors.
This fix solved the e1000e+netconsole crashes i've been seeing:
=============================================================================
BUG skbuff_head_cache: Poison overwritten
-----------------------------------------------------------------------------
INFO: 0xf658ae9c-0xf658ae9c. First byte 0x6a instead of 0x6b
INFO: Allocated in __alloc_skb+0x2c/0x110 age=0 cpu=0 pid=5098
INFO: Freed in __kfree_skb+0x31/0x80 age=0 cpu=1 pid=4440
INFO: Slab 0xc16cc140 objects=16 used=1 fp=0xf658ae00 flags=0x400000c3
INFO: Object 0xf658ae00 @offset=3584 fp=0xf658af00
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
The version numbers of the subrivers will be removed as these ones
will be changed for any other purpose.
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The functions in a header should not belong to another module. The prio functions
belong to v4l2-common.c, so move them to v4l2-common.h.
The ioctl functions belong to v4l2-ioctl.c, so create a new v4l2-ioctl.h header
and move those functions to it.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Move the code that handles ATTR_SIZE changes to its own function. This
makes for a smaller function and reduces the level of indentation.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
In the merge phase of the CAN subsystem the
af_family_clock_key_strings[] have been added to sock.c in commit
443aef0edd
(lockdep: fixup sk_callback_lock annotation). This trivial patch adds
the missing name for address family 29 (AF_CAN).
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
It isn't helping anything and we aren't going to be able to change all
the drivers that do queue wakeups in strange situations.
Just letting a noop_qdisc get scheduled will work because when
qdisc_run() executes via net_tx_work() it will simply find no packets
pending when it makes the ->dequeue() call in qdisc_restart.
Signed-off-by: David S. Miller <davem@davemloft.net>
The original STRIPE_OP_IO removal patch had the following hunk:
- for (i = conf->raid_disks; i--; ) {
+ for (i = conf->raid_disks; i--; )
set_bit(R5_Wantwrite, &sh->dev[i].flags);
- if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
- sh->ops.count++;
- }
However it appears the hunk became broken after merging:
- for (i = conf->raid_disks; i--; ) {
+ for (i = conf->raid_disks; i--; )
set_bit(R5_Wantwrite, &sh->dev[i].flags);
set_bit(R5_LOCKED, &dev->flags);
s.locked++;
- if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
- sh->ops.count++;
- }
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
As reported by Hans Verkuil:
In file included from /home/v4l/master/v4l/dw2102.c:14:
/home/v4l/master/v4l/z0194a.h:93: error: 'STV0229_LOCKOUTPUT_1' undeclared here (not in a function)
This is due to some typos that were fixed on stv0299.
This patch renames it in accord with that fix.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The class_dev field is a normal device, not a class device. This is very
confusing and now that the old 'dev' field has been renamed to 'parent'
we can rename 'class_dev' to just 'dev'.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The field 'dev' is not the video device, but the parent of the video device.
Rename accordingly.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
videodev.c became top-heavy so all the ioctl processing has been split off
into v4l2-ioctl.c. This means videodev.c is back to its original purpose:
creating and registering v4l devices.
Since videodev.c and v4l2-ioctl.c should still remain one module (as least
for now) I also had to rename videodev.c to v4l2-dev.c to prevent a
circular dependency when building a videodev.ko module. This is not a bad
thing, since the source and header now have the same name. And the v4l2-
prefix is useful to see which sources are generic v4l2 support code.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Some dma drivers need to call spin_lock_bh in their device_issue_pending
routines. This change avoids:
WARNING: at kernel/softirq.c:136 local_bh_enable_ip+0x3a/0x85()
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
sdhci: highmem capable PIO routines
sg: reimplement sg mapping iterator
mmc_test: print message when attaching to card
mmc: Remove Russell as primecell mci maintainer
mmc_block: bounce buffer highmem support
sdhci: fix bad warning from commit c8b3e02
sdhci: add warnings for bad buffers in ADMA path
mmc_test: test oversized sg lists
mmc_test: highmem tests
s3cmci: ensure host stopped on machine shutdown
au1xmmc: suspend/resume implementation
s3cmci: fixes for section mismatch warnings
pxamci: trivial fix of DMA alignment register bit clearing
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (24 commits)
I/OAT: I/OAT version 3.0 support
I/OAT: tcp_dma_copybreak default value dependent on I/OAT version
I/OAT: Add watchdog/reset functionality to ioatdma
iop_adma: cleanup iop_chan_xor_slot_count
iop_adma: document how to calculate the minimum descriptor pool size
iop_adma: directly reclaim descriptors on allocation failure
async_tx: make async_tx_test_ack a boolean routine
async_tx: remove depend_tx from async_tx_sync_epilog
async_tx: export async_tx_quiesce
async_tx: fix handling of the "out of descriptor" condition in async_xor
async_tx: ensure the xor destination buffer remains dma-mapped
async_tx: list_for_each_entry_rcu() cleanup
dmaengine: Driver for the Synopsys DesignWare DMA controller
dmaengine: Add slave DMA interface
dmaengine: add DMA_COMPL_SKIP_{SRC,DEST}_UNMAP flags to control dma unmap
dmaengine: Add dma_client parameter to device_alloc_chan_resources
dmatest: Simple DMA memcpy test client
dmaengine: DMA engine driver for Marvell XOR engine
iop-adma: fix platform driver hotplug/coldplug
dmaengine: track the number of clients using a channel
...
Fixed up conflict in drivers/dca/dca-sysfs.c manually
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (60 commits)
ide: small whitespace fixes
ide: ide-cd_ioctl.c fix sparse integer as NULL pointer warnings
ide: ide-cd.c fix sparse endianness warnings
ide-cd: convert to using the new atapi_flags
ide: remove unused PC_FLAG_DRQ_INTERRUPT
ide-scsi: convert to using the new atapi_flags
ide-tape: convert to using the new atapi_flags
ide-floppy: convert to using the new atapi_flags (take 2)
ide: add per-device flags
ide: use rq->cmd instead of pc->c in atapi common code
ide-scsi: pass packet command in rq->cmd
ide-tape: pass packet command in rq->cmd
ide-tape: make room for packet command ids in rq->cmd
ide-floppy: pass packet command in rq->cmd
ide: remove pc->callback member from ide_atapi_pc
ide-scsi: use drive->pc_callback instead of pc->callback
ide-tape: use drive->pc_callback instead of pc->callback
ide-floppy: use drive->pc_callback instead of pc->callback
ide: push pc callback pointer into the ide_drive_t structure
drivers/ide/ide-tape.c: remove double kfree
...
Alter the if expression for calculating Rt. The old implementation would
run unnecessary code when the ADS7843 device was used.
The patch also fixes the code style to kernel standard.
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Also remove the temporary pointer and use ->rx_buf directly.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
