#
# Common functions used by pktgen scripts
#  - Depending on bash 3 (or higher) syntax
#
# Author: Jesper Dangaaard Brouer
# License: GPL

## -- General shell logging cmds --
function err() {
    local exitcode=$1
    shift
    echo "ERROR: $@" >&2
    exit $exitcode
}

function warn() {
    echo "WARN : $@" >&2
}

function info() {
    if [[ -n "$VERBOSE" ]]; then
	echo "INFO : $@" >&2
    fi
}

## -- Pktgen proc config commands -- ##
export PROC_DIR=/proc/net/pktgen
#
# Three different shell functions for configuring the different
# components of pktgen:
#   pg_ctrl(), pg_thread() and pg_set().
#
# These functions correspond to pktgens different components.
# * pg_ctrl()   control "pgctrl" (/proc/net/pktgen/pgctrl)
# * pg_thread() control the kernel threads and binding to devices
# * pg_set()    control setup of individual devices
function pg_ctrl() {
    local proc_file="pgctrl"
    proc_cmd ${proc_file} "$@"
}

function pg_thread() {
    local thread=$1
    local proc_file="kpktgend_${thread}"
    shift
    proc_cmd ${proc_file} "$@"
}

function pg_set() {
    local dev=$1
    local proc_file="$dev"
    shift
    proc_cmd ${proc_file} "$@"
}

# More generic replacement for pgset(), that does not depend on global
# variable for proc file.
function proc_cmd() {
    local result
    local proc_file=$1
    # after shift, the remaining args are contained in $@
    shift
    local proc_ctrl=${PROC_DIR}/$proc_file
    if [[ ! -e "$proc_ctrl" ]]; then
	err 3 "proc file:$proc_ctrl does not exists (dev added to thread?)"
    else
	if [[ ! -w "$proc_ctrl" ]]; then
	    err 4 "proc file:$proc_ctrl not writable, not root?!"
	fi
    fi

    if [[ "$DEBUG" == "yes" ]]; then
	echo "cmd: $@ > $proc_ctrl"
    fi
    # Quoting of "$@" is important for space expansion
    echo "$@" > "$proc_ctrl"
    local status=$?

    result=$(grep "Result: OK:" $proc_ctrl)
    # Due to pgctrl, cannot use exit code $? from grep
    if [[ "$result" == "" ]]; then
	grep "Result:" $proc_ctrl >&2
    fi
    if (( $status != 0 )); then
	err 5 "Write error($status) occurred cmd: \"$@ > $proc_ctrl\""
    fi
}

# Old obsolete "pgset" function, with slightly improved err handling
function pgset() {
    local result

    if [[ "$DEBUG" == "yes" ]]; then
	echo "cmd: $1 > $PGDEV"
    fi
    echo $1 > $PGDEV
    local status=$?

    result=`cat $PGDEV | fgrep "Result: OK:"`
    if [[ "$result" == "" ]]; then
         cat $PGDEV | fgrep Result:
    fi
    if (( $status != 0 )); then
	err 5 "Write error($status) occurred cmd: \"$1 > $PGDEV\""
    fi
}

## -- General shell tricks --

function root_check_run_with_sudo() {
    # Trick so, program can be run as normal user, will just use "sudo"
    #  call as root_check_run_as_sudo "$@"
    if [ "$EUID" -ne 0 ]; then
	if [ -x $0 ]; then # Directly executable use sudo
	    info "Not root, running with sudo"
            sudo "$0" "$@"
            exit $?
	fi
	err 4 "cannot perform sudo run of $0"
    fi
}
/usb?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/serial?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>serial</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/serial/f81534.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>f81534.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='39cb2c9a316e77f6dfba96c543e55b6672d5a37e'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/serial/f81534.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/serial/f81534.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/serial/f81534.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>drivers/usb/serial/f81534.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/serial/f81534.c?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/serial/f81534.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'drivers/usb/serial/f81534.c')</div><table summary='diffstat' class='diffstat'>