In m_can_read_fifo(), if the second call to m_can_fifo_read() fails,
the function jump to the out_fail label and returns without calling
m_can_receive_skb(). This means that the skb previously allocated by
alloc_can_skb() is not freed. In other terms, this is a memory leak.
This patch adds a goto label to destroy the skb if an error occurs.
Issue was found with GCC -fanalyzer, please follow the link below for
details.
Fixes: e39381770e ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20211107050755.70655-1-mailhol.vincent@wanadoo.fr
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
With the design of this driver, this condition is often triggered.
However, the counter that this interrupt indicates an overflow is never
read either, so overflowing is harmless.
On my system, when a CAN bus starts flapping up and down, this locks up
the whole system with lots of interrupts and printks.
Specifically, this interrupt indicates the CEL field of ECR has
overflowed. All reads of ECR mask out CEL.
Fixes: e0d1f4816f ("can: m_can: add Bosch M_CAN controller support")
Link: https://lore.kernel.org/all/20211129222628.7490-1-brian.silverman@bluerivertech.com
Cc: stable@vger.kernel.org
Signed-off-by: Brian Silverman <brian.silverman@bluerivertech.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Alexander Lobakin says:
====================
Samples, at least XDP ones, can be built only with the compiler used
to build the kernel itself.
However, XDP sample infra introduced in Aug'21 was probably tested
with GCC/Binutils only as it's not really compilable for now with
Clang/LLVM.
These two are trivial fixes addressing this.
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Clang doesn't have 'stringop-truncation' group like GCC does, and
complains about it when building samples which use xdp_sample_user
infra:
samples/bpf/xdp_sample_user.h:48:32: warning: unknown warning group '-Wstringop-truncation', ignored [-Wunknown-warning-option]
#pragma GCC diagnostic ignored "-Wstringop-truncation"
^
[ repeat ]
Those are harmless, but avoidable when guarding it with ifdef.
I could guard push/pop as well, but this would require one more
ifdef cruft around a single line which I don't think is reasonable.
Fixes: 156f886cf6 ("samples: bpf: Add basic infrastructure for XDP samples")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211203195004.5803-3-alexandr.lobakin@intel.com
Clang (13) doesn't get the jokes about specifying libraries to link in
cclags of individual .o objects:
clang-13: warning: -lm: 'linker' input unused [-Wunused-command-line-argument]
[ ... ]
LD samples/bpf/xdp_redirect_cpu
LD samples/bpf/xdp_redirect_map_multi
LD samples/bpf/xdp_redirect_map
LD samples/bpf/xdp_redirect
LD samples/bpf/xdp_monitor
/usr/bin/ld: samples/bpf/xdp_sample_user.o: in function `sample_summary_print':
xdp_sample_user.c:(.text+0x84c): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x870): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8cf): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8f3): undefined reference to `ceil'
[ more ]
Specify '-lm' as ldflags for all xdp_sample_user.o users in the main
Makefile and remove it from ccflags of ^ in Makefile.target -- just
like it's done for all other samples. This works with all compilers.
Fixes: 6e1051a54e ("samples: bpf: Convert xdp_monitor to XDP samples helper")
Fixes: b926c55d85 ("samples: bpf: Convert xdp_redirect to XDP samples helper")
Fixes: e531a220cc ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Fixes: bbe65865aa ("samples: bpf: Convert xdp_redirect_map to XDP samples helper")
Fixes: 594a116b2a ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com
Currently, buffers are cleared when smc connections are created and
buffers are reused. This slows down the speed of establishing new
connections. In most cases, the applications want to establish
connections as quickly as possible.
This patch moves memset() from connection creation path to release and
buffer unuse path, this trades off between speed of establishing and
release.
Test environments:
- CPU Intel Xeon Platinum 8 core, mem 32 GiB, nic Mellanox CX4
- socket sndbuf / rcvbuf: 16384 / 131072 bytes
- w/o first round, 5 rounds, avg, 100 conns batch per round
- smc_buf_create() use bpftrace kprobe, introduces extra latency
Latency benchmarks for smc_buf_create():
w/o patch : 19040.0 ns
w/ patch : 1932.6 ns
ratio : 10.2% (-89.8%)
Latency benchmarks for socket create and connect:
w/o patch : 143.3 us
w/ patch : 102.2 us
ratio : 71.3% (-28.7%)
The latency of establishing connections is reduced by 28.7%.
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20211203113331.2818873-1-kgraul@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Arnaldo reported that building all his containers with BUILD_BPF_SKEL=1
to then make this the default he found problems in some distros where
the system linux/bpf.h file was being used and lacked this:
util/bpf_skel/bperf_leader.bpf.c:13:20: error: use of undeclared identifier 'BPF_F_PRESERVE_ELEMS'
__uint(map_flags, BPF_F_PRESERVE_ELEMS);
So use instead the vmlinux.h file generated by bpftool from BTF info.
This fixed these as well, getting the build back working on debian:11,
debian:experimental and ubuntu:21.10:
In file included from In file included from util/bpf_skel/bperf_leader.bpf.cutil/bpf_skel/bpf_prog_profiler.bpf.c::33:
:
In file included from In file included from /usr/include/linux/bpf.h/usr/include/linux/bpf.h::1111:
:
/usr/include/linux/types.h/usr/include/linux/types.h::55::1010:: In file included from util/bpf_skel/bperf_follower.bpf.c:3fatal errorfatal error:
: : In file included from /usr/include/linux/bpf.h:'asm/types.h' file not found11'asm/types.h' file not found:
/usr/include/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
#include <asm/types.h>#include <asm/types.h>
^~~~~~~~~~~~~ ^~~~~~~~~~~~~
#include <asm/types.h>
^~~~~~~~~~~~~
1 error generated.
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/CF175681-8101-43D1-ABDB-449E644BE986@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Some platforms do not have CPU die support, for example s390.
Commit
Cc: Ian Rogers <irogers@google.com>
Fixes: fdf1e29b61 ("perf expr: Add metric literals for topology.")
fails on s390:
# perf test -Fv 7
...
# FAILED tests/expr.c:173 #num_dies >= #num_packages
---- end ----
Simple expression parser: FAILED!
#
Investigating this issue leads to these functions:
build_cpu_topology()
+--> has_die_topology(void)
{
struct utsname uts;
if (uname(&uts) < 0)
return false;
if (strncmp(uts.machine, "x86_64", 6))
return false;
....
}
which always returns false on s390. The caller build_cpu_topology()
checks has_die_topology() return value. On false the the struct
cpu_topology::die_cpu_list is not contructed and has zero entries. This
leads to the failing comparison: #num_dies >= #num_packages. s390 of
course has a positive number of packages.
Fix this and check if the function build_cpu_topology() did build up
a die_cpus_list. The number of entries in this list should be larger
than 0. If the number of list element is zero, the die_cpus_list has
not been created and the check in function test__expr():
TEST_ASSERT_VAL("#num_dies >= #num_packages", \
num_dies >= num_packages)
always fails.
Output after:
# perf test -Fv 7
7: Simple expression parser :
--- start ---
division by zero
syntax error
---- end ----
Simple expression parser: Ok
#
Fixes: fdf1e29b61 ("perf expr: Add metric literals for topology.")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20211129112339.3003036-1-tmricht@linux.ibm.com
[ Added comment in the added 'if (num_dies)' line about architectures not having die topology ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since 66dfdff03d ("perf tools: Add Python 3 support") we don't use
the tools/build/feature/test-libpython-version.c version in any Makefile
feature check:
$ find tools/ -type f | xargs grep feature-libpython-version
$
The only place where this was used was removed in 66dfdff03d:
- ifneq ($(feature-libpython-version), 1)
- $(warning Python 3 is not yet supported; please set)
- $(warning PYTHON and/or PYTHON_CONFIG appropriately.)
- $(warning If you also have Python 2 installed, then)
- $(warning try something like:)
- $(warning $(and ,))
- $(warning $(and ,) make PYTHON=python2)
- $(warning $(and ,))
- $(warning Otherwise, disable Python support entirely:)
- $(warning $(and ,))
- $(warning $(and ,) make NO_LIBPYTHON=1)
- $(warning $(and ,))
- $(error $(and ,))
- else
- LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
- EXTLIBS += $(PYTHON_EMBED_LIBADD)
- LANG_BINDINGS += $(obj-perf)python/perf.so
- $(call detected,CONFIG_LIBPYTHON)
- endif
And nowadays we either build with PYTHON=python3 or just install the
python3 devel packages and perf will build against it.
But the leftover feature-libpython-version check made the fast path
feature detection to break in all cases except when python2 devel files
were installed:
$ rpm -qa | grep python.*devel
python3-devel-3.9.7-1.fc34.x86_64
$ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
$ make -C tools/perf O=/tmp/build/perf install-bin
make: Entering directory '/var/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j32' parallel build
HOSTCC /tmp/build/perf/fixdep.o
<SNIP>
$ cat /tmp/build/perf/feature/test-all.make.output
In file included from test-all.c:18:
test-libpython-version.c:5:10: error: #error
5 | #error
| ^~~~~
$ ldd ~/bin/perf | grep python
libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007fda6dbcf000)
$
As python3 is the norm these days, fix this by just removing the unused
feature-libpython-version feature check, making the test-all fast path
to work with the common case.
With this:
$ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
$ make -C tools/perf O=/tmp/build/perf install-bin |& head
make: Entering directory '/var/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j32' parallel build
HOSTCC /tmp/build/perf/fixdep.o
HOSTLD /tmp/build/perf/fixdep-in.o
LINK /tmp/build/perf/fixdep
Auto-detecting system features:
... dwarf: [ on ]
... dwarf_getlocations: [ on ]
... glibc: [ on ]
$ ldd ~/bin/perf | grep python
libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f58800b0000)
$ cat /tmp/build/perf/feature/test-all.make.output
$
Reviewed-by: James Clark <james.clark@arm.com>
Fixes: 66dfdff03d ("perf tools: Add Python 3 support")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jaroslav Škarvada <jskarvad@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YaYmeeC6CS2b8OSz@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The space allowed for new attributes can be too small if existing header
information is large. That can happen, for example, if there are very
many CPUs, due to having an event ID per CPU per event being stored in the
header information.
Fix by adding the existing header.data_offset. Also increase the extra
space allowed to 8KiB and align to a 4KiB boundary for neatness.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20211125071457.2066863-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This: This reverts commit 92723ea0f1.
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRRRR FAILED!
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRRRR FAILED!
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRRR FAILED!
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRRRRRRRRR Ok
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRR FAILED!
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRR Ok
# perf test 91
91: perf stat --bpf-counters test :RRRRRRRRRRRRRRR Ok
yep, it seems the perf bench is broken so the counts won't correlated if
I revert this one:
92723ea0f1 perf bench: Fix two memory leaks detected with ASan
it works for me again.. it seems to break -t option
[root@dell-r440-01 perf]# ./perf bench sched messaging -g 1 -l 100 -t
# Running 'sched/messaging' benchmark:
RRRperf: CLIENT: ready write: Bad file descriptor
Rperf: SENDER: write: Bad file descriptor
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sohaib Mohamed <sohaib.amhmd@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/lkml/YZev7KClb%2Fud43Lc@krava/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is a short period between a net device starts to be unregistered
and when it is actually gone. In that time frame ethtool operations
could still be performed, which might end up in unwanted or undefined
behaviours[1].
Do not allow ethtool operations after a net device starts its
unregistration. This patch targets the netlink part as the ioctl one
isn't affected: the reference to the net device is taken and the
operation is executed within an rtnl lock section and the net device
won't be found after unregister.
[1] For example adding Tx queues after unregister ends up in NULL
pointer exceptions and UaFs, such as:
BUG: KASAN: use-after-free in kobject_get+0x14/0x90
Read of size 1 at addr ffff88801961248c by task ethtool/755
CPU: 0 PID: 755 Comm: ethtool Not tainted 5.15.0-rc6+ #778
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/014
Call Trace:
dump_stack_lvl+0x57/0x72
print_address_description.constprop.0+0x1f/0x140
kasan_report.cold+0x7f/0x11b
kobject_get+0x14/0x90
kobject_add_internal+0x3d1/0x450
kobject_init_and_add+0xba/0xf0
netdev_queue_update_kobjects+0xcf/0x200
netif_set_real_num_tx_queues+0xb4/0x310
veth_set_channels+0x1c3/0x550
ethnl_set_channels+0x524/0x610
Fixes: 041b1c5d4a ("ethtool: helper functions for netlink interface")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20211203101318.435618-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Andreas reported that a specific build environment for an external
module, being a bit broken, does pass CC_IMPLICIT_FALLTHROUGH quoted as
argument to gcc, causing an error
gcc-11: error: "-Wimplicit-fallthrough=5": linker input file not found: No such file or directory
Until this is more generally fixed as outlined in [1], by fixing
scripts/link-vmlinux.sh, scripts/gen_autoksyms.sh, etc to not directly
include the include/config/auto.conf, and in a second step, change
Kconfig to generate the auto.conf without "", workaround the issue by
explicitly unquoting CC_IMPLICIT_FALLTHROUGH.
Reported-by: Andreas Beckmann <anbe@debian.org>
Link: https://bugs.debian.org/1001083
Link: https://lore.kernel.org/linux-kbuild/CAK7LNAR-VXwHFEJqCcrFDZj+_4+Xd6oynbj_0eS8N504_ydmyw@mail.gmail.com/ [1]
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The iosm driver started using relayfs, but is missing the Kconfig
logic to ensure it's built into the kernel:
x86_64-linux-ld: drivers/net/wwan/iosm/iosm_ipc_trace.o: in function `ipc_trace_create_buf_file_handler':
iosm_ipc_trace.c:(.text+0x16): undefined reference to `relay_file_operations'
x86_64-linux-ld: drivers/net/wwan/iosm/iosm_ipc_trace.o: in function `ipc_trace_subbuf_start_handler':
iosm_ipc_trace.c:(.text+0x31): undefined reference to `relay_buf_full'
x86_64-linux-ld: drivers/net/wwan/iosm/iosm_ipc_trace.o: in function `ipc_trace_ctrl_file_write':
iosm_ipc_trace.c:(.text+0xd5): undefined reference to `relay_flush'
x86_64-linux-ld: drivers/net/wwan/iosm/iosm_ipc_trace.o: in function `ipc_trace_port_rx':
Fixes: 00ef32565b ("net: wwan: iosm: device trace collection using relayfs")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Link: https://lore.kernel.org/r/20211204174033.950528-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir reported csum issues after my recent change in skb_postpull_rcsum()
Issue here is the following:
initial skb->csum is the csum of
[part to be pulled][rest of packet]
Old code:
skb->csum = csum_sub(skb->csum, csum_partial(pull, pull_length, 0));
New code:
skb->csum = ~csum_partial(pull, pull_length, ~skb->csum);
This is broken if the csum of [pulled part]
happens to be equal to skb->csum, because end
result of skb->csum is 0 in new code, instead
of being 0xffffffff
David Laight suggested to use
skb->csum = -csum_partial(pull, pull_length, -skb->csum);
I based my patches on existing code present in include/net/seg6.h,
update_csum_diff4() and update_csum_diff16() which might need
a similar fix.
I guess that my tests, mostly pulling 40 bytes of IPv6 header
were not providing enough entropy to hit this bug.
v2: added wsum_negate() to make sparse happy.
Fixes: 29c3002644 ("net: optimize skb_postpull_rcsum()")
Fixes: 0bd28476f6 ("gro: optimize skb_gro_postpull_rcsum()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: David Lebrun <dlebrun@google.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20211204045356.3659278-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Eric Dumazet says:
====================
net: add preliminary netdev refcount tracking
Two first patches add a generic infrastructure, that will be used
to get tracking of refcount increments/decrements.
The general idea is to be able to precisely pair each decrement with
a corresponding prior increment. Both share a cookie, basically
a pointer to private data storing stack traces.
The third patch adds dev_hold_track() and dev_put_track() helpers
(CONFIG_NET_DEV_REFCNT_TRACKER)
Then a series of 20 patches converts some dev_hold()/dev_put()
pairs to new hepers : dev_hold_track() and dev_put_track().
Hopefully this will be used by developpers and syzbot to
root cause bugs that cause netdevice dismantles freezes.
With CONFIG_PCPU_DEV_REFCNT=n option, we were able to detect
some class of bugs, but too late (when too many dev_put()
were happening).
Another series will be sent after this one is merged.
v3: moved NET_DEV_REFCNT_TRACKER to net/Kconfig.debug
added "depends on DEBUG_KERNEL && STACKTRACE_SUPPORT"
to hopefully get rid of kbuild reports for ARCH=nios2
Reworded patch 3 changelog.
Added missing htmldocs (Jakub)
v2: added four additional patches,
added netdev_tracker_alloc() and netdev_tracker_free()
addressed build error (kernel bots),
use GFP_ATOMIC in test_ref_tracker_timer_func()
====================
Link: https://lore.kernel.org/r/20211205042217.982127-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a netdevice_tracker inside struct net_device, to track
the self reference when a device is in lweventlist.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Note that other ip_tunnel users do not seem to hold a reference
on tunnel->dev. Probably needs some investigations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We want to track all dev_hold()/dev_put() to ease leak hunting.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We want to track all dev_hold()/dev_put() to ease leak hunting.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This helper might hold a netdev reference for a long time,
lets add reference tracking.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This will help debugging pesky netdev reference leaks.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net device are refcounted. Over the years we had numerous bugs
caused by imbalanced dev_hold() and dev_put() calls.
The general idea is to be able to precisely pair each decrement with
a corresponding prior increment. Both share a cookie, basically
a pointer to private data storing stack traces.
This patch adds dev_hold_track() and dev_put_track().
To use these helpers, each data structure owning a refcount
should also use a "netdevice_tracker" to pair the hold and put.
netdevice_tracker dev_tracker;
...
dev_hold_track(dev, &dev_tracker, GFP_ATOMIC);
...
dev_put_track(dev, &dev_tracker);
Whenever a leak happens, we will get precise stack traces
of the point dev_hold_track() happened, at device dismantle phase.
We will also get a stack trace if too many dev_put_track() for the same
netdevice_tracker are attempted.
This is guarded by CONFIG_NET_DEV_REFCNT_TRACKER option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vincent Mailhol