linux.git/net/core/netpoll.c, branch v6.2

net: move from strlcpy with unused retval to strscpy

2022-08-23T01:06:18+00:00

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang 
Link: https://lore.kernel.org/r/20220818210215.8395-1-wsa+renesas@sang-engineering.com
Signed-off-by: Jakub Kicinski

net: rename reference+tracking helpers

2022-06-10T04:52:55+00:00

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
 dev_hold_track()    -> netdev_hold()
 dev_put_track()     -> netdev_put()
 dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

netpoll: add net device refcount tracker to struct netpoll

2021-12-07T00:06:02+00:00

Signed-off-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

Merge tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2021-07-02T19:43:40+00:00

Pull asm/unaligned.h unification from Arnd Bergmann:
 "Unify asm/unaligned.h around struct helper

  The get_unaligned()/put_unaligned() helpers are traditionally
  architecture specific, with the two main variants being the
  "access-ok.h" version that assumes unaligned pointer accesses always
  work on a particular architecture, and the "le-struct.h" version that
  casts the data to a byte aligned type before dereferencing, for
  architectures that cannot always do unaligned accesses in hardware.

  Based on the discussion linked below, it appears that the access-ok
  version is not realiable on any architecture, but the struct version
  probably has no downsides. This series changes the code to use the
  same implementation on all architectures, addressing the few
  exceptions separately"

Link: https://lore.kernel.org/lkml/75d07691-1e4f-741f-9852-38c0b4f520bc@synopsys.com/
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363
Link: https://lore.kernel.org/lkml/20210507220813.365382-14-arnd@kernel.org/
Link: git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git unaligned-rework-v2
Link: https://lore.kernel.org/lkml/CAHk-=whGObOKruA_bU3aPGZfoDqZM1_9wBkwREp0H0FgR-90uQ@mail.gmail.com/

* tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: simplify asm/unaligned.h
  asm-generic: uaccess: 1-byte access is always aligned
  netpoll: avoid put_unaligned() on single character
  mwifiex: re-fix for unaligned accesses
  apparmor: use get_unaligned() only for multi-byte words
  partitions: msdos: fix one-byte get_unaligned()
  asm-generic: unaligned always use struct helpers
  asm-generic: unaligned: remove byteshift helpers
  powerpc: use linux/unaligned/le_struct.h on LE power7
  m68k: select CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  sh: remove unaligned access for sh4a
  openrisc: always use unaligned-struct header
  asm-generic: use asm-generic/unaligned.h for most architectures

netpoll: don't require irqs disabled in rt kernels

2021-06-01T22:15:11+00:00

write_msg(netconsole.c:836) calls netpoll_send_udp after a call to
spin_lock_irqsave, which normally disables interrupts; but in PREEMPT_RT
this call just locks an rt_mutex without disabling irqs. In this case,
netpoll_send_udp is called with interrupts enabled.

Signed-off-by: Wander Lairson Costa 
Signed-off-by: David S. Miller

netpoll: avoid put_unaligned() on single character

2021-05-17T11:30:29+00:00

With a planned cleanup, using put_unaligned() on a single character
results in a harmless warning:

In file included from ./arch/x86/include/generated/asm/unaligned.h:1,
                 from include/linux/etherdevice.h:24,
                 from net/core/netpoll.c:18:
net/core/netpoll.c: In function 'netpoll_send_udp':
include/asm-generic/unaligned.h:23:9: error: 'packed' attribute ignored for field of type 'unsigned char' [-Werror=attributes]
net/core/netpoll.c:431:3: note: in expansion of macro 'put_unaligned'
  431 |   put_unaligned(0x60, (unsigned char *)ip6h);
      |   ^~~~~~~~~~~~~
include/asm-generic/unaligned.h:23:9: error: 'packed' attribute ignored for field of type 'unsigned char' [-Werror=attributes]
net/core/netpoll.c:459:3: note: in expansion of macro 'put_unaligned'
  459 |   put_unaligned(0x45, (unsigned char *)iph);
      |   ^~~~~~~~~~~~~

Replace this with an open-coded pointer dereference.

Signed-off-by: Arnd Bergmann

Revert "net: Have netpoll bring-up DSA management interface"

2021-02-06T22:42:57+00:00

This reverts commit 1532b9778478577152201adbafa7738b1e844868.

The above commit is good and it works, however it was meant as a bugfix
for stable kernels and now we have more self-contained ways in DSA to
handle the situation where the DSA master must be brought up.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Andrew Lunn 
Reviewed-by: Florian Fainelli 
Signed-off-by: Jakub Kicinski

net: Have netpoll bring-up DSA management interface

2020-11-18T19:04:11+00:00

DSA network devices rely on having their DSA management interface up and
running otherwise their ndo_open() will return -ENETDOWN. Without doing
this it would not be possible to use DSA devices as netconsole when
configured on the command line. These devices also do not utilize the
upper/lower linking so the check about the netpoll device having upper
is not going to be a problem.

The solution adopted here is identical to the one done for
net/ipv4/ipconfig.c with 728c02089a0e ("net: ipv4: handle DSA enabled
master network devices"), with the network namespace scope being
restricted to that of the process configuring netpoll.

Fixes: 04ff53f96a93 ("net: dsa: Add netconsole support")
Tested-by: Vladimir Oltean 
Signed-off-by: Florian Fainelli 
Link: https://lore.kernel.org/r/20201117035236.22658-1-f.fainelli@gmail.com
Signed-off-by: Jakub Kicinski

net: make sure napi_list is safe for RCU traversal

2020-09-10T20:08:46+00:00

netpoll needs to traverse dev->napi_list under RCU, make
sure it uses the right iterator and that removal from this
list is handled safely.

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net: disable netpoll on fresh napis

2020-08-26T23:16:39+00:00

napi_disable() makes sure to set the NAPI_STATE_NPSVC bit to prevent
netpoll from accessing rings before init is complete. However, the
same is not done for fresh napi instances in netif_napi_add(),
even though we expect NAPI instances to be added as disabled.

This causes crashes during driver reconfiguration (enabling XDP,
changing the channel count) - if there is any printk() after
netif_napi_add() but before napi_enable().

To ensure memory ordering is correct we need to use RCU accessors.

Reported-by: Rob Sherwood 
Fixes: 2d8bff12699a ("netpoll: Close race condition between poll_one_napi and napi_disable")
Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller