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Esben Haabendal 770d9c6797 net: ll_temac: Fix RX buffer descriptor handling on GFP_ATOMIC pressure
Failures caused by GFP_ATOMIC memory pressure have been observed, and
due to the missing error handling, results in kernel crash such as

[1876998.350133] kernel BUG at mm/slub.c:3952!
[1876998.350141] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[1876998.350147] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.3.0-scnxt #1
[1876998.350150] Hardware name: N/A N/A/COMe-bIP2, BIOS CCR2R920 03/01/2017
[1876998.350160] RIP: 0010:kfree+0x1ca/0x220
[1876998.350164] Code: 85 db 74 49 48 8b 95 68 01 00 00 48 31 c2 48 89 10 e9 d7 fe ff ff 49 8b 04 24 a9 00 00 01 00 75 0b 49 8b 44 24 08 a8 01 75 02 <0f> 0b 49 8b 04 24 31 f6 a9 00 00 01 00 74 06 41 0f b6 74 24
 5b
[1876998.350172] RSP: 0018:ffffc900000f0df0 EFLAGS: 00010246
[1876998.350177] RAX: ffffea00027f0708 RBX: ffff888008d78000 RCX: 0000000000391372
[1876998.350181] RDX: 0000000000000000 RSI: ffffe8ffffd01400 RDI: ffff888008d78000
[1876998.350185] RBP: ffff8881185a5d00 R08: ffffc90000087dd8 R09: 000000000000280a
[1876998.350189] R10: 0000000000000002 R11: 0000000000000000 R12: ffffea0000235e00
[1876998.350193] R13: ffff8881185438a0 R14: 0000000000000000 R15: ffff888118543870
[1876998.350198] FS:  0000000000000000(0000) GS:ffff88811f300000(0000) knlGS:0000000000000000
[1876998.350203] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
s#1 Part1
[1876998.350206] CR2: 00007f8dac7b09f0 CR3: 000000011e20a006 CR4: 00000000001606e0
[1876998.350210] Call Trace:
[1876998.350215]  <IRQ>
[1876998.350224]  ? __netif_receive_skb_core+0x70a/0x920
[1876998.350229]  kfree_skb+0x32/0xb0
[1876998.350234]  __netif_receive_skb_core+0x70a/0x920
[1876998.350240]  __netif_receive_skb_one_core+0x36/0x80
[1876998.350245]  process_backlog+0x8b/0x150
[1876998.350250]  net_rx_action+0xf7/0x340
[1876998.350255]  __do_softirq+0x10f/0x353
[1876998.350262]  irq_exit+0xb2/0xc0
[1876998.350265]  do_IRQ+0x77/0xd0
[1876998.350271]  common_interrupt+0xf/0xf
[1876998.350274]  </IRQ>

In order to handle such failures more graceful, this change splits the
receive loop into one for consuming the received buffers, and one for
allocating new buffers.

When GFP_ATOMIC allocations fail, the receive will continue with the
buffers that is still there, and with the expectation that the allocations
will succeed in a later call to receive.

Fixes: 9274498953 ("net: add Xilinx ll_temac device driver")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 10:58:48 -08:00
arch Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2020-02-20 15:15:16 -08:00
Documentation docs: networking: phy: Rephrase paragraph for clarity 2020-02-23 20:42:47 -08:00
drivers net: ll_temac: Fix RX buffer descriptor handling on GFP_ATOMIC pressure 2020-02-24 10:58:48 -08:00
fs pipe: make sure to wake up everybody when the last reader/writer closes 2020-02-18 14:34:36 -08:00
include TTY/Serial driver fixes for 5.6-rc3 2020-02-21 12:48:29 -08:00
init Various fixes: 2020-02-11 16:39:18 -08:00
ipc Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()" 2020-02-21 11:22:15 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-21 11:59:51 -08:00
lib lib/stackdepot.c: fix global out-of-bounds in stack_slabs 2020-02-21 11:22:15 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/sparsemem: pfn_to_page is not valid yet on SPARSEMEM 2020-02-21 11:22:15 -08:00
net net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register() 2020-02-23 21:17:37 -08:00
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sound ASoC: Fixes for v5.6 2020-02-18 13:33:39 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-21 11:59:51 -08:00
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virt KVM: Disable preemption in kvm_get_running_vcpu() 2020-02-12 12:19:35 +01:00
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.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS open: introduce openat2(2) syscall 2020-01-18 09:19:18 -05:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Char/Misc fixes for 5.6-rc3 2020-02-21 12:57:05 -08:00
Makefile Linux 5.6-rc2 2020-02-16 13:16:59 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.