Kernel sources for Moto G9 (Play) (Guamp)
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Neal Cardwell 67fe3b94a8 tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR
[ Upstream commit af38d07ed391b21f7405fa1f936ca9686787d6d2 ]

Fix tcp_ecn_withdraw_cwr() to clear the correct bit:
TCP_ECN_QUEUE_CWR.

Rationale: basically, TCP_ECN_DEMAND_CWR is a bit that is purely about
the behavior of data receivers, and deciding whether to reflect
incoming IP ECN CE marks as outgoing TCP th->ece marks. The
TCP_ECN_QUEUE_CWR bit is purely about the behavior of data senders,
and deciding whether to send CWR. The tcp_ecn_withdraw_cwr() function
is only called from tcp_undo_cwnd_reduction() by data senders during
an undo, so it should zero the sender-side state,
TCP_ECN_QUEUE_CWR. It does not make sense to stop the reflection of
incoming CE bits on incoming data packets just because outgoing
packets were spuriously retransmitted.

The bug has been reproduced with packetdrill to manifest in a scenario
with RFC3168 ECN, with an incoming data packet with CE bit set and
carrying a TCP timestamp value that causes cwnd undo. Before this fix,
the IP CE bit was ignored and not reflected in the TCP ECE header bit,
and sender sent a TCP CWR ('W') bit on the next outgoing data packet,
even though the cwnd reduction had been undone.  After this fix, the
sender properly reflects the CE bit and does not set the W bit.

Note: the bug actually predates 2005 git history; this Fixes footer is
chosen to be the oldest SHA1 I have tested (from Sep 2007) for which
the patch applies cleanly (since before this commit the code was in a
.h file).

Fixes: bdf1ee5d3b ("[TCP]: Move code from tcp_ecn.h to tcp*.c and tcp.h & remove it")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:09:32 +02:00
arch powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts 2019-09-16 08:22:25 +02:00
block blk-mq: free hw queue's resource in hctx's release handler 2019-09-16 08:22:13 +02:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: chacha20poly1305 - fix atomic sleep when using async algorithm 2019-07-26 09:14:19 +02:00
Documentation drm/panel: Add support for Armadeus ST0700 Adapt 2019-09-16 08:22:21 +02:00
drivers net: phylink: Fix flow control resolution 2019-09-19 09:09:30 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs ext4: unsigned int compared against zero 2019-09-16 08:22:24 +02:00
include isdn/capi: check message length in capi_write() 2019-09-19 09:09:29 +02:00
init initramfs: free initrd memory if opening /initrd.image fails 2019-06-15 11:54:01 +02:00
ipc ipc/mqueue.c: only perform resource calculation if user valid 2019-08-06 19:06:52 +02:00
kernel resource: fix locking in find_next_iomem_res() 2019-09-16 08:22:20 +02:00
lib lib: logic_pio: Add logic_pio_unregister_range() 2019-09-06 10:22:19 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/migrate.c: initialize pud_entry in migrate_vma() 2019-09-16 08:22:22 +02:00
net tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR 2019-09-19 09:09:32 +02:00
samples samples, bpf: suppress compiler warning 2019-07-14 08:11:04 +02:00
scripts scripts/decode_stacktrace: match basepath using shell prefix operator, not regex 2019-09-16 08:21:44 +02:00
security apparmor: reset pos on failure to unpack for various functions 2019-09-16 08:22:16 +02:00
sound ALSA: hda - Fix intermittent CORB/RIRB stall on Intel chips 2019-09-16 08:22:21 +02:00
tools selftests: fib_rule_tests: use pre-defined DEV_ADDR 2019-09-16 08:21:42 +02:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt kvm: Check irqchip mode before assign irqfd 2019-09-16 08:22:15 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS platform/x86: Add Intel AtomISP2 dummy / power-management driver 2019-04-20 09:16:02 +02:00
Makefile Linux 4.19.73 2019-09-16 08:22:25 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.