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Zhaoyang Huang 0f69dae4d1 trace : Have tracing buffer info use kvzalloc instead of kzalloc
High order memory stuff within trace could introduce OOM, use kvzalloc instead.

Please find the bellowing for the call stack we run across in an android system.
The scenario happens when traced_probes is woken up to get a large quantity of
trace even if free memory is even higher than watermark_low. 

traced_probes invoked oom-killer: gfp_mask=0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),  order=2, oom_score_adj=-1

traced_probes cpuset=system-background mems_allowed=0
CPU: 3 PID: 588 Comm: traced_probes Tainted: G        W  O    4.14.181 #1
Hardware name: Generic DT based system
(unwind_backtrace) from [<c010d824>] (show_stack+0x20/0x24)
(show_stack) from [<c0b2e174>] (dump_stack+0xa8/0xec)
(dump_stack) from [<c027d584>] (dump_header+0x9c/0x220)
(dump_header) from [<c027cfe4>] (oom_kill_process+0xc0/0x5c4)
(oom_kill_process) from [<c027cb94>] (out_of_memory+0x220/0x310)
(out_of_memory) from [<c02816bc>] (__alloc_pages_nodemask+0xff8/0x13a4)
(__alloc_pages_nodemask) from [<c02a6a1c>] (kmalloc_order+0x30/0x48)
(kmalloc_order) from [<c02a6a64>] (kmalloc_order_trace+0x30/0x118)
(kmalloc_order_trace) from [<c0223d7c>] (tracing_buffers_open+0x50/0xfc)
(tracing_buffers_open) from [<c02e6f58>] (do_dentry_open+0x278/0x34c)
(do_dentry_open) from [<c02e70d0>] (vfs_open+0x50/0x70)
(vfs_open) from [<c02f7c24>] (path_openat+0x5fc/0x169c)
(path_openat) from [<c02f75c4>] (do_filp_open+0x94/0xf8)
(do_filp_open) from [<c02e7650>] (do_sys_open+0x168/0x26c)
(do_sys_open) from [<c02e77bc>] (SyS_openat+0x34/0x38)
(SyS_openat) from [<c0108bc0>] (ret_fast_syscall+0x0/0x28)

Link: https://lkml.kernel.org/r/1596155265-32365-1-git-send-email-zhaoyang.huang@unisoc.com

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03 11:52:20 -04:00
arch x86/ftrace: Do not jump to direct code in created trampolines 2020-06-29 11:42:48 -04:00
block block-5.8-2020-06-26 2020-06-27 08:59:32 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: drbg - always try to free Jitter RNG instance 2020-06-15 17:38:54 +10:00
Documentation Peter Zijlstra says: 2020-06-28 09:42:47 -07:00
drivers ARM: OMAP fixes for v5.8 2020-06-28 14:57:14 -07:00
fs - Fix build regression on v4.8 and older 2020-06-28 11:42:16 -07:00
include ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU 2020-06-30 17:18:56 -04:00
init Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel trace : Have tracing buffer info use kvzalloc instead of kzalloc 2020-08-03 11:52:20 -04:00
lib Peter Zijlstra says: 2020-06-28 09:42:47 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/memory_hotplug.c: fix false softlockup during pfn range removal 2020-06-26 00:27:38 -07:00
net NFS Client Bugfixes for Linux 5.8-rc 2020-06-27 09:35:47 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-25 18:27:40 -07:00
scripts Paul E. McKenney says: 2020-06-28 10:29:38 -07:00
security selinux/stable-5.8 PR 20200621 2020-06-21 15:41:24 -07:00
sound sound fixes for 5.8-rc3 2020-06-25 09:15:24 -07:00
tools Peter Zijlstra says: 2020-06-28 10:16:15 -07:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt MIPS: 2020-06-12 11:05:52 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: generate vmlinux.symvers and reuse it for the second modpost 2020-06-06 23:38:12 +09:00
.mailmap A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: SoC fixes for v5.8 2020-06-28 14:55:18 -07:00
Makefile Linux 5.8-rc3 2020-06-28 15:00:24 -07:00
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.