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Michael Ellerman 684c68d92e Revert "powerpc/irq: Don't open code irq_soft_mask helpers" This reverts commit `ef5b570d37`. Zhouyi reported that commit is causing crashes when running rcutorture with KASAN enabled: BUG: using smp_processor_id() in preemptible [00000000] code: rcu_torture_rea/100 caller is rcu_preempt_deferred_qs_irqrestore+0x74/0xed0 CPU: 4 PID: 100 Comm: rcu_torture_rea Tainted: G W 5.19.0-rc5-next-20220708-dirty #253 Call Trace: dump_stack_lvl+0xbc/0x108 (unreliable) check_preemption_disabled+0x154/0x160 rcu_preempt_deferred_qs_irqrestore+0x74/0xed0 __rcu_read_unlock+0x290/0x3b0 rcu_torture_read_unlock+0x30/0xb0 rcutorture_one_extend+0x198/0x810 rcu_torture_one_read+0x58c/0xc90 rcu_torture_reader+0x12c/0x360 kthread+0x1e8/0x220 ret_from_kernel_thread+0x5c/0x64 KASAN will generate instrumentation instructions around the WRITE_ONCE(local_paca->irq_soft_mask, mask): 0xc000000000295cb0 <+0>: addis r2,r12,774 0xc000000000295cb4 <+4>: addi r2,r2,16464 0xc000000000295cb8 <+8>: mflr r0 0xc000000000295cbc <+12>: bl 0xc00000000008bb4c <mcount> 0xc000000000295cc0 <+16>: mflr r0 0xc000000000295cc4 <+20>: std r31,-8(r1) 0xc000000000295cc8 <+24>: addi r3,r13,2354 0xc000000000295ccc <+28>: mr r31,r13 0xc000000000295cd0 <+32>: std r0,16(r1) 0xc000000000295cd4 <+36>: stdu r1,-48(r1) 0xc000000000295cd8 <+40>: bl 0xc000000000609b98 <__asan_store1+8> 0xc000000000295cdc <+44>: nop 0xc000000000295ce0 <+48>: li r9,1 0xc000000000295ce4 <+52>: stb r9,2354(r31) 0xc000000000295ce8 <+56>: addi r1,r1,48 0xc000000000295cec <+60>: ld r0,16(r1) 0xc000000000295cf0 <+64>: ld r31,-8(r1) 0xc000000000295cf4 <+68>: mtlr r0 If there is a context switch before "stb r9,2354(r31)", r31 may not equal to r13, in such case, irq soft mask will not work. The usual solution of marking the code ineligible for instrumentation forces the code out-of-line, which we would prefer to avoid. Christophe proposed a partial revert, but Nick raised some concerns with that. So for now do a full revert. Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com> [mpe: Construct change log based on Zhouyi's original report] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220831131052.42250-1-mpe@ellerman.id.au		2022-09-02 18:54:53 +10:00
arch	Revert "powerpc/irq: Don't open code irq_soft_mask helpers"	2022-09-02 18:54:53 +10:00
block	block-6.0-2022-08-19	2022-08-20 10:17:05 -07:00
certs	Kbuild updates for v5.20	2022-08-10 10:40:41 -07:00
crypto	crypto: blake2b: effectively disable frame size warning	2022-08-10 17:59:11 -07:00
Documentation	asm goto: eradicate CC_HAS_ASM_GOTO	2022-08-21 10:06:28 -07:00
drivers	Misc irqchip fixes: LoongArch driver fixes and a Hyper-V IOMMU fix.	2022-08-21 15:09:55 -07:00
fs	5 cifs/smb3 fixes, one for stable	2022-08-21 10:21:16 -07:00
include	block-6.0-2022-08-19	2022-08-20 10:17:05 -07:00
init	asm goto: eradicate CC_HAS_ASM_GOTO	2022-08-21 10:06:28 -07:00
io_uring	io_uring/net: use right helpers for async_data	2022-08-18 07:27:20 -06:00
ipc	Updates to various subsystems which I help look after. lib, ocfs2,	2022-08-07 10:03:24 -07:00
kernel	Various fixes for tracing:	2022-08-21 14:49:42 -07:00
lib	lib/cpumask: drop always-true preprocessor guard	2022-08-15 11:00:44 -07:00
LICENSES	LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers	2021-12-16 14:33:10 +01:00
mm	- hugetlb_vmemmap cleanups from Muchun Song	2022-08-10 11:18:00 -07:00
net	tcp: handle pure FIN case correctly	2022-08-18 11:04:56 -07:00
samples	Tracing updates for 5.20 / 6.0	2022-08-05 09:41:12 -07:00
scripts	asm goto: eradicate CC_HAS_ASM_GOTO	2022-08-21 10:06:28 -07:00
security	hardening fixes for v6.0-rc2	2022-08-19 13:56:14 -07:00
sound	sound fixes for 6.0-rc2	2022-08-19 09:46:11 -07:00
tools	asm goto: eradicate CC_HAS_ASM_GOTO	2022-08-21 10:06:28 -07:00
usr	Not a lot of material this cycle. Many singleton patches against various	2022-05-27 11:22:03 -07:00
virt	KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device()	2022-08-19 04:05:43 -04:00
.clang-format	PCI/DOE: Add DOE mailbox support functions	2022-07-19 15:38:04 -07:00
.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	kbuild: split the second line of .mod into .usyms	2022-05-08 03:16:59 +09:00
.mailmap	Updates to various subsystems which I help look after. lib, ocfs2,	2022-08-07 10:03:24 -07:00
COPYING	COPYING: state that all contributions really are covered by this file	2020-02-10 13:32:20 -08:00
CREDITS	drm for 5.20/6.0	2022-08-03 19:52:08 -07:00
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	5 cifs/smb3 fixes, one for stable	2022-08-21 10:21:16 -07:00
Makefile	Linux 6.0-rc2	2022-08-21 17:32:54 -07:00
README	Drop all 00-INDEX files from Documentation/	2018-09-09 15:08:58 -06:00

README

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.