Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices: OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
Find a file
Christophe Leroy bbffdd2fc7 powerpc/ftrace: Use patch_instruction() return directly
Instead of returning -EPERM when patch_instruction() fails,
just return what patch_instruction returns.

That simplifies ftrace_modify_code():

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 30 	bge     3c <ftrace_modify_code+0x3c>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 1e 28 40 	cmplw   r30,r5
	  24:	40 82 00 34 	bne     58 <ftrace_modify_code+0x58>
	  28:	83 c1 00 38 	lwz     r30,56(r1)
	  2c:	7f e3 fb 78 	mr      r3,r31
	  30:	83 e1 00 3c 	lwz     r31,60(r1)
	  34:	38 21 00 40 	addi    r1,r1,64
	  38:	48 00 00 00 	b       38 <ftrace_modify_code+0x38>
				38: R_PPC_REL24	patch_instruction

Before:

	   0:	94 21 ff c0 	stwu    r1,-64(r1)
	   4:	93 e1 00 3c 	stw     r31,60(r1)
	   8:	7c 7f 1b 79 	mr.     r31,r3
	   c:	40 80 00 4c 	bge     58 <ftrace_modify_code+0x58>
	  10:	93 c1 00 38 	stw     r30,56(r1)
	  14:	7c 9e 23 78 	mr      r30,r4
	  18:	7c a4 2b 78 	mr      r4,r5
	  1c:	80 bf 00 00 	lwz     r5,0(r31)
	  20:	7c 08 02 a6 	mflr    r0
	  24:	90 01 00 44 	stw     r0,68(r1)
	  28:	7c 1e 28 40 	cmplw   r30,r5
	  2c:	40 82 00 48 	bne     74 <ftrace_modify_code+0x74>
	  30:	7f e3 fb 78 	mr      r3,r31
	  34:	48 00 00 01 	bl      34 <ftrace_modify_code+0x34>
				34: R_PPC_REL24	patch_instruction
	  38:	80 01 00 44 	lwz     r0,68(r1)
	  3c:	20 63 00 00 	subfic  r3,r3,0
	  40:	83 c1 00 38 	lwz     r30,56(r1)
	  44:	7c 63 19 10 	subfe   r3,r3,r3
	  48:	7c 08 03 a6 	mtlr    r0
	  4c:	83 e1 00 3c 	lwz     r31,60(r1)
	  50:	38 21 00 40 	addi    r1,r1,64
	  54:	4e 80 00 20 	blr

It improves ftrace activation/deactivation duration by about 3%.

Modify patch_instruction() return on failure to -EPERM in order to
match with ftrace expectations. Other users of patch_instruction()
do not care about the exact error value returned.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/49a8597230713e2633e7d9d7b56140787c4a7e20.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19 23:11:28 +10:00
arch powerpc/ftrace: Use patch_instruction() return directly 2022-05-19 23:11:28 +10:00
block block: don't print I/O error warning for dead disks 2022-04-15 06:33:03 -06:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation Linux 5.18-rc4 2022-05-05 22:09:35 +10:00
drivers cxl/ocxl: Prepare cleanup of powerpc's asm/prom.h 2022-05-11 23:06:39 +10:00
fs mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
include mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel - Fix a corner case when calculating sched runqueue variables 2022-04-24 13:28:06 -07:00
lib XArray: Disallow sibling entries of nodes 2022-04-22 15:35:40 -04:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: Add len and flags parameters to arch_get_mmap_end() 2022-05-05 22:11:57 +10:00
net netlink: reset network and mac headers in netlink_dump() 2022-04-19 15:05:03 +02:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts hardening fixes for v5.18-rc3 2022-04-12 14:29:40 -10:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ALSA: hda/realtek: Add quirk for Clevo NP70PNP 2022-04-21 21:23:47 +02:00
tools Linux 5.18-rc4 2022-05-05 22:09:35 +10:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt KVM: SEV: add cache flush to solve SEV cache incoherency issues 2022-04-21 15:41:00 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.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 .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Vasily Averin's email address 2022-04-08 14:20:36 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
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 Merge branch 'akpm' (patches from Andrew) 2022-04-22 10:10:43 -07:00
Makefile Linux 5.18-rc4 2022-04-24 14:51:22 -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.