linux-stable.git/arch/powerpc/kernel/module_32.c, branch v5.18.2

powerpc/module_32: Fix livepatching for RO modules

2022-02-07T10:03:10+00:00

Livepatching a loaded module involves applying relocations through
apply_relocate_add(), which attempts to write to read-only memory when
CONFIG_STRICT_MODULE_RWX=y.

R_PPC_ADDR16_LO, R_PPC_ADDR16_HI, R_PPC_ADDR16_HA and R_PPC_REL24 are
the types generated by the kpatch-build userspace tool or klp-convert
kernel tree observed applying a relocation to a post-init module.

Use patch_instruction() to patch those relocations.

Commit 8734b41b3efe ("powerpc/module_64: Fix livepatching for
RO modules") did similar change in module_64.

Signed-off-by: Christophe Leroy 
Acked-by: Joe Lawrence 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/d5697157cb7dba3927e19aa17c915a83bc550bb2.1640017960.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32

2021-11-29T11:49:29+00:00

Unlike PPC64, PPC32 doesn't require any special compiler option
to get _mcount() call not clobbering registers.

Provide ftrace_regs_caller() and ftrace_regs_call() and activate
HAVE_DYNAMIC_FTRACE_WITH_REGS.

That's heavily copied from ftrace_64_mprofile.S

For the time being leave livepatching aside, it will come with
following patch.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Add module_trampoline_target() for PPC32

2021-11-29T11:49:29+00:00

module_trampoline_target() is used by __ftrace_modify_call().

Implement it for PPC32 so that CONFIG_DYNAMIC_FTRACE_WITH_REGS
can be activated on PPC32 as well.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu

powerpc/modules: Use PPC_RAW_xx() macros

2021-06-15T14:16:48+00:00

To improve readability, use PPC_RAW_xx() macros instead of
open coding. Those macros are self-explanatory so the comments
can go as well.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/99d9ee8849d3992beeadb310a665aae01c3abfb1.1621506159.git.christophe.leroy@csgroup.eu

powerpc: module_[32|64].c: replace swap function with built-in one

2020-05-11T13:15:14+00:00

Replace relaswap with built-in one, because relaswap
does a simple byte to byte swap.

Since Spectre mitigations have made indirect function calls more
expensive, and the default simple byte copies swap is implemented
without them, an "optimized" custom swap function is now
a waste of time as well as code.

Signed-off-by: Andrey Abramov 
Reviewed-by: George Spelvin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/994931554238042@iva8-b333b7f98ab0.qloud-c.yandex.net

Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-07-13T23:08:36+00:00

Pull powerpc updates from Michael Ellerman:
"Notable changes:

- Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
as well as some other functions only used by drivers that haven't
(yet?) made it upstream.

- A fix for a bug in our handling of hardware watchpoints (eg. perf
record -e mem: ...) which could lead to register corruption and
kernel crashes.

- Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
vmalloc when using the Radix MMU.

- A large but incremental rewrite of our exception handling code to
use gas macros rather than multiple levels of nested CPP macros.

And the usual small fixes, cleanups and improvements.

Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
Jitindar Singh, Thiago Jung Bauermann, YueHaibing"

* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
powerpc/eeh: Handle hugepages in ioremap space
ocxl: Update for AFU descriptor template version 1.1
powerpc/boot: pass CONFIG options in a simpler and more robust way
powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
powerpc/module64: Use symbolic instructions names.
powerpc/module32: Use symbolic instructions names.
powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
powerpc/module64: Fix comment in R_PPC64_ENTRY handling
powerpc/boot: Add lzo support for uImage
powerpc/boot: Add lzma support for uImage
powerpc/boot: don't force gzipped uImage
powerpc/8xx: Add microcode patch to move SMC parameter RAM.
powerpc/8xx: Use IO accessors in microcode programming.
powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
powerpc/8xx: refactor programming of microcode CPM params.
powerpc/8xx: refactor printing of microcode patch name.
powerpc/8xx: Refactor microcode write
powerpc/8xx: refactor writing of CPM microcode arrays
...

powerpc/module32: Use symbolic instructions names.

2019-07-05T14:29:50+00:00

To increase readability/maintainability, replace hard coded
instructions values by symbolic names.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/sparse: Fix plain integer as NULL pointer warning

2018-05-25T02:04:38+00:00

Trivial fix to remove the following sparse warnings:

  arch/powerpc/kernel/module_32.c:112:74: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/module_32.c:117:74: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1155:28: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1230:20: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1385:36: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1752:23: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2084:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2110:32: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2167:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2183:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:277:20: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:155:67: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:247:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:249:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:252:37: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:127:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:148:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:44:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:57:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:87:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:160:31: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:167:22: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:274:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:285:31: warning: Using plain integer as NULL pointer
  arch/powerpc/include/asm/hugetlb.h:204:16: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/ppc_mmu_32.c:170:21: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:1227:23: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:65:24: warning: Using plain integer as NULL pointer

Also use `--fix` command line option from `script/checkpatch --strict` to
remove the following:

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #72: FILE: arch/powerpc/kernel/btext.c:160:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "!vbase"
  #80: FILE: arch/powerpc/kernel/btext.c:167:
  +	if (vbase == NULL)

  CHECK: Comparison to NULL could be written "!base"
  #89: FILE: arch/powerpc/kernel/btext.c:274:
  +	if (base == NULL)

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #98: FILE: arch/powerpc/kernel/btext.c:285:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "strstr"
  #117: FILE: arch/powerpc/kernel/module_32.c:117:
  +		if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != NULL)

  CHECK: Comparison to NULL could be written "!Hash"
  #130: FILE: arch/powerpc/mm/ppc_mmu_32.c:170:
  +	if (Hash == NULL)

  CHECK: Comparison to NULL could be written "Hash"
  #143: FILE: arch/powerpc/mm/tlb_hash32.c:44:
  +	if (Hash != NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #152: FILE: arch/powerpc/mm/tlb_hash32.c:57:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #161: FILE: arch/powerpc/mm/tlb_hash32.c:87:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #170: FILE: arch/powerpc/mm/tlb_hash32.c:127:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #179: FILE: arch/powerpc/mm/tlb_hash32.c:148:
  +	if (Hash == NULL) {

  ERROR: space required after that ';' (ctx:VxV)
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "node"
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "!region"
  #201: FILE: arch/powerpc/platforms/powermac/pci.c:1227:
  +	if (region == NULL)

  CHECK: Comparison to NULL could be written "of_get_property"
  #214: FILE: arch/powerpc/platforms/powermac/setup.c:155:
  +		if (of_get_property(np, "cache-unified", NULL) != NULL && dc) {

  CHECK: Comparison to NULL could be written "!np"
  #223: FILE: arch/powerpc/platforms/powermac/setup.c:247:
  +		if (np == NULL)

  CHECK: Comparison to NULL could be written "np"
  #226: FILE: arch/powerpc/platforms/powermac/setup.c:249:
  +		if (np != NULL) {

  CHECK: Comparison to NULL could be written "l2cr"
  #230: FILE: arch/powerpc/platforms/powermac/setup.c:252:
  +			if (l2cr != NULL) {

  CHECK: Comparison to NULL could be written "via"
  #243: FILE: drivers/macintosh/via-pmu.c:277:
  +	if (via != NULL)

  CHECK: Comparison to NULL could be written "current_req"
  #252: FILE: drivers/macintosh/via-pmu.c:1155:
  +	if (current_req != NULL) {

  CHECK: Comparison to NULL could be written "!req"
  #261: FILE: drivers/macintosh/via-pmu.c:1230:
  +	if (req == NULL || pmu_state != idle

  CHECK: Comparison to NULL could be written "!req"
  #270: FILE: drivers/macintosh/via-pmu.c:1385:
  +			if (req == NULL) {

  CHECK: Comparison to NULL could be written "!pp"
  #288: FILE: drivers/macintosh/via-pmu.c:2084:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #297: FILE: drivers/macintosh/via-pmu.c:2110:
  +	if (count < 1 || pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #306: FILE: drivers/macintosh/via-pmu.c:2167:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "pp"
  #315: FILE: drivers/macintosh/via-pmu.c:2183:
  +	if (pp != NULL) {

Link: https://github.com/linuxppc/linux/issues/37
Signed-off-by: Mathieu Malaterre 
Signed-off-by: Michael Ellerman

powerpc/module: Only try to generate the ftrace_caller() stub once

2016-03-07T03:53:53+00:00

Currently we generate the module stub for ftrace_caller() at the bottom
of apply_relocate_add(). However apply_relocate_add() is potentially
called more than once per module, which means we will try to generate
the ftrace_caller() stub multiple times.

Although the current code deals with that correctly, ie. it only
generates a stub the first time, it would be clearer to only try to
generate the stub once.

Note also on first reading it may appear that we generate a different
stub for each section that requires relocation, but that is not the
case. The code in stub_for_addr() that searches for an existing stub
uses sechdrs[me->arch.stubs_section], ie. the single stub section for
this module.

A cleaner approach is to only generate the ftrace_caller() stub once,
from module_finalize(). Although the original code didn't check to see
if the stub was actually generated correctly, it seems prudent to add a
check, so do that. And an additional benefit is we can clean the ifdefs
up a little.

Finally we must propagate the const'ness of some of the pointers passed
to module_finalize(), but that is also an improvement.

Reviewed-by: Balbir Singh 
Reviewed-by: Torsten Duwe 
Signed-off-by: Michael Ellerman