module: replace module_layout with module_memory

module_layout manages different types of memory (text, data, rodata, etc.)
in one allocation, which is problematic for some reasons:

1. It is hard to enable CONFIG_STRICT_MODULE_RWX.
2. It is hard to use huge pages in modules (and not break strict rwx).
3. Many archs uses module_layout for arch-specific data, but it is not
obvious how these data are used (are they RO, RX, or RW?)

Improve the scenario by replacing 2 (or 3) module_layout per module with
up to 7 module_memory per module:

MOD_TEXT,
MOD_DATA,
MOD_RODATA,
MOD_RO_AFTER_INIT,
MOD_INIT_TEXT,
MOD_INIT_DATA,
MOD_INIT_RODATA,

and allocating them separately. This adds slightly more entries to
mod_tree (from up to 3 entries per module, to up to 7 entries per
module). However, this at most adds a small constant overhead to
__module_address(), which is expected to be fast.

Various archs use module_layout for different data. These data are put
into different module_memory based on their location in module_layout.
IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT;
data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc.

module_memory simplifies quite some of the module code. For example,
ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a
different allocator for the data. kernel/module/strict_rwx.c is also
much cleaner with module_memory.

Signed-off-by: Song Liu <song@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

powerpc/modules: Use PPC_LI macros instead of opencoding

Use PPC_LI_MASK and PPC_LI() instead of opencoding.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3d56d7bc3200403773d54e62659d0e01292a055d.1652074503.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target()

module_trampoline_target() is quite a hot path used when
activating/deactivating function tracer.

Avoid the heavy copy_from_kernel_nofault() by doing four calls
to copy_inst_from_kernel_nofault().

Use __copy_inst_from_kernel_nofault() for the 3 last calls. First call
is done to copy_from_kernel_nofault() to check address is within
kernel space. No risk to wrap out the top of kernel space because the
last page is never mapped so if address is in last page the first copy
will fails and the other ones will never be performed.

And also make it notrace just like all functions that call it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c55559103e014b7863161559d340e8e9484eaaa6.1652074503.git.christophe.leroy@csgroup.eu

powerpc: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr

powerpc/module_32: Fix livepatching for RO modules

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 <christophe.leroy@csgroup.eu>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d5697157cb7dba3927e19aa17c915a83bc550bb2.1640017960.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32

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 <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Add module_trampoline_target() for PPC32

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 <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu

powerpc/modules: Use PPC_RAW_xx() macros

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 <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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

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 <st5pub@yandex.ru>
Reviewed-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/994931554238042@iva8-b333b7f98ab0.qloud-c.yandex.net

powerpc/module32: Use symbolic instructions names.

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

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/sparse: Fix plain integer as NULL pointer warning

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 <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

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 <bsingharora@gmail.com>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

module: use a structure to encapsulate layout.

Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

powerpc: Use pr_fmt in module loader code

Use pr_fmt to give some context to the error messages in the
module code, and convert open coded debug printk to pr_debug.

Use pr_err for error messages.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: Move local setup.h declarations to arch includes

Move the few declarations from arch/powerpc/kernel/setup.h
into arch/powerpc/include/asm/setup.h. This resolves a
sparse warning for arch/powerpc/mm/numa.c which defines
do_init_bootmem() but can't include the setup.h header
in the prior path.

Resolves:
arch/powerpc/mm/numa.c:998:13:
warning: symbol 'do_init_bootmem' was not declared.
Should it be static?

Signed-off-by: Robert C Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Fix kernel panic during kernel module load

This fixes a problem which can causes kernel oopses while loading
a kernel module.

According to the PowerPC EABI specification, GPR r11 is assigned
the dedicated function to point to the previous stack frame.
In the powerpc-specific kernel module loader, do_plt_call()
(in arch/powerpc/kernel/module_32.c), GPR r11 is also used
to generate trampoline code.

This combination crashes the kernel, in the case where the compiler
chooses to use a helper function for saving GPRs on entry, and the
module loader has placed the .init.text section far away from the
.text section, meaning that it has to generate a trampoline for
functions in the .init.text section to call the GPR save helper.
Because the trampoline trashes r11, references to the stack frame
using r11 can cause an oops.

The fix just uses GPR r12 instead of GPR r11 for generating the
trampoline code. According to the statements from Freescale, this is
safe from an EABI perspective.

I've tested the fix for kernel 2.6.33 on MPC8541.

Cc: stable@vger.kernel.org
Signed-off-by: Steffen Rumler <steffen.rumler.ext@nsn.com>
[paulus@samba.org: reworded the description]
Signed-off-by: Paul Mackerras <paulus@samba.org>

modules: make arch's use default loader hooks

This patch removes all the module loader hook implementations in the
architecture specific code where the functionality is the same as that
now provided by the recently added default hooks.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

powerpc/ppc32: ftrace, dynamic ftrace to handle modules

Impact: add ability to trace modules on 32 bit PowerPC

This patch performs the necessary trampoline calls to handle
modules with dynamic ftrace on 32 bit PowerPC.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

powerpc: Move common module code into its own file

Refactor common code between ppc32 and ppc64 module handling into a
shared filed.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Optimize counting distinct entries in the relocation sections

When a module has relocation sections with tens of thousands of
entries, counting the distinct/unique entries only (i.e. no
duplicates) at load time can take tens of seconds and up to minutes.
The sore point is the count_relocs() function which is called as part
of the architecture specific module loading processing path:

-> load_module() generic
-> module_frob_arch_sections() arch specific
-> get_plt_size() 32-bit
-> get_stubs_size() 64-bit
-> count_relocs()

Here count_relocs is being called to find out how many distinct
targets of R_PPC_REL24 relocations there are, since each distinct
target needs a PLT entry or a stub created for it.

The previous counting algorithm has O(n^2) complexity. Basically two
solutions were proposed on the e-mail list: a hash based approach and
a sort based approach.

The hash based approach is the fastest (O(n)) but the has it needs
additional memory and for certain corner cases it could take lots of
memory due to the degeneration of the hash. One such proposal was
submitted here:

http://ozlabs.org/pipermail/linuxppc-dev/2007-June/037641.html

The sort based approach is slower (O(n * log n + n)) but if the
sorting is done "in place" it doesn't need additional memory.
This has O(n + n * log n) complexity with no additional memory
requirements.

This commit implements the in-place sort option.

Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Add support for R_PPC_ADDR16_HI relocations

apply_relocate_add() does not support R_PPC_ADDR16_HI relocations, which
prevents some non gcc-built modules to be loaded.

Signed-off-by: Simon Vallet <svallet@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Generic BUG for powerpc

This makes powerpc use the generic BUG machinery. The biggest reports the
function name, since it is redundant with kallsyms, and not needed in general.

There is an overall reduction of code, since module_32/64 duplicated several
functions.

Unfortunately there's no way to tell gcc that BUG won't return, so the BUG
macro includes a goto loop. This will generate a real jmp instruction, which
is never used.

[akpm@osdl.org: build fix]
[paulus@samba.org: remove infinite loop in BUG_ON]
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Support feature fixups in modules

This patch adds support for feature fixups in modules. This involves
adding support for R_PPC64_REL64 relocs to the 64 bits module loader.
It also modifies modpost.c to ignore the powerpc fixup sections (or it
would warn when used in .init.text).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Move module.c over to arch/powerpc

... and rename it to module_32.c since it is the 32-bit version.
The 32-bit and 64-bit ABIs are sufficiently different that having
a merged version isn't really practical.

Signed-off-by: Paul Mackerras <paulus@samba.org>