Commit graph

26 commits

Author SHA1 Message Date
Christophe Leroy
af8b9f352f powerpc/ftrace: Minimise number of #ifdefs
A lot of #ifdefs can be replaced by IS_ENABLED()

Do so.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in changes suggested by Naveen and Christophe on list]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu
2022-05-22 15:58:26 +10:00
Linus Torvalds
7ae77150d9 powerpc updates for 5.8
- Support for userspace to send requests directly to the on-chip GZIP
    accelerator on Power9.
 
  - Rework of our lockless page table walking (__find_linux_pte()) to make it
    safe against parallel page table manipulations without relying on an IPI for
    serialisation.
 
  - A series of fixes & enhancements to make our machine check handling more
    robust.
 
  - Lots of plumbing to add support for "prefixed" (64-bit) instructions on
    Power10.
 
  - Support for using huge pages for the linear mapping on 8xx (32-bit).
 
  - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound driver.
 
  - Removal of some obsolete 40x platforms and associated cruft.
 
  - Initial support for booting on Power10.
 
  - Lots of other small features, cleanups & fixes.
 
 Thanks to:
   Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Andrey Abramov,
   Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent Abali, Cédric Le
   Goater, Chen Zhou, Christian Zigotzky, Christophe JAILLET, Christophe Leroy,
   Dmitry Torokhov, Emmanuel Nicolet, Erhard F., Gautham R. Shenoy, Geoff Levand,
   George Spelvin, Greg Kurz, Gustavo A. R. Silva, Gustavo Walbon, Haren Myneni,
   Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Kees Cook, Leonardo
   Bras, Madhavan Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael
   Neuling, Michal Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao,
   Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram
   Pai, Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
   Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler, Wolfram
   Sang, Xiongfeng Wang.
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Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Support for userspace to send requests directly to the on-chip GZIP
   accelerator on Power9.

 - Rework of our lockless page table walking (__find_linux_pte()) to
   make it safe against parallel page table manipulations without
   relying on an IPI for serialisation.

 - A series of fixes & enhancements to make our machine check handling
   more robust.

 - Lots of plumbing to add support for "prefixed" (64-bit) instructions
   on Power10.

 - Support for using huge pages for the linear mapping on 8xx (32-bit).

 - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound
   driver.

 - Removal of some obsolete 40x platforms and associated cruft.

 - Initial support for booting on Power10.

 - Lots of other small features, cleanups & fixes.

Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent
Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe
JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F.,
Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A.
R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan
Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal
Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai,
Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler,
Wolfram Sang, Xiongfeng Wang.

* tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits)
  powerpc/pseries: Make vio and ibmebus initcalls pseries specific
  cxl: Remove dead Kconfig options
  powerpc: Add POWER10 architected mode
  powerpc/dt_cpu_ftrs: Add MMA feature
  powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
  powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected
  powerpc: Add support for ISA v3.1
  powerpc: Add new HWCAP bits
  powerpc/64s: Don't set FSCR bits in INIT_THREAD
  powerpc/64s: Save FSCR to init_task.thread.fscr after feature init
  powerpc/64s: Don't let DT CPU features set FSCR_DSCR
  powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()
  powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG
  powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
  powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
  powerpc/module_64: Consolidate ftrace code
  powerpc/32: Disable KASAN with pages bigger than 16k
  powerpc/uaccess: Don't set KUEP by default on book3s/32
  powerpc/uaccess: Don't set KUAP by default on book3s/32
  powerpc/8xx: Reduce time spent in allow_user_access() and friends
  ...
2020-06-05 12:39:30 -07:00
Naveen N. Rao
03b51416e8 powerpc/module_64: Consolidate ftrace code
module_trampoline_target() is only used by ftrace. Move the prototype
within the appropriate #ifdef in the header. Also, move the function
body to the end of module_64.c so as to consolidate all ftrace code in
one place.

No functional changes.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2527351f65c53c5866068ae130dc34c5d4ee8ad9.1587488954.git.naveen.n.rao@linux.vnet.ibm.com
2020-06-02 20:59:15 +10:00
Masahiro Yamada
62d0fd591d arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h>
As the bug report [1] pointed out, <linux/vermagic.h> must be included
after <linux/module.h>.

I believe we should not impose any include order restriction. We often
sort include directives alphabetically, but it is just coding style
convention. Technically, we can include header files in any order by
making every header self-contained.

Currently, arch-specific MODULE_ARCH_VERMAGIC is defined in
<asm/module.h>, which is not included from <linux/vermagic.h>.

Hence, the straight-forward fix-up would be as follows:

|--- a/include/linux/vermagic.h
|+++ b/include/linux/vermagic.h
|@@ -1,5 +1,6 @@
| /* SPDX-License-Identifier: GPL-2.0 */
| #include <generated/utsrelease.h>
|+#include <linux/module.h>
|
| /* Simply sanity version stamp for modules. */
| #ifdef CONFIG_SMP

This works enough, but for further cleanups, I split MODULE_ARCH_VERMAGIC
definitions into <asm/vermagic.h>.

With this, <linux/module.h> and <linux/vermagic.h> will be orthogonal,
and the location of MODULE_ARCH_VERMAGIC definitions will be consistent.

For arc and ia64, MODULE_PROC_FAMILY is only used for defining
MODULE_ARCH_VERMAGIC. I squashed it.

For hexagon, nds32, and xtensa, I removed <asm/modules.h> entirely
because they contained nothing but MODULE_ARCH_VERMAGIC definition.
Kbuild will automatically generate <asm/modules.h> at build-time,
wrapping <asm-generic/module.h>.

[1] https://lore.kernel.org/lkml/20200411155623.GA22175@zn.tnic

Reported-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
2020-04-23 10:50:26 +09:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Nicholas Piggin
abba759796 powerpc/kbuild: move -mprofile-kernel check to Kconfig
This eliminates the workaround that requires disabling
-mprofile-kernel by default in Kconfig.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-11 09:16:29 +09:00
Josh Poimboeuf
8ce621e1d9 powerpc/modules: remove unused mod_arch_specific.toc field
The toc field in the mod_arch_specific struct isn't actually used
anywhere, so remove it.

Also the ftrace-specific fields are now common between 32-bit and
64-bit, so simplify the struct definition a bit by moving them out of
the __powerpc64__ #ifdef.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-28 18:46:34 +10:00
Naveen N. Rao
ae30cc05be powerpc64/ftrace: Implement support for ftrace_regs_caller()
With -mprofile-kernel, we always save the full register state in
ftrace_caller(). While this works, this is inefficient if we're not
interested in the register state, such as when we're using the function
tracer.

Rename the existing ftrace_caller() as ftrace_regs_caller() and provide
a simpler implementation for ftrace_caller() that is used when registers
are not required to be saved.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:29 +10:00
Michael Ellerman
73aca179d7 powerpc/modules: Fix crashes by adding CONFIG_RELOCATABLE to vermagic
If you build the kernel with CONFIG_RELOCATABLE=n, then install the
modules, rebuild the kernel with CONFIG_RELOCATABLE=y and leave the
old modules installed, we crash something like:

  Unable to handle kernel paging request for data at address 0xd000000018d66cef
  Faulting instruction address: 0xc0000000021ddd08
  Oops: Kernel access of bad area, sig: 11 [#1]
  Modules linked in: x_tables autofs4
  CPU: 2 PID: 1 Comm: systemd Not tainted 4.16.0-rc6-gcc_ubuntu_le-g99fec39 #1
  ...
  NIP check_version.isra.22+0x118/0x170
  Call Trace:
    __ksymtab_xt_unregister_table+0x58/0xfffffffffffffcb8 [x_tables] (unreliable)
    resolve_symbol+0xb4/0x150
    load_module+0x10e8/0x29a0
    SyS_finit_module+0x110/0x140
    system_call+0x58/0x6c

This happens because since commit 71810db27c ("modversions: treat
symbol CRCs as 32 bit quantities"), a relocatable kernel encodes and
handles symbol CRCs differently from a non-relocatable kernel.

Although it's possible we could try and detect this situation and
handle it, it's much more robust to simply make the state of
CONFIG_RELOCATABLE part of the module vermagic.

Fixes: 71810db27c ("modversions: treat symbol CRCs as 32 bit quantities")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-09 13:21:02 +10:00
Sergey Senozhatsky
5633e85b2c powerpc64: Add .opd based function descriptor dereference
We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for powerpc64.

For pointers that belong to the kernel
-  Added __start_opd and __end_opd pointers, to track the kernel
   .opd section address range;

-  Added dereference_kernel_function_descriptor(). Now we
   will dereference only function pointers that are within
   [__start_opd, __end_opd);

For pointers that belong to a module
-  Added dereference_module_function_descriptor() to handle module
   function descriptor dereference. Now we will dereference only
   pointers that are within [module->opd.start, module->opd.end).

Link: http://lkml.kernel.org/r/20171109234830.5067-4-sergey.senozhatsky@gmail.com
To: Tony Luck <tony.luck@intel.com>
To: Fenghua Yu <fenghua.yu@intel.com>
To: Helge Deller <deller@gmx.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
To: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-09 10:45:37 +01:00
Michael Ellerman
43e24e82f3 powerpc/modules: If mprofile-kernel is enabled add it to vermagic
On powerpc we can build the kernel with two different ABIs for mcount(), which
is used by ftrace. Kernels built with one ABI do not know how to load modules
built with the other ABI. The new style ABI is called "mprofile-kernel", for
want of a better name.

Currently if we build a module using the old style ABI, and the kernel with
mprofile-kernel, when we load the module we'll oops something like:

  # insmod autofs4-no-mprofile-kernel.ko
  ftrace-powerpc: Unexpected instruction f8810028 around bl _mcount
  ------------[ cut here ]------------
  WARNING: CPU: 6 PID: 3759 at ../kernel/trace/ftrace.c:2024 ftrace_bug+0x2b8/0x3c0
  CPU: 6 PID: 3759 Comm: insmod Not tainted 4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269 #11
  ...
  NIP [c0000000001eaa48] ftrace_bug+0x2b8/0x3c0
  LR [c0000000001eaff8] ftrace_process_locs+0x4a8/0x590
  Call Trace:
    alloc_pages_current+0xc4/0x1d0 (unreliable)
    ftrace_process_locs+0x4a8/0x590
    load_module+0x1c8c/0x28f0
    SyS_finit_module+0x110/0x140
    system_call+0x38/0xfc
  ...
  ftrace failed to modify
  [<d000000002a31024>] 0xd000000002a31024
   actual:   35:65:00:48

We can avoid this by including in the vermagic whether the kernel/module was
built with mprofile-kernel. Which results in:

  # insmod autofs4-pg.ko
  autofs4: version magic
  '4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269 SMP mod_unload modversions '
  should be
  '4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269-dirty SMP mod_unload modversions mprofile-kernel'
  insmod: ERROR: could not insert module autofs4-pg.ko: Invalid module format

Fixes: 8c50b72a3b ("powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-05-15 19:31:38 +10:00
Ard Biesheuvel
71810db27c modversions: treat symbol CRCs as 32 bit quantities
The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.

This has a couple of downsides:

 - Given that the CRCs are treated as memory addresses, we waste 4 bytes
   for each CRC on 64 bit architectures,

 - On architectures that support runtime relocation, a R_<arch>_RELATIVE
   relocation entry is emitted for each CRC value, which identifies it
   as a quantity that requires fixing up based on the actual runtime
   load offset of the kernel. This results in corrupted CRCs unless we
   explicitly undo the fixup (and this is currently being handled in the
   core module code)

 - Such runtime relocation entries take up 24 bytes of __init space
   each, resulting in a x8 overhead in [uncompressed] kernel size for
   CRCs.

Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset.  Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant.  Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.

So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff).  To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.

Note that this mostly reverts commit d4703aefdb ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")

Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03 08:28:25 -08:00
Nicholas Piggin
5b9ff02785 powerpc: Build-time sort the exception table
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14 11:11:51 +11:00
Michael Ellerman
d8c0282f4d Merge branch 'topic/mprofile-kernel' into next
Merge the ftrace changes to support -mprofile-kernel on ppc64le. This is
a prerequisite for live patching, the support for which will be merged
via the livepatch tree based on this topic branch.
2016-03-11 11:20:15 +11:00
Michael Ellerman
f17c4e01e9 powerpc/module: Mark module stubs with a magic value
When a module is loaded, calls out to the kernel go via a stub which is
generated at runtime. One of these stubs is used to call _mcount(),
which is the default target of tracing calls generated by the compiler
with -pg.

If dynamic ftrace is enabled (which it typically is), another stub is
used to call ftrace_caller(), which is the target of tracing calls when
ftrace is actually active.

ftrace then wants to disable the calls to _mcount() at module startup,
and enable/disable the calls to ftrace_caller() when enabling/disabling
tracing - all of these it does by patching the code.

As part of that code patching, the ftrace code wants to confirm that the
branch it is about to modify, is in fact a call to a module stub which
calls _mcount() or ftrace_caller().

Currently it does that by inspecting the instructions and confirming
they are what it expects. Although that works, the code to do it is
pretty intricate because it requires lots of knowledge about the exact
format of the stub.

We can make that process easier by marking the generated stubs with a
magic value, and then looking for that magic value. Altough this is not
as rigorous as the current method, I believe it is sufficient in
practice.

Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-07 14:53:53 +11:00
Michael Ellerman
136cd3450a 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>
2016-03-07 14:53:53 +11:00
Adam Buchbinder
446957ba51 powerpc: Fix misspellings in comments.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-01 19:27:20 +11:00
Anton Blanchard
dd9fa16250 powerpc/modules: Create module_trampoline_target()
ftrace has way too much knowledge of our kernel module trampoline
layout hidden inside it. Create module_trampoline_target() that gives
the target address of a kernel module trampoline.

Signed-off-by: Anton Blanchard <anton@samba.org>
2014-04-23 10:05:34 +10:00
Anton Blanchard
83775b8566 powerpc/modules: Create is_module_trampoline()
ftrace has way too much knowledge of our kernel module trampoline
layout hidden inside it. Create is_module_trampoline() that can
abstract this away inside the module loader code.

Signed-off-by: Anton Blanchard <anton@samba.org>
2014-04-23 10:05:34 +10:00
Rusty Russell
4edebbeae3 powerpc: Fix up TOC. for modules.
The kernel resolved the '.TOC.' to a fake symbol, so we need to fix it up
to point to our .toc section plus 0x8000.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-23 10:05:29 +10:00
Anton Blanchard
0e0ed6406e powerpc/modules: Module CRC relocation fix causes perf issues
Module CRCs are implemented as absolute symbols that get resolved by
a linker script. We build an intermediate .o that contains an
unresolved symbol for each CRC. genksysms parses this .o, calculates
the CRCs and writes a linker script that "resolves" the symbols to
the calculated CRC.

Unfortunately the ppc64 relocatable kernel sees these CRCs as symbols
that need relocating and relocates them at boot. Commit d4703aef
(module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y)
added a hook to reverse the bogus relocations. Part of this patch
created a symbol at 0x0:

# head -2 /proc/kallsyms
0000000000000000 T reloc_start
c000000000000000 T .__start

This reloc_start symbol is causing lots of confusion to perf. It
thinks reloc_start is a massive function that stretches from 0x0 to
0xc000000000000000 and we get various cryptic errors out of perf,
including:

problem incrementing symbol count, skipping event

This patch removes the  reloc_start linker script label and instead
defines it as PHYSICAL_START. We also need to wrap it with
CONFIG_PPC64 because the ppc32 kernel can set a non zero
PHYSICAL_START at compile time and we wouldn't want to subtract
it from the CRCs in that case.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-24 14:18:43 +10:00
David Howells
786d35d45c Make most arch asm/module.h files use asm-generic/module.h
Use the mapping of Elf_[SPE]hdr, Elf_Addr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela,
ELF_R_TYPE() and ELF_R_SYM() to either the 32-bit version or the 64-bit version
into asm-generic/module.h for all arches bar MIPS.

Also, use the generic definition mod_arch_specific where possible.

To this end, I've defined three new config bools:

 (*) HAVE_MOD_ARCH_SPECIFIC

     Arches define this if they don't want to use the empty generic
     mod_arch_specific struct.

 (*) MODULES_USE_ELF_RELA

     Arches define this if their modules can contain RELA records.  This causes
     the Elf_Rela mapping to be emitted and allows apply_relocate_add() to be
     defined by the arch rather than have the core emit an error message.

 (*) MODULES_USE_ELF_REL

     Arches define this if their modules can contain REL records.  This causes
     the Elf_Rel mapping to be emitted and allows apply_relocate() to be
     defined by the arch rather than have the core emit an error message.

Note that it is possible to allow both REL and RELA records: m68k and mips are
two arches that do this.

With this, some arch asm/module.h files can be deleted entirely and replaced
with a generic-y marker in the arch Kbuild file.

Additionally, I have removed the bits from m32r and score that handle the
unsupported type of relocation record as that's now handled centrally.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 14:31:03 +09:30
Rusty Russell
d4703aefdb module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y
powerpc applies relocations to the kcrctab.  They're absolute symbols,
but it's not completely unreasonable: other archs may too, but the
relocation is often 0.

http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html

Inspired-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Paul Mackerras <paulus@samba.org>
2009-12-15 16:28:34 +10:30
Steven Rostedt
7cc45e6432 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>
2008-11-20 10:52:53 -08:00
Steven Rostedt
f48cb8b48b powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace
Impact: Allow 64 bit PowerPC to trace modules with dynamic ftrace

This adds code to handle the PPC64 module trampolines, and allows for
PPC64 to use dynamic ftrace.

Thanks to Paul Mackerras for these updates:

  - fix the mod and rec->arch.mod NULL checks.
  - fix to is_bl_op compare.

Thanks to Milton Miller for:

  - finding the nasty race with using two nops, and recommending
    instead that I use a branch 8 forward.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-20 10:52:28 -08:00
Stephen Rothwell
b8b572e101 powerpc: Move include files to arch/powerpc/include/asm
from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-08-04 12:02:00 +10:00
Renamed from include/asm-powerpc/module.h (Browse further)