linux.git/arch/mips/kernel/relocate.c, branch v6.16

of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify

2024-10-29T20:32:45+00:00

 __pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().

Note that arm64 doesn't need the FDT region reserved in the DT as the
kernel explicitly reserves the passed in FDT. Therefore, only a debug
warning is fixed with this change.

Reported-by: Breno Leitao 
Suggested-by: Mark Rutland 
Signed-off-by: Usama Arif 
Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com
Signed-off-by: Rob Herring (Arm)

MIPS: Fix typos

2024-01-08T09:39:12+00:00

Fix typos, most reported by "codespell arch/mips".  Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas 
Cc: linux-mips@vger.kernel.org
Reviewed-by: Randy Dunlap 
Signed-off-by: Thomas Bogendoerfer

MIPS: move from strlcpy with unused retval to strscpy

2022-09-12T13:34:04+00:00

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang 
Signed-off-by: Thomas Bogendoerfer

kernel.h: split out panic and oops helpers

2021-07-01T18:06:04+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
  Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Reviewed-by: Bjorn Andersson 
Co-developed-by: Andrew Morton 
Acked-by: Mike Rapoport 
Acked-by: Corey Minyard 
Acked-by: Christian Brauner 
Acked-by: Arnd Bergmann 
Acked-by: Kees Cook 
Acked-by: Wei Liu 
Acked-by: Rasmus Villemoes 
Signed-off-by: Andrew Morton 
Acked-by: Sebastian Reichel 
Acked-by: Luis Chamberlain 
Acked-by: Stephen Boyd 
Acked-by: Thomas Bogendoerfer 
Acked-by: Helge Deller  # parisc
Signed-off-by: Linus Torvalds

Merge tag 'mips_5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

2021-02-21T21:18:26+00:00

Pull MIPS updates from Thomas Bogendoerfer:

 - added support for Nintendo N64

 - added support for Realtek RTL83XX SoCs

 - kaslr support for Loongson64

 - first steps to get rid of set_fs()

 - DMA runtime coherent/non-coherent selection cleanup

 - cleanups and fixes

* tag 'mips_5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (98 commits)
  Revert "MIPS: Add basic support for ptrace single step"
  vmlinux.lds.h: catch more UBSAN symbols into .data
  MIPS: kernel: Drop kgdb_call_nmi_hook
  MAINTAINERS: Add git tree for KVM/mips
  MIPS: Use common way to parse elfcorehdr
  MIPS: Simplify EVA cache handling
  Revert "MIPS: kernel: {ftrace,kgdb}: Set correct address limit for cache flushes"
  MIPS: remove CONFIG_DMA_PERDEV_COHERENT
  MIPS: remove CONFIG_DMA_MAYBE_COHERENT
  driver core: lift dma_default_coherent into common code
  MIPS: refactor the runtime coherent vs noncoherent DMA indicators
  MIPS/alchemy: factor out the DMA coherent setup
  MIPS/malta: simplify plat_setup_iocoherency
  MIPS: Add basic support for ptrace single step
  MAINTAINERS: replace non-matching patterns for loongson{2,3}
  MIPS: Make check condition for SDBBP consistent with EJTAG spec
  mips: Replace lkml.org links with lore
  Revert "MIPS: microMIPS: Fix the judgment of mm_jr16_op and mm_jalr_op"
  MIPS: crash_dump.c: Simplify copy_oldmem_page()
  Revert "mips: Manually call fdt_init_reserved_mem() method"
  ...

MIPS: relocatable: Use __kaslr_offset in show_kernel_relocation

2021-02-09T09:56:04+00:00

The type of the VMLINUX_LOAD_ADDRESS macro is the (unsigned long long)
in 32bits kernel but (unsigned long) in the 64-bit kernel. Although there
is no error here, avoid using it to calculate kaslr_offset.

Signed-off-by: Jinyang He 
Signed-off-by: Thomas Bogendoerfer

MIPS: relocatable: Provide kaslr_offset() to get the kernel offset

2021-02-09T09:54:29+00:00

Provide kaslr_offset() to get the kernel offset when KASLR is enabled.
Error may occur before update_kaslr_offset(), so put it at the end of
the offset branch.

Fixes: a307a4ce9ecd ("MIPS: Loongson64: Add KASLR support")
Reported-by: kernel test robot 
Signed-off-by: Jinyang He 
Signed-off-by: Thomas Bogendoerfer

MIPS: relocatable: optimize the relocation process

2021-01-18T14:55:29+00:00

For now, vmlinux relocation functions for relocatable kernel are
implemented as an array of handlers of a particular type.

Convert that array into a single switch-case function to:
 - remove unused arguments;
 - change the return type of simple handlers to void;
 - remove the array and don't use any data at all;
 - avoid using indirect calls;
 - allow the compiler to inline and greatly optimize
   the relocation function[s];

and also mark do_relocations() and show_kernel_relocation() static
as they aren't used anywhere else.

The result on MIPS32 R2 with GCC 10.2 -O2 is:

scripts/bloat-o-meter -c arch/mips/kernel/__relocate.o arch/mips/kernel/relocate.o
add/remove: 0/6 grow/shrink: 1/0 up/down: 356/-640 (-284)
Function                                     old     new   delta
relocate_kernel                              852    1208    +356
apply_r_mips_32_rel                           20       -     -20
apply_r_mips_hi16_rel                         40       -     -40
apply_r_mips_64_rel                           44       -     -44
apply_r_mips_26_rel                          144       -    -144
show_kernel_relocation                       164       -    -164
do_relocations                               228       -    -228
Total: Before=1780, After=1496, chg -15.96%
add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-76 (-76)
Data                                         old     new   delta
reloc_handlers_rel                            76       -     -76
Total: Before=92, After=16, chg -82.61%
add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
RO Data                                      old     new   delta
Total: Before=0, After=0, chg +0.00%

All functions were collapsed into the main one, relocate_kernel().

Signed-off-by: Alexander Lobakin 
Signed-off-by: Thomas Bogendoerfer

MIPS: relocatable: fix possible boot hangup with KASLR enabled

2021-01-13T09:59:04+00:00

LLVM-built Linux triggered a boot hangup with KASLR enabled.

arch/mips/kernel/relocate.c:get_random_boot() uses linux_banner,
which is a string constant, as a random seed, but accesses it
as an array of unsigned long (in rotate_xor()).
When the address of linux_banner is not aligned to sizeof(long),
such access emits unaligned access exception and hangs the kernel.

Use PTR_ALIGN() to align input address to sizeof(long) and also
align down the input length to prevent possible access-beyond-end.

Fixes: 405bc8fd12f5 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Alexander Lobakin 
Tested-by: Nathan Chancellor 
Reviewed-by: Kees Cook 
Signed-off-by: Thomas Bogendoerfer

MIPS: KASLR: Avoid endless loop in sync_icache if synci_step is zero

2020-12-05T10:23:16+00:00

Most platforms do not need to do synci instruction operations when
synci_step is 0. But for example, the synci implementation on Loongson64
platform has some changes. On the one hand, it ensures that the memory
access instructions have been completed. On the other hand, it guarantees
that all prefetch instructions need to be fetched again. And its address
information is useless. Thus, only one synci operation is required when
synci_step is 0 on Loongson64 platform. I guess that some other platforms
have similar implementations on synci, so add judgment conditions in
`while` to ensure that at least all platforms perform synci operations
once. For those platforms that do not need synci, they just do one more
operation similar to nop.

Signed-off-by: Jinyang He 
Signed-off-by: Thomas Bogendoerfer