Pull LoongArch updates from Huacai Chen:

 - Allow usage of LSX/LASX in the kernel, and use them for
   SIMD-optimized RAID5/RAID6 routines

 - Add Loongson Binary Translation (LBT) extension support

 - Add basic KGDB & KDB support

 - Add building with kcov coverage

 - Add KFENCE (Kernel Electric-Fence) support

 - Add KASAN (Kernel Address Sanitizer) support

 - Some bug fixes and other small changes

 - Update the default config file

* tag 'loongarch-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (25 commits)
  LoongArch: Update Loongson-3 default config file
  LoongArch: Add KASAN (Kernel Address Sanitizer) support
  LoongArch: Simplify the processing of jumping new kernel for KASLR
  kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate process
  kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping
  LoongArch: Add KFENCE (Kernel Electric-Fence) support
  LoongArch: Get partial stack information when providing regs parameter
  LoongArch: mm: Add page table mapped mode support for virt_to_page()
  kfence: Defer the assignment of the local variable addr
  LoongArch: Allow building with kcov coverage
  LoongArch: Provide kaslr_offset() to get kernel offset
  LoongArch: Add basic KGDB & KDB support
  LoongArch: Add Loongson Binary Translation (LBT) extension support
  raid6: Add LoongArch SIMD recovery implementation
  raid6: Add LoongArch SIMD syndrome calculation
  LoongArch: Add SIMD-optimized XOR routines
  LoongArch: Allow usage of LSX/LASX in the kernel
  LoongArch: Define symbol 'fault' as a local label in fpu.S
  LoongArch: Adjust {copy, clear}_user exception handler behavior
  LoongArch: Use static defined zero page rather than allocated
  ...

1/8 of kernel addresses reserved for shadow memory. But for LoongArch,
There are a lot of holes between different segments and valid address
space (256T available) is insufficient to map all these segments to kasan
shadow memory with the common formula provided by kasan core, saying
(addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET

So LoongArch has a arch-specific mapping formula, different segments are
mapped individually, and only limited space lengths of these specific
segments are mapped to shadow.

At early boot stage the whole shadow region populated with just one
physical page (kasan_early_shadow_page). Later, this page is reused as
readonly zero shadow for some memory that kasan currently don't track.
After mapping the physical memory, pages for shadow memory are allocated
and mapped.

Functions like memset()/memcpy()/memmove() do a lot of memory accesses.
If bad pointer passed to one of these function it is important to be
caught. Compiler's instrumentation cannot do this since these functions
are written in assembly.

KASan replaces memory functions with manually instrumented variants.
Original functions declared as weak symbols so strong definitions in
mm/kasan/kasan.c could replace them. Original functions have aliases
with '__' prefix in names, so we could call non-instrumented variant
if needed.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Add ARCH_HAS_KCOV and HAVE_GCC_PLUGINS to the LoongArch Kconfig. And
also disable instrumentation of vdso.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

KGDB is intended to be used as a source level debugger for the Linux
kernel. It is used along with gdb to debug a Linux kernel. GDB can be
used to "break in" to the kernel to inspect memory, variables and regs
similar to the way an application developer would use GDB to debug an
application. KDB is a frontend of KGDB which is similar to GDB.

By now, in addition to the generic KGDB features, the LoongArch KGDB
implements the following features:
- Hardware breakpoints/watchpoints;
- Software single-step support for KDB.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>   # Framework & CoreFeature
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> # BreakPoint & SingleStep
Signed-off-by: Hui Li <lihui@loongson.cn>           # Some Minor Improvements
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> # Some Build Error Fixes
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Run the refresh script [1] to document the recent feature additions.

[1] Documentation/features/scripts/features-refresh.sh

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/1689060720-4628-3-git-send-email-yangtiezhu@loongson.cn

We can see that DEBUG_KMEMLEAK depends on HAVE_DEBUG_KMEMLEAK after
commit b69ec42b1b19 ("Kconfig: clean up the long arch list for the
DEBUG_KMEMLEAK config option"), just select HAVE_DEBUG_KMEMLEAK to
support kmemleak on LoongArch.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

The official arch name is LoongArch [1], we should use small letter
loongarch instead of loong in Documentation/features, just use the
features-refresh.sh to refresh all the related files.

[1] https://www.kernel.org/doc/html/latest/loongarch/index.html

Fixes: 5860800e8696 ("Documentation/features: Update the arch support status files")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/1670156327-9631-3-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Run the refresh script to document the recent feature additions
on loong, um and csky as of v6.1-rc7.

Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20221203093750.4145802-1-liwei391@huawei.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Select ARCH_HAS_GCOV_PROFILE_ALL and set GCOV_PROFILE = n inside
arch/xtensa/boot/lib.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Select ARCH_HAS_KCOV and set KCOV_INSTRUMENT = n inside
arch/xtensa/boot/lib.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>