linux.git/Documentation/features/debug, branch v5.18

nds32: Remove the architecture

2022-03-07T12:54:59+00:00

The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao 
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann

powerpc/mm: Revert "powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc"

2021-03-31T05:46:55+00:00

This reverts commit 675bceb097e6 ("powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc")

All the related issues are fixed as of commit:
  f14312e1ed1e ("mm/debug_vm_pgtable: avoid doing memory allocation with pgtable_t mapped.")

Hence re-enable it.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210318034855.74513-1-aneesh.kumar@linux.ibm.com

Documentation: features: refresh feature list

2021-02-25T18:25:57+00:00

Run the update script to document the recent feature additions
on riscv, mips and csky.

Fixes: c109f42450ec ("csky: Add kmemleak support")
Fixes: 8b3165e54566 ("MIPS: Enable GCOV")
Fixes: 1ddc96bd42da ("MIPS: kernel: Support extracting off-line stack traces from user-space with perf")
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Fixes: dcdc7a53a890 ("RISC-V: Implement ptrace regs and stack API")
Signed-off-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20210225142841.3385428-2-arnd@kernel.org
Signed-off-by: Jonathan Corbet

Documentation: features: remove c6x references

2021-02-25T18:25:57+00:00

The references to arch/c6x are obsolete now that the architecture
is gone. Remove them.

Signed-off-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20210225142841.3385428-1-arnd@kernel.org
Signed-off-by: Jonathan Corbet

ARM: 9017/2: Enable KASan for ARM

2020-10-27T12:11:11+00:00

This patch enables the kernel address sanitizer for ARM. XIP_KERNEL
has not been tested and is therefore not allowed for now.

Cc: Andrey Ryabinin 
Cc: Alexander Potapenko 
Cc: Dmitry Vyukov 
Cc: kasan-dev@googlegroups.com
Acked-by: Dmitry Vyukov 
Reviewed-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # QEMU/KVM/mach-virt/LPAE/8G
Tested-by: Florian Fainelli  # Brahma SoCs
Tested-by: Ahmad Fatoum  # i.MX6Q
Signed-off-by: Abbott Liu 
Signed-off-by: Florian Fainelli 
Signed-off-by: Linus Walleij 
Signed-off-by: Russell King

powerpc/mm: Remove DEBUG_VM_PGTABLE support on powerpc

2020-09-02T12:14:26+00:00

The test is broken w.r.t page table update rules and results in kernel
crash as below. Disable the support until we get the tests updated.

[   21.083519] kernel BUG at arch/powerpc/mm/pgtable.c:304!
cpu 0x0: Vector: 700 (Program Check) at [c000000c6d1e76c0]
    pc: c00000000009a5ec: assert_pte_locked+0x14c/0x380
    lr: c0000000005eeeec: pte_update+0x11c/0x190
    sp: c000000c6d1e7950
   msr: 8000000002029033
  current = 0xc000000c6d172c80
  paca    = 0xc000000003ba0000   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/0
kernel BUG at arch/powerpc/mm/pgtable.c:304!
[link register   ] c0000000005eeeec pte_update+0x11c/0x190
[c000000c6d1e7950] 0000000000000001 (unreliable)
[c000000c6d1e79b0] c0000000005eee14 pte_update+0x44/0x190
[c000000c6d1e7a10] c000000001a2ca9c pte_advanced_tests+0x160/0x3d8
[c000000c6d1e7ab0] c000000001a2d4fc debug_vm_pgtable+0x7e8/0x1338
[c000000c6d1e7ba0] c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d1e7c80] c0000000019e4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d1e7db0] c000000000012474 kernel_init+0x24/0x160
[c000000c6d1e7e20] c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c

With DEBUG_VM disabled

[   20.530152] BUG: Kernel NULL pointer dereference on read at 0x00000000
[   20.530183] Faulting instruction address: 0xc0000000000df330
cpu 0x33: Vector: 380 (Data SLB Access) at [c000000c6d19f700]
    pc: c0000000000df330: memset+0x68/0x104
    lr: c00000000009f6d8: hash__pmdp_huge_get_and_clear+0xe8/0x1b0
    sp: c000000c6d19f990
   msr: 8000000002009033
   dar: 0
  current = 0xc000000c6d177480
  paca    = 0xc00000001ec4f400   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/0
[link register   ] c00000000009f6d8 hash__pmdp_huge_get_and_clear+0xe8/0x1b0
[c000000c6d19f990] c00000000009f748 hash__pmdp_huge_get_and_clear+0x158/0x1b0 (unreliable)
[c000000c6d19fa10] c0000000019ebf30 pmd_advanced_tests+0x1f0/0x378
[c000000c6d19fab0] c0000000019ed088 debug_vm_pgtable+0x79c/0x1244
[c000000c6d19fba0] c0000000000116ec do_one_initcall+0xac/0x5f0
[c000000c6d19fc80] c0000000019a4fac kernel_init_freeable+0x4dc/0x5a4
[c000000c6d19fdb0] c000000000012474 kernel_init+0x24/0x160
[c000000c6d19fe20] c00000000000cbd0 ret_from_kernel_thread+0x5c/0x6c
33:mon>

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200902040122.136414-1-aneesh.kumar@linux.ibm.com

Merge tag 'docs-5.9-2' of git://git.lwn.net/linux

2020-08-13T20:57:45+00:00

Pull documentation fixes from Jonathan Corbet:
 "A handful of obvious fixes that wandered in during the merge window"

* tag 'docs-5.9-2' of git://git.lwn.net/linux:
  Documentation/locking/locktypes: fix the typo
  doc/zh_CN: resolve undefined label warning in admin-guide index
  doc/zh_CN: fix title heading markup in admin-guide cpu-load
  docs: remove the 2.6 "Upgrading I2C Drivers" guide
  docs: Correct the release date of 5.2 stable
  mailmap: Update comments for with format and more detalis
  docs: cdrom: Fix a typo and rst markup
  Doc: admin-guide: use correct legends in kernel-parameters.txt
  Documentation/features: refresh RISC-V arch support files
  documentation: coccinelle: Improve command example for make C={1,2}
  Core-api: Documentation: Replace deprecated :c:func: Usage
  Dev-tools: Documentation: Replace deprecated :c:func: Usage
  Filesystems: Documentation: Replace deprecated :c:func: Usage
  docs: trace: fix a typo

Documentation/features: refresh RISC-V arch support files

2020-08-11T16:39:21+00:00

Support for these was added by the following commits:

  f2c9699f6555 ("riscv: Add STACKPROTECTOR supported")
  3c4697982982 ("riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT").
  ed48b297fe21 ("riscv: Enable context tracking")
  cbb3d91d3bcf ("riscv: Add kmemleak support")

Signed-off-by: Tobias Klauser 
Link: https://lore.kernel.org/r/20200810095000.32092-1-tklauser@distanz.ch
Signed-off-by: Jonathan Corbet

Merge tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2020-08-07T17:11:12+00:00

Pull RISC-V updates from Palmer Dabbelt:
 "We have a lot of new kernel features for this merge window:

   - ARCH_SUPPORTS_ATOMIC_RMW, to allow OSQ locks to be enabled

   - The ability to enable NO_HZ_FULL

   - Support for enabling kcov, kmemleak, stack protector, and VM
     debugging

   - JUMP_LABEL support

  There are also a handful of cleanups"

* tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (24 commits)
  riscv: disable stack-protector for vDSO
  RISC-V: Fix build warning for smpboot.c
  riscv: fix build warning of mm/pageattr
  riscv: Fix build warning for mm/init
  RISC-V: Setup exception vector early
  riscv: Select ARCH_HAS_DEBUG_VM_PGTABLE
  riscv: Use generic pgprot_* macros from 
  mm: pgtable: Make generic pgprot_* macros available for no-MMU
  riscv: Cleanup unnecessary define in asm-offset.c
  riscv: Add jump-label implementation
  riscv: Support R_RISCV_ADD64 and R_RISCV_SUB64 relocs
  Replace HTTP links with HTTPS ones: RISC-V
  riscv: Add STACKPROTECTOR supported
  riscv: Fix typo in asm/hwcap.h uapi header
  riscv: Add kmemleak support
  riscv: Allow building with kcov coverage
  riscv: Enable context tracking
  riscv: Support irq_work via self IPIs
  riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT
  riscv: Fixup lockdep_assert_held with wrong param cpu_running
  ...

Merge tag 'docs-5.9' of git://git.lwn.net/linux

2020-08-05T05:47:54+00:00

Pull documentation updates from Jonathan Corbet:
 "It's been a busy cycle for documentation - hopefully the busiest for a
  while to come. Changes include:

   - Some new Chinese translations

   - Progress on the battle against double words words and non-HTTPS
     URLs

   - Some block-mq documentation

   - More RST conversions from Mauro. At this point, that task is
     essentially complete, so we shouldn't see this kind of churn again
     for a while. Unless we decide to switch to asciidoc or
     something...:)

   - Lots of typo fixes, warning fixes, and more"

* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
  scripts/kernel-doc: optionally treat warnings as errors
  docs: ia64: correct typo
  mailmap: add entry for 
  doc/zh_CN: add cpu-load Chinese version
  Documentation/admin-guide: tainted-kernels: fix spelling mistake
  MAINTAINERS: adjust kprobes.rst entry to new location
  devices.txt: document rfkill allocation
  PCI: correct flag name
  docs: filesystems: vfs: correct flag name
  docs: filesystems: vfs: correct sync_mode flag names
  docs: path-lookup: markup fixes for emphasis
  docs: path-lookup: more markup fixes
  docs: path-lookup: fix HTML entity mojibake
  CREDITS: Replace HTTP links with HTTPS ones
  docs: process: Add an example for creating a fixes tag
  doc/zh_CN: add Chinese translation prefer section
  doc/zh_CN: add clearing-warn-once Chinese version
  doc/zh_CN: add admin-guide index
  doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
  futex: MAINTAINERS: Re-add selftests directory
  ...