linux-toradex.git/arch/powerpc/kernel/fadump.c, branch v5.18

Merge tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-03-25T16:39:36+00:00

Pull powerpc updates from Michael Ellerman:
 "Livepatch support for 32-bit is probably the standout new feature,
  otherwise mostly just lots of bits and pieces all over the board.

  There's a series of commits cleaning up function descriptor handling,
  which touches a few other arches as well as LKDTM. It has acks from
  Arnd, Kees and Helge.

  Summary:

   - Enforce kernel RO, and implement STRICT_MODULE_RWX for 603.

   - Add support for livepatch to 32-bit.

   - Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS.

   - Merge vdso64 and vdso32 into a single directory.

   - Fix build errors with newer binutils.

   - Add support for UADDR64 relocations, which are emitted by some
     toolchains. This allows powerpc to build with the latest lld.

   - Fix (another) potential userspace r13 corruption in transactional
     memory handling.

   - Cleanups of function descriptor handling & related fixes to LKDTM.

  Thanks to Abdul Haleem, Alexey Kardashevskiy, Anders Roxell, Aneesh
  Kumar K.V, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Bhaskar
  Chowdhury, Cédric Le Goater, Chen Jingwen, Christophe JAILLET,
  Christophe Leroy, Corentin Labbe, Daniel Axtens, Daniel Henrique
  Barboza, David Dai, Fabiano Rosas, Ganesh Goudar, Guo Zhengkui, Hangyu
  Hua, Haren Myneni, Hari Bathini, Igor Zhbanov, Jakob Koschel, Jason
  Wang, Jeremy Kerr, Joachim Wiberg, Jordan Niethe, Julia Lawall, Kajol
  Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mamatha Inamdar,
  Maxime Bizon, Maxim Kiselev, Maxim Kochetkov, Michal Suchanek,
  Nageswara R Sastry, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
  Nour-eddine Taleb, Paul Menzel, Ping Fang, Pratik R. Sampat, Randy
  Dunlap, Ritesh Harjani, Rohan McLure, Russell Currey, Sachin Sant,
  Segher Boessenkool, Shivaprasad G Bhat, Sourabh Jain, Thierry Reding,
  Tobias Waldekranz, Tyrel Datwyler, Vaibhav Jain, Vladimir Oltean,
  Wedson Almeida Filho, and YueHaibing"

* tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
  powerpc/pseries: Fix use after free in remove_phb_dynamic()
  powerpc/time: improve decrementer clockevent processing
  powerpc/time: Fix KVM host re-arming a timer beyond decrementer range
  powerpc/tm: Fix more userspace r13 corruption
  powerpc/xive: fix return value of __setup handler
  powerpc/64: Add UADDR64 relocation support
  powerpc: 8xx: fix a return value error in mpc8xx_pic_init
  powerpc/ps3: remove unneeded semicolons
  powerpc/64: Force inlining of prevent_user_access() and set_kuap()
  powerpc/bitops: Force inlining of fls()
  powerpc: declare unmodified attribute_group usages const
  powerpc/spufs: Fix build warning when CONFIG_PROC_FS=n
  powerpc/secvar: fix refcount leak in format_show()
  powerpc/64e: Tie PPC_BOOK3E_64 to PPC_FSL_BOOK3E
  powerpc: Move C prototypes out of asm-prototypes.h
  powerpc/kexec: Declare kexec_paca static
  powerpc/smp: Declare current_set static
  powerpc: Cleanup asm-prototypes.c
  powerpc/ftrace: Use STK_GOT in ftrace_mprofile.S
  powerpc/ftrace: Regroup PPC64 specific operations in ftrace_mprofile.S
  ...

powerpc/fadump: opt out from freeing pages on cma activation failure

2022-03-22T22:57:09+00:00

With commit a4e92ce8e4c8 ("powerpc/fadump: Reservationless firmware
assisted dump"), Linux kernel's Contiguous Memory Allocator (CMA) based
reservation was introduced in fadump.  That change was aimed at using CMA
to let applications utilize the memory reserved for fadump while blocking
it from being used for kernel pages.  The assumption was, even if CMA
activation fails for whatever reason, the memory still remains reserved to
avoid it from being used for kernel pages.  But commit 072355c1cf2d
("mm/cma: expose all pages to the buddy if activation of an area fails")
breaks this assumption as it started exposing all pages to buddy allocator
on CMA activation failure.  It led to warning messages like below while
running crash-utility on vmcore of a kernel having above two commits:

  crash: seek error: kernel virtual address: 

To fix this problem, opt out from exposing pages to buddy allocator on CMA
activation failure for fadump reserved memory.

Link: https://lkml.kernel.org/r/20220117075246.36072-3-hbathini@linux.ibm.com
Signed-off-by: Hari Bathini 
Acked-by: David Hildenbrand 
Acked-by: Michael Ellerman 
Cc: Mahesh Salgaonkar 
Cc: Mike Kravetz 
Cc: Oscar Salvador 
Cc: Sourabh Jain 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cma: factor out minimum alignment requirement

2022-03-22T22:57:05+00:00

Patch series "mm: enforce pageblock_order < MAX_ORDER".

Having pageblock_order >= MAX_ORDER seems to be able to happen in corner
cases and some parts of the kernel are not prepared for it.

For example, Aneesh has shown [1] that such kernels can be compiled on
ppc64 with 64k base pages by setting FORCE_MAX_ZONEORDER=8, which will
run into a WARN_ON_ONCE(order >= MAX_ORDER) in comapction code right
during boot.

We can get pageblock_order >= MAX_ORDER when the default hugetlb size is
bigger than the maximum allocation granularity of the buddy, in which
case we are no longer talking about huge pages but instead gigantic
pages.

Having pageblock_order >= MAX_ORDER can only make alloc_contig_range()
of such gigantic pages more likely to succeed.

Reliable use of gigantic pages either requires boot time allcoation or
CMA, no need to overcomplicate some places in the kernel to optimize for
corner cases that are broken in other areas of the kernel.

This patch (of 2):

Let's enforce pageblock_order < MAX_ORDER and simplify.

Especially patch #1 can be regarded a cleanup before:
	[PATCH v5 0/6] Use pageblock_order for cma and alloc_contig_range
	alignment. [2]

[1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com
[2] https://lkml.kernel.org/r/20220211164135.1803616-1-zi.yan@sent.com

Link: https://lkml.kernel.org/r/20220214174132.219303-2-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Zi Yan 
Acked-by: Rob Herring 
Cc: Aneesh Kumar K.V 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Frank Rowand 
Cc: Michael S. Tsirkin 
Cc: Christoph Hellwig 
Cc: Marek Szyprowski 
Cc: Robin Murphy 
Cc: Minchan Kim 
Cc: Vlastimil Babka 
Cc: John Garry via iommu 

Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc/fadump: register for fadump as early as possible

2022-03-01T12:41:00+00:00

Crash recovery (fadump) is setup in the userspace by some service. This
service rebuilds initrd with dump capture capability, if it is not
already dump capture capable before proceeding to register for firmware
assisted dump (echo 1 > /sys/kernel/fadump/registered). But arming the
kernel with crash recovery support does not have to wait for userspace
configuration. So, register for fadump while setting it up itself. This
can at worst lead to a scenario, where /proc/vmcore is ready afer crash
but the initrd does not know how/where to offload it, which is always
better than not having a /proc/vmcore at all due to incomplete
configuration in the userspace at the time of crash.

Commit 0823c68b054b ("powerpc/fadump: re-register firmware-assisted dump
if already registered") ensures this change does not break userspace.

Signed-off-by: Hari Bathini 
[mpe: Reword comment]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220201105305.155511-1-hbathini@linux.ibm.com

powerpc/kernel: Add __init attribute to eligible functions

2021-12-23T11:33:10+00:00

Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/
kexec`) are deserving of an `__init` macro attribute. These functions are
only called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com

powerpc/fadump: Fix inaccurate CPU state info in vmcore generated with panic

2021-12-09T11:41:22+00:00

In panic path, fadump is triggered via a panic notifier function.
Before calling panic notifier functions, smp_send_stop() gets called,
which stops all CPUs except the panic'ing CPU. Commit 8389b37dffdc
("powerpc: stop_this_cpu: remove the cpu from the online map.") and
again commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()")
started marking CPUs as offline while stopping them. So, if a kernel
has either of the above commits, vmcore captured with fadump via panic
path would not process register data for all CPUs except the panic'ing
CPU. Sample output of crash-utility with such vmcore:

  # crash vmlinux vmcore
  ...
        KERNEL: vmlinux
      DUMPFILE: vmcore  [PARTIAL DUMP]
          CPUS: 1
          DATE: Wed Nov 10 09:56:34 EST 2021
        UPTIME: 00:00:42
  LOAD AVERAGE: 2.27, 0.69, 0.24
         TASKS: 183
      NODENAME: XXXXXXXXX
       RELEASE: 5.15.0+
       VERSION: #974 SMP Wed Nov 10 04:18:19 CST 2021
       MACHINE: ppc64le  (2500 Mhz)
        MEMORY: 8 GB
         PANIC: "Kernel panic - not syncing: sysrq triggered crash"
           PID: 3394
       COMMAND: "bash"
          TASK: c0000000150a5f80  [THREAD_INFO: c0000000150a5f80]
           CPU: 1
         STATE: TASK_RUNNING (PANIC)

  crash> p -x __cpu_online_mask
  __cpu_online_mask = $1 = {
    bits = {0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
  }
  crash>
  crash>
  crash> p -x __cpu_active_mask
  __cpu_active_mask = $2 = {
    bits = {0xff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
  }
  crash>

While this has been the case since fadump was introduced, the issue
was not identified for two probable reasons:

  - In general, the bulk of the vmcores analyzed were from crash
    due to exception.

  - The above did change since commit 8341f2f222d7 ("sysrq: Use
    panic() to force a crash") started using panic() instead of
    deferencing NULL pointer to force a kernel crash. But then
    commit de6e5d38417e ("powerpc: smp_send_stop do not offline
    stopped CPUs") stopped marking CPUs as offline till kernel
    commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()")
    reverted that change.

To ensure post processing register data of all other CPUs happens
as intended, let panic() function take the crash friendly path (read
crash_smp_send_stop()) with the help of crash_kexec_post_notifiers
option. Also, as register data for all CPUs is captured by f/w, skip
IPI callbacks here for fadump, to avoid any complications in finding
the right backtraces.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211207103719.91117-2-hbathini@linux.ibm.com

powerpc: rename powerpc_debugfs_root to arch_debugfs_dir

2021-08-13T12:04:26+00:00

No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

powerpc/fadump: Fix sparse warnings

2021-04-22T10:59:04+00:00

Sparse says:
  arch/powerpc/kernel/fadump.c:48:16: warning: symbol 'fadump_kobj' was not declared. Should it be static?
  arch/powerpc/kernel/fadump.c:55:27: warning: symbol 'crash_mrange_info' was not declared. Should it be static?
  arch/powerpc/kernel/fadump.c:61:27: warning: symbol 'reserved_mrange_info' was not declared. Should it be static?
  arch/powerpc/kernel/fadump.c:83:12: warning: symbol 'fadump_cma_init' was not declared. Should it be static?

And indeed none of them are used outside this file, they can all be made
static. Also fadump_kobj needs to be moved inside the ifdef where it's
used.

Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210421125402.1955013-1-mpe@ellerman.id.au

powerpc/fadump: Fix compile error since trap type change

2021-04-19T12:35:40+00:00

sfr reports that the allyesconfig build fails with:

  arch/powerpc/kernel/fadump.c: In function 'crash_fadump':
  arch/powerpc/kernel/fadump.c:731:28: error: 'INTERRUPT_SYSTEM_RESET' undeclared
    731 |  if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {

Add an include of interrupt.h to fix it.

Fixes: 7153d4bf0b37 ("powerpc/traps: Enhance readability for trap types")
Signed-off-by: Stephen Rothwell 
[mpe: Reformat change log]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210419191425.281dc58a@canb.auug.org.au

powerpc/traps: Enhance readability for trap types

2021-04-17T12:20:19+00:00

Define macros to list ppc interrupt types in interttupt.h, replace the
reference of the trap hex values with these macros.

Referred the hex numbers in arch/powerpc/kernel/exceptions-64e.S,
arch/powerpc/kernel/exceptions-64s.S, arch/powerpc/kernel/head_*.S,
arch/powerpc/kernel/head_booke.h and arch/powerpc/include/asm/kvm_asm.h.

Signed-off-by: Xiongwei Song 
[mpe: Resolve conflicts in nmi_disables_ftrace(), fix 40x build]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/1618398033-13025-1-git-send-email-sxwjean@me.com