linux-stable.git/arch/powerpc/kernel/traps.c, branch v6.2

powerpc/64s: early boot machine check handler

2022-09-28T09:22:13+00:00

Use the early boot interrupt fixup in the machine check handler to allow
the machine check handler to run before interrupt endian is set up.
Branch to an early boot handler that just does a basic crash, which
allows it to run before ppc_md is set up. MSR[ME] is enabled on the boot
CPU earlier, and the machine check stack is temporarily set to the
middle of the init task stack.

This allows machine checks (e.g., due to invalid data access in real
mode) to print something useful earlier in boot (as soon as udbg is set
up, if CONFIG_PPC_EARLY_DEBUG=y).

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220926055620.2676869-3-npiggin@gmail.com

powerpc: Change CONFIG_E500 to CONFIG_PPC_E500

2022-09-26T13:00:13+00:00

It will be used outside arch/powerpc, make it clear its a
powerpc configuration item.

And we already have CONFIG_PPC_E500MC, so that will make
it more consistent.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu

powerpc: Remove CONFIG_FSL_BOOKE

2022-09-26T12:47:37+00:00

PPC_85xx is PPC32 only.
PPC_85xx always selects E500 and is the only PPC32 that
selects E500.
FSL_BOOKE is selected when E500 and PPC32 are selected.

So FSL_BOOKE is redundant with PPC_85xx.

Remove FSL_BOOKE.

And rename four files accordingly.

cpu_setup_fsl_booke.S is not renamed because it is linked to
PPC_FSL_BOOK3E and not to FSL_BOOKE as suggested by its name.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/08e3e15594e66d63b9e89c5b4f9c35153913c28f.1663606875.git.christophe.leroy@csgroup.eu

powerpc/math-emu: Inhibit W=1 warnings

2022-09-08T01:11:18+00:00

When building with W=1 you get:

	arch/powerpc/math-emu/fre.c:6:5: error: no previous prototype for 'fre' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous prototype for 'fsqrt' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous prototype for 'fsqrts' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous prototype for 'frsqrtes' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous prototype for 'mtfsf' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous prototype for 'mtfsfi' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fabs.c:7:1: error: no previous prototype for 'fabs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fadd.c:11:1: error: no previous prototype for 'fadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fadds.c:12:1: error: no previous prototype for 'fadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous prototype for 'fcmpo' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous prototype for 'fcmpu' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpu.c:14:19: error: variable 'B_c' set but not used [-Werror=unused-but-set-variable]
	arch/powerpc/math-emu/fcmpu.c:13:19: error: variable 'A_c' set but not used [-Werror=unused-but-set-variable]
	arch/powerpc/math-emu/fctiw.c:11:1: error: no previous prototype for 'fctiw' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous prototype for 'fctiwz' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fdiv.c:11:1: error: no previous prototype for 'fdiv' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fdivs.c:12:1: error: no previous prototype for 'fdivs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmadd.c:11:1: error: no previous prototype for 'fmadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmadds.c:12:1: error: no previous prototype for 'fmadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmsub.c:11:1: error: no previous prototype for 'fmsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous prototype for 'fmsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmul.c:11:1: error: no previous prototype for 'fmul' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmuls.c:12:1: error: no previous prototype for 'fmuls' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnabs.c:7:1: error: no previous prototype for 'fnabs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fneg.c:7:1: error: no previous prototype for 'fneg' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous prototype for 'fnmadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous prototype for 'fnmadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous prototype for 'fnmsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous prototype for 'fnmsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fres.c:7:1: error: no previous prototype for 'fres' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsp.c:12:1: error: no previous prototype for 'frsp' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsel.c:11:1: error: no previous prototype for 'fsel' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/lfs.c:12:1: error: no previous prototype for 'lfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous prototype for 'frsqrte' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsub.c:11:1: error: no previous prototype for 'fsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsubs.c:12:1: error: no previous prototype for 'fsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous prototype for 'mcrfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mffs.c:10:1: error: no previous prototype for 'mffs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous prototype for 'mtfsb0' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous prototype for 'mtfsb1' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous prototype for 'stfiwx' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfs.c:12:1: error: no previous prototype for 'stfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmr.c:7:1: error: no previous prototype for 'fmr' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/lfd.c:10:1: error: no previous prototype for 'lfd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfd.c:7:1: error: no previous prototype for 'stfd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:177:5: error: no previous prototype for 'do_spe_mathemu' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:726:5: error: no previous prototype for 'speround_handler' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:893:12: error: no previous prototype for 'spe_mathemu_init' [-Werror=missing-prototypes]

Fix the warnings in math_efp.c by adding prototypes of do_spe_mathemu()
and speround_handler() to asm/processor.h and declare spe_mathemu_init()
static.

The other warnings are benign and not worth the churn of fixing them,
expecially the 'unused-but-set-variable' which would impact the core
part of 'math-emu'.

So silence them by adding -Wno-missing-prototypes -Wno-unused-but-set-variable.

But then you get:

	arch/powerpc/math-emu/fre.c:6:5: error: no previous declaration for 'fre' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous declaration for 'fsqrt' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous declaration for 'fsqrts' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous declaration for 'frsqrtes' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous declaration for 'mtfsf' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous declaration for 'mtfsfi' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fabs.c:7:1: error: no previous declaration for 'fabs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fadd.c:11:1: error: no previous declaration for 'fadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fadds.c:12:1: error: no previous declaration for 'fadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous declaration for 'fcmpo' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous declaration for 'fcmpu' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fctiw.c:11:1: error: no previous declaration for 'fctiw' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous declaration for 'fctiwz' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fdiv.c:11:1: error: no previous declaration for 'fdiv' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fdivs.c:12:1: error: no previous declaration for 'fdivs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmadd.c:11:1: error: no previous declaration for 'fmadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmadds.c:12:1: error: no previous declaration for 'fmadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmsub.c:11:1: error: no previous declaration for 'fmsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous declaration for 'fmsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmul.c:11:1: error: no previous declaration for 'fmul' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmuls.c:12:1: error: no previous declaration for 'fmuls' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnabs.c:7:1: error: no previous declaration for 'fnabs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fneg.c:7:1: error: no previous declaration for 'fneg' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous declaration for 'fnmadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous declaration for 'fnmadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous declaration for 'fnmsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous declaration for 'fnmsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fres.c:7:1: error: no previous declaration for 'fres' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsp.c:12:1: error: no previous declaration for 'frsp' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsel.c:11:1: error: no previous declaration for 'fsel' [-Werror=missing-declarations]
	arch/powerpc/math-emu/lfs.c:12:1: error: no previous declaration for 'lfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous declaration for 'frsqrte' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsub.c:11:1: error: no previous declaration for 'fsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsubs.c:12:1: error: no previous declaration for 'fsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous declaration for 'mcrfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mffs.c:10:1: error: no previous declaration for 'mffs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous declaration for 'mtfsb0' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous declaration for 'mtfsb1' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous declaration for 'stfiwx' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfs.c:12:1: error: no previous declaration for 'stfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmr.c:7:1: error: no previous declaration for 'fmr' [-Werror=missing-declarations]
	arch/powerpc/math-emu/lfd.c:10:1: error: no previous declaration for 'lfd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfd.c:7:1: error: no previous declaration for 'stfd' [-Werror=missing-declarations]

So also add -Wno-missing-declarations.

Reported-by: kernel test robot 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/688084b40b5ac88f2905cb207d5dad947d8d34dc.1662531153.git.christophe.leroy@csgroup.eu

powerpc: make facility_unavailable_exception 64s

2022-07-28T06:22:14+00:00

The facility unavailable exception is only available on ppc book3s
machines so use CONFIG_PPC_BOOK3S_64 rather than CONFIG_PPC64.
tm_unavailable is only called from facility_unavailable_exception so can
also be under this Kconfig symbol.

Signed-off-by: Rashmica Gupta 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220617042805.426231-1-rashmica@linux.ibm.com

powerpc/kasan: Don't instrument non-maskable or raw interrupts

2022-05-22T05:58:29+00:00

Disable address sanitization for raw and non-maskable interrupt
handlers, because they can run in real mode, where we cannot access
the shadow memory.  (Note that kasan_arch_is_ready() doesn't test for
real mode, since it is a static branch for speed, and in any case not
all the entry points to the generic KASAN code are protected by
kasan_arch_is_ready guards.)

The changes to interrupt_nmi_enter/exit_prepare() look larger than
they actually are.  The changes are equivalent to adding
!IS_ENABLED(CONFIG_KASAN) to the conditions for calling nmi_enter() or
nmi_exit() in real mode.  That is, the code is equivalent to using the
following condition for calling nmi_enter/exit:

	if (((!IS_ENABLED(CONFIG_PPC_BOOK3S_64) ||
			!firmware_has_feature(FW_FEATURE_LPAR) ||
			radix_enabled()) &&
		    !IS_ENABLED(CONFIG_KASAN) ||
		(mfmsr() & MSR_DR))

That unwieldy condition has been split into several statements with
comments, for easier reading.

The nmi_ipi_lock functions that call atomic functions (i.e.,
nmi_ipi_lock_start(), nmi_ipi_lock() and nmi_ipi_unlock()), besides
being marked noinstr, now call arch_atomic_* functions instead of
atomic_* functions because with KASAN enabled, the atomic_* functions
are wrappers which explicitly do address sanitization on their
arguments.  Since we are trying to avoid address sanitization, we have
to use the lower-level arch_atomic_* versions.

In hv_nmi_check_nonrecoverable(), the regs_set_unrecoverable() call
has been open-coded so as to avoid having to either trust the inlining
or mark regs_set_unrecoverable() as noinstr.

[paulus@ozlabs.org: combined a few work-in-progress commits of
 Daniel's and wrote the commit message.]

Signed-off-by: Daniel Axtens 
Signed-off-by: Paul Mackerras 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/YoTFGaKM8Pd46PIK@cleo

exit: Add and use make_task_dead.

2021-12-13T18:04:45+00:00

There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman"

powerpc/64s: Fix unrecoverable MCE calling async handler from NMI

2021-10-07T08:54:55+00:00

The machine check handler is not considered NMI on 64s. The early
handler is the true NMI handler, and then it schedules the
machine_check_exception handler to run when interrupts are enabled.

This works fine except the case of an unrecoverable MCE, where the true
NMI is taken when MSR[RI] is clear, it can not recover, so it calls
machine_check_exception directly so something might be done about it.

Calling an async handler from NMI context can result in irq state and
other things getting corrupted. This can also trigger the BUG at
  arch/powerpc/include/asm/interrupt.h:168
  BUG_ON(!arch_irq_disabled_regs(regs) && !(regs->msr & MSR_EE));

Fix this by making an _async version of the handler which is called
in the normal case, and a NMI version that is called for unrecoverable
interrupts.

Fixes: 2b43dd7653cc ("powerpc/64: enable MSR[EE] in irq replay pt_regs")
Signed-off-by: Nicholas Piggin 
Tested-by: Cédric Le Goater 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211004145642.1331214-6-npiggin@gmail.com

powerpc/traps: do not enable irqs in _exception

2021-10-07T08:54:54+00:00

_exception can be called by machine check handlers when the MCE hits
user code (e.g., pseries and powernv). This will enable local irqs
because, which is a dicey thing to do in NMI or hard irq context.

This seemed to worked out okay because a userspace MCE can basically be
treated like a synchronous interrupt (after async / imprecise MCEs are
filtered out). Since NMI and hard irq handlers have started growing
nmi_enter / irq_enter, and more irq state sanity checks, this has
started to cause problems (or at least trigger warnings).

The Fixes tag to the commit which introduced this rather than try to
work out exactly which commit was the first that could possibly cause a
problem because that may be difficult to prove.

Fixes: 9f2f79e3a3c1 ("powerpc: Disable interrupts in 64-bit kernel FP and vector faults")
Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211004145642.1331214-3-npiggin@gmail.com

Merge branch 'akpm' (patches from Andrew)

2021-09-08T19:55:35+00:00

Merge more updates from Andrew Morton:
 "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f.

  Subsystems affected by this patch series: mm (memory-hotplug, rmap,
  ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
  alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
  checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
  selftests, ipc, and scripts"

* emailed patches from Andrew Morton : (94 commits)
  scripts: check_extable: fix typo in user error message
  mm/workingset: correct kernel-doc notations
  ipc: replace costly bailout check in sysvipc_find_ipc()
  selftests/memfd: remove unused variable
  Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
  configs: remove the obsolete CONFIG_INPUT_POLLDEV
  prctl: allow to setup brk for et_dyn executables
  pid: cleanup the stale comment mentioning pidmap_init().
  kernel/fork.c: unexport get_{mm,task}_exe_file
  coredump: fix memleak in dump_vma_snapshot()
  fs/coredump.c: log if a core dump is aborted due to changed file permissions
  nilfs2: use refcount_dec_and_lock() to fix potential UAF
  nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
  nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
  nilfs2: fix NULL pointer in nilfs_##name##_attr_release
  nilfs2: fix memory leak in nilfs_sysfs_create_device_group
  trap: cleanup trap_init()
  init: move usermodehelper_enable() to populate_rootfs()
  ...