powerpc: Rely on generic printing of preemption model

After the first printk in __die() there is show_regs() ->
show_regs_print_info() which prints the current
preemption model.

Remove the preempio

powerpc: Rely on generic printing of preemption model

After the first printk in __die() there is show_regs() ->
show_regs_print_info() which prints the current
preemption model.

Remove the preempion model from the arch code.

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Reviewed-by: Shrikanth Hegde <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/traps: Use backlight power constants

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality or sema

powerpc/traps: Use backlight power constants

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality or semantics.

traps.c already includes backlight.h where the BACKLIGHT
constants are defined.

Signed-off-by: Thomas Zimmermann <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

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powerpc: Remove core support for 40x

Now that 40x platforms have gone, remove support
for 40x in the core of powerpc arch.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-b

powerpc: Remove core support for 40x

Now that 40x platforms have gone, remove support
for 40x in the core of powerpc arch.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

show more ...

powerpc: Use user_mode() macro when possible

There is a nice macro to check user mode.

Use it instead of open coding anding with MSR_PR to increase
readability and avoid having to comment what that

powerpc: Use user_mode() macro when possible

There is a nice macro to check user mode.

Use it instead of open coding anding with MSR_PR to increase
readability and avoid having to comment what that anding is for.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/fbf74887dcf1f1ba9e1680fc3247cbb581b00662.1708078228.git.christophe.leroy@csgroup.eu

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powerpc: Fix build error due to is_valid_bugaddr()

With CONFIG_GENERIC_BUG=n the build fails with:

arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror

powerpc: Fix build error due to is_valid_bugaddr()

With CONFIG_GENERIC_BUG=n the build fails with:

arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes]
1442 | int is_valid_bugaddr(unsigned long addr)
| ^~~~~~~~~~~~~~~~

The prototype is only defined, and the function is only needed, when
CONFIG_GENERIC_BUG=y, so move the implementation under that.

Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

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powerpc: Remove extern from function implementations

Sparse reports several function implementations annotated with extern.
This is clearly incorrect, likely just copied from an actual extern
declar

powerpc: Remove extern from function implementations

Sparse reports several function implementations annotated with extern.
This is clearly incorrect, likely just copied from an actual extern
declaration in another file.

Fix the sparse warnings by removing extern.

Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

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powerpc: Only define __parse_fpscr() when required

Clang 17 reports:

arch/powerpc/kernel/traps.c:1167:19: error: unused function '__parse_fpscr' [-Werror,-Wunused-function]

__parse_fpscr() is call

powerpc: Only define __parse_fpscr() when required

Clang 17 reports:

arch/powerpc/kernel/traps.c:1167:19: error: unused function '__parse_fpscr' [-Werror,-Wunused-function]

__parse_fpscr() is called from two sites. First call is guarded
by #ifdef CONFIG_PPC_FPU_REGS

Second call is guarded by CONFIG_MATH_EMULATION which selects
CONFIG_PPC_FPU_REGS.

So only define __parse_fpscr() when CONFIG_PPC_FPU_REGS is defined.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: b6254ced4da6 ("powerpc/signal: Don't manage floating point regs when no FPU")
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/5de2998c57f3983563b27b39228ea9a7229d4110.1695385984.git.christophe.leroy@csgroup.eu

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powerpc/dexcr: Move HASHCHK trap handler

Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
handler logic:

BUG: sleeping function called from invalid context at arch/powerpc

powerpc/dexcr: Move HASHCHK trap handler

Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
handler logic:

BUG: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:1518
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 25040, name: syz-executor
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
no locks held by syz-executor/25040.
irq event stamp: 34
hardirqs last enabled at (33): [<c000000000048b38>] prep_irq_for_enabled_exit arch/powerpc/kernel/interrupt.c:56 [inline]
hardirqs last enabled at (33): [<c000000000048b38>] interrupt_exit_user_prepare_main+0x148/0x600 arch/powerpc/kernel/interrupt.c:230
hardirqs last disabled at (34): [<c00000000003e6a4>] interrupt_enter_prepare+0x144/0x4f0 arch/powerpc/include/asm/interrupt.h:176
softirqs last enabled at (0): [<c000000000281954>] copy_process+0x16e4/0x4750 kernel/fork.c:2436
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 15 PID: 25040 Comm: syz-executor Not tainted 6.5.0-rc5-00001-g3ccdff6bb06d #3
Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1040.00 (NL1040_021) hv:phyp pSeries
Call Trace:
[c0000000a8247ce0] [c00000000032b0e4] __might_resched+0x3b4/0x400 kernel/sched/core.c:10189
[c0000000a8247d80] [c0000000008c7dc8] __might_fault+0xa8/0x170 mm/memory.c:5853
[c0000000a8247dc0] [c00000000004160c] do_program_check+0x32c/0xb20 arch/powerpc/kernel/traps.c:1518
[c0000000a8247e50] [c000000000009b2c] program_check_common_virt+0x3bc/0x3c0

To determine if a trap was caused by a HASHCHK instruction, we inspect
the user instruction that triggered the trap. However this may sleep
if the page needs to be faulted in (get_user_instr() reaches
__get_user(), which calls might_fault() and triggers the bug message).

Move the HASHCHK handler logic to after we allow IRQs, which is fine
because we are only interested in HASHCHK if it's a user space trap.

Fixes: 5bcba4e6c13f ("powerpc/dexcr: Handle hashchk exception")
Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

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powerpc/4xx: Remove WatchdogHandler() to fix no previous prototype error

Building ppc40x_defconfig throws the following error:

CC arch/powerpc/kernel/traps.o
arch/powerpc/kernel/traps.c:2232

powerpc/4xx: Remove WatchdogHandler() to fix no previous prototype error

Building ppc40x_defconfig throws the following error:

CC arch/powerpc/kernel/traps.o
arch/powerpc/kernel/traps.c:2232:29: warning: no previous prototype for 'WatchdogHandler' [-Wmissing-prototypes]
2232 | void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
| ^~~~~~~~~~~~~~~

This function was imported by commit 14cf11af6cf6 ("powerpc: Merge
enough to start building in arch/powerpc.") as a weak function but
never defined and/or called outside traps.c

As it has only one caller fold it inside its caller and remove it.

Signed-off-by: Christophe Leroy <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/38fe1078eb403eef74dc8f29387636fd7ecdf43c.1692276041.git.christophe.leroy@csgroup.eu

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powerpc/kuap: Simplify KUAP lock/unlock on BOOK3S/32

On book3s/32 KUAP is performed at segment level. At the moment,
when enabling userspace access, only current segment is modified.
Then if a write

powerpc/kuap: Simplify KUAP lock/unlock on BOOK3S/32

On book3s/32 KUAP is performed at segment level. At the moment,
when enabling userspace access, only current segment is modified.
Then if a write is performed on another user segment, a fault is
taken and all other user segments get enabled for userspace
access. This then require special attention when disabling
userspace access.

Having a userspace write access crossing a segment boundary is
unlikely. Having a userspace write access crossing a segment boundary
back and forth is even more unlikely. So, instead of enabling
userspace access on all segments when a write fault occurs, just
change which segment has userspace access enabled in order to
eliminate the case when more than one segment has userspace access
enabled. That simplifies userspace access deactivation.

There is however a corner case which is even more unlikely but has
to be handled anyway: an unaligned access which is crossing a
segment boundary. That would definitely require at least having
userspace access enabled on the two segments. To avoid complicating
the likely case for a so unlikely happening, handle such situation
like an alignment exception and emulate the store.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/8de8580513c1a6e880bad1ba9a69d3efad3d4fa5.1689091022.git.christophe.leroy@csgroup.eu

show more ...

Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"

This partly reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.

That commit aimed at optimising the cod

Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"

This partly reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.

That commit aimed at optimising the code around generation of
WARN_ON/BUG_ON but this leads to a lot of dead code erroneously
generated by GCC.

That dead code becomes a problem when we start using objtool validation
because objtool will abort validation with a warning as soon as it
detects unreachable code. This is because unreachable code might
be the indication that objtool doesn't properly decode object text.

text data bss dec hex filename
9551585 3627834 224376 13403795 cc8693 vmlinux.before
9535281 3628358 224376 13388015 cc48ef vmlinux.after

Once this change is reverted, in a standard configuration (pmac32 +
function tracer) the text is reduced by 16k which is around 1.7%

We already had problem with it when starting to use objtool on powerpc
as a replacement for recordmcount, see commit 93e3f45a2631 ("powerpc:
Fix __WARN_FLAGS() for use with Objtool")

There is also a problem with at least GCC 12, on ppc64_defconfig +
CONFIG_CC_OPTIMIZE_FOR_SIZE=y + CONFIG_DEBUG_SECTION_MISMATCH=y :

LD .tmp_vmlinux.kallsyms1
powerpc64-linux-ld: net/ipv4/tcp_input.o:(__ex_table+0xc4): undefined reference to `.L2136'
make[2]: *** [scripts/Makefile.vmlinux:36: vmlinux] Error 1
make[1]: *** [/home/chleroy/linux-powerpc/Makefile:1238: vmlinux] Error 2

Taking into account that other problems are encountered with that
'asm goto' in WARN_ON(), including build failures, keeping that
change is not worth it allthough it is primarily a compiler bug.

Revert it for now.

mpe: Retain EMIT_WARN_ENTRY as a synonym for EMIT_BUG_ENTRY to reduce
churn, as there are now nearly as many uses of EMIT_WARN_ENTRY as
EMIT_BUG_ENTRY.

Signed-off-by: Christophe Leroy <[email protected]>
Acked-by: Naveen N Rao <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

show more ...

powerpc/dexcr: Handle hashchk exception

Recognise and pass the appropriate signal to the user program when a
hashchk instruction triggers. This is independent of allowing
configuration of DEXCR[NPHI

powerpc/dexcr: Handle hashchk exception

Recognise and pass the appropriate signal to the user program when a
hashchk instruction triggers. This is independent of allowing
configuration of DEXCR[NPHIE], as a hypervisor can enforce this aspect
regardless of the kernel.

The signal mirrors how ARM reports their similar check failure. For
example, their FPAC handler in arch/arm64/kernel/traps.c do_el0_fpac()
does this. When we fail to read the instruction that caused the fault
we send a segfault, similar to how emulate_math() does it.

Signed-off-by: Benjamin Gray <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]

show more ...

powerpc/64s: early boot machine check handler

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 a

powerpc/64s: early boot machine check handler

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 <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

powerpc: Change CONFIG_E500 to CONFIG_PPC_E500

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

powerpc: Change CONFIG_E500 to CONFIG_PPC_E500

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 <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu

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powerpc: Remove CONFIG_FSL_BOOKE

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 i

powerpc: Remove CONFIG_FSL_BOOKE

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 <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/08e3e15594e66d63b9e89c5b4f9c35153913c28f.1663606875.git.christophe.leroy@csgroup.eu

show more ...

powerpc/math-emu: Inhibit W=1 warnings

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/f

powerpc/math-emu: Inhibit W=1 warnings

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 <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/688084b40b5ac88f2905cb207d5dad947d8d34dc.1662531153.git.christophe.leroy@csgroup.eu

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powerpc: make facility_unavailable_exception 64s

The facility unavailable exception is only available on ppc book3s
machines so use CONFIG_PPC_BOOK3S_64 rather than CONFIG_PPC64.
tm_unavailable is o

powerpc: make facility_unavailable_exception 64s

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 <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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

Disable address sanitization for raw and non-maskable interrupt
handlers, because they can run in real mode, where we cannot access
the

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

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.

[[email protected]: combined a few work-in-progress commits of
Daniel's and wrote the commit message.]

Signed-off-by: Daniel Axtens <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/YoTFGaKM8Pd46PIK@cleo

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exit: Add and use make_task_dead.

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 c

exit: Add and use make_task_dead.

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" <[email protected]>

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

The machine check handler is not considered NMI on 64s. The early
handler is the true NMI handler, and then it schedules the
machine

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

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 <[email protected]>
Tested-by: Cédric Le Goater <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/traps: do not enable irqs in _exception

_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

powerpc/traps: do not enable irqs in _exception

_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 <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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trap: cleanup trap_init()

There are some empty trap_init() definitions in different ARCHs, Introduce
a new weak trap_init() function to clean them up.

Link: https://lkml.kernel.org/r/20210812123602

trap: cleanup trap_init()

There are some empty trap_init() definitions in different ARCHs, Introduce
a new weak trap_init() function to clean them up.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Acked-by: Russell King (Oracle) <[email protected]> [arm32]
Acked-by: Vineet Gupta [arc]
Acked-by: Michael Ellerman <[email protected]> [powerpc]
Cc: Yoshinori Sato <[email protected]>
Cc: Ley Foon Tan <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: James E.J. Bottomley <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Anton Ivanov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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powerpc: Refactor verification of MSR_RI

40x and BOOKE don't have MSR_RI therefore all tests involving
MSR_RI may be problematic on those plateforms.

Create helpers to check or set MSR_RI in regs,

powerpc: Refactor verification of MSR_RI

40x and BOOKE don't have MSR_RI therefore all tests involving
MSR_RI may be problematic on those plateforms.

Create helpers to check or set MSR_RI in regs, and use them
in common code.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/c2fb93708196734f4176dda334aaa3055f213b89.1629707037.git.christophe.leroy@csgroup.eu

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powerpc: Add esr as a synonym for pt_regs.dsisr

Create an anonymous union for dsisr and esr regsiters, we can reference
esr to get the exception detail when CONFIG_4xx=y or CONFIG_BOOKE=y.
Otherwise

powerpc: Add esr as a synonym for pt_regs.dsisr

Create an anonymous union for dsisr and esr regsiters, we can reference
esr to get the exception detail when CONFIG_4xx=y or CONFIG_BOOKE=y.
Otherwise, reference dsisr. This makes code more clear.

Signed-off-by: Xiongwei Song <[email protected]>
[mpe: Reword commit title]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto

Using asm goto in __WARN_FLAGS() and WARN_ON() allows more
flexibility to GCC.

For that add an entry to the exception

powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto

Using asm goto in __WARN_FLAGS() and WARN_ON() allows more
flexibility to GCC.

For that add an entry to the exception table so that
program_check_exception() knowns where to resume execution
after a WARNING.

Here are two exemples. The first one is done on PPC32 (which
benefits from the previous patch), the second is on PPC64.

unsigned long test(struct pt_regs *regs)
{
int ret;

WARN_ON(regs->msr & MSR_PR);

return regs->gpr[3];
}

unsigned long test9w(unsigned long a, unsigned long b)
{
if (WARN_ON(!b))
return 0;
return a / b;
}

Before the patch:

000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr

3bc: 0f e0 00 00 twui r0,0
3c0: 80 63 00 0c lwz r3,12(r3)
3c4: 4e 80 00 20 blr

0000000000000bf0 <.test9w>:
bf0: 7c 89 00 74 cntlzd r9,r4
bf4: 79 29 d1 82 rldicl r9,r9,58,6
bf8: 0b 09 00 00 tdnei r9,0
bfc: 2c 24 00 00 cmpdi r4,0
c00: 41 82 00 0c beq c0c <.test9w+0x1c>
c04: 7c 63 23 92 divdu r3,r3,r4
c08: 4e 80 00 20 blr

c0c: 38 60 00 00 li r3,0
c10: 4e 80 00 20 blr

After the patch:

000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr

3bc: 0f e0 00 00 twui r0,0

0000000000000c50 <.test9w>:
c50: 7c 89 00 74 cntlzd r9,r4
c54: 79 29 d1 82 rldicl r9,r9,58,6
c58: 0b 09 00 00 tdnei r9,0
c5c: 7c 63 23 92 divdu r3,r3,r4
c60: 4e 80 00 20 blr

c70: 38 60 00 00 li r3,0
c74: 4e 80 00 20 blr

In the first exemple, we see GCC doesn't need to duplicate what
happens after the trap.

In the second exemple, we see that GCC doesn't need to emit a test
and a branch in the likely path in addition to the trap.

We've got some WARN_ON() in .softirqentry.text section so it needs
to be added in the OTHER_TEXT_SECTIONS in modpost.c

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/389962b1b702e3c78d169e59bcfac56282889173.1618331882.git.christophe.leroy@csgroup.eu

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