Commit Graph

286 Commits

Author SHA1 Message Date
Christophe Leroy 76222808fc powerpc: Move C prototypes out of asm-prototypes.h
We originally added asm-prototypes.h in commit 42f5b4cacd ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions that are only called from asm, in order to fix sparse
warnings about missing prototypes.

A few months later Nick added a different use case in
commit 4efca4ed05 ("kbuild: modversions for EXPORT_SYMBOL() for asm")
for C prototypes for exported asm functions. This is basically the
inverse of our original usage.

Since then we've added various prototypes to asm-prototypes.h for both
reasons, meaning we now need to unstitch it all.

Dispatch prototypes of C functions into relevant headers and keep
only the prototypes for functions defined in assembly.

For the time being, leave prom_init() there because moving it
into asm/prom.h or asm/setup.h conflicts with
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o
This will be fixed later by untaggling asm/pci.h and asm/prom.h
or by renaming the function in shadowrom.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
2022-03-08 22:06:25 +11:00
Nicholas Piggin 0faf20a1ad powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless perf is in use
Enabling MSR[EE] in interrupt handlers while interrupts are still soft
masked allows PMIs to profile interrupt handlers to some degree, beyond
what SIAR latching allows.

When perf is not being used, this is almost useless work. It requires an
extra mtmsrd in the irq handler, and it also opens the door to masked
interrupts hitting and requiring replay, which is more expensive than
just taking them directly. This effect can be noticable in high IRQ
workloads.

Avoid enabling MSR[EE] unless perf is currently in use. This saves about
60 cycles (or 8%) on a simple decrementer interrupt microbenchmark.
Replayed interrupts drop from 1.4% of all interrupts taken, to 0.003%.

This does prevent the soft-nmi interrupt being taken in these handlers,
but that's not too reliable anyway. The SMP watchdog will continue to be
the reliable way to catch lockups.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210922145452.352571-5-npiggin@gmail.com
2021-12-16 21:31:45 +11:00
Christophe Leroy 047a6fd401 powerpc/config: Add CONFIG_BOOKE_OR_40x
We have many functionnalities common to 40x and BOOKE, it leads to
many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x).

We are going to add a few more with KUAP for booke/40x, so create
a new symbol which is defined when either BOOKE or 40x is defined.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9a3dbd60924cb25c9f944d3d8205ac5a0d15e229.1634627931.git.christophe.leroy@csgroup.eu
2021-12-09 22:41:19 +11:00
Nicholas Piggin ff058a8ada powerpc/64: warn if local irqs are enabled in NMI or hardirq context
This can help catch bugs such as the one fixed by the previous change
to prevent _exception() from enabling irqs.

ppc32 could have a similar warning but it has no good config option to
debug this stuff (the test may be overkill to add for production
kernels).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-4-npiggin@gmail.com
2021-10-07 19:54:55 +11:00
Christophe Leroy 98694166c2 powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()
An interrupt handler shall not be called from another interrupt
handler otherwise this leads to problems like the following:

  Kernel attempted to write user page (afd4fa84) - exploit attempt? (uid: 1000)
  ------------[ cut here ]------------
  Bug: Write fault blocked by KUAP!
  WARNING: CPU: 0 PID: 1617 at arch/powerpc/mm/fault.c:230 do_page_fault+0x484/0x720
  Modules linked in:
  CPU: 0 PID: 1617 Comm: sshd Tainted: G        W         5.13.0-pmac-00010-g8393422eb77 #7
  NIP:  c001b77c LR: c001b77c CTR: 00000000
  REGS: cb9e5bc0 TRAP: 0700   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  00021032 <ME,IR,DR,RI>  CR: 24942424  XER: 00000000

  GPR00: c001b77c cb9e5c80 c1582c00 00000021 3ffffbff 085b0000 00000027 c8eb644c
  GPR08: 00000023 00000000 00000000 00000000 24942424 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90
  GPR24: 00000040 afd4fa96 00000040 02000000 c1fda6c0 afd4fa84 00000300 cb9e5cc0
  NIP [c001b77c] do_page_fault+0x484/0x720
  LR [c001b77c] do_page_fault+0x484/0x720
  Call Trace:
  [cb9e5c80] [c001b77c] do_page_fault+0x484/0x720 (unreliable)
  [cb9e5cb0] [c000424c] DataAccess_virt+0xd4/0xe4
  --- interrupt: 300 at __copy_tofrom_user+0x110/0x20c
  NIP:  c001f9b4 LR: c03250a0 CTR: 00000004
  REGS: cb9e5cc0 TRAP: 0300   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 48028468  XER: 20000000
  DAR: afd4fa84 DSISR: 0a000000
  GPR00: 20726f6f cb9e5d80 c1582c00 00000004 cb9e5e3a 00000016 afd4fa80 00000000
  GPR08: 3835202d 72777872 2d78722d 00000004 28028464 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90
  GPR24: 00000040 afd4fa96 00000040 cb9e5e0c 00000daa a0000000 cb9e5e98 afd4fa56
  NIP [c001f9b4] __copy_tofrom_user+0x110/0x20c
  LR [c03250a0] _copy_to_iter+0x144/0x990
  --- interrupt: 300
  [cb9e5d80] [c03e89c0] n_tty_read+0xa4/0x598 (unreliable)
  [cb9e5df0] [c03e2a0c] tty_read+0xdc/0x2b4
  [cb9e5e80] [c0156bf8] vfs_read+0x274/0x340
  [cb9e5f00] [c01571ac] ksys_read+0x70/0x118
  [cb9e5f30] [c0016048] ret_from_syscall+0x0/0x28
  --- interrupt: c00 at 0xa7855c88
  NIP:  a7855c88 LR: a7855c5c CTR: 00000000
  REGS: cb9e5f40 TRAP: 0c00   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  0000d032 <EE,PR,ME,IR,DR,RI>  CR: 2402446c  XER: 00000000

  GPR00: 00000003 afd4ec70 a72137d0 0000000b afd4ecac 00004000 0065a990 00000800
  GPR08: 00000000 a7947930 00000000 00000004 c15831b0 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 0065a9e0 00000001 0065fac0
  GPR24: 00000000 00000089 00664050 00000000 00668e30 a720c8dc a7943ff4 0065f9b0
  NIP [a7855c88] 0xa7855c88
  LR [a7855c5c] 0xa7855c5c
  --- interrupt: c00
  Instruction dump:
  3884aa88 38630178 48076861 807f0080 48042e45 2f830000 419e0148 3c80c079
  3c60c076 38841be4 386301c0 4801f705 <0fe00000> 3860000b 4bfffe30 3c80c06b
  ---[ end trace fd69b91a8046c2e5 ]---

Here the problem is that by re-enterring an exception handler,
kuap_save_and_lock() is called a second time with this time KUAP
access locked, leading to regs->kuap being overwritten hence
KUAP not being unlocked at exception exit as expected.

Do not call do_IRQ() from timer_interrupt() directly. Instead,
redefine do_IRQ() as a standard function named __do_IRQ(), and
call it from both do_IRQ() and time_interrupt() handlers.

Fixes: 3a96570ffc ("powerpc: convert interrupt handlers to use wrappers")
Cc: stable@vger.kernel.org # v5.12+
Reported-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c17d234f4927d39a1d7100864a8e1145323d33a0.1628611927.git.christophe.leroy@csgroup.eu
2021-08-12 22:21:57 +10:00
Nicholas Piggin 2b43dd7653 powerpc/64: enable MSR[EE] in irq replay pt_regs
Similar to commit 2b48e96be2 ("powerpc/64: fix irq replay
pt_regs->softe value"), enable MSR_EE in pt_regs->msr. This makes the
regs look more normal. It also allows some extra debug checks to be
added to interrupt handler entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210630074621.2109197-7-npiggin@gmail.com
2021-06-30 22:21:20 +10:00
Nicholas Piggin 862fa56352 powerpc/64: interrupt soft-enable race fix
Prevent interrupt restore from allowing racing hard interrupts going
ahead of previous soft-pending ones, by using the soft-masked restart
handler to allow a store to clear the soft-mask while knowing nothing
is soft-pending.

This probably doesn't matter much in practice, but it's a simple
demonstrator / test case to exercise the restart table logic.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-11-npiggin@gmail.com
2021-06-25 00:06:56 +10:00
Christophe Leroy e522331173 powerpc/irq: Enhance readability of trap types
This patch makes use of trap types in irq.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f7f8c9f98c33eaea316755c7fef150d1d77e047d.1618847273.git.christophe.leroy@csgroup.eu
2021-04-21 22:52:32 +10:00
Nicholas Piggin 0c2472de23 powerpc/64e/interrupt: use new interrupt return
Update the new C and asm interrupt return code to account for 64e
specifics, switch over to use it.

The now-unused old ret_from_except code, that was moved to 64e after the
64s conversion, is removed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-5-npiggin@gmail.com
2021-04-14 23:04:20 +10:00
Christophe Leroy 48cf12d889 powerpc/irq: Inline call_do_irq() and call_do_softirq()
call_do_irq() and call_do_softirq() are simple enough to be
worth inlining.

Inlining them avoids an mflr/mtlr pair plus a save/reload on stack.

This is inspired from S390 arch. Several other arches do more or
less the same. The way sparc arch does seems odd thought.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210320122227.345427-1-mpe@ellerman.id.au
2021-03-29 13:22:17 +11:00
Christophe Leroy ad2d234477 powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic
In preparation of porting powerpc32 to C syscall entry/exit,
rename kuap_check_amr() and kuap_get_and_check_amr() as
kuap_assert_locked() and kuap_get_and_assert_locked(), and move in the
generic asm/kup.h the stub for when CONFIG_PPC_KUAP is not selected.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f82614d9b17b83abd739aa18fc08811815d0c2e3.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29 13:22:11 +11:00
Linus Torvalds 29c395c77a Rework of the X86 irq stack handling:
The irq stack switching was moved out of the ASM entry code in course of
   the entry code consolidation. It ended up being suboptimal in various
   ways.
 
   - Make the stack switching inline so the stackpointer manipulation is not
     longer at an easy to find place.
 
   - Get rid of the unnecessary indirect call.
 
   - Avoid the double stack switching in interrupt return and reuse the
     interrupt stack for softirq handling.
 
   - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused
     about the stack pointer manipulation.
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Merge tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 irq entry updates from Thomas Gleixner:
 "The irq stack switching was moved out of the ASM entry code in course
  of the entry code consolidation. It ended up being suboptimal in
  various ways.

  This reworks the X86 irq stack handling:

   - Make the stack switching inline so the stackpointer manipulation is
     not longer at an easy to find place.

   - Get rid of the unnecessary indirect call.

   - Avoid the double stack switching in interrupt return and reuse the
     interrupt stack for softirq handling.

   - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got
     confused about the stack pointer manipulation"

* tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix stack-swizzle for FRAME_POINTER=y
  um: Enforce the usage of asm-generic/softirq_stack.h
  x86/softirq/64: Inline do_softirq_own_stack()
  softirq: Move do_softirq_own_stack() to generic asm header
  softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig
  x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
  x86/softirq: Remove indirection in do_softirq_own_stack()
  x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall
  x86/entry: Convert device interrupts to inline stack switching
  x86/entry: Convert system vectors to irq stack macro
  x86/irq: Provide macro for inlining irq stack switching
  x86/apic: Split out spurious handling code
  x86/irq/64: Adjust the per CPU irq stack pointer by 8
  x86/irq: Sanitize irq stack tracking
  x86/entry: Fix instrumentation annotation
2021-02-24 16:32:23 -08:00
Linus Torvalds b12b472496 powerpc updates for 5.12
A large series adding wrappers for our interrupt handlers, so that irq/nmi/user
 tracking can be isolated in the wrappers rather than spread in each handler.
 
 Conversion of the 32-bit syscall handling into C.
 
 A series from Nick to streamline our TLB flushing when using the Radix MMU.
 
 Switch to using queued spinlocks by default for 64-bit server CPUs.
 
 A rework of our PCI probing so that it happens later in boot, when more generic
 infrastructure is available.
 
 Two small fixes to allow 32-bit little-endian processes to run on 64-bit
 kernels.
 
 Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira
   Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy,
   Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh
   Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus
   Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
   O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan
   Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, Zheng
   Yongjun.
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Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - A large series adding wrappers for our interrupt handlers, so that
   irq/nmi/user tracking can be isolated in the wrappers rather than
   spread in each handler.

 - Conversion of the 32-bit syscall handling into C.

 - A series from Nick to streamline our TLB flushing when using the
   Radix MMU.

 - Switch to using queued spinlocks by default for 64-bit server CPUs.

 - A rework of our PCI probing so that it happens later in boot, when
   more generic infrastructure is available.

 - Two small fixes to allow 32-bit little-endian processes to run on
   64-bit kernels.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh
Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang
Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian
Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong,
Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan
Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu,
Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen
Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun.

* tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits)
  powerpc/perf: Adds support for programming of Thresholding in P10
  powerpc/pci: Remove unimplemented prototypes
  powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user()
  powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size()
  powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user()
  powerpc/64: Fix stack trace not displaying final frame
  powerpc/time: Remove get_tbl()
  powerpc/time: Avoid using get_tbl()
  spi: mpc52xx: Avoid using get_tbl()
  powerpc/syscall: Avoid storing 'current' in another pointer
  powerpc/32: Handle bookE debugging in C in syscall entry/exit
  powerpc/syscall: Do not check unsupported scv vector on PPC32
  powerpc/32: Remove the counter in global_dbcr0
  powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
  powerpc/syscall: implement system call entry/exit logic in C for PPC32
  powerpc/32: Always save non volatile GPRs at syscall entry
  powerpc/syscall: Change condition to check MSR_RI
  powerpc/syscall: Save r3 in regs->orig_r3
  powerpc/syscall: Use is_compat_task()
  powerpc/syscall: Make interrupt.c buildable on PPC32
  ...
2021-02-22 14:34:00 -08:00
Ingo Molnar a3251c1a36 Merge branch 'x86/paravirt' into x86/entry
Merge in the recent paravirt changes to resolve conflicts caused
by objtool annotations.

Conflicts:
	arch/x86/xen/xen-asm.S

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-02-12 13:36:43 +01:00
Alexey Kardashevskiy 60a707d0c9 powerpc/kuap: Restore AMR after replaying soft interrupts
Since de78a9c42a ("powerpc: Add a framework for Kernel Userspace
Access Protection"), user access helpers call user_{read|write}_access_{begin|end}
when user space access is allowed.

Commit 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU") made
the mentioned helpers program a AMR special register to allow such
access for a short period of time, most of the time AMR is expected to
block user memory access by the kernel.

Since the code accesses the user space memory, unsafe_get_user() calls
might_fault() which calls arch_local_irq_restore() if either
CONFIG_PROVE_LOCKING or CONFIG_DEBUG_ATOMIC_SLEEP is enabled.
arch_local_irq_restore() then attempts to replay pending soft
interrupts as KUAP regions have hardware interrupts enabled.

If a pending interrupt happens to do user access (performance
interrupts do that), it enables access for a short period of time so
after returning from the replay, the user access state remains blocked
and if a user page fault happens - "Bug: Read fault blocked by AMR!"
appears and SIGSEGV is sent.

An example trace:
  Bug: Read fault blocked by AMR!
  WARNING: CPU: 0 PID: 1603 at /home/aik/p/kernel/arch/powerpc/include/asm/book3s/64/kup-radix.h:145
  CPU: 0 PID: 1603 Comm: amr Not tainted 5.10.0-rc6_v5.10-rc6_a+fstn1 #24
  NIP:  c00000000009ece8 LR: c00000000009ece4 CTR: 0000000000000000
  REGS: c00000000dc63560 TRAP: 0700   Not tainted  (5.10.0-rc6_v5.10-rc6_a+fstn1)
  MSR:  8000000000021033 <SF,ME,IR,DR,RI,LE>  CR: 28002888  XER: 20040000
  CFAR: c0000000001fa928 IRQMASK: 1
  GPR00: c00000000009ece4 c00000000dc637f0 c000000002397600 000000000000001f
  GPR04: c0000000020eb318 0000000000000000 c00000000dc63494 0000000000000027
  GPR08: c00000007fe4de68 c00000000dfe9180 0000000000000000 0000000000000001
  GPR12: 0000000000002000 c0000000030a0000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 bfffffffffffffff
  GPR20: 0000000000000000 c0000000134a4020 c0000000019c2218 0000000000000fe0
  GPR24: 0000000000000000 0000000000000000 c00000000d106200 0000000040000000
  GPR28: 0000000000000000 0000000000000300 c00000000dc63910 c000000001946730
  NIP __do_page_fault+0xb38/0xde0
  LR  __do_page_fault+0xb34/0xde0
  Call Trace:
    __do_page_fault+0xb34/0xde0 (unreliable)
    handle_page_fault+0x10/0x2c
  --- interrupt: 300 at strncpy_from_user+0x290/0x440
      LR = strncpy_from_user+0x284/0x440
    strncpy_from_user+0x2f0/0x440 (unreliable)
    getname_flags+0x88/0x2c0
    do_sys_openat2+0x2d4/0x5f0
    do_sys_open+0xcc/0x140
    system_call_exception+0x160/0x240
    system_call_common+0xf0/0x27c

To fix it save/restore the AMR when replaying interrupts, and also
add a check if AMR was not blocked prior to replaying interrupts.

Originally found by syzkaller.

Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use normal commit citation format and add full oops log to
      change log, move kuap_check_amr() into the restore routine to
      avoid warnings about unreconciled IRQ state]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210202091541.36499-1-aik@ozlabs.ru
2021-02-11 23:35:05 +11:00
Thomas Gleixner db1cc7aede softirq: Move do_softirq_own_stack() to generic asm header
To avoid include recursion hell move the do_softirq_own_stack() related
content into a generic asm header and include it from all places in arch/
which need the prototype.

This allows architectures to provide an inline implementation of
do_softirq_own_stack() without introducing a lot of #ifdeffery all over the
place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de
2021-02-10 23:34:16 +01:00
Nicholas Piggin 1b1b6a6f4c powerpc: handle irq_enter/irq_exit in interrupt handler wrappers
Move irq_enter/irq_exit into asynchronous interrupt handler wrappers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-35-npiggin@gmail.com
2021-02-09 00:10:49 +11:00
Nicholas Piggin 3a96570ffc powerpc: convert interrupt handlers to use wrappers
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-29-npiggin@gmail.com
2021-02-09 00:02:12 +11:00
Nicholas Piggin 4025c784c5 powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
When an asynchronous interrupt calls irq_exit, it checks for softirqs
that may have been created, and runs them. Running softirqs enables
local irqs, which can replay pending interrupts causing recursion in
replay_soft_interrupts. This abridged trace shows how this can occur:

! NIP replay_soft_interrupts
  LR  interrupt_exit_kernel_prepare
  Call Trace:
    interrupt_exit_kernel_prepare (unreliable)
    interrupt_return
  --- interrupt: ea0 at __rb_reserve_next
  NIP __rb_reserve_next
  LR __rb_reserve_next
  Call Trace:
    ring_buffer_lock_reserve
    trace_function
    function_trace_call
    ftrace_call
    __do_softirq
    irq_exit
    timer_interrupt
!   replay_soft_interrupts
    interrupt_exit_kernel_prepare
    interrupt_return
  --- interrupt: ea0 at arch_local_irq_restore

This can not be prevented easily, because softirqs must not block hard
irqs, so it has to be dealt with.

The recursion is bounded by design in the softirq code because softirq
replay disables softirqs and loops around again to check for new
softirqs created while it ran, so that's not a problem.

However it does mess up interrupt replay state, causing superfluous
interrupts when the second replay_soft_interrupts clears a pending
interrupt, leaving it still set in the first call in the 'happened'
local variable.

Fix this by not caching a copy of irqs_happened across interrupt
handler calls.

Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210123061244.2076145-1-npiggin@gmail.com
2021-01-24 22:27:24 +11:00
Nicholas Piggin 59d512e437 powerpc/64: irq replay remove decrementer overflow check
This is way to catch some cases of decrementer overflow, when the
decrementer has underflowed an odd number of times, while MSR[EE] was
disabled.

With a typical small decrementer, a timer that fires when MSR[EE] is
disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and
8.6 seconds after the timer expires. In any case, the decrementer
interrupt would be taken at 8.6 seconds and the timer would be found at
that point.

So this check is for catching extreme latency events, and it prevents
those latencies from being a further few seconds long.  It's not obvious
this is a good tradeoff. This is already a watchdog magnitude event and
that situation is not improved a significantly with this check. For
large decrementers, it's useless.

Therefore remove this check, which avoids a mftb when enabling hard
disabled interrupts (e.g., when enabling after coming from hardware
interrupt handlers). Perhaps more importantly, it also removes the
clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay
which simplifies the code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
2020-12-09 23:48:15 +11:00
Christophe Leroy 6601ec1c2b powerpc: Remove get_tb_or_rtc()
601 is gone, get_tb_or_rtc() is equivalent to get_tb().

Replace the former by the later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3e8a13ee83418630c753c30cb722ae682d5b2d39.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Nicholas Piggin 455575533c powerpc/64: make restore_interrupts 64e only
This is not used by 64s.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-5-npiggin@gmail.com
2020-10-06 23:22:24 +11:00
Nicholas Piggin 903dd1ff45 powerpc/64e: remove 64s specific interrupt soft-mask code
Since the assembly soft-masking code was moved to 64e specific, there
are some 64s specific interrupt types still there. Remove them.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-4-npiggin@gmail.com
2020-10-06 23:22:23 +11:00
Nicholas Piggin 012a9a97a8 powerpc/64e: remove PACA_IRQ_EE_EDGE
This is not used anywhere.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-3-npiggin@gmail.com
2020-10-06 23:22:23 +11:00
Nicholas Piggin 2b48e96be2 powerpc/64: fix irq replay pt_regs->softe value
Replayed interrupts get an "artificial" struct pt_regs constructed to
pass to interrupt handler functions. This did not get the softe field
set correctly, it's as though the interrupt has hit while irqs are
disabled. It should be IRQS_ENABLED.

This is possibly harmless, asynchronous handlers should not be testing
if irqs were disabled, but it might be possible for example some code
is shared with synchronous or NMI handlers, and it makes more sense if
debug output looks at this.

Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-2-npiggin@gmail.com
2020-10-06 23:22:23 +11:00
Nicholas Piggin 903fd31d32 powerpc/64: fix irq replay missing preempt
Prior to commit 3282a3da25 ("powerpc/64: Implement soft interrupt
replay in C"), replayed interrupts returned by the regular interrupt
exit code, which performs preemption in case an interrupt had set
need_resched.

This logic was missed by the conversion. Adding preempt_disable/enable
around the interrupt replay and final irq enable will reschedule if
needed.

Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-1-npiggin@gmail.com
2020-10-06 23:22:23 +11:00
Mahesh Salgaonkar ada68a66b7 powerpc/64s: Move HMI IRQ stat from percpu variable to paca.
With the proposed change in percpu bootmem allocator to use page
mapping [1], the percpu first chunk memory area can come from vmalloc
ranges. This makes the HMI (Hypervisor Maintenance Interrupt) handler
crash the kernel whenever percpu variable is accessed in real mode.
This patch fixes this issue by moving the HMI IRQ stat inside paca for
safe access in realmode.

[1] https://lore.kernel.org/linuxppc-dev/20200608070904.387440-1-aneesh.kumar@linux.ibm.com/

Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159290806973.3642154.5244613424529764050.stgit@jupiter
2020-07-29 23:47:53 +10:00
Mike Rapoport 65fddcfca8 mm: reorder includes after introduction of linux/pgtable.h
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s <file> <header>" % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include <linux/%s>" % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include <linux/"):
		    in_hdrs = True
		elif not moved and in_hdrs:
		    moved = True
		    print hdr_to_move
		print line

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Mike Rapoport ca5999fde0 mm: introduce include/linux/pgtable.h
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Christoph Hellwig cb0849a990 powerpc: use __vmalloc_node in alloc_vm_stack
alloc_vm_stack can use a slightly higher level vmalloc function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200414131348.444715-29-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:11 -07:00
Nicholas Piggin 0c89649a70 powerpc/64s: Fix doorbell wakeup msgclr optimisation
Commit 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
broke the doorbell wakeup optimisation introduced by commit a9af97aa0a
("powerpc/64s: msgclr when handling doorbell exceptions from system
reset").

This patch restores the msgclr, in C code. It's now done in the system
reset wakeup path rather than doorbell interrupt replay where it used
to be, because it is always the right thing to do in the wakeup case,
but it may be rarely of use in other interrupt replay situations in
which case it's wasted work - we would have to run measurements to see
if that was a worthwhile optimisation, and I suspect it would not be.

The results are similar to those in the original commit, test on POWER8
of context_switch selftests benchmark with polling idle disabled (e.g.,
always nap, giving cross-CPU IPIs) gives the following results:

                                  broken           patched
  Different threads, same core:   317k/s           375k/s    +18.7%
  Different cores:                280k/s           282k/s     +1.0%

Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402121212.1118218-1-npiggin@gmail.com
2020-04-03 00:09:53 +11:00
Nicholas Piggin 6cc0c16d82 powerpc/64s: Implement interrupt exit logic in C
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.

The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.

The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.

This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.

mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.

mpe: Incorporate fix from Nick:

The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.

The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
2020-04-01 13:42:14 +11:00
Nicholas Piggin 3282a3da25 powerpc/64: Implement soft interrupt replay in C
When local_irq_enable() finds a pending soft-masked interrupt, it
"replays" it by setting up registers like the initial interrupt entry,
then calls into the low level handler to set up an interrupt stack
frame and process the interrupt.

This is not necessary, and uses more stack than needed. The high level
interrupt handler can be called directly from C, with just pt_regs set
up on stack. This should be faster and use less stack.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-28-npiggin@gmail.com
2020-04-01 13:42:13 +11:00
Christophe Leroy 532d43a73c powerpc/irq: Use current_stack_pointer in do_IRQ()
Until commit 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to
find the stack"), the current stack base address was obtained by
calling current_thread_info(). That inline function was simply masking
out the value of r1.

In that commit, it was changed to using current_stack_pointer() (since
renamed current_stack_frame()), which is a heavier function as it is
an outline assembly function which cannot be inlined and which reads
the content of the stack at 0(r1).

Convert to using current_stack_pointer for geting r1 and masking out
its value to obtain the base address of the stack pointer as before.

Fixes: 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to find the stack")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-5-mpe@ellerman.id.au
2020-03-04 22:44:30 +11:00
Christophe Leroy 0dec6e1cca powerpc/irq: use IS_ENABLED() in check_stack_overflow()
Instead of #ifdef, use IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW).
This enable GCC to check for code validity even when the option
is not selected.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-4-mpe@ellerman.id.au
2020-03-04 22:44:29 +11:00
Christophe Leroy 84ab148930 powerpc/irq: Use current_stack_pointer in check_stack_overflow()
The purpose of check_stack_overflow() is to verify that the stack has
not overflowed.

To really know whether the stack pointer is still within boundaries,
the check must be done directly on the value of r1.

So use current_stack_pointer, which returns the current value of r1,
rather than current_stack_frame() which causes a frame to be created
and then returns that value.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-3-mpe@ellerman.id.au
2020-03-04 22:44:28 +11:00
Michael Ellerman 3d13e839e8 powerpc: Rename current_stack_pointer() to current_stack_frame()
current_stack_pointer(), which was called __get_SP(), used to just
return the value in r1.

But that caused problems in some cases, so it was turned into a
function in commit bfe9a2cfe9 ("powerpc: Reimplement __get_SP() as a
function not a define").

Because it's a function in a separate compilation unit to all its
callers, it has the effect of causing a stack frame to be created, and
then returns the address of that frame. This is good in some cases
like those described in the above commit, but in other cases it's
overkill, we just need to know what stack page we're on.

On some other arches current_stack_pointer is just a register global
giving the stack pointer, and we'd like to do that too. So rename our
current_stack_pointer() to current_stack_frame() to make that
possible.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
2020-03-04 22:44:28 +11:00
Christophe Leroy 547db12fd8 powerpc/32: Use vmapped stacks for interrupts
In order to also catch overflows on IRQ stacks, use vmapped stacks.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d33ad1b36ddff4dcc19f96c592c12a61cf85d406.1576916812.git.christophe.leroy@c-s.fr
2020-01-27 22:36:15 +11:00
Christophe Leroy 099bc4812f powerpc/irq: fix stack overflow verification
Before commit 0366a1c70b ("powerpc/irq: Run softirqs off the top of
the irq stack"), check_stack_overflow() was called by do_IRQ(), before
switching to the irq stack.
In that commit, do_IRQ() was renamed __do_irq(), and is now executing
on the irq stack, so check_stack_overflow() has just become almost
useless.

Move check_stack_overflow() call in do_IRQ() to do the check while
still on the current stack.

Fixes: 0366a1c70b ("powerpc/irq: Run softirqs off the top of the irq stack")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e033aa8116ab12b7ca9a9c75189ad0741e3b9b5f.1575872340.git.christophe.leroy@c-s.fr
2019-12-14 07:59:36 +11:00
Linus Torvalds 192f0f8e9d powerpc updates for 5.3
Notable changes:
 
  - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well
    as some other functions only used by drivers that haven't (yet?) made it
    upstream.
 
  - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e
    mem: ...) which could lead to register corruption and kernel crashes.
 
  - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc
    when using the Radix MMU.
 
  - A large but incremental rewrite of our exception handling code to use gas
    macros rather than multiple levels of nested CPP macros.
 
 And the usual small fixes, cleanups and improvements.
 
 Thanks to:
   Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju
   T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater,
   Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig,
   Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R.
   Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg
   Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
   Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao,
   Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria,
   Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun
   Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung
   Bauermann, YueHaibing.
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Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
     as well as some other functions only used by drivers that haven't
     (yet?) made it upstream.

   - A fix for a bug in our handling of hardware watchpoints (eg. perf
     record -e mem: ...) which could lead to register corruption and
     kernel crashes.

   - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
     vmalloc when using the Radix MMU.

   - A large but incremental rewrite of our exception handling code to
     use gas macros rather than multiple levels of nested CPP macros.

  And the usual small fixes, cleanups and improvements.

  Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
  Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
  Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
  Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
  Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
  Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
  Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
  Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
  Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
  Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
  Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
  Jitindar Singh, Thiago Jung Bauermann, YueHaibing"

* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
  powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
  powerpc/eeh: Handle hugepages in ioremap space
  ocxl: Update for AFU descriptor template version 1.1
  powerpc/boot: pass CONFIG options in a simpler and more robust way
  powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
  powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
  powerpc/module64: Use symbolic instructions names.
  powerpc/module32: Use symbolic instructions names.
  powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
  powerpc/module64: Fix comment in R_PPC64_ENTRY handling
  powerpc/boot: Add lzo support for uImage
  powerpc/boot: Add lzma support for uImage
  powerpc/boot: don't force gzipped uImage
  powerpc/8xx: Add microcode patch to move SMC parameter RAM.
  powerpc/8xx: Use IO accessors in microcode programming.
  powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
  powerpc/8xx: refactor programming of microcode CPM params.
  powerpc/8xx: refactor printing of microcode patch name.
  powerpc/8xx: Refactor microcode write
  powerpc/8xx: refactor writing of CPM microcode arrays
  ...
2019-07-13 16:08:36 -07:00
Michael Ellerman 0fc12c022a powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
When CONFIG_PPC_IRQ_SOFT_MASK_DEBUG is enabled (uncommon), we have a
series of WARN_ON's in arch_local_irq_restore().

These are "should never happen" conditions, but if they do happen they
can flood the console and render the system unusable. So switch them
to WARN_ON_ONCE().

Fixes: e2b36d5917 ("powerpc/64: Don't trace code that runs with the soft irq mask unreconciled")
Fixes: 9b81c0211c ("powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely")
Fixes: 7c0482e3d0 ("powerpc/irq: Fix another case of lazy IRQ state getting out of sync")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190708061046.7075-1-mpe@ellerman.id.au
2019-07-10 13:20:43 +10:00
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Nicholas Piggin e2b36d5917 powerpc/64: Don't trace code that runs with the soft irq mask unreconciled
"Reconciling" in terms of interrupt handling, is to bring the soft irq
mask state in to synch with the hardware, after an interrupt causes
MSR[EE] to be cleared (while the soft mask may be enabled, and hard
irqs not marked disabled).

General kernel code should not be called while unreconciled, because
local_irq_disable, etc. manipulations can cause surprising irq traces,
and it's fragile because the soft irq code does not really expect to
be called in this situation.

When exiting from an interrupt, MSR[EE] is cleared to prevent races,
but soft irq state is enabled for the returned-to context, so this is
now an unreconciled state. restore_math is called in this state, and
that can be ftraced, and the ftrace subsystem disables local irqs.

Mark restore_math and its callees as notrace. Restore a sanity check
in the soft irq code that had to be disabled for this case, by commit
4da1f79227 ("powerpc/64: Disable irq restore warning for now").

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:58:11 +10:00
Christophe Leroy 502523fd1d powerpc/irq: drop __irq_offset_value
This patch drops__irq_offset_value which has not been used since
commit 9c4cb82515 ("powerpc: Remove use of CONFIG_PPC_MERGE")

This removes a sparse warning.

Fixes: 9c4cb82515 ("powerpc: Remove use of CONFIG_PPC_MERGE")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:58:11 +10:00
Christophe Leroy d608898abc powerpc: clean stack pointers naming
Some stack pointers used to also be thread_info pointers
and were called tp. Now that they are only stack pointers,
rename them sp.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:40 +11:00
Christophe Leroy a7916a1de5 powerpc: regain entire stack space
thread_info is not anymore in the stack, so the entire stack
can now be used.

There is also no risk anymore of corrupting task_cpu(p) with a
stack overflow so the patch removes the test.

When doing this, an explicit test for NULL stack pointer is
needed in validate_sp() as it is not anymore implicitely covered
by the sizeof(thread_info) gap.

In the meantime, with the previous patch all pointers to the stacks
are not anymore pointers to thread_info so this patch changes them
to void*

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:40 +11:00
Christophe Leroy ed1cd6deb0 powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
  - It protects thread_info from corruption in the case of stack
    overflows.
  - Its address is harder to determine if stack addresses are leaked,
    making a number of attacks more difficult.

This has the following consequences:
  - thread_info is now located at the beginning of task_struct.
  - The 'cpu' field is now in task_struct, and only exists when
    CONFIG_SMP is active.
  - thread_info doesn't have anymore the 'task' field.

This patch:
  - Removes all recopy of thread_info struct when the stack changes.
  - Changes the CURRENT_THREAD_INFO() macro to point to current.
  - Selects CONFIG_THREAD_INFO_IN_TASK.
  - Modifies raw_smp_processor_id() to get ->cpu from current without
    including linux/sched.h to avoid circular inclusion and without
    including asm/asm-offsets.h to avoid symbol names duplication
    between ASM constants and C constants.
  - Modifies klp_init_thread_info() to take a task_struct pointer
    argument.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add task_stack.h to livepatch.h to fix build fails]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:40 +11:00
Christophe Leroy 7306e83ccf powerpc: Don't use CURRENT_THREAD_INFO to find the stack
A few places use CURRENT_THREAD_INFO, or the C version, to find the
stack. This will no longer work with THREAD_INFO_IN_TASK so change
them to find the stack in other ways.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:40 +11:00
Christophe Leroy c8e409a33c powerpc/irq: use memblock functions returning virtual address
Since only the virtual address of allocated blocks is used,
lets use functions returning directly virtual address.

Those functions have the advantage of also zeroing the block.

Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:39 +11:00
Christophe Leroy 607ea5090b powerpc/irq: drop arch_early_irq_init()
arch_early_irq_init() does nothing different than the weak
arch_early_irq_init() in kernel/softirq.c

Fixes: 089fb442f3 ("powerpc: Use ARCH_IRQ_INIT_FLAGS")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-14 20:39:27 +11:00