Граф коммитов

132 Коммитов

Автор SHA1 Сообщение Дата
Christophe Leroy 120c0518ec powerpc: Replace RFI by rfi on book3s/32 and booke
For book3s/32 and for booke, RFI is just an rfi.
Only 40x has a non trivial RFI.
CONFIG_PPC_RTAS is never selected by 40x platforms.

Make it more explicit by replacing RFI by rfi wherever possible.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b901ddfdeb8a0a3b7cb59999599cdfde1bbfe834.1604854583.git.christophe.leroy@csgroup.eu
2020-11-19 16:56:54 +11:00
Christophe Leroy 8b14e1dff0 powerpc: Remove support for PowerPC 601
PowerPC 601 has been retired.

Remove all associated specific code.

CPU_FTRS_PPC601 has CPU_FTR_COHERENT_ICACHE and CPU_FTR_COMMON.

CPU_FTR_COMMON is already present via other CPU_FTRS.
None of the remaining CPU selects CPU_FTR_COHERENT_ICACHE.

So CPU_FTRS_PPC601 can be removed from the possible features,
hence can be removed completely.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/60b725d55e21beec3335175c20b77903ff98284f.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy d2a5cd83ee powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
Those macros are now empty at all time. Drop them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7990bb63fc53e460bfa94f8040184881d9e6fbc3.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Nicholas Piggin 2384b36f91 powerpc: Select ARCH_HAS_MEMBARRIER_SYNC_CORE
powerpc return from interrupt and return from system call sequences
are context synchronising.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200716013522.338318-1-npiggin@gmail.com
2020-07-23 17:43:23 +10:00
Christophe Leroy e51c3e1370 powerpc/entry32: Blacklist exception exit points for kprobe.
kprobe does not handle events happening in real mode.

The very last part of exception exits cannot support a trap.
Blacklist them from kprobe.

While we are at it, remove exc_exit_start symbol which is not
used to avoid having to blacklist it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/098b0fd3f6299aa1bd692bd576bd7012c84608de.1585670437.git.christophe.leroy@c-s.fr
2020-06-02 20:59:13 +10:00
Christophe Leroy 7cdf440138 powerpc/entry32: Blacklist syscall exit points for kprobe.
kprobe does not handle events happening in real mode.

The very last part of syscall cannot support a trap.
Add a symbol syscall_exit_finish to identify that part and
blacklist it from kprobe.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/23eddf49abb03d1359fa0be4206998eb3800f42c.1585670437.git.christophe.leroy@c-s.fr
2020-06-02 20:59:12 +10:00
Christophe Leroy a616c44211 powerpc/entry32: Blacklist exception entry points for kprobe.
kprobe does not handle events happening in real mode.

As exception entry points are running with MMU disabled,
blacklist them.

The handling of TLF_NAPPING and TLF_SLEEPING is moved before the
CONFIG_TRACE_IRQFLAGS which contains 'reenable_mmu' because from there
kprobe will be possible as the kernel will run with MMU enabled.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f61ac599855e674ebb592464d0ea32a3ba9c6644.1585670437.git.christophe.leroy@c-s.fr
2020-06-02 20:59:12 +10:00
Christophe Leroy 5f32e8361c powerpc/32: Blacklist functions running with MMU disabled for kprobe
kprobe does not handle events happening in real mode, all
functions running with MMU disabled have to be blacklisted.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3bf57066d05518644dee0840af69d36ab5086729.1585670437.git.christophe.leroy@c-s.fr
2020-06-02 20:59:11 +10:00
Christophe Leroy 32746dfe4c powerpc/rtas: Remove machine_check_in_rtas()
machine_check_in_rtas() is just a trap.

Do the trap directly in the machine check exception handler.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/78899f40f89cb3c4f69bdff7f04eb6ec7cb753d5.1585670437.git.christophe.leroy@c-s.fr
2020-06-02 20:59:11 +10:00
Christophe Leroy 455531e9d8 powerpc: Remove IBM405 Erratum #77
This erratum is dedicated to IBM 405GP and STB03xxx
which are now gone.

Remove this erratum.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/44dbc08e9034681eb28324cbabc086e97044c36c.1590079969.git.christophe.leroy@csgroup.eu
2020-05-28 23:24:36 +10:00
Christophe Leroy feb8e960d7 powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32
CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.

Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().

Change dependency to PPC32 and use r0 instead of r4 in _switch()

Fixes: e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
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/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr
2020-04-22 20:24:02 +10:00
Michael Ellerman 819723a8a2 Merge branch 'fixes' into next
Merge in our fixes branch. In particular we want to merge the TM and KUAP fixes,
so we can add selftests for them in next.
2020-03-10 15:16:42 +11:00
Christophe Leroy 05642cf728 powerpc/32: don't restore r0, r6-r8 on exception entry path after trace_hardirqs_off()
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls don't
use the exception entry path anymore. It is therefore pointless
to restore r0 and r6-r8 after calling trace_hardirqs_off().

In the meantime, drop the '2:' label which is unused and misleading.

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/d2c6dc65d27e83964eb05f16a126161ab6455eea.1578388585.git.christophe.leroy@c-s.fr
2020-02-26 10:34:40 +11:00
Christophe Leroy 9e27086292 powerpc/32: Warn and return ENOSYS on syscalls from kernel
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls from
kernel are unexpected and can have catastrophic consequences
as it will destroy the kernel stack.

Test MSR_PR on syscall entry. In case syscall is from kernel,
emit a warning and return ENOSYS error.

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/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
2020-02-19 22:46:08 +11:00
Christophe Leroy 9eb425b2e0 powerpc/entry: Fix an #if which should be an #ifdef in entry_32.S
Fixes: 12c3f1fd87 ("powerpc/32s: get rid of CPU_FTR_601 feature")
Cc: stable@vger.kernel.org # v5.4+
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/a99fc0ad65b87a1ba51cfa3e0e9034ee294c3e07.1582034961.git.christophe.leroy@c-s.fr
2020-02-19 10:35:22 +11:00
Christophe Leroy 5a528eb679 powerpc/chrp: Fix enter_rtas() with CONFIG_VMAP_STACK
With CONFIG_VMAP_STACK, data MMU has to be enabled
to read data on the stack.

Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_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/d2330584f8c42d3039896e2b56f5d39676dc919c.1581669558.git.christophe.leroy@c-s.fr
2020-02-18 21:31:11 +11:00
Christophe Leroy d4bf905307 powerpc: Fix CONFIG_TRACE_IRQFLAGS with CONFIG_VMAP_STACK
When CONFIG_PROVE_LOCKING is selected together with (now default)
CONFIG_VMAP_STACK, kernel enter deadlock during boot.

At the point of checking whether interrupts are enabled or not, the
value of MSR saved on stack is read using the physical address of the
stack. But at this point, when using VMAP stack the DATA MMU
translation has already been re-enabled, leading to deadlock.

Don't use the physical address of the stack when
CONFIG_VMAP_STACK is set.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 028474876f ("powerpc/32: prepare for CONFIG_VMAP_STACK")
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/daeacdc0dec0416d1c587cc9f9e7191ad3068dc0.1581095957.git.christophe.leroy@c-s.fr
2020-02-08 21:49:06 +11:00
Linus Torvalds 71c3a888cb powerpc updates for 5.6
- Implement user_access_begin() and friends for our platforms that support
    controlling kernel access to userspace.
 
  - Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx.
 
  - Some tweaks to our pseries IOMMU code to allow SVMs ("secure" virtual
    machines) to use the IOMMU.
 
  - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit VDSO, and
    some other improvements.
 
  - A series to use the PCI hotplug framework to control opencapi card's so that
    they can be reset and re-read after flashing a new FPGA image.
 
 As well as other minor fixes and improvements as usual.
 
 Thanks to:
  Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen Zhou, Christophe Leroy,
  Frederic Barrat, Greg Kurz, Jason A. Donenfeld, Joel Stanley, Jordan Niethe,
  Julia Lawall, Krzysztof Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus
  Walleij, Michael Bringmann, Nathan Chancellor, Nicholas Piggin, Nick
  Desaulniers, Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy
  Dunlap, Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn
  Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago Jung
  Bauermann, Tyrel Datwyler, Vaibhav Jain.
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Merge tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "A pretty small batch for us, and apologies for it being a bit late, I
  wanted to sneak Christophe's user_access_begin() series in.

  Summary:

   - Implement user_access_begin() and friends for our platforms that
     support controlling kernel access to userspace.

   - Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx.

   - Some tweaks to our pseries IOMMU code to allow SVMs ("secure"
     virtual machines) to use the IOMMU.

   - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit
     VDSO, and some other improvements.

   - A series to use the PCI hotplug framework to control opencapi
     card's so that they can be reset and re-read after flashing a new
     FPGA image.

  As well as other minor fixes and improvements as usual.

  Thanks to: Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy,
  Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen
  Zhou, Christophe Leroy, Frederic Barrat, Greg Kurz, Jason A.
  Donenfeld, Joel Stanley, Jordan Niethe, Julia Lawall, Krzysztof
  Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus Walleij, Michael
  Bringmann, Nathan Chancellor, Nicholas Piggin, Nick Desaulniers,
  Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy Dunlap,
  Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn
  Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain"

* tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (131 commits)
  powerpc: configs: Cleanup old Kconfig options
  powerpc/configs/skiroot: Enable some more hardening options
  powerpc/configs/skiroot: Disable xmon default & enable reboot on panic
  powerpc/configs/skiroot: Enable security features
  powerpc/configs/skiroot: Update for symbol movement only
  powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV
  powerpc/configs/skiroot: Drop HID_LOGITECH
  powerpc/configs: Drop NET_VENDOR_HP which moved to staging
  powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE
  powerpc/configs: Drop CONFIG_QLGE which moved to staging
  powerpc: Do not consider weak unresolved symbol relocations as bad
  powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACK
  powerpc: indent to improve Kconfig readability
  powerpc: Provide initial documentation for PAPR hcalls
  powerpc: Implement user_access_save() and user_access_restore()
  powerpc: Implement user_access_begin and friends
  powerpc/32s: Prepare prevent_user_access() for user_access_end()
  powerpc/32s: Drop NULL addr verification
  powerpc/kuap: Fix set direction in allow/prevent_user_access()
  powerpc/32s: Fix bad_kuap_fault()
  ...
2020-02-04 13:06:46 +00:00
Christophe Leroy 9933819099 powerpc/32s: Fix CPU wake-up from sleep mode
Commit f7354ccac8 ("powerpc/32: Remove CURRENT_THREAD_INFO and
rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when
_TLF_SLEEPING is set) by delaying the tovirt(r2, r2).

This is because r2 is not restored by fast_exception_return. It used
to work (by chance ?) because CPU wake-up interrupt never comes from
user, so r2 is expected to point to 'current' on return.

Commit e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access
Protection") broke it even more by clobbering r0 which is not
restored by fast_exception_return either.

Use r6 instead of r0. This is possible because r3-r6 are restored by
fast_exception_return and only r3-r5 are used for exception arguments.

For r2 it could be converted back to virtual address, but stay on the
safe side and restore it from the stack instead. It should be live
in the cache at that moment, so loading from the stack should make
no difference compared to converting it from phys to virt.

Fixes: f7354ccac8 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Fixes: e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
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/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr
2020-01-28 23:01:19 +11:00
Christophe Leroy cd08f109e2 powerpc/32s: Enable CONFIG_VMAP_STACK
A few changes to retrieve DAR and DSISR from struct regs
instead of retrieving them directly, as they may have
changed due to a TLB miss.

Also modifies hash_page() and friends to work with virtual
data addresses instead of physical ones. Same on load_up_fpu()
and load_up_altivec().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Fix tovirt_vmstack call in head_32.S to fix CHRP build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e2509a242fd5f3e23df4a06530c18060c4d321e.1576916812.git.christophe.leroy@c-s.fr
2020-01-27 22:37:24 +11:00
Christophe Leroy 3978eb7851 powerpc/32: Add early stack overflow detection with VMAP stack.
To avoid recursive faults, stack overflow detection has to be
performed before writing in the stack in exception prologs.

Do it by checking the alignment. If the stack pointer alignment is
wrong, it means it is pointing to the following or preceding page.

Without VMAP stack, a stack overflow is catastrophic. With VMAP
stack, a stack overflow isn't destructive, so don't panic. Kill
the task with SIGSEGV instead.

A dedicated overflow stack is set up for each CPU.

  lkdtm: Performing direct entry EXHAUST_STACK
  lkdtm: Calling function with 512 frame size to depth 32 ...
  lkdtm: loop 32/32 ...
  lkdtm: loop 31/32 ...
  lkdtm: loop 30/32 ...
  lkdtm: loop 29/32 ...
  lkdtm: loop 28/32 ...
  lkdtm: loop 27/32 ...
  lkdtm: loop 26/32 ...
  lkdtm: loop 25/32 ...
  lkdtm: loop 24/32 ...
  lkdtm: loop 23/32 ...
  lkdtm: loop 22/32 ...
  lkdtm: loop 21/32 ...
  lkdtm: loop 20/32 ...
  Kernel stack overflow in process test[359], r1=c900c008
  Oops: Kernel stack overflow, sig: 6 [#1]
  BE PAGE_SIZE=4K MMU=Hash PowerMac
  Modules linked in:
  CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225
  NIP:  c0622060 LR: c0626710 CTR: 00000000
  REGS: c0895f48 TRAP: 0000   Not tainted  (5.3.0-rc7+)
  MSR:  00001032 <ME,IR,DR,RI>  CR: 28004224  XER: 00000000
  GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc
  GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000
  GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025
  GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4
  NIP [c0622060] format_decode+0x0/0x4d4
  LR [c0626710] vsnprintf+0x80/0x5fc
  Call Trace:
  [c900c068] [c0626ca4] vscnprintf+0x18/0x48
  [c900c078] [c007b944] vprintk_store+0x40/0x214
  [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc
  [c900c0e8] [c007c5cc] printk+0x50/0x60
  [c900c128] [c03da5b0] recursive_loop+0x44/0x6c
  [c900c338] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c548] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c758] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c968] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c
  [c900de18] [c03da3e8] direct_entry+0xc8/0x140
  [c900de48] [c029fb40] full_proxy_write+0x64/0xcc
  [c900de68] [c01500f8] __vfs_write+0x30/0x1d0
  [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4
  [c900df08] [c0152f7c] ksys_write+0x58/0xe8
  [c900df38] [c0014208] ret_from_syscall+0x0/0x34
  --- interrupt: c01 at 0xf806664
      LR = 0x1000c868
  Instruction dump:
  4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089
  8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378

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/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2020-01-27 22:35:49 +11:00
Christophe Leroy 028474876f powerpc/32: prepare for CONFIG_VMAP_STACK
To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU
Translation for accessing the stack. Before doing that it must save
SRR0, SRR1 and also DAR and DSISR when relevant, in order to not
loose them in case there is a Data TLB Miss once the translation is
reactivated.

This patch adds fields in thread struct for saving those registers.
It prepares entry_32.S to handle exception entry with
Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to
save SRR0, SRR1, DAR and DSISR then reenables Data MMU.

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/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy 1ca9db5b65 powerpc/32: save DEAR/DAR before calling handle_page_fault
handle_page_fault() is the only function that save DAR/DEAR itself.

Save DAR/DEAR before calling handle_page_fault() to prepare for
VMAP stack which will require to save even before.

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/3a4d58d378091086f00fde42b59610c80289e120.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy 39bccfd164 powerpc/32: replace MTMSRD() by mtmsr
On PPC32, MTMSRD() is simply defined as mtmsr.

Replace MTMSRD(reg) by mtmsr reg in files dedicated to PPC32,
this makes the code less obscure.

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/22469e78230edea3dbd0c79a555d73124f6c6d93.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:08 +11:00
Thomas Gleixner fdc5569eab sched/rt, powerpc: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the entry code over to use CONFIG_PREEMPTION.

[bigeasy: +Kconfig]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20191024160458.vlnf3wlcyjl2ich7@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-08 14:37:32 +01:00
Christophe Leroy 12c3f1fd87 powerpc/32s: get rid of CPU_FTR_601 feature
Now that 601 is exclusive from other 6xx, CPU_FTR_601 and
associated fixups are useless.

Drop this feature and use #ifdefs instead.

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/ecdb7194a17dbfa01865df6a82979533adc2c70b.1566834712.git.christophe.leroy@c-s.fr
2019-08-28 23:19:33 +10:00
Christophe Leroy ba18025fb0 powerpc/32: replace LOAD_MSR_KERNEL() by LOAD_REG_IMMEDIATE()
LOAD_MSR_KERNEL() and LOAD_REG_IMMEDIATE() are doing the same thing
in the same way. Drop LOAD_MSR_KERNEL()

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/8f04a6df0bc8949517fd8236d50c15008ccf9231.1566311636.git.christophe.leroy@c-s.fr
2019-08-27 13:03:36 +10:00
Michael Ellerman cee3536d24 powerpc: Wire up clone3 syscall
Wire up the new clone3 syscall added in commit 7f192e3cd3 ("fork:
add clone3").

This requires a ppc_clone3 wrapper, in order to save the non-volatile
GPRs before calling into the generic syscall code. Otherwise we hit
the BUG_ON in CHECK_FULL_REGS in copy_thread().

Lightly tested using Christian's test code on a Power8 LE VM.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Christian Brauner <christian@brauner.io>
Link: https://lore.kernel.org/r/20190724140259.23554-1-mpe@ellerman.id.au
2019-07-29 09:34:27 +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
Valentin Schneider 90437bffa5 powerpc/entry: Remove unneeded need_resched() loop
Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
[mpe: Rebase since CURRENT_THREAD_INFO() removal]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:54:57 +10:00
Christophe Leroy d1865e71cd powerpc/32: Don't add dummy frames when calling trace_hardirqs_on/off
No need to add dummy frames when calling trace_hardirqs_on or
trace_hardirqs_off. GCC properly handles empty stacks.

In addition, powerpc doesn't set CONFIG_FRAME_POINTER, therefore
__builtin_return_address(1..) returns NULL at all time. So the
dummy frames are definitely unneeded here.

In the meantime, avoid reading memory for loading r1 with a value
we already know.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:28 +10:00
Christophe Leroy 38b4564cf0 powerpc/32: don't do syscall stuff in transfer_to_handler
As syscalls are now handled via a fast entry path, syscall related
actions can be removed from the generic transfer_to_handler path.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:27 +10:00
Christophe Leroy 1a4b739bbb powerpc/32: implement fast entry for syscalls on BOOKE
This patch implements a fast entry for syscalls.

Syscalls don't have to preserve non volatile registers except LR.

This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.

As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off

It also assumes that the call is always from user, system calls are
unexpected from kernel.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:27 +10:00
Christophe Leroy b86fb88855 powerpc/32: implement fast entry for syscalls on non BOOKE
This patch implements a fast entry for syscalls.

Syscalls don't have to preserve non volatile registers except LR.

This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.

As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off

It also assumes that the call is always from user, system calls are
unexpected from kernel.

The overall series improves null_syscall selftest by 12,5% on an 83xx
and by 17% on a 8xx.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:27 +10:00
Christophe Leroy 40530db7c6 powerpc: Fix 32-bit handling of MSR_EE on exceptions
[text mostly copied from benh's RFC/WIP]

ppc32 are still doing something rather gothic and wrong on 32-bit
which we stopped doing on 64-bit a while ago.

We have that thing where some handlers "copy" the EE value from the
original stack frame into the new MSR before transferring to the
handler.

Thus for a number of exceptions, we enter the handlers with interrupts
enabled.

This is rather fishy, some of the stuff that handlers might do early
on such as irq_enter/exit or user_exit, context tracking, etc...
should be run with interrupts off afaik.

Generally our handlers know when to re-enable interrupts if needed.

The problem we were having is that we assumed these interrupts would
return with interrupts enabled. However that isn't the case.

Instead, this patch changes things so that we always enter exception
handlers with interrupts *off* with the notable exception of syscalls
which are special (and get a fast path).

Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:27 +10:00
Christophe Leroy 37737a2afd powerpc/32: move LOAD_MSR_KERNEL() into head_32.h and use it
As preparation for using head_32.h for head_40x.S, move
LOAD_MSR_KERNEL() there and use it to load r10 with MSR_KERNEL value.

In the mean time, this patch modifies it so that it takes into account
the size of the passed value to determine if 'li' can be used or if
'lis/ori' is needed instead of using the size of MSR_KERNEL. This is
done by using gas macro.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:27 +10:00
Christophe Leroy 31ed2b13c4 powerpc/32s: Implement Kernel Userspace Execution Prevention.
To implement Kernel Userspace Execution Prevention, this patch
sets NX bit on all user segments on kernel entry and clears NX bit
on all user segments on kernel exit.

Note that powerpc 601 doesn't have the NX bit, so KUEP will not
work on it. A warning is displayed at startup.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21 23:11:46 +10:00
Christophe Leroy e2fb9f5444 powerpc/32: Prepare for Kernel Userspace Access Protection
This patch adds ASM macros for saving, restoring and checking
the KUAP state, and modifies setup_32 to call them on exceptions
from kernel.

The macros are defined as empty by default for when CONFIG_PPC_KUAP
is not selected and/or for platforms which don't handle (yet) KUAP.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21 23:11:46 +10:00
Christophe Leroy e291b6d575 powerpc/32: Remove MSR_PR test when returning from syscall
syscalls are from user only, so we can account time without checking
whether returning to kernel or user as it will only be user.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21 23:11:46 +10:00
Christophe Leroy 9580b71b5a powerpc/32: Clear on-stack exception marker upon exception return
Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order
to avoid confusing stacktrace like the one below.

  Call Trace:
  [c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895130] memchr+0x24/0x74
  [c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4
  --- interrupt: c0e9df00 at 0x400f330
      LR = init_stack+0x1f00/0x2000
  [c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable)
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

With this patch the trace becomes:

  Call Trace:
  [c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895150] memchr+0x24/0x74
  [c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4
  [c0e9de80] [c00ae3e4] printk+0xa8/0xcc
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-03-04 00:37:23 +11:00
Christophe Leroy f7354ccac8 powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
Now that thread_info is similar to task_struct, its address is in r2
so CURRENT_THREAD_INFO() macro is useless. This patch removes it.

This patch also moves the 'tovirt(r2, r2)' down just before the
reactivation of MMU translation, so that we keep the physical address
of 'current' in r2 until then. It avoids a few calls to tophys().

At the same time, as the 'cpu' field is not anymore in thread_info,
TI_CPU is renamed TASK_CPU by this patch.

It also allows to get rid of a couple of
'#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE' as ACCOUNT_CPU_USER_ENTRY()
and ACCOUNT_CPU_USER_EXIT() are empty when
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not defined.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Fix a missed conversion of TI_CPU idle_6xx.S]
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 8c1fc5abdc powerpc: Rename THREAD_INFO to TASK_STACK
This patch renames THREAD_INFO to TASK_STACK, because it is in fact
the offset of the pointer to the stack in task_struct so this pointer
will not be impacted by the move of THREAD_INFO.

Also make it available on 64-bit, as we'll need it there when we
activate THREAD_INFO_IN_TASK.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make available on 64-bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23 22:31:40 +11:00
Christophe Leroy 6b9166f078 powerpc/32: Fix CONFIG_VIRT_CPU_ACCOUNTING_NATIVE for 40x/booke
40x/booke have another path to reach 3f from transfer_to_handler,
make sure it also calls ACCOUNT_CPU_USER_ENTRY() when
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is selected.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22 00:10:16 +11:00
Christophe Leroy 0df977eafc powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTAS
When calling RTAS, the stack pointer is stored in SPRN_SPRG2
in order to be able to restore it in case of machine check in RTAS.

As machine check is not a perfomance critical path, this patch
frees SPRN_SPRG2 by using a field in thread struct instead.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22 00:10:16 +11:00
Christophe Leroy ab44840df1 powerpc/32: Remove unneccessary MSR[RI] clearing for 8xx
MSR[RI] has already been cleared a few lines above.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22 00:10:15 +11:00
Christophe Leroy d7cceda96b powerpc: change CONFIG_6xx to CONFIG_PPC_BOOK3S_32
Today we have:

config PPC_BOOK3S_32
	bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
	[depends on PPC32 within a choice]

config PPC_BOOK3S
	def_bool y
	depends on PPC_BOOK3S_32 || PPC_BOOK3S_64

config 6xx
	def_bool y
	depends on PPC32 && PPC_BOOK3S

6xx is therefore redundant with PPC_BOOK3S_32.

In order to make the code clearer, lets use preferably PPC_BOOK3S_32.
This will allow to remove CONFIG_6xx in a later patch.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-11-26 22:33:37 +11:00
Christophe Leroy 51423a9c9b powerpc/traps: merge unrecoverable_exception() and nonrecoverable_exception()
PPC32 uses nonrecoverable_exception() while PPC64 uses
unrecoverable_exception().

Both functions are doing almost the same thing.

This patch removes nonrecoverable_exception()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:01 +10:00
Diana Craciun c28218d4ab powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms
Used barrier_nospec to sanitize the syscall table.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08 00:32:24 +10:00