linux-toradex.git/arch/powerpc/include/asm/spinlock.h, branch v5.4 Linux kernel for Apalis and Colibri modules powerpc/spinlocks: Fix oops in __spin_yield() on bare metal 2019-08-27T11:34:34+00:00 Christopher M. Riedl cmr@informatik.wtf 2019-08-13T03:13:14+00:00 405efc5980f2590a9520dc66cfe295456b8c9818 Booting w/ppc64le_defconfig + CONFIG_PREEMPT on bare metal results in the oops below due to calling into __spin_yield() when not running in an SPLPAR, which means lppaca pointers are NULL. We fixed a similar case previously in commit a6201da34ff9 ("powerpc: Fix oops due to bad access of lppaca on bare metal"), by adding SPLPAR checks in lppaca_shared_proc(). However when PREEMPT is enabled we can call __spin_yield() directly from arch_spin_yield(). To fix it add spin_yield() and rw_yield() which check that shared-processor LPAR is enabled before calling the SPLPAR-only implementation of each. BUG: Kernel NULL pointer dereference at 0x00000100 Faulting instruction address: 0xc000000000097f88 Oops: Kernel access of bad area, sig: 7 [#1] LE PAGE_SIZE=64K MMU=Radix MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.2.0-rc6-00491-g249155c20f9b #28 NIP: c000000000097f88 LR: c000000000c07a88 CTR: c00000000015ca10 REGS: c0000000727079f0 TRAP: 0300 Not tainted (5.2.0-rc6-00491-g249155c20f9b) MSR: 9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 84000424 XER: 20040000 CFAR: c000000000c07a84 DAR: 0000000000000100 DSISR: 00080000 IRQMASK: 1 GPR00: c000000000c07a88 c000000072707c80 c000000001546300 c00000007be38a80 GPR04: c0000000726f0c00 0000000000000002 c00000007279c980 0000000000000100 GPR08: c000000001581b78 0000000080000001 0000000000000008 c00000007279c9b0 GPR12: 0000000000000000 c000000001730000 c000000000142558 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: c00000007be38a80 c000000000c002f4 0000000000000000 0000000000000000 GPR28: c000000072221a00 c0000000726c2600 c00000007be38a80 c00000007be38a80 NIP [c000000000097f88] __spin_yield+0x48/0xa0 LR [c000000000c07a88] __raw_spin_lock+0xb8/0xc0 Call Trace: [c000000072707c80] [c000000072221a00] 0xc000000072221a00 (unreliable) [c000000072707cb0] [c000000000bffb0c] __schedule+0xbc/0x850 [c000000072707d70] [c000000000c002f4] schedule+0x54/0x130 [c000000072707da0] [c0000000001427dc] kthreadd+0x28c/0x2b0 [c000000072707e20] [c00000000000c1cc] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 4d9e0020 552a043e 210a07ff 79080fe0 0b080000 3d020004 3908b878 794a1f24 e8e80000 7ce7502a e8e70000 38e70100 <7ca03c2c> 70a70001 78a50020 4d820020 ---[ end trace 474d6b2b8fc5cb7e ]--- Fixes: 499dcd41378e ("powerpc/64s: Allocate LPPACAs individually") Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf> [mpe: Reword change log a bit] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813031314.1828-4-cmr@informatik.wtf 
Booting w/ppc64le_defconfig + CONFIG_PREEMPT on bare metal results in
the oops below due to calling into __spin_yield() when not running in
an SPLPAR, which means lppaca pointers are NULL.

We fixed a similar case previously in commit a6201da34ff9 ("powerpc:
Fix oops due to bad access of lppaca on bare metal"), by adding SPLPAR
checks in lppaca_shared_proc(). However when PREEMPT is enabled we can
call __spin_yield() directly from arch_spin_yield().

To fix it add spin_yield() and rw_yield() which check that
shared-processor LPAR is enabled before calling the SPLPAR-only
implementation of each.

  BUG: Kernel NULL pointer dereference at 0x00000100
  Faulting instruction address: 0xc000000000097f88
  Oops: Kernel access of bad area, sig: 7 [#1]
  LE PAGE_SIZE=64K MMU=Radix MMU=Hash PREEMPT SMP NR_CPUS=2048 NUMA PowerNV
  Modules linked in:
  CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.2.0-rc6-00491-g249155c20f9b #28
  NIP:  c000000000097f88 LR: c000000000c07a88 CTR: c00000000015ca10
  REGS: c0000000727079f0 TRAP: 0300   Not tainted  (5.2.0-rc6-00491-g249155c20f9b)
  MSR:  9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE>  CR: 84000424  XER: 20040000
  CFAR: c000000000c07a84 DAR: 0000000000000100 DSISR: 00080000 IRQMASK: 1
  GPR00: c000000000c07a88 c000000072707c80 c000000001546300 c00000007be38a80
  GPR04: c0000000726f0c00 0000000000000002 c00000007279c980 0000000000000100
  GPR08: c000000001581b78 0000000080000001 0000000000000008 c00000007279c9b0
  GPR12: 0000000000000000 c000000001730000 c000000000142558 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR24: c00000007be38a80 c000000000c002f4 0000000000000000 0000000000000000
  GPR28: c000000072221a00 c0000000726c2600 c00000007be38a80 c00000007be38a80
  NIP [c000000000097f88] __spin_yield+0x48/0xa0
  LR [c000000000c07a88] __raw_spin_lock+0xb8/0xc0
  Call Trace:
  [c000000072707c80] [c000000072221a00] 0xc000000072221a00 (unreliable)
  [c000000072707cb0] [c000000000bffb0c] __schedule+0xbc/0x850
  [c000000072707d70] [c000000000c002f4] schedule+0x54/0x130
  [c000000072707da0] [c0000000001427dc] kthreadd+0x28c/0x2b0
  [c000000072707e20] [c00000000000c1cc] ret_from_kernel_thread+0x5c/0x70
  Instruction dump:
  4d9e0020 552a043e 210a07ff 79080fe0 0b080000 3d020004 3908b878 794a1f24
  e8e80000 7ce7502a e8e70000 38e70100 <7ca03c2c> 70a70001 78a50020 4d820020
  ---[ end trace 474d6b2b8fc5cb7e ]---

Fixes: 499dcd41378e ("powerpc/64s: Allocate LPPACAs individually")
Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
[mpe: Reword change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190813031314.1828-4-cmr@informatik.wtf
powerpc/spinlocks: Rename SPLPAR-only spinlocks 2019-08-27T03:03:36+00:00 Christopher M. Riedl cmr@informatik.wtf 2019-08-13T03:13:13+00:00 31391ff7ea1ef557a804475436501f33ff0ead95 The __rw_yield and __spin_yield locks only pertain to SPLPAR mode. Rename them to make this relationship obvious. Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813031314.1828-3-cmr@informatik.wtf 
The __rw_yield and __spin_yield locks only pertain to SPLPAR mode.
Rename them to make this relationship obvious.

Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190813031314.1828-3-cmr@informatik.wtf
powerpc/spinlocks: Refactor SHARED_PROCESSOR 2019-08-27T03:03:36+00:00 Christopher M. Riedl cmr@informatik.wtf 2019-08-13T03:13:12+00:00 d57b78353a99f5d813248954dd7d0527a01751ac Determining if a processor is in shared processor mode is not a constant so don't hide it behind a #define. Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190813031314.1828-2-cmr@informatik.wtf 
Determining if a processor is in shared processor mode is not a constant
so don't hide it behind a #define.

Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190813031314.1828-2-cmr@informatik.wtf
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30T18:26:32+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-27T06:55:01+00:00 2874c5fd284268364ece81a7bd936f3c8168e567 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> 
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>
powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code 2019-04-08T11:00:35+00:00 Will Deacon will.deacon@arm.com 2019-02-22T14:45:42+00:00 420af1554790a95e6813f56f63b6d2361614082b In a bid to kill off explicit mmiowb() usage in driver code, hook up the asm-generic mmiowb() tracking code but provide a definition of arch_mmiowb_state() so that the tracking data can remain in the paca as it does at present This replaces the existing (flawed) implementation. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will.deacon@arm.com> 
In a bid to kill off explicit mmiowb() usage in driver code, hook up
the asm-generic mmiowb() tracking code but provide a definition of
arch_mmiowb_state() so that the tracking data can remain in the paca
as it does at present

This replaces the existing (flawed) implementation.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30T12:48:16+00:00 Christophe Leroy christophe.leroy@c-s.fr 2018-07-05T16:24:57+00:00 ec0c464cdbf38bf6ddabec8bfa595bd421cab203 This patch moves ASM_CONST() and stringify_in_c() into dedicated asm-const.h, then cleans all related inclusions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: asm-compat.h should include asm-const.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
This patch moves ASM_CONST() and stringify_in_c() into
dedicated asm-const.h, then cleans all related inclusions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: asm-compat.h should include asm-const.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/405: move PPC405_ERR77 in asm-405.h 2018-07-30T12:48:13+00:00 Christophe Leroy christophe.leroy@c-s.fr 2018-07-05T16:24:55+00:00 36a7eeaff7d06cef253c8df6dfe363bfc4a553f8 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc: Fix oops due to bad access of lppaca on bare metal 2018-04-03T11:50:07+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2018-04-02T07:33:37+00:00 a6201da34ff9366680e97392efd06abb9ff15014 Commit 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized") removed allocation of lppaca on bare metal platforms. But with CONFIG_PPC_SPLPAR enabled, we still access the lppaca on bare metal in some code paths. Fix this but adding runtime checks for SPLPAR (shared processor LPAR). Fixes: 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Commit 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are
not virtualized") removed allocation of lppaca on bare metal
platforms. But with CONFIG_PPC_SPLPAR enabled, we still access the
lppaca on bare metal in some code paths.

Fix this but adding runtime checks for SPLPAR (shared processor LPAR).

Fixes: 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations 2017-10-10T09:50:19+00:00 Will Deacon will.deacon@arm.com 2017-10-03T18:25:29+00:00 a4c1887d4c1462b0ec5a8989f8ba3cdd9057a299 The arch_{read,spin,write}_lock_flags() macros are simply mapped to the non-flags versions by the majority of architectures, so do this in core code and remove the dummy implementations. Also remove the implementation in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call local_irq_save(flags) anyway. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The arch_{read,spin,write}_lock_flags() macros are simply mapped to the
non-flags versions by the majority of architectures, so do this in core
code and remove the dummy implementations. Also remove the implementation
in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call
local_irq_save(flags) anyway.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
locking/core: Remove {read,spin,write}_can_lock() 2017-10-10T09:50:18+00:00 Will Deacon will.deacon@arm.com 2017-10-03T18:25:27+00:00 a8a217c22116eff6c120d753c9934089fb229af0 Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Outside of the locking code itself, {read,spin,write}_can_lock() have no
users in tree. Apparmor (the last remaining user of write_can_lock()) got
moved over to lockdep by the previous patch.

This patch removes the use of {read,spin,write}_can_lock() from the
BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the
lock status, and subsequently removes the unused macros altogether. They
aren't guaranteed to work in a concurrent environment and can give
incorrect results in the case of qrwlock.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>