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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
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Avoids confusion when printing Oops message like below
Faulting instruction address: 0xc00000000008bdb4
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
This was because we never clear the MMU_FTR_HPTE_TABLE feature flag
even if we run with radix translation. It was discussed that we should
look at this feature flag as an indication of the capability to run
hash translation and we should not clear the flag even if we run in
radix translation. All the code paths check for radix_enabled() check and
if found true consider we are running with radix translation. Follow the
same sequence for finding the MMU translation string to be used in Oops
message.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190711145814.17970-1-aneesh.kumar@linux.ibm.com
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Since commit 4388c9b3a6ee ("powerpc: Do not send system reset request
through the oops path"), pstore dmesg file is not updated when dump is
triggered from HMC. This commit modified system reset (sreset) handler
to invoke fadump or kdump (if configured), without pushing dmesg to
pstore. This leaves pstore to have old dmesg data which won't be much
of a help if kdump fails to capture the dump. This patch fixes that by
calling kmsg_dump() before heading to fadump ot kdump.
Fixes: 4388c9b3a6ee ("powerpc: Do not send system reset request through the oops path")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904075949.15607-1-ganeshgr@linux.ibm.com
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
"A source of error over the years has been that force_sig has taken a
task parameter when it is only safe to use force_sig with the current
task.
The force_sig function is built for delivering synchronous signals
such as SIGSEGV where the userspace application caused a synchronous
fault (such as a page fault) and the kernel responded with a signal.
Because the name force_sig does not make this clear, and because the
force_sig takes a task parameter the function force_sig has been
abused for sending other kinds of signals over the years. Slowly those
have been fixed when the oopses have been tracked down.
This set of changes fixes the remaining abusers of force_sig and
carefully rips out the task parameter from force_sig and friends
making this kind of error almost impossible in the future"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
signal: Remove the signal number and task parameters from force_sig_info
signal: Factor force_sig_info_to_task out of force_sig_info
signal: Generate the siginfo in force_sig
signal: Move the computation of force into send_signal and correct it.
signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
signal: Remove the task parameter from force_sig_fault
signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
signal: Explicitly call force_sig_fault on current
signal/unicore32: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from ptrace_break
signal/nds32: Remove tsk parameter from send_sigtrap
signal/riscv: Remove tsk parameter from do_trap
signal/sh: Remove tsk parameter from force_sig_info_fault
signal/um: Remove task parameter from send_sigtrap
signal/x86: Remove task parameter from send_sigtrap
signal: Remove task parameter from force_sig_mceerr
signal: Remove task parameter from force_sig
signal: Remove task parameter from force_sigsegv
...
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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>
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As synchronous exceptions really only make sense against the current
task (otherwise how are you synchronous) remove the task parameter
from from force_sig_fault to make it explicit that is what is going
on.
The two known exceptions that deliver a synchronous exception to a
stopped ptraced task have already been changed to
force_sig_fault_to_task.
The callers have been changed with the following emacs regular expression
(with obvious variations on the architectures that take more arguments)
to avoid typos:
force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)]
->
force_sig_fault(\1,\2,\3)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Currently on panic, kernel will lower the loglevel and print out pending
printk msg only with console_flush_on_panic().
Add an option for users to configure the "panic_print" to replay all
dmesg in buffer, some of which they may have never seen due to the
loglevel setting, which will help panic debugging .
[feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()]
Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com
[feng.tang@intel.com: use logbuf lock to protect the console log index]
Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com
Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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SPEFloatingPointException() is the only exception handler which 'forgets' to
re-enable interrupts. This patch makes sure it does.
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>
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Make sure to include <asm/nmi.h> to provide the following prototype:
hv_nmi_check_nonrecoverable.
Remove the following warning treated as error (W=1):
arch/powerpc/kernel/traps.c:393:6: error: no previous prototype for 'hv_nmi_check_nonrecoverable'
Fixes: ccd477028a20 ("powerpc/64s: Fix HV NMI vs HV interrupt recoverability test")
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The recent commit got this test wrong, it declared the assembler
symbols the wrong way, and also used the wrong symbol name
(xxx_start rather than start_xxx, see asm/head-64.h).
Fixes: ccd477028a ("powerpc/64s: Fix HV NMI vs HV interrupt recoverability test")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Code that uses HSRR registers is not required to clear MSR[RI] by
convention, however the system reset NMI itself may use HSRR
registers (e.g., to call OPAL) and clobber them.
Rather than introduce the requirement to clear RI in order to use
HSRRs, have system reset interrupt save and restore HSRRs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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HV interrupts that use HSRR registers do not enter with MSR[RI] clear,
but their entry code is not recoverable vs NMI, due to shared use of
HSPRG1 as a scratch register to save r13.
This means that a system reset or machine check that hits in HSRR
interrupt entry can cause r13 to be silently corrupted.
Fix this by marking NMIs non-recoverable if they land in HV interrupt
ranges.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Looks like book3s/32 doesn't set RI on machine check, so
checking RI before calling die() will always be fatal
allthought this is not an issue in most cases.
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Today's message is useless:
[ 42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0
This patch fixes it:
[ 66.905235] Kernel stack overflow in process sh[356], r1=c65560b0
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use task_pid_nr()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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On Power9 machines (64-bit Book3S), we can be running with either the
Hash table or Radix tree MMU enabled. So add some text to the __die()
output to tell us which is enabled, for the case where all you have is
the oops output and no other information.
Example output:
kernel BUG at drivers/misc/lkdtm/bugs.c:63!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: kvm vmx_crypto binfmt_misc ip_tables x_tables
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The page size the kernel is built with is useful info when debugging a
crash, so add it to the output in __die().
Result looks like eg:
kernel BUG at drivers/misc/lkdtm/bugs.c:63!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: vmx_crypto kvm binfmt_misc ip_tables
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Using pr_cont() risks having our output interleaved with other output
from other CPUs. Instead print everything in a single printk() call.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Usually a TM Bad Thing exception is raised due to three different problems.
a) touching SPRs in an active transaction; b) using TM instruction with the
facility disabled and c) setting a wrong MSR/SRR1 at RFID.
The two initial cases are easy to identify by looking at the instructions.
The latter case is harder, because the MSR is masked after RFID, so, it is
very useful to look at the previous MSR (SRR1) before RFID as also the
current and masked MSR.
Since MSR is saved at paca just before RFID, this patch prints it if a TM
Bad thing happen, helping to understand what is the invalid TM transition
that is causing the exception.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Notable changes:
- A large series to rewrite our SLB miss handling, replacing a lot of
fairly complicated asm with much fewer lines of C.
- Following on from that, we now maintain a cache of SLB entries for
each process and preload them on context switch. Leading to a 27%
speedup for our context switch benchmark on Power9.
- Improvements to our handling of SLB multi-hit errors. We now print
more debug information when they occur, and try to continue running
by flushing the SLB and reloading, rather than treating them as
fatal.
- Enable THP migration on 64-bit Book3S machines (eg. Power7/8/9).
- Add support for physical memory up to 2PB in the linear mapping on
64-bit Book3S. We only support up to 512TB as regular system
memory, otherwise the percpu allocator runs out of vmalloc space.
- Add stack protector support for 32 and 64-bit, with a per-task
canary.
- Add support for PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP.
- Support recognising "big cores" on Power9, where two SMT4 cores are
presented to us as a single SMT8 core.
- A large series to cleanup some of our ioremap handling and PTE
flags.
- Add a driver for the PAPR SCM (storage class memory) interface,
allowing guests to operate on SCM devices (acked by Dan).
- Changes to our ftrace code to handle very large kernels, where we
need to use a trampoline to get to ftrace_caller().
And many other smaller enhancements and cleanups.
Thanks to: Alan Modra, Alistair Popple, Aneesh Kumar K.V, Anton
Blanchard, Aravinda Prasad, Bartlomiej Zolnierkiewicz, Benjamin
Herrenschmidt, Breno Leitao, Cédric Le Goater, Christophe Leroy,
Christophe Lombard, Dan Carpenter, Daniel Axtens, Finn Thain, Gautham
R. Shenoy, Gustavo Romero, Haren Myneni, Hari Bathini, Jia Hongtao,
Joel Stanley, John Allen, Laurent Dufour, Madhavan Srinivasan, Mahesh
Salgaonkar, Mark Hairgrove, Masahiro Yamada, Michael Bringmann,
Michael Neuling, Michal Suchanek, Murilo Opsfelder Araujo, Nathan
Fontenot, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Oliver
O'Halloran, Paul Mackerras, Petr Vorel, Rashmica Gupta, Reza Arbab,
Rob Herring, Sam Bobroff, Samuel Mendoza-Jonas, Scott Wood, Stan
Johnson, Stephen Rothwell, Stewart Smith, Suraj Jitindar Singh, Tyrel
Datwyler, Vaibhav Jain, Vasant Hegde, YueHaibing, zhong jiang"
* tag 'powerpc-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (221 commits)
Revert "selftests/powerpc: Fix out-of-tree build errors"
powerpc/msi: Fix compile error on mpc83xx
powerpc: Fix stack protector crashes on CPU hotplug
powerpc/traps: restore recoverability of machine_check interrupts
powerpc/64/module: REL32 relocation range check
powerpc/64s/radix: Fix radix__flush_tlb_collapsed_pmd double flushing pmd
selftests/powerpc: Add a test of wild bctr
powerpc/mm: Fix page table dump to work on Radix
powerpc/mm/radix: Display if mappings are exec or not
powerpc/mm/radix: Simplify split mapping logic
powerpc/mm/radix: Remove the retry in the split mapping logic
powerpc/mm/radix: Fix small page at boundary when splitting
powerpc/mm/radix: Fix overuse of small pages in splitting logic
powerpc/mm/radix: Fix off-by-one in split mapping logic
powerpc/ftrace: Handle large kernel configs
powerpc/mm: Fix WARN_ON with THP NUMA migration
selftests/powerpc: Fix out-of-tree build errors
powerpc/time: no steal_time when CONFIG_PPC_SPLPAR is not selected
powerpc/time: Only set CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC64
powerpc/time: isolate scaled cputime accounting in dedicated functions.
...
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commit b96672dd840f ("powerpc: Machine check interrupt is a non-
maskable interrupt") added a call to nmi_enter() at the beginning of
machine check restart exception handler. Due to that, in_interrupt()
always returns true regardless of the state before entering the
exception, and die() panics even when the system was not already in
interrupt.
This patch calls nmi_exit() before calling die() in order to restore
the interrupt state we had before calling nmi_enter()
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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do_exit() already includes a test to panic() is in_interrupt()
This patch removes powerpc one which is redundant.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When printing the machine check cause, the cause appears on the
following line due to bad use of printk without \n:
[ 33.663993] Machine check in kernel mode.
[ 33.664011] Caused by (from SRR1=9032):
[ 33.664036] Data access error at address c90c8000
This patch fixes it by using pr_cont() for the second part:
[ 133.258131] Machine check in kernel mode.
[ 133.258146] Caused by (from SRR1=9032): Data access error at address c90c8000
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The code in machine_check_exception excludes 64s hvmode when
incrementing the MCE counter only to call opal_machine_check to
increment it specifically for this case.
Remove the exclusion and special case.
Fixes: a43c1590426c ("powerpc/pseries: Flush SLB contents on SLB MCE
errors.")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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On a kernel TM Bad thing program exception, the Machine State Register
(MSR) is not being properly displayed. The exception code dumps a 32-bits
value but MSR is a 64 bits register for all platforms that have HTM
enabled.
This patch dumps the MSR value as a 64-bits value instead of 32 bits. In
order to do so, the 'reason' variable could not be used, since it trimmed
MSR to 32-bits (int).
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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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>
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Call force_sig_pkuerr directly instead of rolling it by hand
in _exception_pkey.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Now that _exception no longer calls _exception_pkey it is no longer
necessary to handle any signal with any si_code. All pkey exceptions
are SIGSEGV with paired with SEGV_PKUERR. So just handle
that case and remove the now unnecessary parameters from _exception_pkey.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The callers of _exception don't need the pkey exception logic because
they are not processing a pkey exception. So just call exception_common
directly and then call force_sig_fault to generate the appropriate siginfo
and deliver the appropriate signal.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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It is brittle and wrong to populate si_pkey when there was not a pkey
exception. The field does not exist for all si_codes and in some
cases another field exists in the same memory location.
So factor out the code that all exceptions handlers must run
into exception_common, leaving the individual exception handlers
to generate the signals themselves.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Replace user_single_step_siginfo with user_single_step_report
that allocates siginfo structure on the stack and sends it.
This allows tracehook_report_syscall_exit to become a simple
if statement that calls user_single_step_report or ptrace_report_syscall
depending on the value of step.
Update the default helper function now called user_single_step_report
to explicitly set si_code to SI_USER and to set si_uid and si_pid to 0.
The default helper has always been doing this (using memset) but it
was far from obvious.
The powerpc helper can now just call force_sig_fault.
The x86 helper can now just call send_sigtrap.
Unfortunately the default implementation of user_single_step_report
can not use force_sig_fault as it does not use a SIGTRAP si_code.
So it has to carefully setup the siginfo and use use force_sig_info.
The net result is code that is easier to understand and simpler
to maintain.
Ref: 85ec7fd9f8e5 ("ptrace: introduce user_single_step_siginfo() helper")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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This patch simply fix part of the documentation on the HTM code.
This fixes reference to old fields that were renamed in commit
000ec280e3dd ("powerpc: tm: Rename transct_(*) to ck(\1)_state")
It also documents better the flow after commit eb5c3f1c8647 ("powerpc:
Always save/restore checkpointed regs during treclaim/trecheckpoint"),
where tm_recheckpoint can recheckpoint what is in ck{fp,vr}_state
blindly.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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In the recent commit to add an explicit ratelimit state when showing
unhandled signals, commit 35a52a10c3ac ("powerpc/traps: Use an
explicit ratelimit state for show_signal_msg()"), I put the check of
show_unhandled_signals and the ratelimit state before the call to
unhandled_signal() so as to avoid unnecessarily calling the latter
when show_unhandled_signals is false.
However that causes us to check the ratelimit state on every call, so
if we take a lot of *handled* signals that has the effect of making
the ratelimit code print warnings that callbacks have been suppressed
when they haven't.
So rearrange the code so that we check show_unhandled_signals first,
then call unhandled_signal() and finally check the ratelimit state.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
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Call show_user_instructions() in arch/powerpc/kernel/traps.c to dump
instructions at faulty location, useful to debugging.
Before this patch, an unhandled signal message looked like:
pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 code 2 in pandafault[10000000+10000]
After this patch, it looks like:
pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 code 2 in pandafault[10000000+10000]
pandafault[10524]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
pandafault[10524]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This adds VMA address in the message printed for unhandled signals,
similarly to what other architectures, like x86, print.
Before this patch, a page fault looked like:
pandafault[61470]: unhandled signal 11 at 100007d0 nip 1000061c lr 7fff8d185100 code 2
After this patch, a page fault looks like:
pandafault[6303]: segfault 11 at 100007d0 nip 1000061c lr 7fff93c55100 code 2 in pandafault[10000000+10000]
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Use %lx format to print registers. This avoids having two different
formats and avoids checking for MSR_64BIT, improving readability of the
function.
Even though we could have used %px, which is functionally equivalent to %lx
as per Documentation/core-api/printk-formats.rst, it is not semantically
correct because the data printed are not pointers. And using %px requires
casting data to (void *).
Besides that, %lx matches the format used in show_regs().
Before this patch:
pandafault[4808]: unhandled signal 11 at 0000000010000718 nip 0000000010000574 lr 00007fff935e7a6c code 2
After this patch:
pandafault[4732]: unhandled signal 11 at 10000718 nip 10000574 lr 7fff86697a6c code 2
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Replace printk_ratelimited() by printk() and a default rate limit
burst to limit displaying unhandled signals messages.
This will allow us to call print_vma_addr() in a future patch, which
does not work with printk_ratelimited().
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Isolate the logic of printing unhandled signals out of _exception_pkey().
No functional change, only code rearrangement.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Using an si_code of 0 that aliases with SI_USER is clearly the wrong
thing todo, and causes problems in interesting ways.
For use in unknown_exception the recently defined TRAP_UNK
semantically is a perfect fit. For use in RunModeException it looks
like something more specific than TRAP_UNK could be used. No one has
bothered to find a better fit than the broken si_code of 0 in all of
these years and I don't see an obvious better fit so TRAP_UNK is
switching RunModeException to return TRAP_UNK is clearly an
improvement.
Recent history suggests no actually cares about crazy corner
cases of the kernel behavior like this so I don't expect any
regressions from changing this. However if something does
happen this change is easy to revert.
Though I wonder if SIGKILL might not be a better fit.
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Fixes: 9bad068c24d7 ("[PATCH] ppc32: support for e500 and 85xx")
Fixes: 0ed70f6105ef ("PPC32: Provide proper siginfo information on various exceptions.")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Using an si_code of 0 that aliases with SI_USER is clearly the
wrong thing todo, and causes problems in interesting ways.
The newly defined FPE_FLTUNK semantically appears to fit the
bill so use it instead.
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Fixes: 9bad068c24d7 ("[PATCH] ppc32: support for e500 and 85xx")
Fixes: 0ed70f6105ef ("PPC32: Provide proper siginfo information on various exceptions.")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.
Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.
The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.
In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.
Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The function get_user() can sleep while trying to fetch instruction
from user address space and causes the following warning from the
scheduler.
BUG: sleeping function called from invalid context
Though interrupts get enabled back but it happens bit later after
get_user() is called. This change moves enabling these interrupts
earlier covering the function get_user(). While at this, lets check
for kernel mode and crash as this interrupt should not have been
triggered from the kernel context.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When using SIG_DBG_BRANCH_TRACING, MSR.BE is left enabled in the
user context when single_step_exception() prepares the SIGTRAP
delivery. The resulting branch-trap-within-the-SIGTRAP-handler
isn't healthy.
Commit 2538c2d08f46141550a1e68819efa8fe31c6e3dc broke this, by
replacing an MSR mask operation of ~(MSR_SE | MSR_BE) with a call
to clear_single_step() which only clears MSR_SE.
This patch adds a new helper, clear_br_trace(), which clears the
debug trap before invoking the signal handler. This helper is a
NOP for BookE as SIG_DBG_BRANCH_TRACING isn't supported on BookE.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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system_reset_exception does most of its own crash handling now,
invoking the debugger or crash dumps if they are registered. If not,
then it goes through to die() to print stack traces, and then is
supposed to panic (according to comments).
However after die() prints oopses, it does its own handling which
doesn't allow system_reset_exception to panic (e.g., it may just
kill the current process). This patch causes sreset exceptions to
return from die after it prints messages but before acting.
This also stops die from invoking the debugger on 0x100 crashes.
system_reset_exception similarly calls the debugger. It had been
thought this was harmless (because if the debugger was disabled,
neither call would fire, and if it was enabled the first call
would return). However in some cases like xmon 'X' command, the
debugger returns 0, which currently causes it to be entered
again (first in system_reset_exception, then in die), which is
confusing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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For addresses above 512TB we allocate additional mmu contexts. To make
it all easy, addresses above 512TB are handled with IR/DR=1 and with
stack frame setup.
The mmu_context_t is also updated to track the new extended_ids. To
support upto 4PB we need a total 8 contexts.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Minor formatting tweaks and comment wording, switch BUG to WARN
in get_ea_context().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights:
- Enable support for memory protection keys aka "pkeys" on Power7/8/9
when using the hash table MMU.
- Extend our interrupt soft masking to support masking PMU interrupts
as well as "normal" interrupts, and then use that to implement
local_t for a ~4x speedup vs the current atomics-based
implementation.
- A new driver "ocxl" for "Open Coherent Accelerator Processor
Interface (OpenCAPI)" devices.
- Support for new device tree properties on PowerVM to describe
hotpluggable memory and devices.
- Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit
VDSO.
- Freescale updates from Scott: fixes for CPM GPIO and an FSL PCI
erratum workaround, plus a minor cleanup patch.
As well as quite a lot of other changes all over the place, and small
fixes and cleanups as always.
Thanks to: Alan Modra, Alastair D'Silva, Alexey Kardashevskiy,
Alistair Popple, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V,
Anju T Sudhakar, Anshuman Khandual, Anton Blanchard, Arnd Bergmann,
Balbir Singh, Benjamin Herrenschmidt, Bhaktipriya Shridhar, Bryant G.
Ly, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Cyril Bur,
David Gibson, Desnes A. Nunes do Rosario, Dmitry Torokhov, Frederic
Barrat, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo A. R. Silva,
Gustavo Romero, Ivan Mikhaylov, Joakim Tjernlund, Joe Perches, Josh
Poimboeuf, Juan J. Alvarez, Julia Cartwright, Kamalesh Babulal,
Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot,
Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud,
Ram Pai, Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee,
Simon Guo, Stewart Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann,
Vaibhav Jain, Vasyl Gomonovych"
* tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (199 commits)
powerpc/mm/radix: Fix build error when RADIX_MMU=n
macintosh/ams-input: Use true and false for boolean values
macintosh: change some data types from int to bool
powerpc/watchdog: Print the NIP in soft_nmi_interrupt()
powerpc/watchdog: regs can't be null in soft_nmi_interrupt()
powerpc/watchdog: Tweak watchdog printks
powerpc/cell: Remove axonram driver
rtc-opal: Fix handling of firmware error codes, prevent busy loops
powerpc/mpc52xx_gpt: make use of raw_spinlock variants
macintosh/adb: Properly mark continued kernel messages
powerpc/pseries: Fix cpu hotplug crash with memoryless nodes
powerpc/numa: Ensure nodes initialized for hotplug
powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes
powerpc/kernel: Block interrupts when updating TIDR
powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn
powerpc/mm/nohash: do not flush the entire mm when range is a single page
powerpc/pseries: Add Initialization of VF Bars
powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV
powerpc/eeh: Add EEH notify resume sysfs
powerpc/eeh: Add EEH operations to notify resume
...
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signal_code is always TRAP_HWBKPT
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Platforms with a panic handler that halts the system can have problems
getting kernel messages out, because the panic notifiers are called
before kernel/panic.c does its flushing of printk buffers an console
etc.
This was attempted to be solved with commit a3b2cb30f252 ("powerpc: Do
not call ppc_md.panic in fadump panic notifier"), but that wasn't the
right approach and caused other problems, and was reverted by commit
ab9dbf771ff9.
Instead, the powernv shutdown paths have already had a similar
problem, fixed by taking the message flushing sequence from
kernel/panic.c. That's a little bit ugly, but while we have the code
duplicated, it will work for this case as well. So have ppc panic
handlers do the same flushing before they terminate.
Without this patch, a qemu pseries_le_defconfig guest stops silently
when issued the nmi command when xmon is off and no crash dumpers
enabled. Afterwards, an oops is printed by each CPU as expected.
Fixes: ab9dbf771ff9 ("Revert "powerpc: Do not call ppc_md.panic in fadump panic notifier"")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Symbolic macros are unintuitive and hard to read, whereas octal constants
are much easier to interpret. Replace macros for the basic permission
flags (user/group/other read/write/execute) with numeric constants
instead, across the whole powerpc tree.
Introducing a significant number of changes across the tree for no runtime
benefit isn't exactly desirable, but so long as these macros are still
used in the tree people will keep sending patches that add them. Not only
are they hard to parse at a glance, there are multiple ways of coming to
the same value (as you can see with 0444 and 0644 in this patch) which
hurts readability.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The AMR/IAMR/UAMOR are part of the program context.
Allow it to be accessed via ptrace and through core files.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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