[ Upstream commit e42404fa10 ]
To start stack unwinding (SP, PC and BLINK) are needed. When the
explicit execution context (pt_regs etc) is not available, unwinder
assumes the task is sleeping (in __switch_to()) and fetches SP and BLINK
from kernel mode stack.
But this assumption is not true, specially in a SMP system, when top
runs on 1 core, there may be active running processes on all cores.
So when unwinding non courrent tasks, ensure they are NOT running.
And while at it, handle the self unwinding case explicitly.
This came out of investigation of a customer reported hang with
rcutorture+top
Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/31
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8c42a5c02b upstream.
commit feb92d7d38 "(ARC: perf: don't bail setup if pct irq
missing in device-tree)" introduced a silly brown-paper bag bug:
The assignment and comparison in an if statement were not bracketed
correctly leaving the order of evaluation undefined.
|
| if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
| ^^^ ^^^^
And given such a chance, the compiler will bite you hard, fully entitled
to generating this piece of beauty:
|
| # if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|
| bl.d @platform_get_irq <-- irq returned in r0
|
| setge r2, r0, 0 <-- r2 is bool 1 or 0 if irq >= 0 true/false
| brlt.d r0, 0, @.L114
|
| st_s r2,[sp] <-- irq saved is bool 1 or 0, not actual return val
| st 1,[r3,160] # arc_pmu.18_29->irq <-- drops bool and assumes 1
|
| # return __request_percpu_irq(irq, handler, 0,
|
| bl.d @__request_percpu_irq;
| mov_s r0,1 <-- drops even bool and assumes 1 which fails
With the snafu fixed, everything is as expected.
| bl.d @platform_get_irq <-- returns irq in r0
|
| mov_s r2,r0
| brlt.d r2, 0, @.L112
|
| st_s r0,[sp] <-- irq isaved is actual return value above
| st r0,[r13,160] #arc_pmu.18_27->irq
|
| bl.d @__request_percpu_irq <-- r0 unchanged so actual irq returned
| add r4,r4,r12 #, tmp363, __ptr
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit feb92d7d38 upstream.
Current code inadventely bails if hardware supports sampling/overflow
interrupts, but the irq is missing from device tree.
|
| # perf stat -e cycles,instructions,major-faults,minor-faults ../hackbench
| Running with 10 groups 400 process
| Time: 0.921
|
| Performance counter stats for '../hackbench':
|
| <not supported> cycles
| <not supported> instructions
| 0 major-faults
| 8679 minor-faults
This need not be as we can still do simple counting based perf stat.
This unborks perf on HSDK-4xD
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00fdec98d9 upstream.
Trap handler for syscall tracing reads EFA (Exception Fault Address),
in case strace wants PC of trap instruction (EFA is not part of pt_regs
as of current code).
However this EFA read is racy as it happens after dropping to pure
kernel mode (re-enabling interrupts). A taken interrupt could
context-switch, trigger a different task's trap, clobbering EFA for this
execution context.
Fix this by reading EFA early, before re-enabling interrupts. A slight
side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler.
The trap handler is common to both ARCompact and ARCv2 builds too.
This just came out of code rework/review and no real problem was reported
but is clearly a potential problem specially for strace.
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 43900edf67 ]
As of today the ICCM and DCCM size checks are incorrectly using
mismatched units (KiB checked against bytes). The CONFIG_ARC_DCCM_SZ
and CONFIG_ARC_ICCM_SZ are in KiB, but the size calculated in
runtime and stored in cpu->dccm.sz and cpu->iccm.sz is in bytes.
Fix that.
Reported-by: Paul Greco <pmgreco@us.ibm.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
8-letter strings representing ARC perf events are stores in two
32-bit registers as ASCII characters like that: "IJMP", "IALL", "IJMPTAK" etc.
And the same order of bytes in the word is used regardless CPU endianness.
Which means in case of big-endian CPU core we need to swap bytes to get
the same order as if it was on little-endian CPU.
Otherwise we're seeing the following error message on boot:
------------------------->8----------------------
ARC perf : 8 counters (32 bits), 40 conditions, [overflow IRQ support]
sysfs: cannot create duplicate filename '/devices/arc_pct/events/pmji'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
arc_unwind_core+0xd4/0xfc
dump_stack+0x64/0x80
sysfs_warn_dup+0x46/0x58
sysfs_add_file_mode_ns+0xb2/0x168
create_files+0x70/0x2a0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/events/core.c:12144 perf_event_sysfs_init+0x70/0xa0
Failed to register pmu: arc_pct, reason -17
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
arc_unwind_core+0xd4/0xfc
dump_stack+0x64/0x80
__warn+0x9c/0xd4
warn_slowpath_fmt+0x22/0x2c
perf_event_sysfs_init+0x70/0xa0
---[ end trace a75fb9a9837bd1ec ]---
------------------------->8----------------------
What happens here we're trying to register more than one raw perf event
with the same name "PMJI". Why? Because ARC perf events are 4 to 8 letters
and encoded into two 32-bit words. In this particular case we deal with 2
events:
* "IJMP____" which counts all jump & branch instructions
* "IJMPC___" which counts only conditional jumps & branches
Those strings are split in two 32-bit words this way "IJMP" + "____" &
"IJMP" + "C___" correspondingly. Now if we read them swapped due to CPU core
being big-endian then we read "PMJI" + "____" & "PMJI" + "___C".
And since we interpret read array of ASCII letters as a null-terminated string
on big-endian CPU we end up with 2 events of the same name "PMJI".
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Hi Linus,
Please, pull the following patches that mark switch cases where we are
expecting to fall through.
- Fix fall-through warnings on arc and nds32 for multiple
configurations.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Merge tag 'Wimplicit-fallthrough-5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull fallthrough fixes from Gustavo A. R. Silva:
"Fix fall-through warnings on arc and nds32 for multiple
configurations"
* tag 'Wimplicit-fallthrough-5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
nds32: Mark expected switch fall-throughs
ARC: unwind: Mark expected switch fall-through
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: haps_hs_defconfig arc):
arch/arc/kernel/unwind.c: In function ‘read_pointer’:
./include/linux/compiler.h:328:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
do { \
^
./include/linux/compiler.h:338:2: note: in expansion of macro ‘__compiletime_assert’
__compiletime_assert(condition, msg, prefix, suffix)
^~~~~~~~~~~~~~~~~~~~
./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^~~~~~~~~~~~~~~~
arch/arc/kernel/unwind.c:573:3: note: in expansion of macro ‘BUILD_BUG_ON’
BUILD_BUG_ON(sizeof(u32) != sizeof(value));
^~~~~~~~~~~~
arch/arc/kernel/unwind.c:575:2: note: here
case DW_EH_PE_native:
^~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
This adds support for an optional extra interrupt cell to specify edge
vs level triggered. It is backward compatible with dts files with only
one cell, and will default to level-triggered in such a case.
Note that I had to make a change to idu_irq_set_affinity as well, as
this function was setting the interrupt type to "level" unconditionally,
since this was the only type supported previously.
Signed-off-by: Mischa Jonker <mischa.jonker@synopsys.com>
Reviewed-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: haps_hs_defconfig arc):
arch/arc/kernel/unwind.c:827:20: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arc/kernel/unwind.c:836:20: warning: this statement may fall through [-Wimplicit-fallthrough=]
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- long due rewrite of do_page_fault
- refactoring of entry/exit code to utilize the double load/store instructions
- hsdk platform updates
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Merge tag 'arc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta:
- long due rewrite of do_page_fault
- refactoring of entry/exit code to utilize the double load/store
instructions
- hsdk platform updates
* tag 'arc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: [plat-hsdk]: Enable AXI DW DMAC in defconfig
ARC: [plat-hsdk]: enable DW SPI controller
ARC: hide unused function unw_hdr_alloc
ARC: [haps] Add Virtio support
ARCv2: entry: simplify return to Delay Slot via interrupt
ARC: entry: EV_Trap expects r10 (vs. r9) to have exception cause
ARCv2: entry: rewrite to enable use of double load/stores LDD/STD
ARCv2: entry: avoid a branch
ARCv2: entry: push out the Z flag unclobber from common EXCEPTION_PROLOGUE
ARCv2: entry: comments about hardware auto-save on taken interrupts
ARC: mm: do_page_fault refactor #8: release mmap_sem sooner
ARC: mm: do_page_fault refactor #7: fold the various error handling
ARC: mm: do_page_fault refactor #6: error handlers to use same pattern
ARC: mm: do_page_fault refactor #5: scoot no_context to end
ARC: mm: do_page_fault refactor #4: consolidate retry related logic
ARC: mm: do_page_fault refactor #3: tidyup vma access permission code
ARC: mm: do_page_fault refactor #2: remove short lived variable
ARC: mm: do_page_fault refactor #1: remove label @good_area
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
...
As kernelci.org reports, this function is not used in
vdk_hs38_defconfig:
arch/arc/kernel/unwind.c:188:14: warning: 'unw_hdr_alloc' defined but not used [-Wunused-function]
Fixes: bc79c9a721 ("ARC: dw2 unwind: Reinstante unwinding out of modules")
Link: https://kernelci.org/build/id/5d1cae3f59b514300340c132/logs/
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Commit 4255b07f2c ("ARCv2: STAR 9000793984: Handle return
from intr to Delay Slot") involved a complex 2 staged trampoline.
Apparently this can be greatly simplified by returning from pure
kernel mode (iso interrupt) so drop to pure kernel mdoe and execute
the normal exception return path.
Testing this was a bit of challenge as return from interrupt is rarely
executed now after commit 4de0e52867 ("ARCv2: STAR 9000814690:
Really Re-enable interrupts to avoid deadlocks"). That fix is necessary
evil and pct interrupts etc do exercise intr return path.
Anyhow after a revert of above in my local test setup I was able to hit
this case and verify the patch works.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- the motivation was to be remove blatent copy-paste due to hasty support
of CONFIG_ARC_IRQ_NO_AUTOSAVE support
- but with refactoring we could use LDD/STD to greatly optimize the code
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Based on 2 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 version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 2 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 version 2 as
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
publishhed by the free software foundation
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 48 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.292339952@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Update the calls of force_sig_fault that pass in a variable that is
set to current earlier to explicitly use current.
This is to make the next change that removes the task parameter
from force_sig_fault easier to verify.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
All of the remaining callers pass current into force_sig so
remove the task parameter to make this obvious and to make
misuse more difficult in the future.
This also makes it clear force_sig passes current into force_sig_info.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The function force_sigsegv is always called on the current task
so passing in current is redundant and not passing in current
makes this fact obvious.
This also makes it clear force_sigsegv always calls force_sig
on the current task.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
As all the memblock allocation functions return NULL in case of error
rather than panic(), the duplicates with _nopanic suffix can be removed.
Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com> [printk]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com> [c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com> [Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without bleeding edge gcc, kernel builds were tripping everywhere.
So current gcc will generate unaligned code despite
!CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS but that is something we have to
live with.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The syscall ABI has long been fixed, so no need to call that out now.
Also, there's no need to print really fine details such as norm,
barrel-shifter etc. Those are given in a Linux enabled hardware config.
So now we print just 1 line for all optional "instruction" related
hardware features
|
| ISA Extn : atomic ll64 unalign mpy[opt 9] div_rem
vs. 2 before
|
|ISA Extn : atomic ll64 unalign
| : mpy[opt 9] div_rem norm barrel-shift swap minmax swape
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
HS core names and releases have so far been identified based solely on
IDENTIFY.ARCVER field. With the future HS releases this will not
be sufficient as same ARCVER 0x54 could be an HS38 or HS48.
So rewrite the code to use a new BCR to identify the cores properly.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
In case of devboards we really often disable bootloader and load
Linux image in memory via JTAG. Even if kernel tries to verify
uboot_tag and uboot_arg there is sill a chance that we treat some
garbage in registers as valid u-boot arguments in JTAG case.
E.g. it is enough to have '1' in r0 to treat any value in r2 as
a boot command line.
So check that magic number passed from u-boot is correct and drop
u-boot arguments otherwise. That helps to reduce the possibility
of using garbage as u-boot arguments in JTAG case.
We can safely check U-boot magic value (0x0) in linux passed via
r1 register as U-boot pass it from the beginning. So there is no
backward-compatibility issues.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
As of today we enable unaligned access unconditionally on ARCv2.
Do this under a Kconfig option to allow disable it for test, benchmarking
etc. Also while at it
- Select HAVE_EFFICIENT_UNALIGNED_ACCESS
- Although gcc defaults to unaligned access (since GNU 2018.03), add the
right toggles for enabling or disabling as appropriate
- update bootlog to prints both HW feature status (exists, enabled/disabled)
and SW status (used / not used).
- wire up the relaxed memcpy for unaligned access
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: squashed patches, handle gcc -mno-unaligned-access quick]
The first release of core4 (0x54) was dual issue only (HS4x).
Newer releases allow hardware to be configured as single issue (HS3x)
or dual issue.
Prevent accessing a HS4x only aux register in HS3x, which otherwise
leads to illegal instruction exceptions
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
After reworking U-boot args handling code and adding paranoid
arguments check we can eliminate CONFIG_ARC_UBOOT_SUPPORT and
enable uboot support unconditionally.
For JTAG case we can assume that core registers will come up
reset value of 0 or in worst case we rely on user passing
'-on=clear_regs' to Metaware debugger.
Cc: stable@vger.kernel.org
Tested-by: Corentin LABBE <clabbe@baylibre.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Handle U-boot arguments paranoidly:
* don't allow to pass unknown tag.
* try to use external device tree blob only if corresponding tag
(TAG_DTB) is set.
* don't check uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.
NOTE:
If U-boot args are invalid we skip them and try to use embedded device
tree blob. We can't panic on invalid U-boot args as we really pass
invalid args due to bug in U-boot code.
This happens if we don't provide external DTB to U-boot and
don't set 'bootargs' U-boot environment variable (which is default
case at least for HSDK board) In that case we will pass
{r0 = 1 (bootargs in r2); r1 = 0; r2 = 0;} to linux which is invalid.
While I'm at it refactor U-boot arguments handling code.
Cc: stable@vger.kernel.org
Tested-by: Corentin LABBE <clabbe@baylibre.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
There's a hardware bug which affects the HSDK platform, triggered by
micro-ops for auto-saving regfile on taken interrupt. The workaround is
to inhibit autosave.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
It is currently done in arc_init_IRQ() which might be too late
considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned
memory accesses by default
Cc: stable@vger.kernel.org #4.4+
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
signal handling core calls show_regs() with preemption disabled which
on ARC takes mmap_sem for mm/vma access, causing lockdep splat.
| [ARCLinux]# ./segv-null-ptr
| potentially unexpected fatal signal 11.
| BUG: sleeping function called from invalid context at kernel/fork.c:1011
| in_atomic(): 1, irqs_disabled(): 0, pid: 70, name: segv-null-ptr
| no locks held by segv-null-ptr/70.
| CPU: 0 PID: 70 Comm: segv-null-ptr Not tainted 4.18.0+ #69
|
| Stack Trace:
| arc_unwind_core+0xcc/0x100
| ___might_sleep+0x17a/0x190
| mmput+0x16/0xb8
| show_regs+0x52/0x310
| get_signal+0x5ee/0x610
| do_signal+0x2c/0x218
| resume_user_mode_begin+0x90/0xd8
Workaround by re-enabling preemption temporarily.
Note that the preemption disabling in core code around show_regs()
was introduced by commit 3a9f84d354 ("signals, debug: fix BUG: using
smp_processor_id() in preemptible code in print_fatal_signal()")
to silence a differnt lockdep seen on x86 bakc in 2009.
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
and use smaller/on-stack buffer instead
The motivation for this change was lockdep splat like below.
| potentially unexpected fatal signal 11.
| BUG: sleeping function called from invalid context at ../mm/page_alloc.c:4317
| in_atomic(): 1, irqs_disabled(): 0, pid: 57, name: segv
| no locks held by segv/57.
| Preemption disabled at:
| [<8182f17e>] get_signal+0x4a6/0x7c4
| CPU: 0 PID: 57 Comm: segv Not tainted 4.17.0+ #23
|
| Stack Trace:
| arc_unwind_core.constprop.1+0xd0/0xf4
| __might_sleep+0x1f6/0x234
| __get_free_pages+0x174/0xca0
| show_regs+0x22/0x330
| get_signal+0x4ac/0x7c4 # print_fatal_signals() -> preempt_disable()
| do_signal+0x30/0x224
| resume_user_mode_begin+0x90/0xd8
So signal handling core calls show_regs() with preemption disabled but
an ensuing GFP_KERNEL page allocator call is flagged by lockdep.
We could have switched to GFP_NOWAIT, but turns out that is not enough
anways and eliding page allocator call leads to less code and
instruction traces to sift thru when debugging pesky crashes.
FWIW, this patch doesn't cure the lockdep splat (which next patch does).
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Move HW events mapping to separate function to make code more readable.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Export all available ARC architected hardware events as
kernel PMU events to make non-generic events accessible.
ARC PMU HW allow us to read the list of all available
events names. So we generate kernel PMU event list
dynamically in arc_pmu_device_probe() using
human-readable events names we got from HW instead of
using pre-defined events list.
-------------------------->8--------------------------
$ perf list
[snip]
arc_pmu/bdata64/ [Kernel PMU event]
arc_pmu/bdcstall/ [Kernel PMU event]
arc_pmu/bdslot/ [Kernel PMU event]
arc_pmu/bfbmp/ [Kernel PMU event]
arc_pmu/bfirqex/ [Kernel PMU event]
arc_pmu/bflgstal/ [Kernel PMU event]
arc_pmu/bflush/ [Kernel PMU event]
-------------------------->8--------------------------
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Use BIT(), lower_32_bits(), upper_32_bits() macroses,
fix code style violations.
* Use u32, u64, s64 instead of uint32_t, uint64_t, int64_t
* Fix description comment as this code doesn't belong only to
ARC700 anymore.
* Use SPDX License Identifier.
* Remove useless ifdefs. ifdef around 'arc_pmu_match' structure
declaration is useless as we refer to 'arc_pmu_match' in
several places which aren't guarded with ifdef. Nevertheless
'ARC' option selects 'OF' unconditionally so we can simply
get rid of this ifdef.
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull vfs mount API prep from Al Viro:
"Mount API prereqs.
Mostly that's LSM mount options cleanups. There are several minor
fixes in there, but nothing earth-shattering (leaks on failure exits,
mostly)"
* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
smack: rewrite smack_sb_eat_lsm_opts()
smack: get rid of match_token()
smack: take the guts of smack_parse_opts_str() into a new helper
LSM: new method: ->sb_add_mnt_opt()
selinux: rewrite selinux_sb_eat_lsm_opts()
selinux: regularize Opt_... names a bit
selinux: switch away from match_token()
selinux: new helper - selinux_add_opt()
LSM: bury struct security_mnt_opts
smack: switch to private smack_mnt_opts
selinux: switch to private struct selinux_mnt_opts
LSM: hide struct security_mnt_opts from any generic code
selinux: kill selinux_sb_get_mnt_opts()
LSM: turn sb_eat_lsm_opts() into a method
nfs_remount(): don't leak, don't ignore LSM options quietly
btrfs: sanitize security_mnt_opts use
selinux; don't open-code a loop in sb_finish_set_opts()
LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()
new helper: security_sb_eat_lsm_opts()
...
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>
Mostly clean ups although whilst Doug's was chasing down a odd
lockdep warning he also did some work to improved debugger resilience
when some CPUs fail to respond to the round up request.
The main changes are:
* Fixing a lockdep warning on architectures that cannot use an NMI for
the round up plus related changes to make CPU round up and all CPU
backtrace more resilient.
* Constify the arch ops tables
* A couple of other small clean ups
Two of the three patchsets here include changes that spill over into
arch/. Changes in the arch space are relatively narrow in scope
(and directly related to kgdb). Didn't get comprehensive acks but
all impacted maintainers were Cc:ed in good time.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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Merge tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"Mostly clean ups although while Doug's was chasing down a odd lockdep
warning he also did some work to improved debugger resilience when
some CPUs fail to respond to the round up request.
The main changes are:
- Fixing a lockdep warning on architectures that cannot use an NMI
for the round up plus related changes to make CPU round up and all
CPU backtrace more resilient.
- Constify the arch ops tables
- A couple of other small clean ups
Two of the three patchsets here include changes that spill over into
arch/. Changes in the arch space are relatively narrow in scope (and
directly related to kgdb). Didn't get comprehensive acks but all
impacted maintainers were Cc:ed in good time"
* tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops
mips/kgdb: prepare arch_kgdb_ops for constness
kdb: use bool for binary state indicators
kdb: Don't back trace on a cpu that didn't round up
kgdb: Don't round up a CPU that failed rounding up before
kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()
kgdb: Remove irq flags from roundup
checkpatch.pl reports the following:
WARNING: struct kgdb_arch should normally be const
#28: FILE: arch/mips/kernel/kgdb.c:397:
+struct kgdb_arch arch_kgdb_ops = {
This report makes sense, as all other ops struct, this
one should also be const. This patch does the change.
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
When I had lockdep turned on and dropped into kgdb I got a nice splat
on my system. Specifically it hit:
DEBUG_LOCKS_WARN_ON(current->hardirq_context)
Specifically it looked like this:
sysrq: SysRq : DEBUG
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(current->hardirq_context)
WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27
pstate: 604003c9 (nZCv DAIF +PAN -UAO)
pc : lockdep_hardirqs_on+0xf0/0x160
...
Call trace:
lockdep_hardirqs_on+0xf0/0x160
trace_hardirqs_on+0x188/0x1ac
kgdb_roundup_cpus+0x14/0x3c
kgdb_cpu_enter+0x53c/0x5cc
kgdb_handle_exception+0x180/0x1d4
kgdb_compiled_brk_fn+0x30/0x3c
brk_handler+0x134/0x178
do_debug_exception+0xfc/0x178
el1_dbg+0x18/0x78
kgdb_breakpoint+0x34/0x58
sysrq_handle_dbg+0x54/0x5c
__handle_sysrq+0x114/0x21c
handle_sysrq+0x30/0x3c
qcom_geni_serial_isr+0x2dc/0x30c
...
...
irq event stamp: ...45
hardirqs last enabled at (...44): [...] __do_softirq+0xd8/0x4e4
hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130
softirqs last enabled at (...42): [...] _local_bh_enable+0x2c/0x34
softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100
---[ end trace adf21f830c46e638 ]---
Looking closely at it, it seems like a really bad idea to be calling
local_irq_enable() in kgdb_roundup_cpus(). If nothing else that seems
like it could violate spinlock semantics and cause a deadlock.
Instead, let's use a private csd alongside
smp_call_function_single_async() to round up the other CPUs. Using
smp_call_function_single_async() doesn't require interrupts to be
enabled so we can remove the offending bit of code.
In order to avoid duplicating this across all the architectures that
use the default kgdb_roundup_cpus(), we'll add a "weak" implementation
to debug_core.c.
Looking at all the people who previously had copies of this code,
there were a few variants. I've attempted to keep the variants
working like they used to. Specifically:
* For arch/arc we passed NULL to kgdb_nmicallback() instead of
get_irq_regs().
* For arch/mips there was a bit of extra code around
kgdb_nmicallback()
NOTE: In this patch we will still get into trouble if we try to round
up a CPU that failed to round up before. We'll try to round it up
again and potentially hang when we try to grab the csd lock. That's
not new behavior but we'll still try to do better in a future patch.
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
The function kgdb_roundup_cpus() was passed a parameter that was
documented as:
> the flags that will be used when restoring the interrupts. There is
> local_irq_save() call before kgdb_roundup_cpus().
Nobody used those flags. Anyone who wanted to temporarily turn on
interrupts just did local_irq_enable() and local_irq_disable() without
looking at them. So we can definitely remove the flags.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Vineet Gupta