19 Commits

Author SHA1 Message Date
Dmitry Safonov
9cb8f069de kernel: rename show_stack_loglvl() => show_stack()
Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Dmitry Safonov
18a4753f90 nds32: add show_stack_loglvl()
Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-23-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:11 -07:00
Dmitry Safonov
2062a4e8ae kallsyms/printk: add loglvl to print_ip_sym()
Patch series "Add log level to show_stack()", v3.

Add log level argument to show_stack().

Done in three stages:
1. Introducing show_stack_loglvl() for every architecture
2. Migrating old users with an explicit log level
3. Renaming show_stack_loglvl() into show_stack()

Justification:

- It's a design mistake to move a business-logic decision into platform
  realization detail.

- I have currently two patches sets that would benefit from this work:
  Removing console_loglevel jumps in sysrq driver [1] Hung task warning
  before panic [2] - suggested by Tetsuo (but he probably didn't realise
  what it would involve).

- While doing (1), (2) the backtraces were adjusted to headers and other
  messages for each situation - so there won't be a situation when the
  backtrace is printed, but the headers are missing because they have
  lesser log level (or the reverse).

- As the result in (2) plays with console_loglevel for kdb are removed.

The least important for upstream, but maybe still worth to note that every
company I've worked in so far had an off-list patch to print backtrace
with the needed log level (but only for the architecture they cared
about).  If you have other ideas how you will benefit from show_stack()
with a log level - please, reply to this cover letter.

See also discussion on v1:
https://lore.kernel.org/linux-riscv/20191106083538.z5nlpuf64cigxigh@pathway.suse.cz/

This patch (of 50):

print_ip_sym() needs to have a log level parameter to comply with other
parts being printed.  Otherwise, half of the expected backtrace would be
printed and other may be missing with some logging level.

The following callee(s) are using now the adjusted log level:
- microblaze/unwind: the same level as headers & userspace unwind.
  Note that pr_debug()'s there are for debugging the unwinder itself.
- nds32/traps: symbol addresses are printed with the same log level
  as backtrace headers.
- lockdep: ip for locking issues is printed with the same log level
  as other part of the warning.
- sched: ip where preemption was disabled is printed as error like
  the rest part of the message.
- ftrace: bug reports are now consistent in the log level being used.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-2-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:10 -07:00
Eric W. Biederman
2e1661d267 signal: Remove the task parameter from force_sig_fault
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>
2019-05-29 09:31:43 -05:00
Eric W. Biederman
351b6825b3 signal: Explicitly call force_sig_fault on current
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>
2019-05-29 09:31:43 -05:00
Eric W. Biederman
07bd88a9a5 signal/nds32: Remove tsk parameter from send_sigtrap
The send_sigtrap function is always called with tsk == current.
Make that obvious by removing the tsk parameter.

This also makes it clear that send_sigtrap always calls
force_sig_fault on the current task.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-29 09:31:42 -05:00
Eric W. Biederman
3cf5d076fb signal: Remove task parameter from force_sig
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>
2019-05-27 09:36:28 -05:00
Vincent Chen
e46bf83c18 nds32: nds32 FPU port
This patch set contains basic components for supporting the nds32 FPU,
such as exception handlers and context switch for FPU registers. By
default, the lazy FPU scheme is supported and the user can configure it via
CONFIG_LZAY_FPU.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-11-22 18:13:13 +08:00
Greentime Hu
487c4b2323 nds32: Only print one page of stack when die to prevent printing too much information.
It may print too much information sometimes if the stack is wrong or
too big. This patch can limit the debug information in a page of stack.

Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-09-04 14:45:19 +08:00
Zong Li
95f93ed7fe nds32: Add macro definition for offset of lp register on stack
Use macro to replace the magic number.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-09-04 14:45:19 +08:00
Zong Li
c5fdf7e00d nds32: Remove the deprecated ABI implementation
We are not using NDS32 ABI 2 for now, just remove the preprocessor
directives __NDS32_ABI_2.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-09-04 14:45:19 +08:00
Zong Li
1e377ae9b0 nds32/stack: Get real return address by using ftrace_graph_ret_addr
Function graph tracer has modified the return address to
'return_to_handler' on stack, and provide the 'ftrace_graph_ret_addr' to
get the real return address.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-09-04 14:45:18 +08:00
Zong Li
c17df79605 nds32: Fix empty call trace
The compiler predefined macro 'NDS32_ABI_2' had been removed, it should
use the '__NDS32_ABI_2' here.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-09-04 14:45:16 +08:00
Eric W. Biederman
d808e918ed signal/nds32: Use force_sig_fault where appropriate
Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper force_sig_fault.  Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.

In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Acked-by: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:42:47 -05:00
Eric W. Biederman
3eb0f5193b signal: Ensure every siginfo we send has all bits initialized
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>
2018-04-25 10:40:51 -05:00
Eric W. Biederman
f6ed1ecad5 signal/nds32: Use force_sig(SIGILL) in do_revisn
As originally committed do_revisn would deliver a siginfo for SIGILL
with an si_code composed of random stack contents.  That makes no
sense and is not something userspace can depend on.  So simplify
the code and just use "force_sig(SIG_ILL, current)" instead.

Fixes: 2923f5ea7738 ("nds32: Exception handling")
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:33 -05:00
Eric W. Biederman
be5c2ff06c signal/nds32: Use force_sig in unhandled_interruption and unhandled_exceptions
Neither unhandled_interrupt nor unhandled_exceptions fills in any of the
siginfo fields whend sending SIGKILL.  Further because it is SIGKILL
even if all of the fields were filled out appropriately it would be impossible
for the process to read any of the siginfo fields.  So simplfy things and
just use force_sig instead of force_sig_info.

Fixes: 2923f5ea7738 ("nds32: Exception handling")
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:39:49 -05:00
Greentime Hu
6fc61ee694 nds32: To use the generic dump_stack()
Use the generic dump_stack() instead of nds32 one because they are doing
the same thing.

Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2018-03-16 15:45:23 +08:00
Greentime Hu
2923f5ea77 nds32: Exception handling
This patch includes the exception/interrupt entries, pt_reg structure and
related accessors.

/* Unaligned accessing handling*/
Andes processors cannot load/store information which is not naturally
aligned on the bus, i.e., loading a 4 byte data whose start address must
be divisible by 4. If unaligned data accessing is happened, data
unaligned exception will be triggered and user will get SIGSEGV or
kernel oops according to the unaligned address. In order to make user be
able to load/store data from an unaligned address, software load/store
emulation is implemented in arch/nds32/mm/alignment.c to address data
unaligned exception.

Unaligned accessing handling is disabled by default because it is not a
normal case. User can enable this feature by following steps.

A. Compile time:
    1. Enable kernel config CONFIG_ALIGNMENT_TRAP
B. Run time:
    1. Enter /proc/sys/nds32/unaligned_acess folder
    2. Write 1 to file enable_mode to enable unaligned accessing
       handling. User can disable it by writing 0 to this file.
    3. Write 1 to file debug to show which unaligned address is under
       processing. User can disable it by writing 0 to this file.

However, unaligned accessing handler cannot work if this unaligned
address is not accessible such as protection violation. On this
condition, the default behaviors for addressing data unaligned exception
still happen

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2018-02-22 10:44:31 +08:00