linux.git/arch/riscv/kernel/stacktrace.c, branch v5.9

kernel: rename show_stack_loglvl() => show_stack()

2020-06-09T16:39:13+00:00

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 
Signed-off-by: Andrew Morton 
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds

riscv: add show_stack_loglvl()

2020-06-09T16:39:11+00:00

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 
Signed-off-by: Andrew Morton 
Cc: Albert Ou 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Link: http://lkml.kernel.org/r/20200418201944.482088-28-dima@arista.com
Signed-off-by: Linus Torvalds

kallsyms/printk: add loglvl to print_ip_sym()

2020-06-09T16:39:10+00:00

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 
Signed-off-by: Andrew Morton 
Acked-by: Steven Rostedt (VMware) 
Cc: Albert Ou 
Cc: Ben Segall 
Cc: Dietmar Eggemann 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Hogan 
Cc: Juri Lelli 
Cc: Mel Gorman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Paul Walmsley 
Cc: Peter Zijlstra 
Cc: Ralf Baechle 
Cc: Thomas Gleixner 
Cc: Vincent Chen 
Cc: Vincent Guittot 
Cc: Will Deacon 
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Dmitry Safonov 
Cc: Jiri Slaby 
Cc: Petr Mladek 
Cc: Sergey Senozhatsky 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Richard Henderson 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Aurelien Jacquiot 
Cc: Mark Salter 
Cc: Guo Ren 
Cc: Yoshinori Sato 
Cc: Brian Cain 
Cc: Fenghua Yu 
Cc: Tony Luck 
Cc: Geert Uytterhoeven 
Cc: Ley Foon Tan 
Cc: Jonas Bonn 
Cc: Stafford Horne 
Cc: Stefan Kristiansson 
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Benjamin Herrenschmidt 
Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: Christian Borntraeger 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Rich Felker 
Cc: "David S. Miller" 
Cc: Anton Ivanov 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Guan Xuetao 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Len Brown 
Cc: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: "Rafael J. Wysocki" 
Cc: Daniel Thompson 
Cc: Douglas Anderson 
Cc: Jason Wessel 
Link: http://lkml.kernel.org/r/20200418201944.482088-2-dima@arista.com
Signed-off-by: Linus Torvalds

riscv: stacktrace: Fix undefined reference to `walk_stackframe'

2020-05-13T00:04:25+00:00

Drop static declaration to fix following build error if FRAME_POINTER disabled,
  riscv64-linux-ld: arch/riscv/kernel/perf_callchain.o: in function `.L0':
  perf_callchain.c:(.text+0x2b8): undefined reference to `walk_stackframe'

Reported-by: Hulk Robot 
Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt

RISC-V: stacktrace: Declare sp_in_global outside ifdef

2020-04-21T17:50:45+00:00

riscv:allnoconfig and riscv:tinyconfig fail to compile.

arch/riscv/kernel/stacktrace.c: In function 'walk_stackframe':
arch/riscv/kernel/stacktrace.c:78:8: error: 'sp_in_global' undeclared

sp_in_global is declared inside CONFIG_FRAME_POINTER but used outside
of it.

Fixes: 52e7c52d2ded ("RISC-V: Stop relying on GCC's register allocator's hueristics")
Signed-off-by: Guenter Roeck 
Reviewed-by: Palmer Dabbelt 
Signed-off-by: Palmer Dabbelt

RISC-V: Stop relying on GCC's register allocator's hueristics

2020-03-03T18:28:13+00:00

GCC allows users to hint to the register allocation that a variable should be
placed in a register by using a syntax along the lines of

    function(...) {
        register long in_REG __asm__("REG");
    }

We've abused this a bit throughout the RISC-V port to access fixed registers
directly as C variables.  In practice it's never going to blow up because GCC
isn't going to allocate these registers, but it's not a well defined syntax so
we really shouldn't be relying upon this.  Luckily there is a very similar but
well defined syntax that allows us to still access these registers directly as
C variables, which is to simply declare the register variables globally.  For
fixed variables this doesn't change the ABI.

LLVM disallows this ambiguous syntax, so this isn't just strictly a formatting
change.

Signed-off-by: Palmer Dabbelt

riscv: Add perf callchain support

2019-09-04T19:43:00+00:00

This patch add support for perf callchain sampling on riscv platforms.
The return address of leaf function is retrieved from pt_regs as
it is not saved in the outmost frame.

Signed-off-by: Mao Han 
Cc: Paul Walmsley 
Cc: Greentime Hu 
Cc: Palmer Dabbelt 
Cc: linux-riscv 
Cc: Christoph Hellwig 
Cc: Guo Ren 
Tested-by: Greentime Hu 
[paul.walmsley@sifive.com: fixed some 'checkpatch.pl --strict' issues;
 fixed patch description spelling]
Signed-off-by: Paul Walmsley

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

2019-05-30T18:26:41+00:00

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 version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

Merge tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

2019-05-19T16:56:36+00:00

Pull RISC-V updates from Palmer Dabbelt:
"This contains an assortment of RISC-V related patches that I'd like to
target for the 5.2 merge window. Most of the patches are cleanups, but
there are a handful of user-visible changes:

- The nosmp and nr_cpus command-line arguments are now supported,
which work like normal.

- The SBI console no longer installs itself as a preferred console,
we rely on standard mechanisms (/chosen, command-line, hueristics)
instead.

- sfence_remove_sfence_vma{,_asid} now pass their arguments along to
the SBI call.

- Modules now support BUG().

- A missing sfence.vma during boot has been added. This bug only
manifests during boot.

- The arch/riscv support for SiFive's L2 cache controller has been
merged, which should un-block the EDAC framework work.

I've only tested this on QEMU again, as I didn't have time to get
things running on the Unleashed. The latest master from this morning
merges in cleanly and passes the tests as well"

* tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (31 commits)
riscv: fix locking violation in page fault handler
RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs
RISC-V: Add DT documentation for SiFive L2 Cache Controller
RISC-V: Avoid using invalid intermediate translations
riscv: Support BUG() in kernel module
riscv: Add the support for c.ebreak check in is_valid_bugaddr()
riscv: support trap-based WARN()
riscv: fix sbi_remote_sfence_vma{,_asid}.
riscv: move switch_mm to its own file
riscv: move flush_icache_{all,mm} to cacheflush.c
tty: Don't force RISCV SBI console as preferred console
RISC-V: Access CSRs using CSR numbers
RISC-V: Add interrupt related SCAUSE defines in asm/csr.h
RISC-V: Use tabs to align macro values in asm/csr.h
RISC-V: Fix minor checkpatch issues.
RISC-V: Support nr_cpus command line option.
RISC-V: Implement nosmp commandline option.
RISC-V: Add RISC-V specific arch_match_cpu_phys_id
riscv: vdso: drop unnecessary cc-ldoption
riscv: call pm_power_off from machine_halt / machine_power_off
...

riscv: remove duplicate macros from ptrace.h

2019-04-25T21:51:11+00:00

No need to have two names for the same thing.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Palmer Dabbelt