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  1. 06 Jan, 2020 16 commits
    • Thomas Hebb's avatar
      kconfig: fix nesting of symbol help text · a9609686
      Thomas Hebb authored 
      When we generate the help text of a symbol (e.g. when a user presses '?'
in menuconfig), we do two things:

 1. We iterate through every prompt that belongs to that symbol,
    printing its text and its location in the menu tree.
 2. We print symbol-wide information that's not linked to a particular
    prompt, such as what it selects/is selected by and what it
    implies/is implied by.

Each prompt we print for 1 starts with a line that's not indented
indicating where the prompt is defined, then continues with indented
lines that describe properties of that particular definition.

Once we get to 2, however, we print all the global data indented as
well! Visually, this makes it look like the symbol-wide data is
associated with the last prompt we happened to print rather than
the symbol as a whole.

Fix this by removing the indentation for symbol-wide information.

Before:

  Symbol: CPU_FREQ [=n]
  Type  : bool
  Defined at drivers/cpufreq/Kconfig:4
    Prompt: CPU Frequency scaling
    Location:
      -> CPU Power Management
        -> CPU Frequency scaling
    Selects: SRCU [=n]
    Selected by [n]:
    - ARCH_SA1100 [=n] && <choice>

After:

  Symbol: CPU_FREQ [=n]
  Type  : bool
  Defined at drivers/cpufreq/Kconfig:4
    Prompt: CPU Frequency scaling
    Location:
      -> CPU Power Management
        -> CPU Frequency scaling
  Selects: SRCU [=n]
  Selected by [n]:
    - ARCH_SA1100 [=n] && <choice>
Signed-off-by: default avatarThomas Hebb <tommyhebb@gmail.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      a9609686
    • Thomas Hebb's avatar
      kconfig: distinguish between dependencies and visibility in help text · 3460d0bc
      Thomas Hebb authored 
      Kconfig makes a distinction between dependencies (defined by "depends
on" expressions and enclosing "if" blocks) and visibility (which
includes all dependencies, but also includes inline "if" expressions of
individual properties as well as, for prompts, "visible if" expressions
of enclosing menus).

Before commit bcdedcc1 ("menuconfig: print more info for symbol
without prompts"), the "Depends on" lines of a symbol's help text
indicated the visibility of the prompt property they appeared under.
After bcdedcc1, there was always only a single "Depends on" line,
which indicated the visibility of the first P_SYMBOL property of the
symbol. Since P_SYMBOLs never have inline if expressions, this was in
effect the same as the dependencies of the menu item that the P_SYMBOL
was attached to.

Neither of these situations accurately conveyed the dependencies of a
symbol--the first because it was actually the visibility, and the second
because it only showed the dependencies from a single definition.

With this series, we are back to printing separate dependencies for each
definition, but we print the actual dependencies (rather than the
visibility) in the "Depends on" line. However, it can still be useful to
know the visibility of a prompt, so this patch adds a "Visible if" line
that shows the visibility only if the visibility is different from the
dependencies (which it isn't for most prompts in Linux).

Before:

  Symbol: THUMB2_KERNEL [=n]
  Type  : bool
  Defined at arch/arm/Kconfig:1417
    Prompt: Compile the kernel in Thumb-2 mode
    Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n]
    Location:
      -> Kernel Features
    Selects: ARM_UNWIND [=n]

After:

   Symbol: THUMB2_KERNEL [=n]
   Type  : bool
   Defined at arch/arm/Kconfig:1417
     Prompt: Compile the kernel in Thumb-2 mode
     Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n]
     Visible if: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n] && !CPU_THUMBONLY [=n]
     Location:
       -> Kernel Features
     Selects: ARM_UNWIND [=n]
Signed-off-by: default avatarThomas Hebb <tommyhebb@gmail.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      3460d0bc
    • Thomas Hebb's avatar
      kconfig: list all definitions of a symbol in help text · edda15f2
      Thomas Hebb authored 
      In Kconfig, each symbol (representing a config option) can be defined in
multiple places. Each definition may or may not have a prompt, which
allows the option to be set via an interface like menuconfig. Each
definition has a set of dependencies, which determine whether its prompt
is visible and whether other pieces of the definition, like a default
value, take effect.

Historically, a symbol's help text (i.e. what's shown when a user
presses '?' in menuconfig) contained some symbol-wide information not
tied to any particular definition (e.g. what other symbols it selects)
as well as the location (file name and line number) and dependencies of
each prompt. Notably, the help text did not show the location or
dependencies of definitions without prompts.

Because this made it hard to reason about symbols that had no prompts,
commit bcdedcc1 ("menuconfig: print more info for symbol without
prompts") changed the help text so that, instead of containing the
location and dependencies of each prompt, it contained the location and
dependencies of the symbol's first definition, regardless of whether or
not that definition had a prompt.

For symbols with only one definition, that change makes sense. However,
it breaks down for symbols with multiple definitions: each definition
has its own set of dependencies (the `dep` field of `struct menu`), and
those dependencies are ORed together to get the symbol's dependency list
(the `dir_dep` field of `struct symbol`). By printing only the
dependencies of the first definition, the help text misleads users into
believing that an option is more narrowly-applicable than it actually
is.

For an extreme example of this, we can look at the SYS_TEXT_BASE symbol
in the Das U-Boot project (version 2019.10), which also uses Kconfig. (I
unfortunately could not find an illustrative example in Linux.) This
config option specifies the load address of the built binary and, as
such, is applicable to basically every configuration possible. And yet,
without this patch, its help text is as follows:

  Symbol: SYS_TEXT_BASE [=]
  Type  : hex
  Prompt: U-Boot base address
    Location:
      -> ARM architecture
  Prompt: Text Base
    Location:
      -> Boot images
    Defined at arch/arm/mach-aspeed/Kconfig:9
    Depends on: ARM [=n] && ARCH_ASPEED [=n]

The help text indicates that the option is applicable only for a
specific unselected architecture (aspeed), because that architecture's
promptless definition (which just sets a default value), happens to be
the first one seen. No definition or dependency information is printed
for either of the two prompts listed.

Because source locations and dependencies are fundamentally properties
of definitions and not of symbols, we should treat them as such. This
patch brings back the pre-bcdedcc1 behavior for definitions with
prompts but also separately prints the location and dependencies of
those without prompts, solving the original problem in a different way.
With this change, our SYS_TEXT_BASE example becomes

   Symbol: SYS_TEXT_BASE [=]
   Type  : hex
   Defined at arch/arm/mach-stm32mp/Kconfig:83
     Prompt: U-Boot base address
     Depends on: ARM [=n] && ARCH_STM32MP [=n]
     Location:
       -> ARM architecture
   Defined at Kconfig:532
     Prompt: Text Base
     Depends on: !NIOS2 [=n] && !XTENSA [=n] && !EFI_APP [=n]
     Location:
       -> Boot images
   Defined at arch/arm/mach-aspeed/Kconfig:9
     Depends on: ARM [=n] && ARCH_ASPEED [=n]
   Defined  at arch/arm/mach-socfpga/Kconfig:25
     Depends on: ARM [=n] && ARCH_SOCFPGA [=n]
   <snip>
   Defined at board/sifive/fu540/Kconfig:15
     Depends on: RISCV [=n] && TARGET_SIFIVE_FU540 [=n]

which is a much more accurate representation.

Note that there is one notable difference between what gets printed for
prompts after this change and what got printed before bcdedcc1: the
"Depends on" line now accurately represents the prompt's dependencies
instead of conflating those with the prompt's visibility (which can
include extra conditions). See the patch later in this series titled
"kconfig: distinguish between dependencies and visibility in help text"
for more details and better handling of that nuance.
Signed-off-by: default avatarThomas Hebb <tommyhebb@gmail.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      edda15f2
    • Tetsuo Handa's avatar
      kconfig: Add yes2modconfig and mod2yesconfig targets. · 89b90609
      Tetsuo Handa authored 
      Since kernel configs provided by syzbot are close to "make allyesconfig",
it takes long time to rebuild. This is especially waste of time when we
need to rebuild for many times (e.g. doing manual printk() inspection,
bisect operations).

We can save time if we can exclude modules which are irrelevant to each
problem. But "make localmodconfig" cannot exclude modules which are built
into vmlinux because /sbin/lsmod output is used as the source of modules.

Therefore, this patch adds "make yes2modconfig" which converts from =y
to =m if possible. After confirming that the interested problem is still
reproducible, we can try "make localmodconfig" (and/or manually tune
based on "Modules linked in:" line) in order to exclude modules which are
irrelevant to the interested problem. While we are at it, this patch also
adds "make mod2yesconfig" which converts from =m to =y in case someone
wants to convert from =m to =y after "make localmodconfig".
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      89b90609
    • Masahiro Yamada's avatar
      kconfig: use $(PERL) in Makefile · c8138a57
      Masahiro Yamada authored 
      The top Makefile defines and exports the variable 'PERL'. Use it in
case somebody wants to specify a particular version of perl from the
command line.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      c8138a57
    • Masahiro Yamada's avatar
      kconfig: fix too deep indentation in Makefile · 1d135237
      Masahiro Yamada authored 
      The indentation for if ... else ... fi is too deep. Fix it.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      1d135237
    • Masahiro Yamada's avatar
      kconfig: localmodconfig: fix indentation for closing brace · 68f0d627
      Masahiro Yamada authored 
      This is the closing brace for the foreach loop. Fix the misleading
indentation.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      68f0d627
    • Masahiro Yamada's avatar
      kconfig: localmodconfig: remove unused $config · 5edcef84
      Masahiro Yamada authored 
      This is unused since commit cdfc4795 ("kconfig: search for a config
to base the local(mod|yes)config on").

Having unused $config is confusing because $config is used as a local
variable in various sub-routines.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      5edcef84
    • Masahiro Yamada's avatar
      kconfig: squash prop_alloc() into menu_add_prop() · adf7c5bd
      Masahiro Yamada authored 
      prop_alloc() is only called from menu_add_prop(). Squash it.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      adf7c5bd
    • Masahiro Yamada's avatar
      kconfig: remove sym from struct property · 6397d96b
      Masahiro Yamada authored 
      struct property can reference to the symbol that it is associated with
by prop->menu->sym.

Fix up the one usage of prop->sym, and remove sym from struct property.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      6397d96b
    • Masahiro Yamada's avatar
      kconfig: remove 'prompt' argument from menu_add_prop() · 2ffeef61
      Masahiro Yamada authored 
      This function no longer uses the 'prompt' argument.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      2ffeef61
    • Masahiro Yamada's avatar
      kconfig: move prompt handling to menu_add_prompt() from menu_add_prop() · 024352ff
      Masahiro Yamada authored 
      menu_add_prompt() is the only function that calls menu_add_prop() with
non-NULL prompt.

So, the code inside the if-conditional block of menu_add_prop() can be
moved to menu_add_prompt().
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      024352ff
    • Masahiro Yamada's avatar
      kconfig: remove 'prompt' symbol · 1be6e791
      Masahiro Yamada authored 
      Now that 'prompt' is only reduced from T_WORD_QUOTE without any action,
use T_WORD_QUOTE directly.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      1be6e791
    • Masahiro Yamada's avatar
      kconfig: drop T_WORD from the RHS of 'prompt' symbol · 801b27db
      Masahiro Yamada authored 
      Commit 8636a1f9 ("treewide: surround Kconfig file paths with double
quotes") killed use-cases to reduce an unquoted string into the 'prompt'
symbol.

Kconfig still allows to use an unquoted string in the context of menu,
source, or prompt.

So, you can omit quoting if the prompt is a single word:

    bool foo

..., but I do not think this is so useful.

Let's require quoting:

    bool "foo"

All the Kconfig files in the kernel are written in this way.

Remove the T_WORD from the right-hand side of the symbol 'prompt'.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      801b27db
    • Masahiro Yamada's avatar
      kconfig: use parent->dep as the parentdep of 'menu' · de026ca9
      Masahiro Yamada authored 
      In menu_finalize(), the dependency of a menu entry is propagated
downwards.

For the 'menu', parent->dep and parent->prompt->visible.expr have
the same expression. Both accumulate the 'depends on' of itself and
upper menu entries.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      de026ca9
    • Masahiro Yamada's avatar
      kconfig: remove the rootmenu check in menu_add_prop() · f64048a2
      Masahiro Yamada authored 
      This reverts commit ba6ff60d ("kconfig: don't emit warning upon
rootmenu's prompt redefinition").

At that time, rootmenu.prompt was always set first, then it was set
again if a "mainmenu" statement was specified in the Kconfig file.

This is no longer the case since commit 0724a7c3 ("kconfig: Don't
leak main menus during parsing"). Remove the unneeded check.
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      f64048a2
  3. 05 Jan, 2020 7 commits
    • Linus Torvalds's avatar
      Linux 5.5-rc5 · c79f46a2
      Linus Torvalds authored
      c79f46a2
    • Linus Torvalds's avatar
      Merge tag 'riscv/for-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · 768fc661
      Linus Torvalds authored 
      Pull RISC-V fixes from Paul Walmsley:
 "Several fixes for RISC-V:

   - Fix function graph trace support

   - Prefix the CSR IRQ_* macro names with "RV_", to avoid collisions
     with macros elsewhere in the Linux kernel tree named "IRQ_TIMER"

   - Use __pa_symbol() when computing the physical address of a kernel
     symbol, rather than __pa()

   - Mark the RISC-V port as supporting GCOV

  One DT addition:

   - Describe the L2 cache controller in the FU540 DT file

  One documentation update:

   - Add patch acceptance guideline documentation"

* tag 'riscv/for-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  Documentation: riscv: add patch acceptance guidelines
  riscv: prefix IRQ_ macro names with an RV_ namespace
  clocksource: riscv: add notrace to riscv_sched_clock
  riscv: ftrace: correct the condition logic in function graph tracer
  riscv: dts: Add DT support for SiFive L2 cache controller
  riscv: gcov: enable gcov for RISC-V
  riscv: mm: use __pa_symbol for kernel symbols
      768fc661
    • Paul Walmsley's avatar
      Documentation: riscv: add patch acceptance guidelines · 0e194d9d
      Paul Walmsley authored 
      Formalize, in kernel documentation, the patch acceptance policy for
arch/riscv.  In summary, it states that as maintainers, we plan to
only accept patches for new modules or extensions that have been
frozen or ratified by the RISC-V Foundation.

We've been following these guidelines for the past few months.  In the
meantime, we've received quite a bit of feedback that it would be
helpful to have these guidelines formally documented.

Based on a suggestion from Matthew Wilcox, we also add a link to this
file to Documentation/process/index.rst, to make this document easier
to find.  The format of this document has also been changed to align
to the format outlined in the maintainer entry profiles, in accordance
with comments from Jon Corbet and Dan Williams.
Signed-off-by: default avatarPaul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Krste Asanovic <krste@berkeley.edu>
Cc: Andrew Waterman <waterman@eecs.berkeley.edu>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
      0e194d9d
    • Paul Walmsley's avatar
      riscv: prefix IRQ_ macro names with an RV_ namespace · 2f3035da
      Paul Walmsley authored 
      "IRQ_TIMER", used in the arch/riscv CSR header file, is a sufficiently
generic macro name that it's used by several source files across the
Linux code base.  Some of these other files ultimately include the
arch/riscv CSR include file, causing collisions.  Fix by prefixing the
RISC-V csr.h IRQ_ macro names with an RV_ prefix.

Fixes: a4c3733d ("riscv: abstract out CSR names for supervisor vs machine mode")
Reported-by: default avatarOlof Johansson <olof@lixom.net>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarPaul Walmsley <paul.walmsley@sifive.com>
      2f3035da
    • Zong Li's avatar
      clocksource: riscv: add notrace to riscv_sched_clock · 9d05c18e
      Zong Li authored 
      When enabling ftrace graph tracer, it gets the tracing clock in
ftrace_push_return_trace().  Eventually, it invokes riscv_sched_clock()
to get the clock value.  If riscv_sched_clock() isn't marked with
'notrace', it will call ftrace_push_return_trace() and cause infinite
loop.

The result of failure as follow:

command: echo function_graph >current_tracer
[   46.176787] Unable to handle kernel paging request at virtual address ffffffe04fb38c48
[   46.177309] Oops [#1]
[   46.177478] Modules linked in:
[   46.177770] CPU: 0 PID: 256 Comm: $d Not tainted 5.5.0-rc1 #47
[   46.177981] epc: ffffffe00035e59a ra : ffffffe00035e57e sp : ffffffe03a7569b0
[   46.178216]  gp : ffffffe000d29b90 tp : ffffffe03a756180 t0 : ffffffe03a756968
[   46.178430]  t1 : ffffffe00087f408 t2 : ffffffe03a7569a0 s0 : ffffffe03a7569f0
[   46.178643]  s1 : ffffffe00087f408 a0 : 0000000ac054cda4 a1 : 000000000087f411
[   46.178856]  a2 : 0000000ac054cda4 a3 : 0000000000373ca0 a4 : ffffffe04fb38c48
[   46.179099]  a5 : 00000000153e22a8 a6 : 00000000005522ff a7 : 0000000000000005
[   46.179338]  s2 : ffffffe03a756a90 s3 : ffffffe00032811c s4 : ffffffe03a756a58
[   46.179570]  s5 : ffffffe000d29fe0 s6 : 0000000000000001 s7 : 0000000000000003
[   46.179809]  s8 : 0000000000000003 s9 : 0000000000000002 s10: 0000000000000004
[   46.180053]  s11: 0000000000000000 t3 : 0000003fc815749c t4 : 00000000000efc90
[   46.180293]  t5 : ffffffe000d29658 t6 : 0000000000040000
[   46.180482] status: 0000000000000100 badaddr: ffffffe04fb38c48 cause: 000000000000000f
Signed-off-by: default avatarZong Li <zong.li@sifive.com>
Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
[paul.walmsley@sifive.com: cleaned up patch description]
Fixes: 92e0d143 ("clocksource/drivers/riscv_timer: Provide the sched_clock")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaul Walmsley <paul.walmsley@sifive.com>
      9d05c18e
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 36487907
      Linus Torvalds authored 
      Merge misc fixes from Andrew Morton:
 "17 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  hexagon: define ioremap_uc
  ocfs2: fix the crash due to call ocfs2_get_dlm_debug once less
  ocfs2: call journal flush to mark journal as empty after journal recovery when mount
  mm/hugetlb: defer freeing of huge pages if in non-task context
  mm/gup: fix memory leak in __gup_benchmark_ioctl
  mm/oom: fix pgtables units mismatch in Killed process message
  fs/posix_acl.c: fix kernel-doc warnings
  hexagon: work around compiler crash
  hexagon: parenthesize registers in asm predicates
  fs/namespace.c: make to_mnt_ns() static
  fs/nsfs.c: include headers for missing declarations
  fs/direct-io.c: include fs/internal.h for missing prototype
  mm: move_pages: return valid node id in status if the page is already on the target node
  memcg: account security cred as well to kmemcg
  kcov: fix struct layout for kcov_remote_arg
  mm/zsmalloc.c: fix the migrated zspage statistics.
  mm/memory_hotplug: shrink zones when offlining memory
      36487907
    • Linus Torvalds's avatar
      Merge tag 'apparmor-pr-2020-01-04' of... · a125bcda
      Linus Torvalds authored 
      Merge tag 'apparmor-pr-2020-01-04' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor fixes from John Johansen:

 - performance regression: only get a label reference if the fast path
   check fails

 - fix aa_xattrs_match() may sleep while holding a RCU lock

 - fix bind mounts aborting with -ENOMEM

* tag 'apparmor-pr-2020-01-04' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock
  apparmor: only get a label reference if the fast path check fails
  apparmor: fix bind mounts aborting with -ENOMEM
      a125bcda
  5. 04 Jan, 2020 17 commits
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