If the user selects the very first entry in a page and performs a
search-up operation, or selects the very last entry in a page and
performs a search-down operation that will not succeed (e.g., via
[/]asdfzzz[Up Arrow]), nconf will never terminate searching the page.

The reason is that in this case, the starting point will be set to -1
or n, which is then translated into (n - 1) (i.e., the last entry of
the page) or 0 (i.e., the first entry of the page) and finally the
search begins. This continues to work fine until the index reaches 0 or
(n - 1), at which point it will be decremented to -1 or incremented to
n, but not checked against the starting point right away. Instead, it's
wrapped around to the bottom or top again, after which the starting
point check occurs... and naturally fails.

My original implementation added another check for -1 before wrapping
the running index variable around, but Masahiro Yamada pointed out that
the actual issue is that the comparison point (starting point) exceeds
bounds (i.e., the [0,n-1] interval) in the first place and that,
instead, the starting point should be fixed.

This has the welcome side-effect of also fixing the case where the
starting point was n while searching down, which also lead to an
infinite loop.

OTOH, this code is now essentially all his work.

Amazingly, nobody seems to have been hit by this for 11 years - or at
the very least nobody bothered to debug and fix this.
Signed-off-by: Mihai Moldovan <ionic@ionic.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Compile menu.c as an independent compilation unit.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This helper is the same as the sample code in the NCURSES HOWTO [1],
but it is over-engineering to be used for nconf.

I do not see any good reason to use the 'float' type just for the
division by 2.

All the call-sites pass a non-NULL pointer to the first argument,
so 'if (win == NULL) win = stdscr;' is dead code.

'if (startx != 0) x = startx;' is dead code because 'x' will be
overridden some lines below, by 'x = startx + (int)temp;'.

All the call-sites pass a non-zero value to the second argument,
so 'if (starty != 0)' is always true.

getyx(win, y, x) is also dead-code because both 'y' and 'x' are
overridden.

All the call-sites pass 0 to the third parameter, so 'startx' can
be removed.

All the call-sites pass a non-zero value to the fourth parameter,
so 'if (width == 0) width = 80;' is dead code.

The window will be refreshed later, so there is no need to call
refresh() in this function.

Change the type of the last parameter from 'chtype' to 'int' to be
aligned with the prototype, 'int wattrset(WINDOW *win, int attrs);'

I also slightly cleaned up the indentation style.

[1]: https://tldp.org/HOWTO/NCURSES-Programming-HOWTO/color.htmlSigned-off-by: Masahiro Yamada <masahiroy@kernel.org>

This attribute is not used because it will be overridden some lines
below:

  wattrset(main_window, attr_main_menu_box);
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

No one uses the return value of this function.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The current attributes setup code is strange; the array attribute[]
is set to values outside the range of the attribute_t enum.

At least,

  attributes_t attributes[ATTR_MAX+1] = {0};

... should be

  int attribute[ATTR_MAX+1] = {0};

Also, there is no need to hard-code the color-pair numbers in
attributes_t.

The current code is messy. Rewrite it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The rootmenu always has a prompt even if the 'mainmenu' statement is
missing in the top Kconfig file.

conf_parse() calls menu_add_prompt(P_MENU, "Main menu", NULL) in this
case.

So, every 'menu' has a prompt.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This reverts commit 10175ba6 ("nconfig: Silence unused return values
from wattrset").

With this patch applied, recent GCC versions can cleanly build nconf
without "value computed is not used" warnings.

The wattrset() used to be implemented as a macro, like this:

  #define wattrset(win,at) \
          (NCURSES_OK_ADDR(win) \
            ? ((win)->_attrs = NCURSES_CAST(attr_t, at), \
               OK) \
            : ERR)

The GCC bugzilla [1] reported a false-positive -Wunused-value warning
in a similar test case. It was fixed by GCC 4.4.1.

Let's revert that commit, and see if somebody will claim the issue.

[1]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39889Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The lower 8-bit of attributes should be 0, but this code wrongly
sets it to NORMAL (=1). The correct one is A_NORMAL.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

snprintf() always terminates the destination buffer with '\0' even if
the buffer is not long enough. (In this case, the last element of the
buffer becomes '\0'.)

The explicit termination is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

When the .config file is missing, 'make config', 'make menuconfig', etc.
uses a file listed in DEFCONFIG_LIST, if found, as base configuration.

Ususally, /boot/config-$(uname -r) exists, and is used as default.

However, when you are cross-compiling the kernel, it does not make
sense to use /boot/config-* on the build host. It should default to
arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG).

UML previously did not use DEFCONFIG_LIST at all, but it should be
able to use arch/um/configs/$(KBUILD_DEFCONFIG) as a base config file.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

sym_change_count has no good reason to be 'int' type.

sym_set_change_count() compares the old and new values after casting
both of them to (bool). I do not see any practical diffrence between
sym_set_change_count(1) and sym_add_change_count(1).

Use the boolean flag, conf_changed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The following code in get_mext_match():

  index = (index + items_num) % items_num;

... makes the program crash when items_num is zero (that is, the menu
is empty).

A menu can be empty when all the options in it are hidden by unmet
'depends on'.

For example,

  menu "This menu will be empty"

  config FOO
         bool "foo"
         depends on BROKEN

  endmenu

If you visit this menu and press a '/' key and then another key, nconf
crashes with:

  Floating point exception (core dumped)

When the number of items is zero, it does not make sense to search in
the menu. In this case, current_item() returns NULL, and item_index()
ERR, but get_mext_match() does not check it.

Let's make get_mext_match() just return if the menu is empty.

While I am here, change items_num from 'int' to 'unsigned int' because
it should never become negative.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

s/propperly/properly/
s/thats/that\'s/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

s/configuraton/configuration/
s/orignal/original/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

fixed the following coccicheck:
./scripts/kconfig/confdata.c:36:9-10: WARNING: return of 0/1 in function
'is_dir' with return type bool
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Now "modules" is the only member of the "option" property.

Remove "option", and move "modules" to the top level property.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Now that the only user, CONFIG_EMBEDDED has stopped using this option,
remove it entirely.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

allnoconfig_y is an ugly hack that sets a symbol to 'y' by allnoconfig.

allnoconfig does not mean a minimal set of CONFIG options because a
bunch of prompts are hidden by 'if EMBEDDED' or 'if EXPERT', but I do
not like to hack Kconfig this way.

Use the pre-existing feature, KCONFIG_ALLCONFIG, to provide a one
liner config fragment. CONFIG_EMBEDDED=y is still forced when
allnoconfig is invoked as a part of tinyconfig.

No change in the .config file produced by 'make tinyconfig'.

The output of 'make allnoconfig' will be changed; we will get
CONFIG_EMBEDDED=n because allnoconfig literally sets all symbols to n.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This is a partial revert of commit 2a86f661 ("kbuild: use
KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST").

Now that the reference to $(DEFCONFIG_LIST) was removed from
init/Kconfig, the default KBUILD_DEFCONFIG can go back home.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

"defconfig_list" is a weird option that defines a static symbol that
declares the list of base config files in case the .config does not
exist yet.

This is quite different from other normal symbols; we just abused the
"string" type and the "default" properties to list out the input files.
They must be fixed values since these are searched for and loaded in
the parse stage.

It is an ugly hack, and should not exist in the first place. Providing
this feature as an environment variable is a saner approach.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This macro is only used in mconf.c.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This function is only used in conf.c. Move it there together with the
randomize_choice_values() helper.

Define 'enum conf_def_mode' locally in conf.c as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This function is only used in conf.c.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pass av[optind] to conf_parse() directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Add missing options and make the help message more readable.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

They are long options for -h and -s, respectively.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The current option parse code is clumsy.

The 's' option is separately handled in an if-conditional due to the
following code:

    input_mode = (enum input_mode)opt;

If 's' is moved to the switch statement, the invalid value 's' would
be assigned to the input_mode.

Another potential problem is that we are mixing 'enum input_mode' and
ASCII characters. They could overwrap if we add more input modes.

To separate them out, set the flag field of long options to a pointer
of input_mode_opt. For mode select options, getopt_long() returns 0,
which never causes overwrap with ASCII characters that represent short
options.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This code is too big to be placed in the switch statement.

Move the code into a new helper function. I slightly refactor the code
without changing the behavior.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Doing a

	prctl(PR_SET_MM, PR_SET_MM_AUXV, addr, 1);

will copy 1 byte from userspace to (quite big) on-stack array
and then stash everything to mm->saved_auxv.
AT_NULL terminator will be inserted at the very end.

/proc/*/auxv handler will find that AT_NULL terminator
and copy original stack contents to userspace.

This devious scheme requires CAP_SYS_RESOURCE.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull irq fixes from Thomas Gleixner:
 "A set of irqchip updates:

   - Make the GENERIC_IRQ_MULTI_HANDLER configuration correct

   - Add a missing DT compatible string for the Ingenic driver

   - Remove the pointless debugfs_file pointer from struct irqdomain"

* tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ingenic: Add support for the JZ4760
  dt-bindings/irq: Add compatible string for the JZ4760B
  irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly
  irqdomain: Remove debugfs_file from struct irq_domain

Pull timer fix from Thomas Gleixner:
 "A single fix in for hrtimers to prevent an interrupt storm caused by
  the lack of reevaluation of the timers which expire in softirq context
  under certain circumstances, e.g. when the clock was set"

* tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler updates:

   - Prevent a NULL pointer dereference in the migration_stop_cpu()
     mechanims

   - Prevent self concurrency of affine_move_task()

   - Small fixes and cleanups related to task migration/affinity setting

   - Ensure that sync_runqueues_membarrier_state() is invoked on the
     current CPU when it is in the cpu mask"

* tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/membarrier: fix missing local execution of ipi_sync_rq_state()
  sched: Simplify set_affinity_pending refcounts
  sched: Fix affine_move_task() self-concurrency
  sched: Optimize migration_cpu_stop()
  sched: Collate affine_move_task() stoppers
  sched: Simplify migration_cpu_stop()
  sched: Fix migration_cpu_stop() requeueing

Pull objtool fix from Thomas Gleixner:
 "A single objtool fix to handle the PUSHF/POPF validation correctly for
  the paravirt changes which modified arch_local_irq_restore not to use
  popf"

* tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool,x86: Fix uaccess PUSHF/POPF validation

Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - A fix for the static_call mechanism so it handles unaligned
     addresses correctly.

   - Make u64_stats_init() a macro so every instance gets a seperate
     lockdep key.

   - Make seqcount_latch_init() a macro as well to preserve the static
     variable which is used for the lockdep key"

* tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  seqlock,lockdep: Fix seqcount_latch_init()
  u64_stats,lockdep: Fix u64_stats_init() vs lockdep
  static_call: Fix the module key fixup

Pull perf fixes from Borislav Petkov:

 - Make sure PMU internal buffers are flushed for per-CPU events too and
   properly handle PID/TID for large PEBS.

 - Handle the case properly when there's no PMU and therefore return an
   empty list of perf MSRs for VMX to switch instead of reading random
   garbage from the stack.

* tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case
  perf/x86/intel: Set PERF_ATTACH_SCHED_CB for large PEBS and LBR
  perf/core: Flush PMU internal buffers for per-CPU events

Pull EFI fix from Ard Biesheuvel via Borislav Petkov:
 "Fix an oversight in the handling of EFI_RT_PROPERTIES_TABLE, which was
  added v5.10, but failed to take the SetVirtualAddressMap() RT service
  into account"

* tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table

Pull x86 fixes from Borislav Petkov:

 - A couple of SEV-ES fixes and robustifications: verify usermode stack
   pointer in NMI is not coming from the syscall gap, correctly track
   IRQ states in the #VC handler and access user insn bytes atomically
   in same handler as latter cannot sleep.

 - Balance 32-bit fast syscall exit path to do the proper work on exit
   and thus not confuse audit and ptrace frameworks.

 - Two fixes for the ORC unwinder going "off the rails" into KASAN
   redzones and when ORC data is missing.

* tag 'x86_urgent_for_v5.12_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev-es: Use __copy_from_user_inatomic()
  x86/sev-es: Correctly track IRQ states in runtime #VC handler
  x86/sev-es: Check regs->sp is trusted before adjusting #VC IST stack
  x86/sev-es: Introduce ip_within_syscall_gap() helper
  x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls
  x86/unwind/orc: Silence warnings caused by missing ORC data
  x86/unwind/orc: Disable KASAN checking in the ORC unwinder, part 2

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.12:

   - Fix wrong instruction encoding for lis in ppc_function_entry(),
     which could potentially lead to missed kprobes.

   - Fix SET_FULL_REGS on 32-bit and 64e, which prevented ptrace of
     non-volatile GPRs immediately after exec.

   - Clean up a missed SRR specifier in the recent interrupt rework.

   - Don't treat unrecoverable_exception() as an interrupt handler, it's
     called from other handlers so shouldn't do the interrupt entry/exit
     accounting itself.

   - Fix build errors caused by missing declarations for
     [en/dis]able_kernel_vsx().

  Thanks to Christophe Leroy, Daniel Axtens, Geert Uytterhoeven, Jiri
  Olsa, Naveen N. Rao, and Nicholas Piggin"

* tag 'powerpc-5.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/traps: unrecoverable_exception() is not an interrupt handler
  powerpc: Fix missing declaration of [en/dis]able_kernel_vsx()
  powerpc/64s/exception: Clean up a missed SRR specifier
  powerpc: Fix inverted SET_FULL_REGS bitop
  powerpc/64s: Use symbolic macros for function entry encoding
  powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()