scripts/checkpatch.pl: Resync with v5.16

This resyncs us with the version found in v5.16 of the Linux kernel with
the following exceptions:
- Keep our u-boot specific tests / code area.
- Change the location of checkpatch.rst
- Drop the "use strscpy" test as we don't have that, but do have strlcpy
  and want that used now.
- Keep debug/printf in the list for $logFunctions

This also syncs the spdxcheck.py tool and all the associated
documentation.
S
Signed-off-by: Simon Glass <sjg@chromium.org>

doc/develop/checkpatch.rst

@@ -246,6 +246,7 @@ Allocation style
     The first argument for kcalloc or kmalloc_array should be the
     number of elements.  sizeof() as the first argument is generally
     wrong.
+
     See: https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html
 
   **ALLOC_SIZEOF_STRUCT**
@@ -264,6 +265,7 @@ Allocation style
   **ALLOC_WITH_MULTIPLY**
     Prefer kmalloc_array/kcalloc over kmalloc/kzalloc with a
     sizeof multiply.
+
     See: https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html
 
 
@@ -284,6 +286,7 @@ API usage
     BUG() or BUG_ON() should be avoided totally.
     Use WARN() and WARN_ON() instead, and handle the "impossible"
     error condition as gracefully as possible.
+
     See: https://www.kernel.org/doc/html/latest/process/deprecated.html#bug-and-bug-on
 
   **CONSIDER_KSTRTO**
@@ -292,12 +295,161 @@ API usage
     may lead to unexpected results in callers.  The respective kstrtol(),
     kstrtoll(), kstrtoul(), and kstrtoull() functions tend to be the
     correct replacements.
+
     See: https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull
 
+  **CONSTANT_CONVERSION**
+    Use of __constant_<foo> form is discouraged for the following functions::
+
+      __constant_cpu_to_be[x]
+      __constant_cpu_to_le[x]
+      __constant_be[x]_to_cpu
+      __constant_le[x]_to_cpu
+      __constant_htons
+      __constant_ntohs
+
+    Using any of these outside of include/uapi/ is not preferred as using the
+    function without __constant_ is identical when the argument is a
+    constant.
+
+    In big endian systems, the macros like __constant_cpu_to_be32(x) and
+    cpu_to_be32(x) expand to the same expression::
+
+      #define __constant_cpu_to_be32(x) ((__force __be32)(__u32)(x))
+      #define __cpu_to_be32(x)          ((__force __be32)(__u32)(x))
+
+    In little endian systems, the macros __constant_cpu_to_be32(x) and
+    cpu_to_be32(x) expand to __constant_swab32 and __swab32.  __swab32
+    has a __builtin_constant_p check::
+
+      #define __swab32(x)				\
+        (__builtin_constant_p((__u32)(x)) ?	\
+        ___constant_swab32(x) :			\
+        __fswab32(x))
+
+    So ultimately they have a special case for constants.
+    Similar is the case with all of the macros in the list.  Thus
+    using the __constant_... forms are unnecessarily verbose and
+    not preferred outside of include/uapi.
+
+    See: https://lore.kernel.org/lkml/1400106425.12666.6.camel@joe-AO725/
+
+  **DEPRECATED_API**
+    Usage of a deprecated RCU API is detected.  It is recommended to replace
+    old flavourful RCU APIs by their new vanilla-RCU counterparts.
+
+    The full list of available RCU APIs can be viewed from the kernel docs.
+
+    See: https://www.kernel.org/doc/html/latest/RCU/whatisRCU.html#full-list-of-rcu-apis
+
+  **DEPRECATED_VARIABLE**
+    EXTRA_{A,C,CPP,LD}FLAGS are deprecated and should be replaced by the new
+    flags added via commit f77bf01425b1 ("kbuild: introduce ccflags-y,
+    asflags-y and ldflags-y").
+
+    The following conversion scheme maybe used::
+
+      EXTRA_AFLAGS    ->  asflags-y
+      EXTRA_CFLAGS    ->  ccflags-y
+      EXTRA_CPPFLAGS  ->  cppflags-y
+      EXTRA_LDFLAGS   ->  ldflags-y
+
+    See:
+
+      1. https://lore.kernel.org/lkml/20070930191054.GA15876@uranus.ravnborg.org/
+      2. https://lore.kernel.org/lkml/1313384834-24433-12-git-send-email-lacombar@gmail.com/
+      3. https://www.kernel.org/doc/html/latest/kbuild/makefiles.html#compilation-flags
+
+  **DEVICE_ATTR_FUNCTIONS**
+    The function names used in DEVICE_ATTR is unusual.
+    Typically, the store and show functions are used with <attr>_store and
+    <attr>_show, where <attr> is a named attribute variable of the device.
+
+    Consider the following examples::
+
+      static DEVICE_ATTR(type, 0444, type_show, NULL);
+      static DEVICE_ATTR(power, 0644, power_show, power_store);
+
+    The function names should preferably follow the above pattern.
+
+    See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
+
+  **DEVICE_ATTR_RO**
+    The DEVICE_ATTR_RO(name) helper macro can be used instead of
+    DEVICE_ATTR(name, 0444, name_show, NULL);
+
+    Note that the macro automatically appends _show to the named
+    attribute variable of the device for the show method.
+
+    See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
+
+  **DEVICE_ATTR_RW**
+    The DEVICE_ATTR_RW(name) helper macro can be used instead of
+    DEVICE_ATTR(name, 0644, name_show, name_store);
+
+    Note that the macro automatically appends _show and _store to the
+    named attribute variable of the device for the show and store methods.
+
+    See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
+
+  **DEVICE_ATTR_WO**
+    The DEVICE_AATR_WO(name) helper macro can be used instead of
+    DEVICE_ATTR(name, 0200, NULL, name_store);
+
+    Note that the macro automatically appends _store to the
+    named attribute variable of the device for the store method.
+
+    See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
+
+  **DUPLICATED_SYSCTL_CONST**
+    Commit d91bff3011cf ("proc/sysctl: add shared variables for range
+    check") added some shared const variables to be used instead of a local
+    copy in each source file.
+
+    Consider replacing the sysctl range checking value with the shared
+    one in include/linux/sysctl.h.  The following conversion scheme may
+    be used::
+
+      &zero     ->  SYSCTL_ZERO
+      &one      ->  SYSCTL_ONE
+      &int_max  ->  SYSCTL_INT_MAX
+
+    See:
+
+      1. https://lore.kernel.org/lkml/20190430180111.10688-1-mcroce@redhat.com/
+      2. https://lore.kernel.org/lkml/20190531131422.14970-1-mcroce@redhat.com/
+
+  **ENOSYS**
+    ENOSYS means that a nonexistent system call was called.
+    Earlier, it was wrongly used for things like invalid operations on
+    otherwise valid syscalls.  This should be avoided in new code.
+
+    See: https://lore.kernel.org/lkml/5eb299021dec23c1a48fa7d9f2c8b794e967766d.1408730669.git.luto@amacapital.net/
+
+  **ENOTSUPP**
+    ENOTSUPP is not a standard error code and should be avoided in new patches.
+    EOPNOTSUPP should be used instead.
+
+    See: https://lore.kernel.org/netdev/20200510182252.GA411829@lunn.ch/
+
+  **EXPORT_SYMBOL**
+    EXPORT_SYMBOL should immediately follow the symbol to be exported.
+
+  **IN_ATOMIC**
+    in_atomic() is not for driver use so any such use is reported as an ERROR.
+    Also in_atomic() is often used to determine if sleeping is permitted,
+    but it is not reliable in this use model.  Therefore its use is
+    strongly discouraged.
+
+    However, in_atomic() is ok for core kernel use.
+
+    See: https://lore.kernel.org/lkml/20080320201723.b87b3732.akpm@linux-foundation.org/
+
   **LOCKDEP**
     The lockdep_no_validate class was added as a temporary measure to
     prevent warnings on conversion of device->sem to device->mutex.
     It should not be used for any other purpose.
+
     See: https://lore.kernel.org/lkml/1268959062.9440.467.camel@laptop/
 
   **MALFORMED_INCLUDE**
@@ -308,14 +460,21 @@ API usage
   **USE_LOCKDEP**
     lockdep_assert_held() annotations should be preferred over
     assertions based on spin_is_locked()
+
     See: https://www.kernel.org/doc/html/latest/locking/lockdep-design.html#annotations
 
   **UAPI_INCLUDE**
     No #include statements in include/uapi should use a uapi/ path.
 
+  **USLEEP_RANGE**
+    usleep_range() should be preferred over udelay(). The proper way of
+    using usleep_range() is mentioned in the kernel docs.
 
-Comment style
+    See: https://www.kernel.org/doc/html/latest/timers/timers-howto.html#delays-information-on-the-various-kernel-delay-sleep-mechanisms
--------------
+
+
+Comments
+--------
 
   **BLOCK_COMMENT_STYLE**
     The comment style is incorrect.  The preferred style for multi-
@@ -338,8 +497,24 @@ Comment style
   **C99_COMMENTS**
     C99 style single line comments (//) should not be used.
     Prefer the block comment style instead.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
 
+  **DATA_RACE**
+    Applications of data_race() should have a comment so as to document the
+    reasoning behind why it was deemed safe.
+
+    See: https://lore.kernel.org/lkml/20200401101714.44781-1-elver@google.com/
+
+  **FSF_MAILING_ADDRESS**
+    Kernel maintainers reject new instances of the GPL boilerplate paragraph
+    directing people to write to the FSF for a copy of the GPL, since the
+    FSF has moved in the past and may do so again.
+    So do not write paragraphs about writing to the Free Software Foundation's
+    mailing address.
+
+    See: https://lore.kernel.org/lkml/20131006222342.GT19510@leaf/
+
 
 Commit message
 --------------
@@ -347,6 +522,7 @@ Commit message
   **BAD_SIGN_OFF**
     The signed-off-by line does not fall in line with the standards
     specified by the community.
+
     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin-1-1
 
   **BAD_STABLE_ADDRESS_STYLE**
@@ -368,12 +544,33 @@ Commit message
   **COMMIT_MESSAGE**
     The patch is missing a commit description.  A brief
     description of the changes made by the patch should be added.
+
     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
 
+  **EMAIL_SUBJECT**
+    Naming the tool that found the issue is not very useful in the
+    subject line.  A good subject line summarizes the change that
+    the patch brings.
+
+    See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
+
+  **FROM_SIGN_OFF_MISMATCH**
+    The author's email does not match with that in the Signed-off-by:
+    line(s). This can be sometimes caused due to an improperly configured
+    email client.
+
+    This message is emitted due to any of the following reasons::
+
+      - The email names do not match.
+      - The email addresses do not match.
+      - The email subaddresses do not match.
+      - The email comments do not match.
+
   **MISSING_SIGN_OFF**
     The patch is missing a Signed-off-by line.  A signed-off-by
     line should be added according to Developer's certificate of
     Origin.
+
     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin
 
   **NO_AUTHOR_SIGN_OFF**
@@ -382,6 +579,7 @@ Commit message
     end of explanation of the patch to denote that the author has
     written it or otherwise has the rights to pass it on as an open
     source patch.
+
     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin
 
   **DIFF_IN_COMMIT_MSG**
@@ -389,6 +587,7 @@ Commit message
     This causes problems when one tries to apply a file containing both
     the changelog and the diff because patch(1) tries to apply the diff
     which it found in the changelog.
+
     See: https://lore.kernel.org/lkml/20150611134006.9df79a893e3636019ad2759e@linux-foundation.org/
 
   **GERRIT_CHANGE_ID**
@@ -431,6 +630,7 @@ Comparison style
   **BOOL_COMPARISON**
     Comparisons of A to true and false are better written
     as A and !A.
+
     See: https://lore.kernel.org/lkml/1365563834.27174.12.camel@joe-AO722/
 
   **COMPARISON_TO_NULL**
@@ -442,6 +642,120 @@ Comparison style
     side of the test should be avoided.
 
 
+Indentation and Line Breaks
+---------------------------
+
+  **CODE_INDENT**
+    Code indent should use tabs instead of spaces.
+    Outside of comments, documentation and Kconfig,
+    spaces are never used for indentation.
+
+    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
+
+  **DEEP_INDENTATION**
+    Indentation with 6 or more tabs usually indicate overly indented
+    code.
+
+    It is suggested to refactor excessive indentation of
+    if/else/for/do/while/switch statements.
+
+    See: https://lore.kernel.org/lkml/1328311239.21255.24.camel@joe2Laptop/
+
+  **SWITCH_CASE_INDENT_LEVEL**
+    switch should be at the same indent as case.
+    Example::
+
+      switch (suffix) {
+      case 'G':
+      case 'g':
+              mem <<= 30;
+              break;
+      case 'M':
+      case 'm':
+              mem <<= 20;
+              break;
+      case 'K':
+      case 'k':
+              mem <<= 10;
+              fallthrough;
+      default:
+              break;
+      }
+
+    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
+
+  **LONG_LINE**
+    The line has exceeded the specified maximum length.
+    To use a different maximum line length, the --max-line-length=n option
+    may be added while invoking checkpatch.
+
+    Earlier, the default line length was 80 columns.  Commit bdc48fa11e46
+    ("checkpatch/coding-style: deprecate 80-column warning") increased the
+    limit to 100 columns.  This is not a hard limit either and it's
+    preferable to stay within 80 columns whenever possible.
+
+    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings
+
+  **LONG_LINE_STRING**
+    A string starts before but extends beyond the maximum line length.
+    To use a different maximum line length, the --max-line-length=n option
+    may be added while invoking checkpatch.
+
+    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings
+
+  **LONG_LINE_COMMENT**
+    A comment starts before but extends beyond the maximum line length.
+    To use a different maximum line length, the --max-line-length=n option
+    may be added while invoking checkpatch.
+
+    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings
+
+  **SPLIT_STRING**
+    Quoted strings that appear as messages in userspace and can be
+    grepped, should not be split across multiple lines.
+
+    See: https://lore.kernel.org/lkml/20120203052727.GA15035@leaf/
+
+  **MULTILINE_DEREFERENCE**
+    A single dereferencing identifier spanned on multiple lines like::
+
+      struct_identifier->member[index].
+      member = <foo>;
+
+    is generally hard to follow. It can easily lead to typos and so makes
+    the code vulnerable to bugs.
+
+    If fixing the multiple line dereferencing leads to an 80 column
+    violation, then either rewrite the code in a more simple way or if the
+    starting part of the dereferencing identifier is the same and used at
+    multiple places then store it in a temporary variable, and use that
+    temporary variable only at all the places. For example, if there are
+    two dereferencing identifiers::
+
+      member1->member2->member3.foo1;
+      member1->member2->member3.foo2;
+
+    then store the member1->member2->member3 part in a temporary variable.
+    It not only helps to avoid the 80 column violation but also reduces
+    the program size by removing the unnecessary dereferences.
+
+    But if none of the above methods work then ignore the 80 column
+    violation because it is much easier to read a dereferencing identifier
+    on a single line.
+
+  **TRAILING_STATEMENTS**
+    Trailing statements (for example after any conditional) should be
+    on the next line.
+    Statements, such as::
+
+      if (x == y) break;
+
+    should be::
+
+      if (x == y)
+              break;
+
+
 Macros, Attributes and Symbols
 ------------------------------
 
@@ -472,7 +786,7 @@ Macros, Attributes and Symbols
 
   **BIT_MACRO**
     Defines like: 1 << <digit> could be BIT(digit).
-    The BIT() macro is defined in include/linux/bitops.h::
+    The BIT() macro is defined via include/linux/bits.h::
 
       #define BIT(nr)         (1UL << (nr))
 
@@ -492,6 +806,7 @@ Macros, Attributes and Symbols
     The kernel does *not* use the ``__DATE__`` and ``__TIME__`` macros,
     and enables warnings if they are used as they can lead to
     non-deterministic builds.
+
     See: https://www.kernel.org/doc/html/latest/kbuild/reproducible-builds.html#timestamps
 
   **DEFINE_ARCH_HAS**
@@ -502,8 +817,12 @@ Macros, Attributes and Symbols
     want architectures able to override them with optimized ones, we
     should either use weak functions (appropriate for some cases), or
     the symbol that protects them should be the same symbol we use.
+
     See: https://lore.kernel.org/lkml/CA+55aFycQ9XJvEOsiM3txHL5bjUc8CeKWJNR_H+MiicaddB42Q@mail.gmail.com/
 
+  **DO_WHILE_MACRO_WITH_TRAILING_SEMICOLON**
+    do {} while(0) macros should not have a trailing semicolon.
+
   **INIT_ATTRIBUTE**
     Const init definitions should use __initconst instead of
     __initdata.
@@ -528,6 +847,20 @@ Macros, Attributes and Symbols
               ...
       }
 
+  **MISPLACED_INIT**
+    It is possible to use section markers on variables in a way
+    which gcc doesn't understand (or at least not the way the
+    developer intended)::
+
+      static struct __initdata samsung_pll_clock exynos4_plls[nr_plls] = {
+
+    does not put exynos4_plls in the .initdata section. The __initdata
+    marker can be virtually anywhere on the line, except right after
+    "struct". The preferred location is before the "=" sign if there is
+    one, or before the trailing ";" otherwise.
+
+    See: https://lore.kernel.org/lkml/1377655732.3619.19.camel@joe-AO722/
+
   **MULTISTATEMENT_MACRO_USE_DO_WHILE**
     Macros with multiple statements should be enclosed in a
     do - while block.  Same should also be the case for macros
@@ -541,6 +874,42 @@ Macros, Attributes and Symbols
 
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl
 
+  **PREFER_FALLTHROUGH**
+    Use the `fallthrough;` pseudo keyword instead of
+    `/* fallthrough */` like comments.
+
+  **TRAILING_SEMICOLON**
+    Macro definition should not end with a semicolon. The macro
+    invocation style should be consistent with function calls.
+    This can prevent any unexpected code paths::
+
+      #define MAC do_something;
+
+    If this macro is used within a if else statement, like::
+
+      if (some_condition)
+              MAC;
+
+      else
+              do_something;
+
+    Then there would be a compilation error, because when the macro is
+    expanded there are two trailing semicolons, so the else branch gets
+    orphaned.
+
+    See: https://lore.kernel.org/lkml/1399671106.2912.21.camel@joe-AO725/
+
+  **SINGLE_STATEMENT_DO_WHILE_MACRO**
+    For the multi-statement macros, it is necessary to use the do-while
+    loop to avoid unpredictable code paths. The do-while loop helps to
+    group the multiple statements into a single one so that a
+    function-like macro can be used as a function only.
+
+    But for the single statement macros, it is unnecessary to use the
+    do-while loop. Although the code is syntactically correct but using
+    the do-while loop is redundant. So remove the do-while loop for single
+    statement macros.
+
   **WEAK_DECLARATION**
     Using weak declarations like __attribute__((weak)) or __weak
     can have unintended link defects.  Avoid using them.
@@ -551,8 +920,51 @@ Functions and Variables
 
   **CAMELCASE**
     Avoid CamelCase Identifiers.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#naming
 
+  **CONST_CONST**
+    Using `const <type> const *` is generally meant to be
+    written `const <type> * const`.
+
+  **CONST_STRUCT**
+    Using const is generally a good idea.  Checkpatch reads
+    a list of frequently used structs that are always or
+    almost always constant.
+
+    The existing structs list can be viewed from
+    `scripts/const_structs.checkpatch`.
+
+    See: https://lore.kernel.org/lkml/alpine.DEB.2.10.1608281509480.3321@hadrien/
+
+  **EMBEDDED_FUNCTION_NAME**
+    Embedded function names are less appropriate to use as
+    refactoring can cause function renaming.  Prefer the use of
+    "%s", __func__ to embedded function names.
+
+    Note that this does not work with -f (--file) checkpatch option
+    as it depends on patch context providing the function name.
+
+  **FUNCTION_ARGUMENTS**
+    This warning is emitted due to any of the following reasons:
+
+      1. Arguments for the function declaration do not follow
+         the identifier name.  Example::
+
+           void foo
+           (int bar, int baz)
+
+         This should be corrected to::
+
+           void foo(int bar, int baz)
+
+      2. Some arguments for the function definition do not
+         have an identifier name.  Example::
+
+           void foo(int)
+
+         All arguments should have identifier names.
+
   **FUNCTION_WITHOUT_ARGS**
     Function declarations without arguments like::
 
@@ -573,6 +985,11 @@ Functions and Variables
     Your compiler (or rather your loader) automatically does
     it for you.
 
+  **MULTIPLE_ASSIGNMENTS**
+    Multiple assignments on a single line makes the code unnecessarily
+    complicated. So on a single line assign value to a single variable
+    only, this makes the code more readable and helps avoid typos.
+
   **RETURN_PARENTHESES**
     return is not a function and as such doesn't need parentheses::
 
@@ -583,6 +1000,45 @@ Functions and Variables
       return bar;
 
 
+Permissions
+-----------
+
+  **DEVICE_ATTR_PERMS**
+    The permissions used in DEVICE_ATTR are unusual.
+    Typically only three permissions are used - 0644 (RW), 0444 (RO)
+    and 0200 (WO).
+
+    See: https://www.kernel.org/doc/html/latest/filesystems/sysfs.html#attributes
+
+  **EXECUTE_PERMISSIONS**
+    There is no reason for source files to be executable.  The executable
+    bit can be removed safely.
+
+  **EXPORTED_WORLD_WRITABLE**
+    Exporting world writable sysfs/debugfs files is usually a bad thing.
+    When done arbitrarily they can introduce serious security bugs.
+    In the past, some of the debugfs vulnerabilities would seemingly allow
+    any local user to write arbitrary values into device registers - a
+    situation from which little good can be expected to emerge.
+
+    See: https://lore.kernel.org/linux-arm-kernel/cover.1296818921.git.segoon@openwall.com/
+
+  **NON_OCTAL_PERMISSIONS**
+    Permission bits should use 4 digit octal permissions (like 0700 or 0444).
+    Avoid using any other base like decimal.
+
+  **SYMBOLIC_PERMS**
+    Permission bits in the octal form are more readable and easier to
+    understand than their symbolic counterparts because many command-line
+    tools use this notation. Experienced kernel developers have been using
+    these traditional Unix permission bits for decades and so they find it
+    easier to understand the octal notation than the symbolic macros.
+    For example, it is harder to read S_IWUSR|S_IRUGO than 0644, which
+    obscures the developer's intent rather than clarifying it.
+
+    See: https://lore.kernel.org/lkml/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@mail.gmail.com/
+
+
 Spacing and Brackets
 --------------------
 
@@ -616,7 +1072,7 @@ Spacing and Brackets
 
     1. With a type on the left::
 
-        ;int [] a;
+        int [] a;
 
     2. At the beginning of a line for slice initialisers::
 
@@ -626,12 +1082,6 @@ Spacing and Brackets
 
         = { [0...10] = 5 }
 
-  **CODE_INDENT**
-    Code indent should use tabs instead of spaces.
-    Outside of comments, documentation and Kconfig,
-    spaces are never used for indentation.
-    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
-
   **CONCATENATED_STRING**
     Concatenated elements should have a space in between.
     Example::
@@ -644,17 +1094,20 @@ Spacing and Brackets
 
   **ELSE_AFTER_BRACE**
     `else {` should follow the closing block `}` on the same line.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
 
   **LINE_SPACING**
     Vertical space is wasted given the limited number of lines an
     editor window can display when multiple blank lines are used.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
 
   **OPEN_BRACE**
     The opening brace should be following the function definitions on the
     next line.  For any non-functional block it should be on the same line
     as the last construct.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
 
   **POINTER_LOCATION**
@@ -671,37 +1124,47 @@ Spacing and Brackets
 
   **SPACING**
     Whitespace style used in the kernel sources is described in kernel docs.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
 
-  **SWITCH_CASE_INDENT_LEVEL**
-    switch should be at the same indent as case.
-    Example::
-
-      switch (suffix) {
-      case 'G':
-      case 'g':
-              mem <<= 30;
-              break;
-      case 'M':
-      case 'm':
-              mem <<= 20;
-              break;
-      case 'K':
-      case 'k':
-              mem <<= 10;
-              /* fall through */
-      default:
-              break;
-      }
-
-    See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
-
   **TRAILING_WHITESPACE**
     Trailing whitespace should always be removed.
     Some editors highlight the trailing whitespace and cause visual
     distractions when editing files.
+
     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
 
+  **UNNECESSARY_PARENTHESES**
+    Parentheses are not required in the following cases:
+
+      1. Function pointer uses::
+
+          (foo->bar)();
+
+        could be::
+
+          foo->bar();
+
+      2. Comparisons in if::
+
+          if ((foo->bar) && (foo->baz))
+          if ((foo == bar))
+
+        could be::
+
+          if (foo->bar && foo->baz)
+          if (foo == bar)
+
+      3. addressof/dereference single Lvalues::
+
+          &(foo->bar)
+          *(foo->bar)
+
+        could be::
+
+          &foo->bar
+          *foo->bar
+
   **WHILE_AFTER_BRACE**
     while should follow the closing bracket on the same line::
 
@@ -723,17 +1186,50 @@ Others
     The patch seems to be corrupted or lines are wrapped.
     Please regenerate the patch file before sending it to the maintainer.
 
+  **CVS_KEYWORD**
+    Since linux moved to git, the CVS markers are no longer used.
+    So, CVS style keywords ($Id$, $Revision$, $Log$) should not be
+    added.
+
+  **DEFAULT_NO_BREAK**
+    switch default case is sometimes written as "default:;".  This can
+    cause new cases added below default to be defective.
+
+    A "break;" should be added after empty default statement to avoid
+    unwanted fallthrough.
+
   **DOS_LINE_ENDINGS**
     For DOS-formatted patches, there are extra ^M symbols at the end of
     the line.  These should be removed.
 
-  **EXECUTE_PERMISSIONS**
+  **DT_SCHEMA_BINDING_PATCH**
-    There is no reason for source files to be executable.  The executable
+    DT bindings moved to a json-schema based format instead of
-    bit can be removed safely.
+    freeform text.
 
-  **NON_OCTAL_PERMISSIONS**
+    See: https://www.kernel.org/doc/html/latest/devicetree/bindings/writing-schema.html
-    Permission bits should use 4 digit octal permissions (like 0700 or 0444).
+
-    Avoid using any other base like decimal.
+  **DT_SPLIT_BINDING_PATCH**
+    Devicetree bindings should be their own patch.  This is because
+    bindings are logically independent from a driver implementation,
+    they have a different maintainer (even though they often
+    are applied via the same tree), and it makes for a cleaner history in the
+    DT only tree created with git-filter-branch.
+
+    See: https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters
+
+  **EMBEDDED_FILENAME**
+    Embedding the complete filename path inside the file isn't particularly
+    useful as often the path is moved around and becomes incorrect.
+
+  **FILE_PATH_CHANGES**
+    Whenever files are added, moved, or deleted, the MAINTAINERS file
+    patterns can be out of sync or outdated.
+
+    So MAINTAINERS might need updating in these cases.
+
+  **MEMSET**
+    The memset use appears to be incorrect.  This may be caused due to
+    badly ordered parameters.  Please recheck the usage.
 
   **NOT_UNIFIED_DIFF**
     The patch file does not appear to be in unified-diff format.  Please
@@ -742,14 +1238,12 @@ Others
   **PRINTF_0XDECIMAL**
     Prefixing 0x with decimal output is defective and should be corrected.
 
-  **TRAILING_STATEMENTS**
+  **SPDX_LICENSE_TAG**
-    Trailing statements (for example after any conditional) should be
+    The source file is missing or has an improper SPDX identifier tag.
-    on the next line.
+    The Linux kernel requires the precise SPDX identifier in all source files,
-    Like::
+    and it is thoroughly documented in the kernel docs.
 
-      if (x == y) break;
+    See: https://www.kernel.org/doc/html/latest/process/license-rules.html
 
-    should be::
+  **TYPO_SPELLING**
-
+    Some words may have been misspelled.  Consider reviewing them.
-      if (x == y)
-              break;

scripts/checkpatch.pl

@@ -63,6 +63,7 @@ my $min_conf_desc_length = 4;
 my $spelling_file = "$D/spelling.txt";
 my $codespell = 0;
 my $codespellfile = "/usr/share/codespell/dictionary.txt";
+my $user_codespellfile = "";
 my $conststructsfile = "$D/const_structs.checkpatch";
 my $u_boot = 0;
 my $docsfile = "$D/../doc/develop/checkpatch.rst";
@@ -131,7 +132,7 @@ Options:
   --ignore-perl-version      override checking of perl version.  expect
                              runtime errors.
   --codespell                Use the codespell dictionary for spelling/typos
-                             (default:/usr/share/codespell/dictionary.txt)
+                             (default:$codespellfile)
   --codespellfile            Use this codespell dictionary
   --typedefsfile             Read additional types from this file
   --color[=WHEN]             Use colors 'always', 'never', or only when output
@@ -319,7 +320,7 @@ GetOptions(
 	'debug=s'	=> \%debug,
 	'test-only=s'	=> \$tst_only,
 	'codespell!'	=> \$codespell,
-	'codespellfile=s'	=> \$codespellfile,
+	'codespellfile=s'	=> \$user_codespellfile,
 	'typedefsfile=s'	=> \$typedefsfile,
 	'u-boot'	=> \$u_boot,
 	'color=s'	=> \$color,
@@ -328,9 +329,32 @@ GetOptions(
 	'kconfig-prefix=s'	=> \${CONFIG_},
 	'h|help'	=> \$help,
 	'version'	=> \$help
-) or help(1);
+) or $help = 2;
 
-help(0) if ($help);
+if ($user_codespellfile) {
+	# Use the user provided codespell file unconditionally
+	$codespellfile = $user_codespellfile;
+} elsif (!(-f $codespellfile)) {
+	# If /usr/share/codespell/dictionary.txt is not present, try to find it
+	# under codespell's install directory: <codespell_root>/data/dictionary.txt
+	if (($codespell || $help) && which("codespell") ne "" && which("python") ne "") {
+		my $python_codespell_dict = << "EOF";
+
+import os.path as op
+import codespell_lib
+codespell_dir = op.dirname(codespell_lib.__file__)
+codespell_file = op.join(codespell_dir, 'data', 'dictionary.txt')
+print(codespell_file, end='')
+EOF
+
+		my $codespell_dict = `python -c "$python_codespell_dict" 2> /dev/null`;
+		$codespellfile = $codespell_dict if (-f $codespell_dict);
+	}
+}
+
+# $help is 1 if either -h, --help or --version is passed as option - exitcode: 0
+# $help is 2 if invalid option is passed - exitcode: 1
+help($help - 1) if ($help);
 
 die "$P: --git cannot be used with --file or --fix\n" if ($git && ($file || $fix));
 die "$P: --verbose cannot be used with --terse\n" if ($verbose && $terse);
@@ -492,7 +516,8 @@ our $Attribute	= qr{
 			____cacheline_aligned|
 			____cacheline_aligned_in_smp|
 			____cacheline_internodealigned_in_smp|
-			__weak
+			__weak|
+			__alloc_size\s*\(\s*\d+\s*(?:,\s*\d+\s*)?\)
 		  }x;
 our $Modifier;
 our $Inline	= qr{inline|__always_inline|noinline|__inline|__inline__};
@@ -504,7 +529,7 @@ our $Binary	= qr{(?i)0b[01]+$Int_type?};
 our $Hex	= qr{(?i)0x[0-9a-f]+$Int_type?};
 our $Int	= qr{[0-9]+$Int_type?};
 our $Octal	= qr{0[0-7]+$Int_type?};
-our $String	= qr{"[X\t]*"};
+our $String	= qr{(?:\b[Lu])?"[X\t]*"};
 our $Float_hex	= qr{(?i)0x[0-9a-f]+p-?[0-9]+[fl]?};
 our $Float_dec	= qr{(?i)(?:[0-9]+\.[0-9]*|[0-9]*\.[0-9]+)(?:e-?[0-9]+)?[fl]?};
 our $Float_int	= qr{(?i)[0-9]+e-?[0-9]+[fl]?};
@@ -1089,10 +1114,10 @@ sub is_maintained_obsolete {
 sub is_SPDX_License_valid {
 	my ($license) = @_;
 
-	return 1 if (!$tree || which("python") eq "" || !(-e "$root/scripts/spdxcheck.py") || !(-e "$gitroot"));
+	return 1 if (!$tree || which("python3") eq "" || !(-x "$root/scripts/spdxcheck.py") || !(-e "$gitroot"));
 
 	my $root_path = abs_path($root);
-	my $status = `cd "$root_path"; echo "$license" | python scripts/spdxcheck.py -`;
+	my $status = `cd "$root_path"; echo "$license" | scripts/spdxcheck.py -`;
 	return 0 if ($status ne "");
 	return 1;
 }
@@ -1186,7 +1211,8 @@ sub git_commit_info {
 #		    git log --format='%H %s' -1 $line |
 #		    echo "commit $(cut -c 1-12,41-)"
 #		done
-	} elsif ($lines[0] =~ /^fatal: ambiguous argument '$commit': unknown revision or path not in the working tree\./) {
+	} elsif ($lines[0] =~ /^fatal: ambiguous argument '$commit': unknown revision or path not in the working tree\./ ||
+		 $lines[0] =~ /^fatal: bad object $commit/) {
 		$id = undef;
 	} else {
 		$id = substr($lines[0], 0, 12);
@@ -2697,6 +2723,8 @@ sub process {
 	my $reported_maintainer_file = 0;
 	my $non_utf8_charset = 0;
 
+	my $last_git_commit_id_linenr = -1;
+
 	my $last_blank_line = 0;
 	my $last_coalesced_string_linenr = -1;
 
@@ -3019,10 +3047,10 @@ sub process {
 					my ($email_name, $email_comment, $email_address, $comment1) = parse_email($ctx);
 					my ($author_name, $author_comment, $author_address, $comment2) = parse_email($author);
 
-					if ($email_address eq $author_address && $email_name eq $author_name) {
+					if (lc $email_address eq lc $author_address && $email_name eq $author_name) {
 						$author_sob = $ctx;
 						$authorsignoff = 2;
-					} elsif ($email_address eq $author_address) {
+					} elsif (lc $email_address eq lc $author_address) {
 						$author_sob = $ctx;
 						$authorsignoff = 3;
 					} elsif ($email_name eq $author_name) {
@@ -3280,10 +3308,20 @@ sub process {
 		}
 
 # Check for git id commit length and improperly formed commit descriptions
-		if ($in_commit_log && !$commit_log_possible_stack_dump &&
+# A correctly formed commit description is:
+#    commit <SHA-1 hash length 12+ chars> ("Complete commit subject")
+# with the commit subject '("' prefix and '")' suffix
+# This is a fairly compilicated block as it tests for what appears to be
+# bare SHA-1 hash with  minimum length of 5.  It also avoids several types of
+# possible SHA-1 matches.
+# A commit match can span multiple lines so this block attempts to find a
+# complete typical commit on a maximum of 3 lines
+		if ($perl_version_ok &&
+		    $in_commit_log && !$commit_log_possible_stack_dump &&
 		    $line !~ /^\s*(?:Link|Patchwork|http|https|BugLink|base-commit):/i &&
 		    $line !~ /^This reverts commit [0-9a-f]{7,40}/ &&
-		    ($line =~ /\bcommit\s+[0-9a-f]{5,}\b/i ||
+		    (($line =~ /\bcommit\s+[0-9a-f]{5,}\b/i ||
+		      ($line =~ /\bcommit\s*$/i && defined($rawlines[$linenr]) && $rawlines[$linenr] =~ /^\s*[0-9a-f]{5,}\b/i)) ||
 		     ($line =~ /(?:\s|^)[0-9a-f]{12,40}(?:[\s"'\(\[]|$)/i &&
 		      $line !~ /[\<\[][0-9a-f]{12,40}[\>\]]/i &&
 		      $line !~ /\bfixes:\s*[0-9a-f]{12,40}/i))) {
@@ -3293,49 +3331,56 @@ sub process {
 			my $long = 0;
 			my $case = 1;
 			my $space = 1;
-			my $hasdesc = 0;
-			my $hasparens = 0;
 			my $id = '0123456789ab';
 			my $orig_desc = "commit description";
 			my $description = "";
+			my $herectx = $herecurr;
+			my $has_parens = 0;
+			my $has_quotes = 0;
 
-			if ($line =~ /\b(c)ommit\s+([0-9a-f]{5,})\b/i) {
+			my $input = $line;
-				$init_char = $1;
+			if ($line =~ /(?:\bcommit\s+[0-9a-f]{5,}|\bcommit\s*$)/i) {
-				$orig_commit = lc($2);
+				for (my $n = 0; $n < 2; $n++) {
-			} elsif ($line =~ /\b([0-9a-f]{12,40})\b/i) {
+					if ($input =~ /\bcommit\s+[0-9a-f]{5,}\s*($balanced_parens)/i) {
-				$orig_commit = lc($1);
+						$orig_desc = $1;
+						$has_parens = 1;
+						# Always strip leading/trailing parens then double quotes if existing
+						$orig_desc = substr($orig_desc, 1, -1);
+						if ($orig_desc =~ /^".*"$/) {
+							$orig_desc = substr($orig_desc, 1, -1);
+							$has_quotes = 1;
+						}
+						last;
+					}
+					last if ($#lines < $linenr + $n);
+					$input .= " " . trim($rawlines[$linenr + $n]);
+					$herectx .= "$rawlines[$linenr + $n]\n";
+				}
+				$herectx = $herecurr if (!$has_parens);
 			}
 
-			$short = 0 if ($line =~ /\bcommit\s+[0-9a-f]{12,40}/i);
+			if ($input =~ /\b(c)ommit\s+([0-9a-f]{5,})\b/i) {
-			$long = 1 if ($line =~ /\bcommit\s+[0-9a-f]{41,}/i);
+				$init_char = $1;
-			$space = 0 if ($line =~ /\bcommit [0-9a-f]/i);
+				$orig_commit = lc($2);
-			$case = 0 if ($line =~ /\b[Cc]ommit\s+[0-9a-f]{5,40}[^A-F]/);
+				$short = 0 if ($input =~ /\bcommit\s+[0-9a-f]{12,40}/i);
-			if ($line =~ /\bcommit\s+[0-9a-f]{5,}\s+\("([^"]+)"\)/i) {
+				$long = 1 if ($input =~ /\bcommit\s+[0-9a-f]{41,}/i);
-				$orig_desc = $1;
+				$space = 0 if ($input =~ /\bcommit [0-9a-f]/i);
-				$hasparens = 1;
+				$case = 0 if ($input =~ /\b[Cc]ommit\s+[0-9a-f]{5,40}[^A-F]/);
-			} elsif ($line =~ /\bcommit\s+[0-9a-f]{5,}\s*$/i &&
+			} elsif ($input =~ /\b([0-9a-f]{12,40})\b/i) {
-				 defined $rawlines[$linenr] &&
+				$orig_commit = lc($1);
-				 $rawlines[$linenr] =~ /^\s*\("([^"]+)"\)/) {
-				$orig_desc = $1;
-				$hasparens = 1;
-			} elsif ($line =~ /\bcommit\s+[0-9a-f]{5,}\s+\("[^"]+$/i &&
-				 defined $rawlines[$linenr] &&
-				 $rawlines[$linenr] =~ /^\s*[^"]+"\)/) {
-				$line =~ /\bcommit\s+[0-9a-f]{5,}\s+\("([^"]+)$/i;
-				$orig_desc = $1;
-				$rawlines[$linenr] =~ /^\s*([^"]+)"\)/;
-				$orig_desc .= " " . $1;
-				$hasparens = 1;
 			}
 
 			($id, $description) = git_commit_info($orig_commit,
 							      $id, $orig_desc);
 
 			if (defined($id) &&
-			   ($short || $long || $space || $case || ($orig_desc ne $description) || !$hasparens)) {
+			    ($short || $long || $space || $case || ($orig_desc ne $description) || !$has_quotes) &&
+			    $last_git_commit_id_linenr != $linenr - 1) {
 				ERROR("GIT_COMMIT_ID",
-				      "Please use git commit description style 'commit <12+ chars of sha1> (\"<title line>\")' - ie: '${init_char}ommit $id (\"$description\")'\n" . $herecurr);
+				      "Please use git commit description style 'commit <12+ chars of sha1> (\"<title line>\")' - ie: '${init_char}ommit $id (\"$description\")'\n" . $herectx);
 			}
+			#don't report the next line if this line ends in commit and the sha1 hash is the next line
+			$last_git_commit_id_linenr = $linenr if ($line =~ /\bcommit\s*$/i);
 		}
 
 # Check for added, moved or deleted files
@@ -4542,6 +4587,7 @@ sub process {
 			#   XXX(foo);
 			#   EXPORT_SYMBOL(something_foo);
 			my $name = $1;
+			$name =~ s/^\s*($Ident).*/$1/;
 			if ($stat =~ /^(?:.\s*}\s*\n)?.([A-Z_]+)\s*\(\s*($Ident)/ &&
 			    $name =~ /^${Ident}_$2/) {
 #print "FOO C name<$name>\n";
@@ -5475,9 +5521,13 @@ sub process {
 			}
 		}
 
-#goto labels aren't indented, allow a single space however
+# check that goto labels aren't indented (allow a single space indentation)
-		if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and
+# and ignore bitfield definitions like foo:1
-		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
+# Strictly, labels can have whitespace after the identifier and before the :
+# but this is not allowed here as many ?: uses would appear to be labels
+		if ($sline =~ /^.\s+[A-Za-z_][A-Za-z\d_]*:(?!\s*\d+)/ &&
+		    $sline !~ /^. [A-Za-z\d_][A-Za-z\d_]*:/ &&
+		    $sline !~ /^.\s+default:/) {
 			if (WARN("INDENTED_LABEL",
 				 "labels should not be indented\n" . $herecurr) &&
 			    $fix) {
@@ -5572,7 +5622,7 @@ sub process {
 # Return of what appears to be an errno should normally be negative
 		if ($sline =~ /\breturn(?:\s*\(+\s*|\s+)(E[A-Z]+)(?:\s*\)+\s*|\s*)[;:,]/) {
 			my $name = $1;
-			if ($name ne 'EOF' && $name ne 'ERROR') {
+			if ($name ne 'EOF' && $name ne 'ERROR' && $name !~ /^EPOLL/) {
 				WARN("USE_NEGATIVE_ERRNO",
 				     "return of an errno should typically be negative (ie: return -$1)\n" . $herecurr);
 			}
@@ -6242,7 +6292,8 @@ sub process {
 		}
 
 # concatenated string without spaces between elements
-		if ($line =~ /$String[A-Za-z0-9_]/ || $line =~ /[A-Za-z0-9_]$String/) {
+		if ($line =~ /$String[A-Z_]/ ||
+		    ($line =~ /([A-Za-z0-9_]+)$String/ && $1 !~ /^[Lu]$/)) {
 			if (CHK("CONCATENATED_STRING",
 				"Concatenated strings should use spaces between elements\n" . $herecurr) &&
 			    $fix) {
@@ -6255,7 +6306,7 @@ sub process {
 		}
 
 # uncoalesced string fragments
-		if ($line =~ /$String\s*"/) {
+		if ($line =~ /$String\s*[Lu]?"/) {
 			if (WARN("STRING_FRAGMENTS",
 				 "Consecutive strings are generally better as a single string\n" . $herecurr) &&
 			    $fix) {

scripts/spdxcheck.py

@@ -44,7 +44,7 @@ def read_spdxdata(repo):
                 continue
 
             exception = None
-            for l in open(el.path).readlines():
+            for l in open(el.path, encoding="utf-8").readlines():
                 if l.startswith('Valid-License-Identifier:'):
                     lid = l.split(':')[1].strip().upper()
                     if lid in spdx.licenses: