docs: bump minimal GNU Make version to 3.81

Since 2014, you can't successfully build kernels with GNU Make version
3.80. Example errors:

  $ git describe
  v4.11
  $ make --version | head -1
  GNU Make 3.80
  $ make defconfig
    HOSTCC  scripts/basic/fixdep
  scripts/Makefile.host:135: *** missing separator.  Stop.
  make: *** [defconfig] Error 2
  $ make ARCH=arm64 help
  arch/arm64/Makefile:43: *** unterminated call to function `warning': missing `)'.  Stop.
  $ make help >/dev/null
  ./Documentation/Makefile.sphinx:25: Extraneous text after `else' directive
  ./Documentation/Makefile.sphinx:31: *** only one `else' per conditional.  Stop.
  make: *** [help] Error 2

The first breakage was introduced by commit c8589d1e9e01 ("kbuild:
handle multi-objs dependency appropriately").  Since then (i.e. v3.18),
GNU Make 3.80 has not been able to compile the kernel, but nobody has
ever complained aboutt (or noticed) it.

Even GNU Make 3.81 is more than 10 years old.  It would not hurt to
match the documentation with reality instead of fixing makefiles.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index 01c5dbcd0f847ebb3ead78646c8b9d0a00d243c9..cef7bc4d1f9bef2a2343ab1c754380383951fcf5 100644 (file)
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -30,7 +30,7 @@ you probably needn't concern yourself with isdn4k-utils.
         Program        Minimal version       Command to check the version
 ====================== ===============  ========================================
 GNU C                  3.2              gcc --version
-GNU make               3.80             make --version
+GNU make               3.81             make --version
 binutils               2.12             ld -v
 util-linux             2.10o            fdformat --version
 module-init-tools      0.9.10           depmod -V