kernel_optimize_test/arch/s390
Matteo Croce eec4844fae proc/sysctl: add shared variables for range check
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range.  This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.

On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.

The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.

This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data                                         old     new   delta
    sysctl_vals                                    -      12     +12
    __kstrtab_sysctl_vals                          -      12     +12
    max                                           14      10      -4
    int_max                                       16       -     -16
    one                                           68       -     -68
    zero                                         128      28    -100
    Total: Before=20583249, After=20583085, chg -0.00%

[mcroce@redhat.com: tipc: remove two unused variables]
  Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
  Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
..
appldata proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
boot s390/boot: fix compiler error due to missing awk strtonum 2019-05-07 14:37:14 +02:00
configs Kbuild updates for v5.3 2019-07-12 16:03:16 -07:00
crypto s390/crypto: sha: Use -ENODEV instead of -EOPNOTSUPP 2019-06-15 12:24:48 +02:00
hypfs s390/kernel: introduce .dma sections 2019-04-29 10:47:10 +02:00
include arch: replace _BITUL() in kernel-space headers with BIT() 2019-07-16 19:23:22 -07:00
kernel proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
kvm ARM: 2019-07-12 15:35:14 -07:00
lib s390: enforce CONFIG_SMP 2019-06-07 10:09:37 +02:00
mm mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE 2019-07-18 17:08:06 -07:00
net s390: bpf: eliminate zero extension code-gen 2019-05-24 18:58:38 -07:00
numa treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
oprofile s390/unwind: introduce stack unwind API 2019-05-02 13:54:11 +02:00
pci s390 updates for the 5.3 merge window #2 2019-07-12 15:39:22 -07:00
purgatory s390/purgatory: update .gitignore 2019-06-04 15:03:42 +02:00
scripts s390: make chkbss work with clang 2019-04-11 13:36:52 +02:00
tools s390/disassembler: update opcode table 2019-06-04 15:03:58 +02:00
Kbuild s390/kexec_file: Add purgatory 2018-04-16 09:10:22 +02:00
Kconfig mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP 2019-07-12 11:05:44 -07:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile Kconfig updates for v5.3 2019-07-12 16:06:27 -07:00