From: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Date: Mon, 1 Aug 2016 03:24:50 +0000 (-0400)
Subject: x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables
X-Git-Tag: v4.8-rc2~10^2~10
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5e44258d168b2bdee51d9e2e1f1f4726ff9775cd;p=karo-tx-linux.git

x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables

Building an X86_64 kernel with W=1 throws a total of 9,948 lines of warnings of
this form for both 32-bit and 64-bit syscall tables. Given that the entire rest
of the build for my config only generates 8,375 lines of output, this is a big
reduction in the warnings generated.

The warnings follow this pattern:

  ./arch/x86/include/generated/asm/syscalls_32.h:885:21: warning: initialized field overwritten [-Woverride-init]
   __SYSCALL_I386(379, compat_sys_pwritev2, )
                     ^
  arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
   #define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
                                              ^~~
  ./arch/x86/include/generated/asm/syscalls_32.h:885:21: note: (near initialization for 'ia32_sys_call_table[379]')
   __SYSCALL_I386(379, compat_sys_pwritev2, )
                     ^
  arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
   #define __SYSCALL_I386(nr, sym, qual) [nr] = sym,

Since we intentionally build the syscall tables this way, ignore that one
warning in the two files.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/7464.1470021890@turing-police.cc.vt.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index fe91c25092da..77f28ce9c646 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -5,6 +5,8 @@
 OBJECT_FILES_NON_STANDARD_entry_$(BITS).o   := y
 OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y
 
+CFLAGS_syscall_64.o		+= -Wno-override-init
+CFLAGS_syscall_32.o		+= -Wno-override-init
 obj-y				:= entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
 obj-y				+= common.o