On Fri, Jan 25, 2019 at 11:43 AM Laura Abbott <labb...@redhat.com> wrote:
>
> Commit bee20031772a ("disable -Wattribute-alias warning for
> SYSCALL_DEFINEx()") disabled -Wattribute-alias with gcc8.
> gcc9 changed the format of -Wattribute-alias to take a parameter.
> This doesn't quite match with the existing disabling mechanism
> so update for gcc9 to match with the default (-Wattribute-alias=1).
>
> Signed-off-by: Laura Abbott <labb...@redhat.com>
> ---
> This is RFC because it feels ugly. I went ahead and did the obvious fixup
> but it's worth discussing if we're going to end up with an explosion or
> if there's a better way to handle this in one macro.Bernd Edlinger has sent a patch to gcc for this: https://gcc.gnu.org/ml/gcc-patches/2019-01/msg01120.html and Miguel Ojeda said he wanted to send a patch for it to the kernel as well, not sure if he wanted to take a different approach there, so adding both to Cc here. Arnd > --- > include/linux/compat.h | 2 ++ > include/linux/compiler-gcc.h | 7 ++++++- > include/linux/syscalls.h | 2 ++ > 3 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/include/linux/compat.h b/include/linux/compat.h > index 056be0d03722..d5d7700f26a6 100644 > --- a/include/linux/compat.h > +++ b/include/linux/compat.h > @@ -75,6 +75,8 @@ > __diag_push(); > \ > __diag_ignore(GCC, 8, "-Wattribute-alias", > \ > "Type aliasing is used to sanitize syscall arguments");\ > + __diag_ignore(GCC, 9, "-Wattribute-alias=1", > \ > + "Type aliasing is used to sanitize syscall arguments");\ > asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); > \ > asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) > \ > __attribute__((alias(__stringify(__se_compat_sys##name)))); > \ > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index e8579412ad21..75079668344c 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -165,8 +165,13 @@ > #define __diag_str(s) __diag_str1(s) > #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) > > -#if GCC_VERSION >= 80000 > +#if GCC_VERSION >= 90000 > +#define __diag_GCC_8(s) > +#define __diag_GCC_9(s) __diag(s) > +#elif GCC_VERSION >= 80000 > #define __diag_GCC_8(s) __diag(s) > +#define __diag_GCC_9(s) > #else > #define __diag_GCC_8(s) > +#define __diag_GCC_9(s) > #endif > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > index 257cccba3062..a08059e1ccf4 100644 > --- a/include/linux/syscalls.h > +++ b/include/linux/syscalls.h > @@ -236,6 +236,8 @@ static inline int is_syscall_trace_event(struct > trace_event_call *tp_event) > __diag_push(); \ > __diag_ignore(GCC, 8, "-Wattribute-alias", \ > "Type aliasing is used to sanitize syscall arguments");\ > + __diag_ignore(GCC, 9, "-Wattribute-alias=1", \ > + "Type aliasing is used to sanitize syscall arguments");\ > asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ > __attribute__((alias(__stringify(__se_sys##name)))); \ > ALLOW_ERROR_INJECTION(sys##name, ERRNO); \ > -- > 2.20.1 >
