On Tue, Jun 04, 2019 at 03:24:40PM +0200, Stefan Agner wrote: > From: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> > > [ Upstream commit c0d9782f5b6d7157635ae2fd782a4b27d55a6013 ] > > >From the GCC manual: > > copy > copy(function) > > The copy attribute applies the set of attributes with which function > has been declared to the declaration of the function to which > the attribute is applied. The attribute is designed for libraries > that define aliases or function resolvers that are expected > to specify the same set of attributes as their targets. The copy > attribute can be used with functions, variables, or types. However, > the kind of symbol to which the attribute is applied (either > function or variable) must match the kind of symbol to which > the argument refers. The copy attribute copies only syntactic and > semantic attributes but not attributes that affect a symbol’s > linkage or visibility such as alias, visibility, or weak. > The deprecated attribute is also not copied. > > https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html > > The upcoming GCC 9 release extends the -Wmissing-attributes warnings > (enabled by -Wall) to C and aliases: it warns when particular function > attributes are missing in the aliases but not in their target, e.g.: > > void __cold f(void) {} > void __alias("f") g(void); > > diagnoses: > > warning: 'g' specifies less restrictive attribute than > its target 'f': 'cold' [-Wmissing-attributes] > > Using __copy(f) we can copy the __cold attribute from f to g: > > void __cold f(void) {} > void __copy(f) __alias("f") g(void); > > This attribute is most useful to deal with situations where an alias > is declared but we don't know the exact attributes the target has. > > For instance, in the kernel, the widely used module_init/exit macros > define the init/cleanup_module aliases, but those cannot be marked > always as __init/__exit since some modules do not have their > functions marked as such. > > Cc: <stable@xxxxxxxxxxxxxxx> # 4.14+ > Suggested-by: Martin Sebor <msebor@xxxxxxxxxxx> > Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> > Signed-off-by: Stefan Agner <stefan@xxxxxxxx> > --- > include/linux/compiler-gcc.h | 4 ++++ > include/linux/compiler_types.h | 4 ++++ > 2 files changed, 8 insertions(+) Thanks for this, and the 4.14 updated series, I've applied them all now. greg k-h
