Messages in this thread | | | Date | Thu, 5 Dec 2019 02:08:19 +0000 | From | Al Viro <> | Subject | Re: [PATCH] fix cast of gfp_t to ulong in __def_gfpflag_names |
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On Wed, Dec 04, 2019 at 06:54:25PM +0100, Luc Van Oostenryck wrote: > The macro '__def_gfpflag_names' is used to define arrays of > struct trace_print_flags. This structure is defined as being > a pair of 'unsigned long' - 'const char *'. > > However, the macro __def_gfpflag_names is used to for GFP flags > and thus take entries of type gfp_t (plus their name) which > is a bitwise type, non-convertible to usual integers. > These entries are casted to 'unsigned long' but this doesn't > prevent Sparse to rughtfully complain: > warning: cast from restricted gfp_t > > The correct way to cast a bitwise type to a normal integer > (which is OK here) is to use '__force'. > > So, fix the cast by adding the '__force' required for such casts.
Ugh... > - {(unsigned long)GFP_TRANSHUGE, "GFP_TRANSHUGE"}, \ <plenty of such> > + {(__force ulong)GFP_TRANSHUGE, "GFP_TRANSHUGE"}, \
# operator is there for purpose; as in #define FOO(name) {(__force unsigned long)name, #name} with those becoming #define __def_gfpflag_names \ FOO(GFP_TRANSHUGE), \ FOO(GFP_TRANSHUGE_LIGHT), \ etc.
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