Re: [PATCH] libbpf: ensure functions with always_inline attribute are inline
From: James Hilliard
Date: Wed Aug 03 2022 - 11:17:33 EST
On Wed, Aug 3, 2022 at 2:19 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
>
> On Tue, Aug 02, 2022 at 05:27:41PM -0600, James Hilliard wrote:
> > GCC expects the always_inline attribute to only be set on inline
> > functions, as such we should make all functions with this attribute
> > inline.
> >
> > Fixes errors like:
> > /home/buildroot/bpf-next/tools/testing/selftests/bpf/tools/include/bpf/bpf_tracing.h:439:1: error: ‘always_inline’ function might not be inlinable [-Werror=attributes]
> > 439 | ____##name(unsigned long long *ctx, ##args)
> > | ^~~~
> >
> > Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
> > ---
> > tools/lib/bpf/bpf_tracing.h | 14 +++++++-------
> > tools/lib/bpf/usdt.bpf.h | 4 ++--
> > 2 files changed, 9 insertions(+), 9 deletions(-)
> >
> > diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
> > index 43ca3aff2292..ae67fcee912c 100644
> > --- a/tools/lib/bpf/bpf_tracing.h
> > +++ b/tools/lib/bpf/bpf_tracing.h
> > @@ -426,7 +426,7 @@ struct pt_regs;
> > */
> > #define BPF_PROG(name, args...) \
> > name(unsigned long long *ctx); \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
>
> could you use __always_inline that does exactly that?
Sure, changed to use the __always_inline macro in v2:
https://lore.kernel.org/bpf/20220803151403.793024-1-james.hilliard1@xxxxxxxxx/
>
> jirka
>
> > ____##name(unsigned long long *ctx, ##args); \
> > typeof(name(0)) name(unsigned long long *ctx) \
> > { \
> > @@ -435,7 +435,7 @@ typeof(name(0)) name(unsigned long long *ctx) \
> > return ____##name(___bpf_ctx_cast(args)); \
> > _Pragma("GCC diagnostic pop") \
> > } \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(unsigned long long *ctx, ##args)
> >
> > struct pt_regs;
> > @@ -460,7 +460,7 @@ struct pt_regs;
> > */
> > #define BPF_KPROBE(name, args...) \
> > name(struct pt_regs *ctx); \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args); \
> > typeof(name(0)) name(struct pt_regs *ctx) \
> > { \
> > @@ -469,7 +469,7 @@ typeof(name(0)) name(struct pt_regs *ctx) \
> > return ____##name(___bpf_kprobe_args(args)); \
> > _Pragma("GCC diagnostic pop") \
> > } \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args)
> >
> > #define ___bpf_kretprobe_args0() ctx
> > @@ -484,7 +484,7 @@ ____##name(struct pt_regs *ctx, ##args)
> > */
> > #define BPF_KRETPROBE(name, args...) \
> > name(struct pt_regs *ctx); \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args); \
> > typeof(name(0)) name(struct pt_regs *ctx) \
> > { \
> > @@ -540,7 +540,7 @@ static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
> > #define BPF_KSYSCALL(name, args...) \
> > name(struct pt_regs *ctx); \
> > extern _Bool LINUX_HAS_SYSCALL_WRAPPER __kconfig; \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args); \
> > typeof(name(0)) name(struct pt_regs *ctx) \
> > { \
> > @@ -555,7 +555,7 @@ typeof(name(0)) name(struct pt_regs *ctx) \
> > return ____##name(___bpf_syscall_args(args)); \
> > _Pragma("GCC diagnostic pop") \
> > } \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args)
> >
> > #define BPF_KPROBE_SYSCALL BPF_KSYSCALL
> > diff --git a/tools/lib/bpf/usdt.bpf.h b/tools/lib/bpf/usdt.bpf.h
> > index 4f2adc0bd6ca..2bd2d80b3751 100644
> > --- a/tools/lib/bpf/usdt.bpf.h
> > +++ b/tools/lib/bpf/usdt.bpf.h
> > @@ -232,7 +232,7 @@ long bpf_usdt_cookie(struct pt_regs *ctx)
> > */
> > #define BPF_USDT(name, args...) \
> > name(struct pt_regs *ctx); \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args); \
> > typeof(name(0)) name(struct pt_regs *ctx) \
> > { \
> > @@ -241,7 +241,7 @@ typeof(name(0)) name(struct pt_regs *ctx) \
> > return ____##name(___bpf_usdt_args(args)); \
> > _Pragma("GCC diagnostic pop") \
> > } \
> > -static __attribute__((always_inline)) typeof(name(0)) \
> > +static inline __attribute__((always_inline)) typeof(name(0)) \
> > ____##name(struct pt_regs *ctx, ##args)
> >
> > #endif /* __USDT_BPF_H__ */
> > --
> > 2.34.1
> >