Message ID | 20200703095111.3268961-9-jolsa@kernel.org |
---|---|
State | Changes Requested |
Delegated to: | BPF Maintainers |
Headers | show |
Series | bpf: Add d_path helper - preparation changes | expand |
On Fri, Jul 3, 2020 at 2:53 AM Jiri Olsa <jolsa@kernel.org> wrote: > > It will be needed by bpf selftest for resolve_btfids tool. > > Also adding __PASTE macro as btf_ids.h dependency, which is > defined in: > > include/linux/compiler_types.h > > but because tools/include do not have this header, I'm putting > the macro into linux/compiler.h header. > > Acked-by: Andrii Nakryiko <andriin@fb.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/include/linux/btf_ids.h | 87 ++++++++++++++++++++++++++++++++++ > tools/include/linux/compiler.h | 4 ++ > 2 files changed, 91 insertions(+) > create mode 100644 tools/include/linux/btf_ids.h > > diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h > new file mode 100644 > index 000000000000..d317150bc9e3 > --- /dev/null > +++ b/tools/include/linux/btf_ids.h > @@ -0,0 +1,87 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef _LINUX_BTF_IDS_H > +#define _LINUX_BTF_IDS_H > + > +#include <linux/compiler.h> /* for __PASTE */ > + > +/* > + * Following macros help to define lists of BTF IDs placed > + * in .BTF_ids section. They are initially filled with zeros One more inconsistency with .BTF_ids vs .BTF.ids (probably same in the original header, which I missed). > + * (during compilation) and resolved later during the > + * linking phase by btfid tool. typo: resolve_btfids tool > + * > + * Any change in list layout must be reflected in btfid > + * tool logic. > + */ > + [...]
On Mon, Jul 06, 2020 at 05:56:09PM -0700, Andrii Nakryiko wrote: > On Fri, Jul 3, 2020 at 2:53 AM Jiri Olsa <jolsa@kernel.org> wrote: > > > > It will be needed by bpf selftest for resolve_btfids tool. > > > > Also adding __PASTE macro as btf_ids.h dependency, which is > > defined in: > > > > include/linux/compiler_types.h > > > > but because tools/include do not have this header, I'm putting > > the macro into linux/compiler.h header. > > > > Acked-by: Andrii Nakryiko <andriin@fb.com> > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > tools/include/linux/btf_ids.h | 87 ++++++++++++++++++++++++++++++++++ > > tools/include/linux/compiler.h | 4 ++ > > 2 files changed, 91 insertions(+) > > create mode 100644 tools/include/linux/btf_ids.h > > > > diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h > > new file mode 100644 > > index 000000000000..d317150bc9e3 > > --- /dev/null > > +++ b/tools/include/linux/btf_ids.h > > @@ -0,0 +1,87 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > + > > +#ifndef _LINUX_BTF_IDS_H > > +#define _LINUX_BTF_IDS_H > > + > > +#include <linux/compiler.h> /* for __PASTE */ > > + > > +/* > > + * Following macros help to define lists of BTF IDs placed > > + * in .BTF_ids section. They are initially filled with zeros > > One more inconsistency with .BTF_ids vs .BTF.ids (probably same in the > original header, which I missed). ok > > > + * (during compilation) and resolved later during the > > + * linking phase by btfid tool. > > typo: resolve_btfids tool will fix thanks, jirka > > > + * > > + * Any change in list layout must be reflected in btfid > > + * tool logic. > > + */ > > + > > [...] >
diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h new file mode 100644 index 000000000000..d317150bc9e3 --- /dev/null +++ b/tools/include/linux/btf_ids.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_BTF_IDS_H +#define _LINUX_BTF_IDS_H + +#include <linux/compiler.h> /* for __PASTE */ + +/* + * Following macros help to define lists of BTF IDs placed + * in .BTF_ids section. They are initially filled with zeros + * (during compilation) and resolved later during the + * linking phase by btfid tool. + * + * Any change in list layout must be reflected in btfid + * tool logic. + */ + +#define BTF_IDS_SECTION ".BTF.ids" + +#define ____BTF_ID(symbol) \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".local " #symbol " ; \n" \ +".type " #symbol ", @object; \n" \ +".size " #symbol ", 4; \n" \ +#symbol ": \n" \ +".zero 4 \n" \ +".popsection; \n"); + +#define __BTF_ID(symbol) \ + ____BTF_ID(symbol) + +#define __ID(prefix) \ + __PASTE(prefix, __COUNTER__) + +/* + * The BTF_ID defines unique symbol for each ID pointing + * to 4 zero bytes. + */ +#define BTF_ID(prefix, name) \ + __BTF_ID(__ID(__BTF_ID__##prefix##__##name##__)) + +/* + * The BTF_ID_LIST macro defines pure (unsorted) list + * of BTF IDs, with following layout: + * + * BTF_ID_LIST(list1) + * BTF_ID(type1, name1) + * BTF_ID(type2, name2) + * + * list1: + * __BTF_ID__type1__name1__1: + * .zero 4 + * __BTF_ID__type2__name2__2: + * .zero 4 + * + */ +#define __BTF_ID_LIST(name) \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".local " #name "; \n" \ +#name ":; \n" \ +".popsection; \n"); \ + +#define BTF_ID_LIST(name) \ +__BTF_ID_LIST(name) \ +extern u32 name[]; + +/* + * The BTF_ID_UNUSED macro defines 4 zero bytes. + * It's used when we want to define 'unused' entry + * in BTF_ID_LIST, like: + * + * BTF_ID_LIST(bpf_skb_output_btf_ids) + * BTF_ID(struct, sk_buff) + * BTF_ID_UNUSED + * BTF_ID(struct, task_struct) + */ + +#define BTF_ID_UNUSED \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".zero 4 \n" \ +".popsection; \n"); + + +#endif diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 9f9002734e19..6eac24d44e81 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -201,4 +201,8 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s # define __fallthrough #endif +/* Indirect macros required for expanded argument pasting, eg. __LINE__. */ +#define ___PASTE(a, b) a##b +#define __PASTE(a, b) ___PASTE(a, b) + #endif /* _TOOLS_LINUX_COMPILER_H */