Hi Cupetino, On 1/8/24 03:05, Cupertino Miranda wrote: > Hi everyone, > > This patch address the problem reported in: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113225 > > Looking forward to your review.
LGTM, thanks. Please apply. > > Cheers, > Cupertino > > > This patch fix a problem with kernel_helper attribute BTF information, > which incorrectly generates BTF_KIND_FUNC entry. > This BTF entry although accurate with traditional extern function > declarations, once the function is attributed with kernel_helper, it is > semantically incompatible of the kernel helpers in BPF infrastructure. > > gcc/ChangeLog: > PR target/113225 > * btfout.cc (btf_collect_datasec): Skip creating BTF info for > extern and kernel_helper attributed function decls. > gcc/testsuite/ChangeLog: > * gcc.target/bpf/attr-kernel-helper.c: New test. > --- > gcc/btfout.cc | 7 +++++++ > gcc/testsuite/gcc.target/bpf/attr-kernel-helper.c | 15 +++++++++++++++ > 2 files changed, 22 insertions(+) > create mode 100644 gcc/testsuite/gcc.target/bpf/attr-kernel-helper.c > > diff --git a/gcc/btfout.cc b/gcc/btfout.cc > index 04218adc9e66..39e7bec43bfb 100644 > --- a/gcc/btfout.cc > +++ b/gcc/btfout.cc > @@ -35,6 +35,8 @@ along with GCC; see the file COPYING3. If not see > #include "diagnostic-core.h" > #include "cgraph.h" > #include "varasm.h" > +#include "stringpool.h" > +#include "attribs.h" > #include "dwarf2out.h" /* For lookup_decl_die. */ > > static int btf_label_num; > @@ -429,6 +431,11 @@ btf_collect_datasec (ctf_container_ref ctfc) > if (dtd == NULL) > continue; > > + if (DECL_EXTERNAL (func->decl) > + && (lookup_attribute ("kernel_helper", > + DECL_ATTRIBUTES (func->decl))) != NULL_TREE) > + continue; > + > /* Functions actually get two types: a BTF_KIND_FUNC_PROTO, and > also a BTF_KIND_FUNC. But the CTF container only allocates one > type per function, which matches closely with BTF_KIND_FUNC_PROTO. > diff --git a/gcc/testsuite/gcc.target/bpf/attr-kernel-helper.c > b/gcc/testsuite/gcc.target/bpf/attr-kernel-helper.c > new file mode 100644 > index 000000000000..7c5a0007c979 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/bpf/attr-kernel-helper.c > @@ -0,0 +1,15 @@ > +/* Basic test for kernel_helper attribute BTF information. */ > + > +/* { dg-do compile } */ > +/* { dg-options "-O0 -dA -gbtf" } */ > + > +extern int foo_helper(int) __attribute((kernel_helper(42))); > +extern int foo_nohelper(int); > + > +int bar (int arg) > +{ > + return foo_helper (arg) + foo_nohelper (arg); > +} > + > +/* { dg-final { scan-assembler-times "BTF_KIND_FUNC 'foo_nohelper'" 1 } } */ > +/* { dg-final { scan-assembler-times "BTF_KIND_FUNC 'foo_helper'" 0 } } */