On Wed, May 1, 2019 at 3:55 PM Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx> wrote: > > When build perf for ARC recently, there was a build failure due to lack > of __NR_bpf. > > | Auto-detecting system features: > | > | ... get_cpuid: [ OFF ] > | ... bpf: [ on ] > | > | # error __NR_bpf not defined. libbpf does not support your arch. > ^~~~~ > | bpf.c: In function 'sys_bpf': > | bpf.c:66:17: error: '__NR_bpf' undeclared (first use in this function) > | return syscall(__NR_bpf, cmd, attr, size); > | ^~~~~~~~ > | sys_bpf > > The fix is to define a fallbak __NR_bpf. > > The obvious fix with be __arc__ specific value, but i think a better fix > is to use the asm-generic uapi value applicable to ARC as well as any new > arch (hopefully we don't add an old existing arch here). Otherwise I can > just add __arc__ I prefer explicitly guard with __arc__. We still have arm/sh with different __NR_bpf values. This patch will give wrong bpf syscall values for these two architectures. Alternatively, you could add support for arm/sh together with your current patch. Hopefully I did not miss other architectures. > > Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> > --- > tools/lib/bpf/bpf.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > index 9cd015574e83..2c5eb7928400 100644 > --- a/tools/lib/bpf/bpf.c > +++ b/tools/lib/bpf/bpf.c > @@ -47,7 +47,10 @@ > # elif defined(__s390__) > # define __NR_bpf 351 > # else > -# error __NR_bpf not defined. libbpf does not support your arch. > +/* > + * Any non listed arch (new) will have to asm-generic uapi complient > + */ > +# define __NR_bpf 280 > # endif > #endif > > -- > 2.7.4 > _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
