On Thu, Sep 28, 2023 at 04:19:02AM -0500, Jinghao Jia wrote:
>
>
> On 9/28/23 3:15 AM, Jiri Olsa wrote:
> > On Wed, Sep 27, 2023 at 06:19:10PM -0500, ruowenq2@xxxxxxxxxxxx wrote:
> >>
> >>
> >> On 9/27/23 6:03 AM, Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
> >>> On Tue, Sep 26, 2023 at 11:50:30PM -0500, ruowenq2@xxxxxxxxxxxx wrote:
> >>>> From: Ruowen Qin <ruowenq2@xxxxxxxxxxxx>
> >>>>
> >>>> The sanitizer flag, which is supported by both clang and gcc, would make
> >>>> it easier to debug array index out-of-bounds problems in these programs.
> >>>>
> >>>> Make the Makfile smarter to detect ubsan support from the compiler and
> >>>> add the '-fsanitize=bounds' accordingly.
> >>>>
> >>>> Suggested-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> >>>> Signed-off-by: Jinghao Jia <jinghao@xxxxxxxxxxxxx>
> >>>> Signed-off-by: Jinghao Jia <jinghao7@xxxxxxxxxxxx>
> >>>> Signed-off-by: Ruowen Qin <ruowenq2@xxxxxxxxxxxx>
> >>>> ---
> >>>> samples/bpf/Makefile | 3 +++
> >>>> 1 file changed, 3 insertions(+)
> >>>>
> >>>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> >>>> index 6c707ebcebb9..90af76fa9dd8 100644
> >>>> --- a/samples/bpf/Makefile
> >>>> +++ b/samples/bpf/Makefile
> >>>> @@ -169,6 +169,9 @@ endif
> >>>> TPROGS_CFLAGS += -Wall -O2
> >>>> TPROGS_CFLAGS += -Wmissing-prototypes
> >>>> TPROGS_CFLAGS += -Wstrict-prototypes
> >>>> +TPROGS_CFLAGS += $(call try-run,\
> >>>> + printf "int main() { return 0; }" |\
> >>>> + $(CC) -Werror -fsanitize=bounds -x c - -o "$$TMP",-fsanitize=bounds,)
> >>>
> >>> I haven't checked deeply, but could we use just cc-option? looks simpler
> >>>
> >>> TPROGS_CFLAGS += $(call cc-option, -fsanitize=bounds)
> >>>
> >>> jirka
> >>
> >> Hi, thanks for your quick reply! When checking for flags, cc-option does not execute the linker, but on Fedora, an error appears and stating that "/usr/lib64/libubsan.so.1.0.0" cannot be found during linking. So I try this seemingly cumbersome way.
> >
> > I see, there's also ld-option, would that work?
> >
> > jirka
> >
>
> IMHO I don't think ld-option would solve the problem. It directly sends the
> flag to the linker but -fsanitize=bounds is a compiler flag, not a linker
> flag.
>
> Basically, what's special about this case is that the feature we want to
> probe is behind a gcc/clang flag but we do not know whether it is supported
> until link time (e.g. the sanitizer library is missing on Fedora so we get
> a link error).
ok, I tested on fedora, looks good
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
thanks,
jirka
>
> --Jinghao
>
> >>
> >> Ruowen
> >>
> >>>> > TPROGS_CFLAGS += -I$(objtree)/usr/include
> >>>> TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
> >>>> -- > 2.42.0
> >>>>
> >>>>
> >>>
