Hi Eduard,
On Wed, Feb 28, 2024 at 11:33:28PM +0200, Eduard Zingerman wrote:
> On Wed, 2024-02-28 at 09:07 -0700, Daniel Xu wrote:
> > Hi Eduard,
> >
> > Apologies for long delay - life has been busy.
>
> Hi Daniel,
>
> No problem, thank you for reaching back.
>
> [...]
>
> > > > +static char *get_func_name(const char *sym)
> > > > +{
> > > > + char *func, *end;
> > > > +
> > > > + if (strncmp(sym, BTF_ID_FUNC_PFX, sizeof(BTF_ID_FUNC_PFX) - 1))
> > > > + return NULL;
> > > > +
> > > > + /* Strip prefix */
> > > > + func = strdup(sym + sizeof(BTF_ID_FUNC_PFX) - 1);
> > > > +
> > > > + /* Strip suffix */
> > > > + end = strrchr(func, '_');
> > > > + if (!end || *(end - 1) != '_') {
> > >
> > > Nit: this would do out of bounds access on malformed input
> > > "__BTF_ID__func___"
> >
> > I think this is actually ok. Reason is we have the strncmp() above
> > so we know the prefix is there. Then the strdup() in the malformed cased
> > returns empty string. And strrchr() will then return NULL, so we don't
> > enter the branch.
> >
> > I tested it with: https://pastes.dxuuu.xyz/c3j4kk
> >
> > $ gcc test.c
> > dxu@kashmir~/scratch $ ./a.out
> > name=(null)
> >
>
> The test is for "__BTF_ID__func__", but nitpick is for "__BTF_ID__func___"
> (three underscores in the end).
>
Ha, got it. Didn't see the 3rd one. Fixed in v5.
[...]
Thanks,
Daniel
