Re: [PATCH v2 dwarves 4/5] man-pages: document true_signature btf_feature
Alan Maguire <[email protected]>
| Newsgroups | org.kernel.vger.dwarves,org.kernel.vger.bpf |
|---|---|
| Message-ID | <[email protected]> |
On 26/01/2026 10:02, Matt Bobrowski wrote: > On Fri, Jan 23, 2026 at 05:26:49PM +0000, Alan Maguire wrote: >> Ensure non-default "true_signature" feature is documented in >> the manual page. >> >> Signed-off-by: Alan Maguire <[email protected]> > > Acked-by: Matt Bobrowski <[email protected]> > >> --- >> man-pages/pahole.1 | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/man-pages/pahole.1 b/man-pages/pahole.1 >> index 3125de3..90a8f45 100644 >> --- a/man-pages/pahole.1 >> +++ b/man-pages/pahole.1 >> @@ -337,6 +337,11 @@ Supported non-standard features (not enabled for 'default') >> of split BTF with a possibly changed base, storing >> it in a .BTF.base ELF section. >> global_var Encode all global variables using BTF_KIND_VAR in BTF. >> + true_signature Encode functions ensuring that binary-level >> + (rather than source-level) signatures are used; > ^ > within the generated BTF. > >> + for gcc these are ".isra.0" and ".costprop.0" >> + optimized functions > > For BTF generation, would there ever be a situation whereby we > wouldn't want true signature support? I'm just trying to understand > why this isn't defaulted to true. The key reason is the "." in the name for gcc-optimized functions "function.isra.0" ; older kernels will reject BTF function names with a "." in them, so we have to guard against new pahole with the feature enabled by default being run on older kernels. So by having the newer kernels request the feature only we avoid this.