On 4/7/21 6:46 AM, Arnaldo Carvalho de Melo wrote:
Em Tue, Apr 06, 2021 at 11:23:27PM -0700, Yonghong Song escreveu:
On 4/6/21 8:01 PM, Sedat Dilek wrote:
On Tue, Apr 6, 2021 at 6:13 PM Yonghong Song <yhs@xxxxxx> wrote:
Masahiro and Michal,
Friendly ping. Any comments on this patch?
The addition LTO .notes information emitted by kernel is used by pahole
in the following patch:
https://lore.kernel.org/bpf/20210401025825.2254746-1-yhs@xxxxxx/
(dwarf_loader: check .notes section for lto build info)
the above pahole patch has this define and comment:
-static bool cus__merging_cu(Dwarf *dw)
+/* Match the define in linux:include/linux/elfnote.h */
+#define LINUX_ELFNOTE_BUILD_LTO 0x101
...and does not fit with the define and comment in this kernel patch:
+#include <linux/elfnote.h>
+
+#define LINUX_ELFNOTE_LTO_INFO 0x101
Thanks, Sedat. I am aware of this. I think we can wait in pahole
to make a change until the kernel patch is finalized and merged.
The kernel patch may still change as we haven't get
maintainer's comment. This will avoid unnecessary churn's
in pahole side.
So, I tested with clang 12 on fedora rawhide as well on fedora 33, and
I'm satisfied with the current state to release v1.21, Masahiro, have
you had the time to look at this?
Yonghong, as we have a fallback in case the ELF note isn't available, I
think we're safe even if the notes patch merge gets delayed, right?
Right. That is why I separated the notes patch from other patches.
We can revisit it once the kernel patch is settled.
- Arnaldo
