On Wed, 2 Jul 2025 14:57:22 +0200
Jens Remus [off-list ref] wrote:
Hello Steve!
On 01.07.2025 20:49, Steven Rostedt wrote:
quoted
This code is based on top of:
https://lore.kernel.org/linux-trace-kernel/20250701005321.942306427@goodmis.org/ (local)
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git unwind/core
This is the implementation of parsing the SFrame section in an ELF file.
...
quoted
The code for this patch series can be found here:
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git unwind/sframe
Wouldn't it make sense to include your related perf (tools) series [1]
in that branch to ease testing? Provided you also include the minor
fix [2] to make perf tools work. :-)
I was planning on making a branch with perf and sframe merged (haven't
pushed it out yet). Since sframe doesn't technically rely on it (I use
tracing too test it too) I'm keeping them separate.
Additionally it would make sense to include the patches from Josh that
add SFrame information to the vDSO on x86 [3].
[1]: [PATCH v12 00/11] perf: Support the deferred unwinding infrastructure,
https://lore.kernel.org/linux-trace-kernel/20250701180410.755491417@goodmis.org/ (local)
[2]: https://lore.kernel.org/linux-trace-kernel/51903e66-56bc-42a4-b80c-9c3223e2a48a@linux.ibm.com/ (local)
[3]: [PATCH v6 0/6] x86/vdso: VDSO updates and fixes for sframes,
https://lore.kernel.org/all/20250425023750.669174660@goodmis.org/ (local)
I have them in separate branches too and will be posting them
separately. Again, the "merged" branch will contain them all.
quoted
Changes since v6: https://lore.kernel.org/linux-trace-kernel/20250617225009.233007152@goodmis.org/ (local)
quoted
- Moved the addition of the prctl(), that allows libraries to add the elf
sections to the kernel, to the last patch and labeled it as "DO NOT APPLY".
This should instead be a proper system call and work to make it robust and
flexible still needs to be done. The prctl() patch is added for debugging
purposes only.
Does PR_SET_VMA [4] create a precedent case for the SFrame prctls?
[4]: https://man7.org/linux/man-pages/man2/pr_set_vma.2const.html
At the last sframe meeting we came to the decision to make it a proper
system call. Just seems cleaner that way. If others feel prctl() is the
way to go, we can definitely do that too.
-- Steve