28 Nov
2024
28 Nov
'24
10:33
On 27. 11. 24, 20:15, Andrii Nakryiko wrote:
You can do DWARF unwinding in the kernel as well (as well as stack capturing for FP based unwinding).
Not really. Kernel itself doesn't support it, and if you were to implement it in a BPF program yourself you'd run into many practical issues. The most damning would be inability to page in memory that contains .eh_frame section contents from non-sleepable context, in which stack trace is typically captured (NMI, tracepoints, kprobes). See above.
We won't enable FPs in kernels in any case. Assembler is annotated only by ORC and many asm functions do not save/restore FP, so it'd be kind of useless anyway. regards, -- js suse labs