Re: [RFC PATCH v2 06/24] unwind_user: Enable archs that define CFA = SP_callsite + offset
| Newsgroups | org.kernel.vger.linux-s390,org.kernel.vger.linux-trace-kernel |
|---|---|
| Message-ID | <[email protected]> |
> Most architectures define their CFA as the value of the stack pointer > (SP) at the call site in the previous frame, as suggested by the DWARF > standard. Therefore the SP at call site can be unwound using an > implicitly assumed value offset from CFA rule with an offset of zero: > > .cfi_val_offset <SP>, 0 > > As a result the SP at call site computes as follows: > > SP = CFA > > Enable unwinding of user space for architectures, such as s390, which > define their CFA as the value of the SP at the call site in the previous > frame with an offset. Do so by enabling architectures to override the > default SP value offset from CFA of zero with an architecture-specific > one: > > .cfi_val_offset <SP>, offset > > So that the SP at call site computes as follows: > > SP = CFA + offset > > Signed-off-by: Jens Remus <[email protected]> Sashiko has reviewed this patch and found no issues. It looks great! -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=6