Skip to content

Conversation

@pull
Copy link

@pull pull bot commented Jan 2, 2026

See Commits and Changes for more details.


Created by pull[bot] (v2.0.0-alpha.4)

Can you help keep this open source service alive? 💖 Please sponsor : )

Recently, the addition of some vector register save restore logic from:
#28990

Triggered an issue in our quic_multistream_test, notably causing a
connection shutdown with error code 1, rather than successful
completion.

The problem has been root caused to an error in how the ppc aes code
saves and restores vector registers.

The aes gcm code uses VSR instructions (vsldoi, etc), to maniuplate
vector registers, which only operate on the upper half of the vector
register file (VS32-63), and operands are implicitly offset to do this.
(i.e. <instr> v31 actually operates on register vs63).

However, the SAVE/RESTORE macros which save and restore those values use
stxv/lxv instructions to do the save and restore, which are VSX
instructions that have access to the full vector register file, and so
by restoring V1, rather than V33, etc, we actuall restore values to the
wrong registers, causing various issues (most notably the above
misconfiguration of the quic SSL shutdown event, which sets the error
code erroneously to 1 instead of the expected 0 value).

Fix it by offsetting the SAVE_REGS and RESTORE_REGS macros to reference
the proper registers when doing save and restore.

Fixes #29516

Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from #29528)
@pull pull bot locked and limited conversation to collaborators Jan 2, 2026
@pull pull bot added the ⤵️ pull label Jan 2, 2026
@pull pull bot merged commit 441a2c1 into All-Blockchains:master Jan 2, 2026
76 of 89 checks passed
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant