checkpoint: riscv64 post-merge review follow-ups - #203
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The riscv64 sc_fpregs memcpy carries no bound of its own: it is safe only because validate rejects fpstate_len > FP_MAX and FP_MAX (516) happens to fit the 528-byte field. Nothing enforced that relation, so raising FP_MAX or shrinking the struct would silently turn the copy into a stack overflow inside the signal frame. Assert it at the struct definition, next to the copy it protects. Signed-off-by: Cong Wang <cwang@multikernel.io>
Capture and rearm_restartable_syscall each carried their own copy of the sentinel check plus a near-identical multi-line error, and the two messages had already drifted. Route both through one helper so the check and its wording cannot diverge again. Signed-off-by: Cong Wang <cwang@multikernel.io>
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@sachin2605 Please take a look. Thanks |
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Two follow-ups from the post-merge review of #192.
Assert FP_MAX fits sc_fpregs in the restore stub. The riscv64 sc_fpregs memcpy has no bound of its own: it is safe because validate rejects fpstate_len > FP_MAX and FP_MAX (516) fits the 528-byte field, but nothing enforced that relation. Raising FP_MAX or shrinking the struct would silently turn the copy into a stack overflow inside the signal frame, so a _Static_assert now pins it at the struct definition.
Share the riscv64 restart-sentinel rejection. Capture and rearm_restartable_syscall each carried their own copy of the sentinel check plus a near-identical multi-line error, and the two messages had already drifted. Both now route through one reject_restart_sentinel helper so the check and its wording cannot diverge again.
Verified locally: the stub compiles for riscv64 (clang -fsyntax-only cross-check, which also proves the assert holds) and the 38 checkpoint lib tests pass on x86_64. The riscv64 Rust paths rely on the cross-build CI job, as usual on this machine.