[TEST] Reduce crypto_sign_signature_internal stack usage
#791
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This was referenced Dec 15, 2025
Signed-off-by: Hanno Becker <beckphan@amazon.co.uk>
Signed-off-by: Hanno Becker <beckphan@amazon.co.uk>
crypto_sign_verify_internal stack: before: 26928/37232/49776 after: 22784/31040/41536 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
crypto_sign_verify_internal stack: 21743/30016/40515 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
crypto_sign_verify_internal stack: 17664/24864/33312 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
crypto_sign_verify_internal stack: 14592/19744/26144 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
crypto_sign_verify_internal stack: 13568/18720/25120 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
71168 -> 64000 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
64000 -> 55808 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
55808 -> 40448 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
40448 -> 34304 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Dec 30, 2025
Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
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Dec 31, 2025
Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
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Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
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Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
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Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). The computation of z is moved into a separate function (compute_pack_z) to vastly speed up the CBMC proofs. De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
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this pull request
Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Dec 31, 2025
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). The computation of z is moved into a separate function (compute_pack_z) to vastly speed up the CBMC proofs. De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
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Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). The computation of z is moved into a separate function (compute_pack_z) to vastly speed up the CBMC proofs. De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). The computation of z is moved into a separate function (compute_pack_z) to vastly speed up the CBMC proofs. De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). The computation of z is moved into a separate function (compute_pack_z) to vastly speed up the CBMC proofs. De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
mkannwischer
added a commit
that referenced
this pull request
Jan 3, 2026
This commit reduces the stack usage of signing by computing z = y + s1*cp incrementally (one polynomial at a time) allowing to eliminate the polyvecl z (at to cost of a single poly z). De-facto this saves L-1 KB irrespective of MLD_CONFIG_REDUCE_RAM. Practically, the same buffer was used early in the function too. Here we instead introduce a new polyvecl buffer tmp, but that can be placed in a union together with w1. Unfortuantely, with the current struct workaround for diffblue/cbmc#8813, this results in an increase in stack space by L KB. This gets eliminated when MLD_CONFIG_REDUCE_RAM is set. Hoisted out from #791 Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>
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