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Sridhar" Cc: hannes@cmpxchg.org, nphamcs@gmail.com, chengming.zhou@linux.dev, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, herbert@gondor.apana.org.au, senozhatsky@chromium.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 28774180008 X-Stat-Signature: iys5s9ynfiw9ydsjwuxbaw75kq5f76x4 X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1774984988-388230 X-HE-Meta: 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 RQr9xROy 12A00NbkPIAjgw6xjlV7+1FjyhYrV6Hge+MgIwVWk2+2sQjqmbNSYuexvb3W1mtGJWY2sdto6Bs/N1ss6vTarzvbIHWz34mZjWfri/pssN8JlWzfDULbNxrAsj4ivSU19Hqg63ZT/RiMmPeLxqwZaV6UeM5sJFYmArjpcJSaUeIYy8TfC3JgQPDvR2T8PgNlNSTUepvtuXGzT1RjWKQ3TKwyV34vIGIfutCWTiLcTkIdrVCXoQPt5X5C32mccL1wTfQC5IUVyz8/aKGI5MZifwsyUq0tcQ+VCqbnvJ7vo0Jw6nfoZfpJ3scQgGKauALuwM7Knc7STQ5w778KsB3s8XMXle6TCEvXY0FuQYbwGUKB0Rv4ifkLU7905dYXdyivqbeO0yzhpeKL/4uLa32ffzXSvKimO2pVB2sKJVZmv7dtsEgKe0YPpIMZOfQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Mar 31, 2026 at 11:34=E2=80=AFAM Kanchana P. Sridhar wrote: > > This patchset first removes redundant checks on the acomp_ctx and its > "req" member in zswap_cpu_comp_dead(). > > Next, it persists the zswap pool's per-CPU acomp_ctx resources to > last until the pool is destroyed. It then simplifies the per-CPU > acomp_ctx mutex locking in zswap_compress()/zswap_decompress(). > > Code comments added after allocation and before checking to deallocate > the per-CPU acomp_ctx's members, based on expected crypto API return > values and zswap changes this patchset makes. > > Patch 2 is an independent submission of patch 23 from [1], to > facilitate merging. > > [1]: https://patchwork.kernel.org/project/linux-mm/list/?series=3D1046677 > > Changes since v2: > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > 1) Rebased to mm-unstable as of 3-31-2026 (commit 24e341657c28). > 2) Collected Acks. > > Changes since v1: > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > 1) Made the changes to eliminate redundant checks on > acomp_ctx/acomp_ctx->req in zswap_cpu_comp_dead(), per Yosry. > 2) Renamed acomp_ctx_dealloc() to acomp_ctx_free(), per Yosry. > 3) Incorporated suggestions from Yosry and Sashiko to reset the > acomp_ctx's members to NULL after freeing them, to prevent UAF and > double free issues. > 4) Replaced v1's patch 2 with v2's patch 1. > > > Kanchana P. Sridhar (2): > mm: zswap: Remove redundant checks in zswap_cpu_comp_dead(). > mm: zswap: Tie per-CPU acomp_ctx lifetime to the pool. Sashiko was able to apply the patches and doesn't seem to find any regressions: https://sashiko.dev/#/patchset/20260331183351.29844-1-kanchana= psridhar2026%40gmail.com.