From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96CBC24EAB1 for ; Sun, 29 Mar 2026 00:41:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774744860; cv=none; b=TIMUpx4jspoCmBrU+x8NuykdwllEbz0km8JXk3wjAePGhruX6Y2Lmo3wDnFB0wAyVtXBmrq8skvqnzRp8q9oMnzZwn8PILU7BcX2o63eozsS3uAof5GztiDmFlKVoQe7TWf79566145M94Pm/6vu1W0xp7vCA31TljFEEmKo9R4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774744860; c=relaxed/simple; bh=3o+0IiLnmhJdENB05HNAvCGiyEWEWXQHc4t0uepg1PM=; h=Date:To:From:Subject:Message-Id; b=SY8yCL46L81+n32/Ud5la+H1odYBIlnttVpSl6QcNUVGlnPOuK5DGgNO6AWWpNFASsYJCRduTT2JgQcuTkb6dI2rQ5yEb2oyrDIE1eSVjBCQ8G4ZnFebLxpmSpuREDnw2RWbOq5ZwfghW2LmKHuUIfUhQoxaX3XLNoOrBoc9/ck= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=HMgsepPX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="HMgsepPX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70992C4CEF7; Sun, 29 Mar 2026 00:41:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774744860; bh=3o+0IiLnmhJdENB05HNAvCGiyEWEWXQHc4t0uepg1PM=; h=Date:To:From:Subject:From; b=HMgsepPXrl7wXMigDgQ4tpzSwj9My+PkJzbp0+WW82JUdUszHvozsCt7J/YxqbYuw 9vwT5xK5O3NzFa1FjqMPgQt47r92JdRTr7XzNJpUp8eIO5pC0ClwT22BEHdiSvagxb q0bSDrAbYPqGCD7/qHExSPRzDuEeTWDSRPwPg1E4= Date: Sat, 28 Mar 2026 17:40:59 -0700 To: mm-commits@vger.kernel.org,minchan@kernel.org,gaoxu2@honor.com,bgeffon@google.com,axboe@kernel.dk,senozhatsky@chromium.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] zram-unify-and-harden-algo-priority-params-handling.patch removed from -mm tree Message-Id: <20260329004100.70992C4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: zram: unify and harden algo/priority params handling has been removed from the -mm tree. Its filename was zram-unify-and-harden-algo-priority-params-handling.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sergey Senozhatsky Subject: zram: unify and harden algo/priority params handling Date: Wed, 11 Mar 2026 17:42:49 +0900 We have two functions that accept algo= and priority= params - algorithm_params_store() and recompress_store(). This patch unifies and hardens handling of those parameters. There are 4 possible cases: - only priority= provided [recommended] We need to verify that provided priority value is within permitted range for each particular function. - both algo= and priority= provided We cannot prioritize one over another. All we should do is to verify that zram is configured in the way that user-space expects it to be. Namely that zram indeed has compressor algo= setup at given priority=. - only algo= provided [not recommended] We should lookup priority in compressors list. - none provided [not recommended] Just use function's defaults. Link: https://lkml.kernel.org/r/20260311084312.1766036-7-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Suggested-by: Minchan Kim Cc: Brian Geffon Cc: gao xu Cc: Jens Axboe Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 106 +++++++++++++++++++------------- 1 file changed, 66 insertions(+), 40 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-unify-and-harden-algo-priority-params-handling +++ a/drivers/block/zram/zram_drv.c @@ -1619,6 +1619,37 @@ static void zram_debugfs_register(struct static void zram_debugfs_unregister(struct zram *zram) {}; #endif +/* Only algo parameter given, lookup by algo name */ +static int lookup_algo_priority(struct zram *zram, const char *algo, + u32 min_prio) +{ + s32 prio; + + for (prio = min_prio; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + if (!strcmp(zram->comp_algs[prio], algo)) + return prio; + } + + return -EINVAL; +} + +/* Both algo and priority parameters given, validate them */ +static int validate_algo_priority(struct zram *zram, const char *algo, u32 prio) +{ + if (prio >= ZRAM_MAX_COMPS) + return -EINVAL; + /* No algo at given priority */ + if (!zram->comp_algs[prio]) + return -EINVAL; + /* A different algo at given priority */ + if (strcmp(zram->comp_algs[prio], algo)) + return -EINVAL; + return 0; +} + static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg) { zram->comp_algs[prio] = alg; @@ -1691,6 +1722,7 @@ static ssize_t algorithm_params_store(st char *args, *param, *val, *algo = NULL, *dict_path = NULL; struct deflate_params deflate_params; struct zram *zram = dev_to_zram(dev); + bool prio_param = false; int ret; deflate_params.winbits = ZCOMP_PARAM_NOT_SET; @@ -1703,6 +1735,7 @@ static ssize_t algorithm_params_store(st return -EINVAL; if (!strcmp(param, "priority")) { + prio_param = true; ret = kstrtoint(val, 10, &prio); if (ret) return ret; @@ -1738,24 +1771,22 @@ static ssize_t algorithm_params_store(st if (init_done(zram)) return -EBUSY; - /* Lookup priority by algorithm name */ - if (algo) { - s32 p; - - prio = -EINVAL; - for (p = ZRAM_PRIMARY_COMP; p < ZRAM_MAX_COMPS; p++) { - if (!zram->comp_algs[p]) - continue; + if (prio_param) { + if (prio < ZRAM_PRIMARY_COMP || prio >= ZRAM_MAX_COMPS) + return -EINVAL; + } - if (!strcmp(zram->comp_algs[p], algo)) { - prio = p; - break; - } - } + if (algo && prio_param) { + ret = validate_algo_priority(zram, algo, prio); + if (ret) + return ret; } - if (prio < ZRAM_PRIMARY_COMP || prio >= ZRAM_MAX_COMPS) - return -EINVAL; + if (algo && !prio_param) { + prio = lookup_algo_priority(zram, algo, ZRAM_PRIMARY_COMP); + if (prio < 0) + return -EINVAL; + } ret = comp_params_store(zram, prio, level, dict_path, &deflate_params); return ret ? ret : len; @@ -2396,9 +2427,6 @@ static int recompress_slot(struct zram * void *src; int ret = 0; - if (!zram->comps[prio]) - return -EINVAL; - handle_old = get_slot_handle(zram, index); if (!handle_old) return -EINVAL; @@ -2500,10 +2528,11 @@ static ssize_t recompress_store(struct d char *args, *param, *val, *algo = NULL; u64 num_recomp_pages = ULLONG_MAX; struct zram_pp_ctl *ctl = NULL; - u32 prio = ZRAM_SECONDARY_COMP; - struct zram_pp_slot *pps; + s32 prio = ZRAM_SECONDARY_COMP; u32 mode = 0, threshold = 0; + struct zram_pp_slot *pps; struct page *page = NULL; + bool prio_param = false; ssize_t ret; args = skip_spaces(buf); @@ -2551,7 +2580,8 @@ static ssize_t recompress_store(struct d } if (!strcmp(param, "priority")) { - ret = kstrtouint(val, 10, &prio); + prio_param = true; + ret = kstrtoint(val, 10, &prio); if (ret) return ret; continue; @@ -2565,30 +2595,26 @@ static ssize_t recompress_store(struct d if (!init_done(zram)) return -EINVAL; - if (algo) { - bool found = false; - - for (; prio < ZRAM_MAX_COMPS; prio++) { - if (!zram->comp_algs[prio]) - continue; - - if (!strcmp(zram->comp_algs[prio], algo)) { - found = true; - break; - } - } + if (prio_param) { + if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS) + return -EINVAL; + } - if (!found) { - ret = -EINVAL; - goto out; - } + if (algo && prio_param) { + ret = validate_algo_priority(zram, algo, prio); + if (ret) + return ret; } - if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS) { - ret = -EINVAL; - goto out; + if (algo && !prio_param) { + prio = lookup_algo_priority(zram, algo, ZRAM_SECONDARY_COMP); + if (prio < 0) + return -EINVAL; } + if (!zram->comps[prio]) + return -EINVAL; + page = alloc_page(GFP_KERNEL); if (!page) { ret = -ENOMEM; _ Patches currently in -mm which might be from senozhatsky@chromium.org are