From nobody Mon Dec 15 21:42:46 2025 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 03B142248AE for ; Thu, 6 Feb 2025 06:15:21 +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=1738822522; cv=none; b=Cyc/RtBHnBcle2JkqTjwNoLxvZuOUtqjmbmGeqZU3TaoE2mKlfqPW1UTxgKQ9e/x4GJ9A2UmO3DNxxW+lwal1vp8Ry9A5oA4wCqSrlXakiCRggGMohwAVTtPBqR53R0a4PafRYgL0DW5UvJlgQiBuQLQ19lf2R1ojfr28e6m7qw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738822522; c=relaxed/simple; bh=v9imdnw1laUwcaZ0L7TzqeKruhJu/RKKPxXcWFCWS6k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Yg0HNopH97dEGAgkgZ+gyIWMm+pMLtiq5X/MzOhzwzFEqEtixvR2Y3Uv63x+HCVwkgMGLOEDXPjfrYRPMtAl4DjeqOzFNwFs3G/R6H6U9vNqDZB8lEWtMk0bo0RVKj3AuHi0e6zY5IAoxLl/7CDEMuG4KKprj2h21KmqTZa/lS0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vuq0xk1G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vuq0xk1G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35113C4CEE0; Thu, 6 Feb 2025 06:15:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738822521; bh=v9imdnw1laUwcaZ0L7TzqeKruhJu/RKKPxXcWFCWS6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vuq0xk1GFf7K7aLeK5IU/IWvtpIglV8lakjb0V1/ii6zxiXGBD7/syJXUxK25irCD iLncnsB2VIC+lM7KH0pa40jsRpBrHH4xRq4h7UeGVNck+6bFLUiZdQOXJxL7AHwzit mc1qT0ZG4agZsNnCC/uog9DbOayV7qesHAV1FG3A4B2dQ3KscqoMUeDSDkQ9sS4KFV yE7O7Ux7EBw1ZLLvXd1SENfTf1iaH7Fh0wvrfuRYu9h1dozqHbZ3wxkitTWgN52j5v LlNfVrlTyxwSeRZ4IRTNGSt7IEN6bwYhHFuPU1D7a8S3YmM4QSF9FXPB0Clld9tlmh t1ZkiV4Tmwafg== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Davidlohr Bueso , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/4] mm/madvise: split out mmap locking operations for madvise() Date: Wed, 5 Feb 2025 22:15:14 -0800 Message-Id: <20250206061517.2958-2-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250206061517.2958-1-sj@kernel.org> References: <20250206061517.2958-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Split out the madvise behavior-dependent mmap_lock operations from do_madvise(), for easier reuse of the logic in an upcoming change. Reviewed-by: Shakeel Butt Reviewed-by: Lorenzo Stoakes Reviewed-by: Davidlohr Bueso Signed-off-by: SeongJae Park Reviewed-by: Liam R. Howlett --- mm/madvise.c | 45 ++++++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 13 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index c8e28d51978a..df5a87a1846a 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1567,6 +1567,33 @@ int madvise_set_anon_name(struct mm_struct *mm, unsi= gned long start, madvise_vma_anon_name); } #endif /* CONFIG_ANON_VMA_NAME */ + +static int madvise_lock(struct mm_struct *mm, int behavior) +{ + +#ifdef CONFIG_MEMORY_FAILURE + if (behavior =3D=3D MADV_HWPOISON || behavior =3D=3D MADV_SOFT_OFFLINE) + return 0; +#endif + + if (madvise_need_mmap_write(behavior)) { + if (mmap_write_lock_killable(mm)) + return -EINTR; + } else { + mmap_read_lock(mm); + } + return 0; + +} + +static void madvise_unlock(struct mm_struct *mm, int behavior) +{ + if (madvise_need_mmap_write(behavior)) + mmap_write_unlock(mm); + else + mmap_read_unlock(mm); +} + /* * The madvise(2) system call. * @@ -1643,7 +1670,6 @@ int do_madvise(struct mm_struct *mm, unsigned long st= art, size_t len_in, int beh { unsigned long end; int error; - int write; size_t len; struct blk_plug plug; =20 @@ -1665,19 +1691,15 @@ int do_madvise(struct mm_struct *mm, unsigned long = start, size_t len_in, int beh if (end =3D=3D start) return 0; =20 + error =3D madvise_lock(mm, behavior); + if (error) + return error; + #ifdef CONFIG_MEMORY_FAILURE if (behavior =3D=3D MADV_HWPOISON || behavior =3D=3D MADV_SOFT_OFFLINE) return madvise_inject_error(behavior, start, start + len_in); #endif =20 - write =3D madvise_need_mmap_write(behavior); - if (write) { - if (mmap_write_lock_killable(mm)) - return -EINTR; - } else { - mmap_read_lock(mm); - } - start =3D untagged_addr_remote(mm, start); end =3D start + len; =20 @@ -1694,10 +1716,7 @@ int do_madvise(struct mm_struct *mm, unsigned long s= tart, size_t len_in, int beh } blk_finish_plug(&plug); =20 - if (write) - mmap_write_unlock(mm); - else - mmap_read_unlock(mm); + madvise_unlock(mm, behavior); =20 return error; } --=20 2.39.5 From nobody Mon Dec 15 21:42:46 2025 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 4ED36224B04 for ; Thu, 6 Feb 2025 06:15:23 +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=1738822524; cv=none; b=ITL9nRHKZ7auf4xAApAJgghyFc2yhISUWktIw/DAF2JRs2IM/ujdll5JEaeCM3fEKCy8CikNbwistWgXBjx35oYnYGKYM1ZPvG83snahVQbFfKc7RMDanvB4+NBMxjQ/YxDzwANsDI10rYA+Ma2KbEUjvu2k55TrYjeXdYT6AJA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738822524; c=relaxed/simple; bh=mfBMQDGwCijsuSEaM5RCGlWQCxDRxNtkNxhQORCqX0Y=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ECys4QKAwbePByAcUfhiBTg5oLK0XTrsriP5EP1AifhpfrYgQyd34HuQEOIM0I+uviXslqmlb95Hp0HFbp7Z9lVtSA+gW6z7jqLQ1Q5NEHesS0Zj9OXenr0ZHam6/GdrE5/ahXzle8ALKyMGB1Bqb6VOJgKFMWesHJvWwvwlNOU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E1xkWOmc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="E1xkWOmc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BACD7C4CEE5; Thu, 6 Feb 2025 06:15:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738822523; bh=mfBMQDGwCijsuSEaM5RCGlWQCxDRxNtkNxhQORCqX0Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E1xkWOmctRFfUviRHAuoF/YWqqtLhCLSeVJMBCIZ5GOfqX1Em3z6RE1AsxPdoFvDD DcmtmDzLgBMTvvl9UJA+Jpmt30YKmA5ghNeJS2A6DqzlEe5dDoE7SVFsK1znh2SXXT m8kJckllh6o8rTjHTiWiWPNXY3TwvPqqeRkdlvE+X0eUk1rxbmFdJZ0d7CXqty/uXB 5vk5WFGbcI9uK2h/3oAZu064VNDhZGcd6TYV76rphB8u6smNhIJBi6Npo6PCYlWj02 1vcsPrkLrYI7Gp5UPuIGgBGedOPuWnhC4dxe6EWSGe+Gxxj6S3PhBWLyYVz4sV36CU 2vGrcVjrwY5IA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Davidlohr Bueso , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/4] mm/madvise: split out madvise input validity check Date: Wed, 5 Feb 2025 22:15:15 -0800 Message-Id: <20250206061517.2958-3-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250206061517.2958-1-sj@kernel.org> References: <20250206061517.2958-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Split out the madvise parameters validation logic from do_madvise(), for easy reuse of the logic from a future change. Reviewed-by: Shakeel Butt Reviewed-by: Lorenzo Stoakes Reviewed-by: Davidlohr Bueso Signed-off-by: SeongJae Park Reviewed-by: Liam R. Howlett --- mm/madvise.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index df5a87a1846a..efab2878be7c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1594,6 +1594,27 @@ static void madvise_unlock(struct mm_struct *mm, int= behavior) mmap_read_unlock(mm); } =20 +static bool is_valid_madvise(unsigned long start, size_t len_in, int behav= ior) +{ + size_t len; + + if (!madvise_behavior_valid(behavior)) + return false; + + if (!PAGE_ALIGNED(start)) + return false; + len =3D PAGE_ALIGN(len_in); + + /* Check to see whether len was rounded up from small -ve to zero */ + if (len_in && !len) + return false; + + if (start + len < start) + return false; + + return true; +} + /* * The madvise(2) system call. * @@ -1673,20 +1694,11 @@ int do_madvise(struct mm_struct *mm, unsigned long = start, size_t len_in, int beh size_t len; struct blk_plug plug; =20 - if (!madvise_behavior_valid(behavior)) + if (!is_valid_madvise(start, len_in, behavior)) return -EINVAL; =20 - if (!PAGE_ALIGNED(start)) - return -EINVAL; len =3D PAGE_ALIGN(len_in); - - /* Check to see whether len was rounded up from small -ve to zero */ - if (len_in && !len) - return -EINVAL; - end =3D start + len; - if (end < start) - return -EINVAL; =20 if (end =3D=3D start) return 0; --=20 2.39.5 From nobody Mon Dec 15 21:42:46 2025 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 98404224B13 for ; Thu, 6 Feb 2025 06:15:25 +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=1738822525; cv=none; b=DLA+SS9NcFDjJ+HQCoOvRybrLuI4LH5Rd+wiTfXIODpxTXNFKixnQlXWK8pS+Z9/clxI98o8vD327iAHiBB/+Ck+EA3R6ZBtr+qz+mBup8MhuMquyMFmtsxEx/fHGifddCaPZtonRbNHUqaX2MLMLvuFR+yS5d4qj8Iq71z5gLU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738822525; c=relaxed/simple; bh=+hjnCmx0FZ2b8X/9Br4bzXPNjaytMayZsysgOyR4ceE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=F4qaHgSUWkkajvwCu8zc9gXFmJHzUXBNHfBhgo6K2lSpq2YMeEYsWFaFMyc1e2lDA5LyOM6sBFY7UOhWPezBljxgUFL3UU6y3yjvdwAWrRjKLeEPejwWIJyo+lakHPiHHBqf96jteTR3LPs3aUDU4QLp19C/208gO/p6WmV2N/o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K/3arlxO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="K/3arlxO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C383CC4CEE5; Thu, 6 Feb 2025 06:15:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738822525; bh=+hjnCmx0FZ2b8X/9Br4bzXPNjaytMayZsysgOyR4ceE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K/3arlxOqIDaHiwNUfUWykQ8SDElT+W0dUaWTeLY7i0YEUNiktTduB7k3yK4gEaYf oK6SlGmzF25bAPkjWNd5Pqb4UF2JHmWaQRzVkvQ0HuA4br4Sqxqje2aWCdixuhjB+i KBm6fYYCM1QN2ZH7n4XXqvyITFZXT/aXmhx9oHtmuHlGBgYUqz5WXklyQ0nV1474md OsTGJV6+mPIVG3xq3BifF/4vf6+6hYpkg4mSZVve9pXPTG0zH94YvSTHv0guey0axZ yIM5ieBVsnOCNHth37flLuikLX6fnuHjDaQH10yps+aBuYBdimQCS645z/lHJlsDQT /58KitQjTM5fg== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Davidlohr Bueso , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 3/4] mm/madvise: split out madvise() behavior execution Date: Wed, 5 Feb 2025 22:15:16 -0800 Message-Id: <20250206061517.2958-4-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250206061517.2958-1-sj@kernel.org> References: <20250206061517.2958-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Split out the madvise behavior applying logic from do_madvise() to make it easier to reuse from the following change. Reviewed-by: Shakeel Butt Reviewed-by: Lorenzo Stoakes Signed-off-by: SeongJae Park Reviewed-by: Liam R. Howlett --- mm/madvise.c | 53 +++++++++++++++++++++++++++++----------------------- 1 file changed, 30 insertions(+), 23 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index efab2878be7c..31e5df75b926 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1615,6 +1615,35 @@ static bool is_valid_madvise(unsigned long start, si= ze_t len_in, int behavior) return true; } =20 +static int madvise_do_behavior(struct mm_struct *mm, + unsigned long start, size_t len_in, size_t len, int behavior) +{ + struct blk_plug plug; + unsigned long end; + int error; + +#ifdef CONFIG_MEMORY_FAILURE + if (behavior =3D=3D MADV_HWPOISON || behavior =3D=3D MADV_SOFT_OFFLINE) + return madvise_inject_error(behavior, start, start + len_in); +#endif + start =3D untagged_addr_remote(mm, start); + end =3D start + len; + + blk_start_plug(&plug); + switch (behavior) { + case MADV_POPULATE_READ: + case MADV_POPULATE_WRITE: + error =3D madvise_populate(mm, start, end, behavior); + break; + default: + error =3D madvise_walk_vmas(mm, start, end, behavior, + madvise_vma_behavior); + break; + } + blk_finish_plug(&plug); + return error; +} + /* * The madvise(2) system call. * @@ -1692,7 +1721,6 @@ int do_madvise(struct mm_struct *mm, unsigned long st= art, size_t len_in, int beh unsigned long end; int error; size_t len; - struct blk_plug plug; =20 if (!is_valid_madvise(start, len_in, behavior)) return -EINVAL; @@ -1706,28 +1734,7 @@ int do_madvise(struct mm_struct *mm, unsigned long s= tart, size_t len_in, int beh error =3D madvise_lock(mm, behavior); if (error) return error; - -#ifdef CONFIG_MEMORY_FAILURE - if (behavior =3D=3D MADV_HWPOISON || behavior =3D=3D MADV_SOFT_OFFLINE) - return madvise_inject_error(behavior, start, start + len_in); -#endif - - start =3D untagged_addr_remote(mm, start); - end =3D start + len; - - blk_start_plug(&plug); - switch (behavior) { - case MADV_POPULATE_READ: - case MADV_POPULATE_WRITE: - error =3D madvise_populate(mm, start, end, behavior); - break; - default: - error =3D madvise_walk_vmas(mm, start, end, behavior, - madvise_vma_behavior); - break; - } - blk_finish_plug(&plug); - + error =3D madvise_do_behavior(mm, start, len_in, len, behavior); madvise_unlock(mm, behavior); =20 return error; --=20 2.39.5 From nobody Mon Dec 15 21:42:46 2025 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 A401F2253EB for ; Thu, 6 Feb 2025 06:15:26 +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=1738822526; cv=none; b=oAWkh7PFvyJP3RJ5hLzxketvjuSnChwwT8YdPTDi9xiRQBcQi6Kp4bFgx81eg9XV0MRYwHM+jlsr2Xo0Dc11V862rDPqsUH1ldO77ockxmmkgahh3TLXza4iL4obWmlIkCQPGx20RgCN96lOAWdB6RPdL9glFmZ1M1obrW+dX60= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738822526; c=relaxed/simple; bh=MP/17pf09yAFjnq6HfK1rSNsdKEXlrcNK/A1rjmLh9Y=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XFmwz9ImJdGaWghZqV/31fkrtmYZoHqHmE06CqRBRzq6l9jKTs6vuOE9qLnKW2muhBPWo6IJicCKd0VYIMXHPkQWVgkch3PQn5q12+O0iUvPZKISAW6GePSMijrwnyydsMa27QGM465306WgbE3sV0rhHaQaoOeJQ6Xgj/RjqUU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AeS+zBDr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AeS+zBDr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5517C4CEE7; Thu, 6 Feb 2025 06:15:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738822526; bh=MP/17pf09yAFjnq6HfK1rSNsdKEXlrcNK/A1rjmLh9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AeS+zBDrcocIE5whSD/5gWTiHktVgl4p1z2AIiKeTcCh7xmQYLD+OXL/RaZfFtNcu hV1sCJcNigWgqPbttaPV4aOO1TIGzB6zT9MtTB+m3BwqfA2+u4O+xc8GLeo8W9DGds x/93/07bnlYUuqh3x8jnyxl6WwwrXLZigIC2mljeqwpA2HmsX3TgbDO+Cm91Gdq4C+ cBU/LRxPoRAAuv426uEieDoORu6nhMXi7jb0qNlNssLt7jWZwV6J4rVPBQ5G9ittRh Sb1TCC8ZuELFpKY3xHwi1CO6RGRYiv1weim8TPZB9h22iVgvfa+V83ScIn6iNEVS0V URqSXH8iKa+hg== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Davidlohr Bueso , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 4/4] mm/madvise: remove redundant mmap_lock operations from process_madvise() Date: Wed, 5 Feb 2025 22:15:17 -0800 Message-Id: <20250206061517.2958-5-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250206061517.2958-1-sj@kernel.org> References: <20250206061517.2958-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Optimize redundant mmap lock operations from process_madvise() by directly doing the mmap locking first, and then the remaining works for all ranges in the loop. Reviewed-by: Shakeel Butt Signed-off-by: SeongJae Park Reviewed-by: Liam R. Howlett Reviewed-by: Lorenzo Stoakes --- mm/madvise.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 31e5df75b926..5a0a1fc99d27 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1754,9 +1754,26 @@ static ssize_t vector_madvise(struct mm_struct *mm, = struct iov_iter *iter, =20 total_len =3D iov_iter_count(iter); =20 + ret =3D madvise_lock(mm, behavior); + if (ret) + return ret; + while (iov_iter_count(iter)) { - ret =3D do_madvise(mm, (unsigned long)iter_iov_addr(iter), - iter_iov_len(iter), behavior); + unsigned long start =3D (unsigned long)iter_iov_addr(iter); + size_t len_in =3D iter_iov_len(iter); + size_t len; + + if (!is_valid_madvise(start, len_in, behavior)) { + ret =3D -EINVAL; + break; + } + + len =3D PAGE_ALIGN(len_in); + if (start + len =3D=3D start) + ret =3D 0; + else + ret =3D madvise_do_behavior(mm, start, len_in, len, + behavior); /* * An madvise operation is attempting to restart the syscall, * but we cannot proceed as it would not be correct to repeat @@ -1772,12 +1789,17 @@ static ssize_t vector_madvise(struct mm_struct *mm,= struct iov_iter *iter, ret =3D -EINTR; break; } + + /* Drop and reacquire lock to unwind race. */ + madvise_unlock(mm, behavior); + madvise_lock(mm, behavior); continue; } if (ret < 0) break; iov_iter_advance(iter, iter_iov_len(iter)); } + madvise_unlock(mm, behavior); =20 ret =3D (total_len - iov_iter_count(iter)) ? : ret; =20 --=20 2.39.5