From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 90E934A3851; Tue, 15 Sep 2026 11:33:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789472014; cv=none; b=ej8NPyImHKyRBLMCkQhhirVVNE9H4+64KuGN3/oCHYvA9ojR2FAkIl8AYb1JTdjeuurKkkQWwaAunzZTIWpJNKM2hl3x+MP80BUTOctrjCmfp0f82vaavmsks2rWAA3upYkPn/IrA3h5aDmN0N0kJ3sB+ieVnhG2PL62n0f9aUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789472014; c=relaxed/simple; bh=S9sXo+/yQO9aORTIGU5zP9aw99mbVPSatnA1JIW5H/M=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=a9/8MhcZOBXgS//8q3N0Lh0uHQSKN0dfp+oGR6Fg5ssdqx0FTkDS3KlGnSec7n1ATKfgbKYhwdGwnw2Vomg1lnJL8dDXR8ehbNbc4A8k9kcqAXG3MNslgc9JmxCGSMCNRm+hrVhIwCH18lwgaG4K050w1wLkhqwIi9fa2H3LAiM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jUmSavNi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jUmSavNi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E8D71F00898; Tue, 15 Sep 2026 11:33:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789472011; bh=LsNpEFA01NMLmoDGH+WQ2k5w2caYKI3aFXCKnW6fq4M=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=jUmSavNiamqp7sEiSGUpt1XZfKBJkPkcG/PFCGuuE8ULC/JC+9Uv/jivWwgpx6a/O ndFuFYQRnEyeD6+NTxQCHA1WQfYk7Jmw39axkxPneZ0ZlWHflWnPtQntegHAjSQOHr qvPuy2KIMTAU8QpGMIZajMcBNJZLx1KDydcGwu/7Fq4Sm2suht1GMp/5OShBghjByJ Wo0vc/D/MORpmKTNOKDNlY4+TTriFUPTu4Y02yC+j0UyASaEIruvlKlSwBV+MXdIZL vi9GUupn2o56nWtYus7diY/kBIvVMBlvyHSKLH2hV7NTFX1VBgWRv0lAAGJXCHoiGT eaCHwlU6HAvXg== From: Christian Brauner Date: Tue, 15 Sep 2026 13:31:03 +0200 Subject: [PATCH RFC POC 17/50] um: commit fds on syscall exit Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260915-work-fd-reserve-unify-folded-v1-17-4d5217d6b246@kernel.org> References: <20260915-work-fd-reserve-unify-folded-v1-0-4d5217d6b246@kernel.org> In-Reply-To: <20260915-work-fd-reserve-unify-folded-v1-0-4d5217d6b246@kernel.org> To: Linus Torvalds Cc: Alexander Viro , Jann Horn , Jan Kara , Ingo Molnar , Peter Zijlstra , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Oleg Nesterov , linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, Jens Axboe , io-uring@vger.kernel.org, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-gpio@vger.kernel.org, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, bpf@vger.kernel.org, David Airlie , virtualization@lists.linux.dev, kvm@vger.kernel.org, kexec@lists.infradead.org, linux-hyperv@vger.kernel.org, "Christian Brauner (Amutable)" X-Mailer: b4 0.17-dev-db0b7 X-Developer-Signature: v=1; a=openpgp-sha256; l=1865; i=brauner@kernel.org; h=from:subject:message-id; bh=S9sXo+/yQO9aORTIGU5zP9aw99mbVPSatnA1JIW5H/M=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWSt1KldP/NzGWPyQ7vZ1w8Z91Y4Xry4dOW/w5ekHD1Nn i1f3lHo1FHKwiDGxSArpsji0G4SLrecp2KzUaYGzBxWJpAhDFycAjCRnzMY/tdevWsc17Pol1js drW1Ndl3Uj4rJ6jNqM1Qvbkzdcr/kFkM//PT/U4ukVght9Iz6NLyeqmVG29b1dz/x+3x4GR56M6 Uan4A X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Add TIF_FD_SLOTS. handle_syscall() calls syscall_trace_leave() after every system call, so test the flag there and commit the reservations before audit and the ptrace exit stop. Signed-off-by: Christian Brauner (Amutable) --- arch/um/include/asm/thread_info.h | 2 ++ arch/um/kernel/ptrace.c | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h index 7a6f4dc99fa1..7140516ee0b6 100644 --- a/arch/um/include/asm/thread_info.h +++ b/arch/um/include/asm/thread_info.h @@ -44,6 +44,7 @@ struct thread_info { #define TIF_SECCOMP 9 /* secure computing */ #define TIF_SINGLESTEP 10 /* single stepping userspace */ #define TIF_SYSCALL_TRACEPOINT 11 /* syscall tracepoint instrumentation */ +#define TIF_FD_SLOTS 12 /* syscall prepared descriptors */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) @@ -55,6 +56,7 @@ struct thread_info { #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SECCOMP (1 << TIF_SECCOMP) #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) +#define _TIF_FD_SLOTS (1 << TIF_FD_SLOTS) #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL | \ _TIF_NOTIFY_RESUME) diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 7da0a5223aa6..f1f89181fb7e 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -4,6 +4,7 @@ */ #include +#include #include #include #include @@ -142,6 +143,9 @@ void syscall_trace_leave(struct pt_regs *regs) { int ptraced = current->ptrace; + if (test_thread_flag(TIF_FD_SLOTS)) + fd_slots_commit(regs); + audit_syscall_exit(regs); /* Fake a debug trap */ -- 2.53.0