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 B694649DBAA; Tue, 15 Sep 2026 11:32:14 +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=1789471936; cv=none; b=CjW7fyiugtGAGtyRHZLJ4pMytXcL1Iu1HnqsGQ6fTCf7SQ0xtzWq5U/0cgkEF3k4OMFtqULWe0RFpQtOJ4Cc0AB6q8wNSvtIWBpy1sLilYnA1+vLyBRJc577XTBFhcdyBnm7ZLFhTE/fPCZ6U0T7K7kWcSiCsOaEMCUscIPEzac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789471936; c=relaxed/simple; bh=a9znqAkO+hvOtZefxwIBQ5T2UBtQYyo8n09NKXNA7dw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bcnmGEq/gJOESOg0YH7Khy8f2bQJO+8UVDWC9kdZO+kEe1y9GLsuL7Ea5QOfR7rwnfHj25nr0kGnfOsZaRkgiPd6jBlgXzZPlMY1lL6uDzj153rPekV2sgCb6vc6bYRJhkZyERG04/Nyu6SRvaSB3u0FJPgMFT9vlS7UVRItbmE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GUEfB7kz; 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="GUEfB7kz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FD8B1F000FF; Tue, 15 Sep 2026 11:32:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789471934; bh=E/WcE2lGsMFSob/cBMgO+hea6aPl2xaxNOKxSHdhki0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=GUEfB7kz965znZtfpHqb8eIiCiLO6486hnBmkQwRyzaxNwEFt42WOgfKGny2AO9jY DpqE0IKoYZQ3CDqUbNbcjMdJnHniI4Fwuvms6GgbMB9wf1VAHv7229/U9I1vFe9NJ2 qY36omvqqIoX9NFkJOdvBvJQPo9mZFT+l30lGkj4F5tMWGVWdBHQTO1lqNMxuFrqVO OfO8kqQ7j1k9tC1TlYJ8bqUqsF+G/mO7jEhf7l0Ip9oOnDoxcn+y9v2WqMllKuuodC iV25Lg90bMELqmrBnnnzxEgH4HOX9MN+zPjb9ZEZ2BQQYFgld28sSUlqTUgIhK2Mo5 y/yD7KaWeZ/WQ== From: Christian Brauner Date: Tue, 15 Sep 2026 13:30:53 +0200 Subject: [PATCH RFC POC 07/50] csky: commit fds on syscall exit Precedence: bulk X-Mailing-List: netdev@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-v1-7-4d5217d6b246@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=2976; i=brauner@kernel.org; h=from:subject:message-id; bh=a9znqAkO+hvOtZefxwIBQ5T2UBtQYyo8n09NKXNA7dw=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWSt1KmReJL5+9/LafuaZn07vvD2NNsTS/r9pju0zTneI MsZ4PDocUcpC4MYF4OsmCKLQ7tJuNxynorNRpkaMHNYmUCGMHBxCsBE4p0Z/vsI/l1WJ+2YWb1+ rv5bmZs79nw5b7JPKv5J5eJeHt8sXQeG/zUtrlyha6a8POM74Rhn8++6CEYXZZkjm45o/epqCbm 3lRkA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Add TIF_FD_SLOTS and test it after the untraced system call has stored its return value. A task that reserved descriptors joins the traced path, where syscall_trace_exit() commits them before audit and the ptrace exit stop. Signed-off-by: Christian Brauner (Amutable) --- arch/csky/include/asm/thread_info.h | 2 ++ arch/csky/kernel/entry.S | 9 +++++++++ arch/csky/kernel/ptrace.c | 4 ++++ 3 files changed, 15 insertions(+) diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index fdd4f8ad45ac..59109ce64695 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -61,6 +61,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SYSCALL_TRACEPOINT 5 /* syscall tracepoint instrumentation */ #define TIF_SYSCALL_AUDIT 6 /* syscall auditing */ #define TIF_NOTIFY_SIGNAL 7 /* signal notifications exist */ +#define TIF_FD_SLOTS 8 /* syscall prepared descriptors */ #define TIF_POLLING_NRFLAG 16 /* poll_idle() is TIF_NEED_RESCHED */ #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */ @@ -73,6 +74,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) +#define _TIF_FD_SLOTS (1 << TIF_FD_SLOTS) #define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_MEMDIE (1 << TIF_MEMDIE) diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 3261f46f2244..6ff3074b9787 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -80,6 +80,15 @@ ENTRY(csky_systemcall) jsr syscallid #endif stw a0, (sp, LSAVE_A0) /* Save return value */ + /* descriptors reserved by the syscall are committed in syscall_trace_exit() */ + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r10, (r9, TINFO_FLAGS) + lrw r9, _TIF_FD_SLOTS + and r10, r9 + cmpnei r10, 0 + bt 1f jmpi ret_from_exception csky_syscall_trace: diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index ee2867a1576e..b19fef9d396d 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -335,6 +336,9 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) asmlinkage void syscall_trace_exit(struct pt_regs *regs) { + if (test_thread_flag(TIF_FD_SLOTS)) + fd_slots_commit(regs); + audit_syscall_exit(regs); if (test_thread_flag(TIF_SYSCALL_TRACE)) -- 2.53.0