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bh=arLEymkUVoitQLqfzvX2ap3GpzLfAGuJIPCpZdsJGXY=; b=KUm1VnpBfYK9SXe+mGXg+Qn3vvLnCACE1XIX1crfmJzmqMUW3W3kke8dmBu/5FgSSNZGJ+nnJeQGSvPpeGrbYMcfStJDCn8NpVIvbrf/PjixfByOh6h3ALtCxOttShGaOfhKoLRNQR/rjCBu2u3xguFN0yW2+Yd+D2LbnbxboN8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1784212462; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=arLEymkUVoitQLqfzvX2ap3GpzLfAGuJIPCpZdsJGXY=; b=lUOjiNEAs6gVFsKJ7ywvKHQj6bgQShhP9SBhiAd2VMu3l7Ql7s3RfxW1DptBI0CP 49ibTx/3SwuBWhvFvcqhWYc+mdU7WGi1PfJOzrBX8g9dP1KfROPORzf+n0VoF5T/xAB ZXtnxpMJqC6Zlzdxg3QescLRlZH2IuiCV70W7H3E= Received: by mx.zohomail.com with SMTPS id 17842124595011012.3223632220755; Thu, 16 Jul 2026 07:34:19 -0700 (PDT) From: Li Chen To: Christian Brauner Cc: Kees Cook , Gabriel Krisman Bertazi , Josh Triplett , Mateusz Guzik , Andy Lutomirski , John Ericson , Jonathan Corbet , Shuah Khan , Arnd Bergmann , Oleg Nesterov , Andrew Morton , Paul Moore , Eric Paris , =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , =?UTF-8?q?G=C3=BCnther=20Noack?= , Alexander Viro , Jan Kara , linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, audit@vger.kernel.org, linux-security-module@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Li Chen Subject: [RFC PATCH 13/24] fork: let new tasks start with task work Date: Thu, 16 Jul 2026 22:31:39 +0800 Message-ID: <6a841a3d1ca2e4c5dfeccf1863d4e07290d33351.1784204592.git.me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External X-Rspamd-Queue-Id: B664C1C0004 X-Stat-Signature: regw1h9ckscpraj8868hozt6utje93rg X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1784212786-102890 X-HE-Meta: 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 xldRcUuu 1TVE4zKmtOWCBsf2aUiCR4z7t1Pu1gPrLF9LTGNmOIM4dWFtPp5NWDW7BiwFy94QKJQlel0yBTdObaWDQVP6uLxWLPGFAWlOaoY5oDSJOKMHuobp11DPS9P+hyiCC8yp8IxWI4Irr4aCEBFSGSBEDgfBAsFxmKqrzXdXu44FiRpT1hJ7QEkLNOZOkM5F4r5kTAMJMvWI2Vx+JI/zvFcGKGTdCoFdITyzlpiTjVr09zYOIldybTirXhxvYgfBzLBYgQHK6rGHIH+voHnsMX6G+ht9RpYIV9826d//GSiZ8uvM/t0Nsn3VidWKTnWUYNEAneydfoAkpTmNq1fkAqjT3RiBuVzujmkjJNmdw2rEqBzhCmn7nxQB5RCpPttuLpmIEau+3+lyvDBPeb+DLTvPoCf9BSZA182rfQ4mImt/sHyany6YLqw3f6li00vwwggIR1Ozx Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Process builders need to run setup in the child before its first return to userspace without storing a kernel callback in architecture-specific saved registers. Allow an internal clone caller to supply task work. Queue it after the last ordinary fork failure check, while the child is still TASK_NEW. A NULL work pointer leaves existing clone callers unchanged. Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Li Chen --- include/linux/sched/task.h | 2 ++ kernel/fork.c | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 5b7facf12b33b..830de99aabaed 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -43,6 +43,8 @@ struct kernel_clone_args { int idle; int (*fn)(void *); void *fn_arg; + /* Run before the new task first returns to userspace. */ + struct callback_head *task_work; struct cgroup *cgrp; struct css_set *cset; bool embryonic_exec; diff --git a/kernel/fork.c b/kernel/fork.c index e3ade83b2d4e2..c0584eaa74711 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -109,6 +109,7 @@ #include #include #include +#include #include #include #include @@ -2504,6 +2505,11 @@ __latent_entropy struct task_struct *copy_process( retval = -EINTR; goto bad_fork_core_free; } + if (args->task_work) { + retval = task_work_add(p, args->task_work, TWA_RESUME); + if (WARN_ON_ONCE(retval)) + goto bad_fork_core_free; + } /* No more failure paths after this point. */ -- 2.52.0