From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out03.mta.xmission.com (out03.mta.xmission.com [166.70.13.233]) (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 95BE63EA957 for ; Fri, 26 Jun 2026 17:00:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.70.13.233 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782493253; cv=none; b=RzJ2EQlJtB9qhmMyf9UjdhD7dgnC+iJlDnpmg3Exh6h7HlQoNCjAf6+8kiMA04ogL1WGvZkHd3yUbRLadZULTZCMq2STIVf6sh2TKpVxvwNHT983EfmdHlktafzwavy4jT6xHuICYkV0yJY9Tp/uiivqTusqxPlPLj363rlIi/Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782493253; c=relaxed/simple; bh=VOjKCF8TGymcpMxhEeteUr5xwnPrr+hmF1Ll4Bspj4k=; h=From:To:Cc:In-Reply-To:References:Date:Message-ID:MIME-Version: Content-Type:Subject; b=gQfIxCFGoz8XzxGv8mYnP+utGf1DGJrrjZ5ad0z5tcGBgUZMs9/Uaf2gb1kmGgtfpvNOWYsnj8LUG3Lv7F3VuA88Ipg3ZV4kCKFjXUxGKzwBLeYsBMg8txOgMnJ/egA/pQGV4V5Bhz4FBupuA4d7NmkU0knwr3tTUC15R+aPFt4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com; spf=pass smtp.mailfrom=xmission.com; dkim=pass (1024-bit key) header.d=xmission.com header.i=@xmission.com header.b=XCjqPBom; arc=none smtp.client-ip=166.70.13.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xmission.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=xmission.com header.i=@xmission.com header.b="XCjqPBom" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=simple/simple; d=xmission.com; s=xmission; h=Subject:Content-Type:MIME-Version:Message-ID:Date:References: In-Reply-To:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=VOjKCF8TGymcpMxhEeteUr5xwnPrr+hmF1Ll4Bspj4k=; b=XCjqPBomPIJ3G9oNVbUVWcgN2r +rMulkflbfGlskQ/OW9WNWMqqtKP5vL5v/5MiPxSxjbFHPITLyg2aeWp9spkAgBvSUQy6JBkwjIHN /j10EXTStfY1P3Sp7r8kizbtC0we4+Oz3T1ZBfWWqyEpSSvWahGZsnEsbBlcXFYXlAUE=; Received: from in01.mta.xmission.com ([166.70.13.51]:49032) by out03.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1wd9v9-0058CD-PH; Fri, 26 Jun 2026 11:00:51 -0600 Received: from ip72-198-198-28.om.om.cox.net ([72.198.198.28]:37512 helo=email.froward.int.ebiederm.org.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1wd9v8-00Gkm5-O2; Fri, 26 Jun 2026 11:00:51 -0600 From: "Eric W. Biederman" To: Andrew Morton Cc: Andy Lutomirski , Kees Cook , Kusaram Devineni , Peter Zijlstra , Thomas Gleixner , Will Drewry , linux-kernel@vger.kernel.org, Oleg Nesterov In-Reply-To: <87o6gx9rc4.fsf@email.froward.int.ebiederm.org> (Eric W. Biederman's message of "Fri, 26 Jun 2026 11:52:43 -0500") References: <87o6gx9rc4.fsf@email.froward.int.ebiederm.org> Date: Fri, 26 Jun 2026 12:00:45 -0500 Message-ID: <87v7b56xtu.fsf_-_@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1wd9v8-00Gkm5-O2;;;mid=<87v7b56xtu.fsf_-_@email.froward.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=72.198.198.28;;;frm=ebiederm@xmission.com;;;sPfnum=0;;;sPf=pass X-XM-AID: U2FsdGVkX18QvKQbViKO5m83MWciLrSPZ5SXQ2qPxzo= X-Spam-Level: X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.1 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4946] * 1.5 XMNoVowels Alpha-numberic number with no vowels * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Andrew Morton X-Spam-Relay-Country: X-Spam-Timing: total 606 ms - load_scoreonly_sql: 0.06 (0.0%), signal_user_changed: 11 (1.8%), b_tie_ro: 10 (1.6%), parse: 0.97 (0.2%), extract_message_metadata: 3.6 (0.6%), get_uri_detail_list: 1.39 (0.2%), tests_pri_-2000: 3.5 (0.6%), tests_pri_-1000: 2.6 (0.4%), tests_pri_-950: 1.24 (0.2%), tests_pri_-900: 1.03 (0.2%), tests_pri_-90: 273 (45.1%), check_bayes: 272 (44.9%), b_tokenize: 9 (1.4%), b_tok_get_all: 32 (5.3%), b_comp_prob: 2.7 (0.4%), b_tok_touch_all: 224 (37.0%), b_finish: 1.15 (0.2%), tests_pri_0: 290 (47.8%), check_dkim_signature: 0.64 (0.1%), check_dkim_adsp: 2.8 (0.5%), poll_dns_idle: 0.53 (0.1%), tests_pri_10: 2.2 (0.4%), tests_pri_500: 8 (1.3%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 11/11] signal: Remove SA_IMMUTABLE X-SA-Exim-Connect-IP: 166.70.13.51 X-SA-Exim-Rcpt-To: oleg@redhat.com, linux-kernel@vger.kernel.org, wad@chromium.org, tglx@kernel.org, peterz@infradead.org, kusaram@devineni.in, kees@kernel.org, luto@kernel.org, akpm@linux-foundation.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on out03.mta.xmission.com); SAEximRunCond expanded to false Now that fatal signals experience short circuit delivery in __send_signal_locked. There is no longer a race between sigaction changing the signal handler and the signal handler being forced to SIG_DFL, for fatal forced signals. So remove SA_IMMUTABLE whose job it was to stop that race. --- include/linux/signal_types.h | 3 --- include/uapi/asm-generic/signal-defs.h | 1 - kernel/signal.c | 9 +-------- 3 files changed, 1 insertion(+), 12 deletions(-) diff --git a/include/linux/signal_types.h b/include/linux/signal_types.h index caf4f7a59ab9..1a3bb540f1c7 100644 --- a/include/linux/signal_types.h +++ b/include/linux/signal_types.h @@ -70,9 +70,6 @@ struct ksignal { int sig; }; -/* Used to kill the race between sigaction and forced signals */ -#define SA_IMMUTABLE 0x00800000 - #ifndef __ARCH_UAPI_SA_FLAGS #ifdef SA_RESTORER #define __ARCH_UAPI_SA_FLAGS SA_RESTORER diff --git a/include/uapi/asm-generic/signal-defs.h b/include/uapi/asm-generic/signal-defs.h index 7572f2f46ee8..fe929e7b77ca 100644 --- a/include/uapi/asm-generic/signal-defs.h +++ b/include/uapi/asm-generic/signal-defs.h @@ -45,7 +45,6 @@ #define SA_UNSUPPORTED 0x00000400 #define SA_EXPOSE_TAGBITS 0x00000800 /* 0x00010000 used on mips */ -/* 0x00800000 used for internal SA_IMMUTABLE */ /* 0x01000000 used on x86 */ /* 0x02000000 used on x86 */ /* diff --git a/kernel/signal.c b/kernel/signal.c index 0b602dfb0b78..d1decfef86c0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1328,8 +1328,6 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, blocked = sigismember(&t->blocked, sig); if (blocked || ignored || (handler != HANDLER_CURRENT)) { action->sa.sa_handler = SIG_DFL; - if (handler == HANDLER_EXIT) - action->sa.sa_flags |= SA_IMMUTABLE; if (blocked) sigdelset(&t->blocked, sig); } @@ -2946,8 +2944,7 @@ bool get_signal(struct ksignal *ksig) if (!signr) break; /* will return 0 */ - if (unlikely(current->ptrace) && (signr != SIGKILL) && - !(sighand->action[signr -1].sa.sa_flags & SA_IMMUTABLE)) { + if (unlikely(current->ptrace) && (signr != SIGKILL)) { signr = ptrace_signal(signr, &ksig->info, type); if (!signr) continue; @@ -4351,10 +4348,6 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) k = &p->sighand->action[sig-1]; spin_lock_irq(&p->sighand->siglock); - if (k->sa.sa_flags & SA_IMMUTABLE) { - spin_unlock_irq(&p->sighand->siglock); - return -EINVAL; - } if (oact) *oact = *k; -- 2.41.0