From nobody Mon Dec 15 00:00:50 2025 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 064F328641E for ; Wed, 28 May 2025 12:36:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435769; cv=none; b=Ai1YCvhovFbvRrnVQizyrSOa7taD0Hi2OSM2dObx6GPH5IEMMn46ibg8BHNbY6vzbxgxO18WTsYM10cPIIXNBgbLOzJdbwbvssP9qVpIqxM0xhcWVlEav7sMcg+Jx7bO7geFdXHlI0B36mxWBvcZu+7N3CYz8rjpLpV5rbpoFzk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435769; c=relaxed/simple; bh=Ao6Yj7X14J3VPAgLaAb1nmrQ9mdqFFBKa+cv/pz23LM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jLaDa/RMd1z5UnCC8+vn48qHbSOH146U+aeVpjJMcnA1NDpV5Fzz+UloVdCsyToVhtnMtkZ/NLir8KKHFI52EULmEDRlD/4uVscQdSGmh20jSZW1g99ZviJsU/YcgyT/1v6DoARzeXydRCnEoS4dHr6MoYMMjV+NjavHPsChfD4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 35AD321BEA; Wed, 28 May 2025 12:36:06 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id BFC36136E0; Wed, 28 May 2025 12:36:05 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Q2/nLDUDN2idKQAAD6G6ig (envelope-from ); Wed, 28 May 2025 12:36:05 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: xin@zytor.com, Juergen Gross , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , stable@vger.kernel.org Subject: [PATCH 1/3] x86/execmem: don't use PAGE_KERNEL protection for code pages Date: Wed, 28 May 2025 14:35:55 +0200 Message-ID: <20250528123557.12847-2-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250528123557.12847-1-jgross@suse.com> References: <20250528123557.12847-1-jgross@suse.com> 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 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Queue-Id: 35AD321BEA X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Level: X-Spam-Flag: NO X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Score: -4.00 Content-Type: text/plain; charset="utf-8" In case X86_FEATURE_PSE isn't available (e.g. when running as a Xen PV guest), execmem_arch_setup() will fall back to use PAGE_KERNEL protection for the EXECMEM_MODULE_TEXT range. This will result in attempts to execute code with the NX bit set in case of ITS mitigation being applied. Avoid this problem by using PAGE_KERNEL_EXEC protection instead, which will not set the NX bit. Cc: Reported-by: Xin Li Fixes: 5185e7f9f3bd ("x86/module: enable ROX caches for module text on 64 b= it") Signed-off-by: Juergen Gross --- arch/x86/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 7456df985d96..f5012ae31d8b 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -1089,7 +1089,7 @@ struct execmem_info __init *execmem_arch_setup(void) pgprot =3D PAGE_KERNEL_ROX; flags =3D EXECMEM_KASAN_SHADOW | EXECMEM_ROX_CACHE; } else { - pgprot =3D PAGE_KERNEL; + pgprot =3D PAGE_KERNEL_EXEC; flags =3D EXECMEM_KASAN_SHADOW; } =20 --=20 2.43.0 From nobody Mon Dec 15 00:00:50 2025 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4364B2836BE for ; Wed, 28 May 2025 12:36:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435777; cv=none; b=YOHo6Rnm5/MI3fwAyznxkfJdfRWKiVSCT8+xgvsLRDU5i1P38r1NIUPudos1XxK7AzASEnBFCzwzio3PRNqFEulvDWKDWzXJ4EbjJeuZmhTT02MQ8z3LoMKMwbS5xN5eP62vIbZQygOjaavgQuHVerJ2mLM5J9KoMI/CpljIIp8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435777; c=relaxed/simple; bh=ssJ0Vjc2+wN1MmE+iyXyH6fQJtr9m258QsChEelUTm4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LJqmMxwG7uTPWPdCQN+9TIn1V2g+2We/DMTxqVQnv0n4j9gxUIzM6SptuM693ASMOWafBKiRVzOEBzWEU2L/R70bgSEFe93lsKb/lp3YG2shgv90lwIQbT1v6zsfZIVk+NLUnV3cYjJAx9cD6j9CoEwOLzCPTW5eoqfUAzy5Pu4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=d31Gx/GP; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=R/7pgUp+; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="d31Gx/GP"; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="R/7pgUp+" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 27C0F21AE4; Wed, 28 May 2025 12:36:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1748435773; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zlzcsl/OislF/CTk7Ff7aWZAEbJyJ7hReAUFJ1BEXf0=; b=d31Gx/GPN2G366m/LTUDl7etfCfaCQfrAfLT6i5US++QI9lrfLD1RnXEoEuQ2GTvzZca+R naRXUT6f6A7+j+hX/ro6XD0f33RVBOuttpK8CPRex+XXrQFHe1LfXCfK+RSi2oP2ZyYdup JmVxbZhE/9+aH3F8RV8iFtjr2UM5o1E= Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1748435772; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zlzcsl/OislF/CTk7Ff7aWZAEbJyJ7hReAUFJ1BEXf0=; b=R/7pgUp+6V9xuegpTJwo28lkzGp9cn3fX//TJnLRUDj+Qf6zj0AOEuScKHCNXZqNbK2iX3 gqJVWCYuxNf0PrN/quDPzqP79n2nIzaFOy6cGMkzRXikSNjr9JAg/yflfKsU0h4BPjZmEZ el+BZnljuWlllEQm6HtcPJwpID1KxDo= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id AB43E136E0; Wed, 28 May 2025 12:36:11 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id V60YKDsDN2ijKQAAD6G6ig (envelope-from ); Wed, 28 May 2025 12:36:11 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: xin@zytor.com, Juergen Gross , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , stable@vger.kernel.org Subject: [PATCH 2/3] x86/mm/pat: don't collapse pages without PSE set Date: Wed, 28 May 2025 14:35:56 +0200 Message-ID: <20250528123557.12847-3-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250528123557.12847-1-jgross@suse.com> References: <20250528123557.12847-1-jgross@suse.com> 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 X-Spam-Flag: NO X-Spam-Score: -6.80 X-Spamd-Result: default: False [-6.80 / 50.00]; REPLY(-4.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_TWELVE(0.00)[12]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:mid,suse.com:email,imap1.dmz-prg2.suse.org:helo]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_TLS_ALL(0.00)[] X-Spam-Level: Content-Type: text/plain; charset="utf-8" Collapsing pages to a leaf PMD or PUD should be done only if X86_FEATURE_PSE is available, which is not the case when running e.g. as a Xen PV guest. Cc: Fixes: 41d88484c71c ("x86/mm/pat: restore large ROX pages after fragmentati= on") Signed-off-by: Juergen Gross --- arch/x86/mm/pat/set_memory.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 30ab4aced761..e6a6ac8cdc1d 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1257,6 +1257,9 @@ static int collapse_pmd_page(pmd_t *pmd, unsigned lon= g addr, pgprot_t pgprot; int i =3D 0; =20 + if (!cpu_feature_enabled(X86_FEATURE_PSE)) + return 0; + addr &=3D PMD_MASK; pte =3D pte_offset_kernel(pmd, addr); first =3D *pte; --=20 2.43.0 From nobody Mon Dec 15 00:00:50 2025 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD2C528688D for ; Wed, 28 May 2025 12:36:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435781; cv=none; b=NS/+VcH6nOGkv++LwQPMAxIpb88cj59vNkIDfAejWBIGoQlRMqOvOsoSpNp777RqPSV1oZ1iUHXsoGRULzBVEGlfuNN1IqieMP+PgRJ/usZYqe6RibhBswjcJuUhWVp4vz734Zmw5GyFw1jRVqjdFIeIdldk5JfeGhdgJ05UbKU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748435781; c=relaxed/simple; bh=DDn3bDzacoLdEbYTtaefGSuDRRRTSSmIS3JDSnPZlR4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QPuo0uSvGIsuiYOvvPhvOQoYy53cKO1+XmdmGREQEuTBsaopzTJws+KoUB5qcIjhPNM8tIDSGWMovMatFXki16wWoyDVXoOu0ZONI81Sd2XPl6ap9yxcG231W3/CXwJtM3yvSwhIaoHXsi47fmnwY/GywCsswAsjvICY7Ik/yH0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=s1EnRGDG; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=s1EnRGDG; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="s1EnRGDG"; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="s1EnRGDG" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id D45411F8B9; Wed, 28 May 2025 12:36:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1748435777; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j/hGv7jZb/4TX+WGvVm1B9o6zeX04OtGYX/XldpPRP0=; b=s1EnRGDGGug3fifeX50rJKby6jd0HYMtDaLrLLcOoQ4BvOcApT9NX1c2yaGdzf89038Izn hcgH8XJEmPHXri2HhA8O9wk+RmjLAaIdo5pP4CUmaQmymrc2fNSnaRc8v3QDI54kfQkUvD lyLg+5Avc/Ziv1sawOO/u6Dbx4myZPI= Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1748435777; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j/hGv7jZb/4TX+WGvVm1B9o6zeX04OtGYX/XldpPRP0=; b=s1EnRGDGGug3fifeX50rJKby6jd0HYMtDaLrLLcOoQ4BvOcApT9NX1c2yaGdzf89038Izn hcgH8XJEmPHXri2HhA8O9wk+RmjLAaIdo5pP4CUmaQmymrc2fNSnaRc8v3QDI54kfQkUvD lyLg+5Avc/Ziv1sawOO/u6Dbx4myZPI= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 85331136E0; Wed, 28 May 2025 12:36:17 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id BDIbH0EDN2ipKQAAD6G6ig (envelope-from ); Wed, 28 May 2025 12:36:17 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: xin@zytor.com, Juergen Gross , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , stable@vger.kernel.org Subject: [PATCH 3/3] x86/alternative: make kernel ITS thunks read-only Date: Wed, 28 May 2025 14:35:57 +0200 Message-ID: <20250528123557.12847-4-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250528123557.12847-1-jgross@suse.com> References: <20250528123557.12847-1-jgross@suse.com> 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 X-Spamd-Result: default: False [-6.80 / 50.00]; REPLY(-4.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_TWO(0.00)[2]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; RCPT_COUNT_SEVEN(0.00)[10]; FUZZY_BLOCKED(0.00)[rspamd.com]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,suse.com:email,suse.com:mid]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; R_RATELIMIT(0.00)[to_ip_from(RLfdszjqhz8kzzb9uwpzdm8png)]; RCVD_TLS_ALL(0.00)[] X-Spam-Level: X-Spam-Flag: NO X-Spam-Score: -6.80 Content-Type: text/plain; charset="utf-8" When allocating memory pages for kernel ITS thunks, make them read-only after having written the last thunk. This will be needed when X86_FEATURE_PSE isn't available, as the thunk memory will have PAGE_KERNEL_EXEC protection, which is including the write permission. Cc: Fixes: 5185e7f9f3bd ("x86/module: enable ROX caches for module text on 64 b= it") Signed-off-by: Juergen Gross --- arch/x86/kernel/alternative.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ecfe7b497cad..bd974a0ac88a 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -217,6 +217,15 @@ static void *its_alloc(void) return no_free_ptr(page); } =20 +static void its_set_kernel_ro(void *addr) +{ +#ifdef CONFIG_MODULES + if (its_mod) + return; +#endif + execmem_restore_rox(addr, PAGE_SIZE); +} + static void *its_allocate_thunk(int reg) { int size =3D 3 + (reg / 8); @@ -234,6 +243,8 @@ static void *its_allocate_thunk(int reg) #endif =20 if (!its_page || (its_offset + size - 1) >=3D PAGE_SIZE) { + if (its_page) + its_set_kernel_ro(its_page); its_page =3D its_alloc(); if (!its_page) { pr_err("ITS page allocation failed\n"); @@ -2338,6 +2349,11 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); =20 + /* Make potential last thunk page read-only. */ + if (its_page) + its_set_kernel_ro(its_page); + its_page =3D NULL; + /* * Adjust all CALL instructions to point to func()-10, including * those in .altinstr_replacement. --=20 2.43.0