From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F298E1AD3FA; Mon, 23 Jun 2025 21:55:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750715705; cv=none; b=fi6eB/eSdxfxP3HDd0SVSKHaGV87seMnguWqsdjrCh2Tntds5mTk8YDjO0+bcJVVacQEgug0F7P/0hc2l6tAMLWnTp7BJB0Tr4FfdnJ7uppb8HWVpbR58YKeA4IzyEmP4bdhYGthRUO2eSX2YNS7HSXMMB/FV2knRlXWQB2Q0dU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750715705; c=relaxed/simple; bh=y3WvLTkFX9npRT+Tf+AwNsGiGeyu5Cq2hHWH5xwXixI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rVPXKh+Y/LEEDEYGSZjBhAFkW/iCM/TVAFvpd0CGKdmpo0KE59eoVI9eaPVzl8LRd2PE9m+PnkKXRwVjIJQITyC8oRPzOVlElaXmCmo2mGhVlG7lj/XdnlWZUddxDtoQnN2Lyi5pt8E2UsOLWmO0O2c6aUrD/RyFWBBlY2NwVyw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JA0lyIAg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JA0lyIAg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88DBAC4CEEA; Mon, 23 Jun 2025 21:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750715704; bh=y3WvLTkFX9npRT+Tf+AwNsGiGeyu5Cq2hHWH5xwXixI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JA0lyIAgVsCZQMVUwxk/AQ0L/RnUHxPP156KqeOziqQ/Av27G+9/AGgCFaQ9BqksS pRQ4SqhzSRAvmmWW3p+GUT/0gRVWNEO3sghlElYo1q/6QfQIJXfi/tBm/BJBWrmRUP 2WGBRoi555LTfWVpv2ocbORMZt2C1e4zLgsvWZGQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Mike Rapoport (Microsoft)" , "Peter Zijlstra (Intel)" Subject: [PATCH 6.15 475/592] Revert "mm/execmem: Unify early execmem_cache behaviour" Date: Mon, 23 Jun 2025 15:07:13 +0200 Message-ID: <20250623130711.730836622@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130700.210182694@linuxfoundation.org> References: <20250623130700.210182694@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Rapoport (Microsoft) commit 7cd9a11dd0c3d1dd225795ed1b5b53132888e7b5 upstream. The commit d6d1e3e6580c ("mm/execmem: Unify early execmem_cache behaviour") changed early behaviour of execemem ROX cache to allow its usage in early x86 code that allocates text pages when CONFIG_MITGATION_ITS is enabled. The permission management of the pages allocated from execmem for ITS mitigation is now completely contained in arch/x86/kernel/alternatives.c and therefore there is no need to special case early allocations in execmem. This reverts commit d6d1e3e6580ca35071ad474381f053cbf1fb6414. Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-6-rppt@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/init_32.c | 3 --- arch/x86/mm/init_64.c | 3 --- include/linux/execmem.h | 8 +------- mm/execmem.c | 40 +++------------------------------------- 4 files changed, 4 insertions(+), 50 deletions(-) --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -30,7 +30,6 @@ #include #include #include -#include #include #include @@ -756,8 +755,6 @@ void mark_rodata_ro(void) pr_info("Write protecting kernel text and read-only data: %luk\n", size >> 10); - execmem_cache_make_ro(); - kernel_set_to_readonly = 1; #ifdef CONFIG_CPA_DEBUG --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -34,7 +34,6 @@ #include #include #include -#include #include #include @@ -1392,8 +1391,6 @@ void mark_rodata_ro(void) (end - start) >> 10); set_memory_ro(start, (end - start) >> PAGE_SHIFT); - execmem_cache_make_ro(); - kernel_set_to_readonly = 1; /* --- a/include/linux/execmem.h +++ b/include/linux/execmem.h @@ -54,7 +54,7 @@ enum execmem_range_flags { EXECMEM_ROX_CACHE = (1 << 1), }; -#if defined(CONFIG_ARCH_HAS_EXECMEM_ROX) && defined(CONFIG_EXECMEM) +#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX /** * execmem_fill_trapping_insns - set memory to contain instructions that * will trap @@ -94,15 +94,9 @@ int execmem_make_temp_rw(void *ptr, size * Return: 0 on success or negative error code on failure. */ int execmem_restore_rox(void *ptr, size_t size); - -/* - * Called from mark_readonly(), where the system transitions to ROX. - */ -void execmem_cache_make_ro(void); #else static inline int execmem_make_temp_rw(void *ptr, size_t size) { return 0; } static inline int execmem_restore_rox(void *ptr, size_t size) { return 0; } -static inline void execmem_cache_make_ro(void) { } #endif /** --- a/mm/execmem.c +++ b/mm/execmem.c @@ -254,34 +254,6 @@ out_unlock: return ptr; } -static bool execmem_cache_rox = false; - -void execmem_cache_make_ro(void) -{ - struct maple_tree *free_areas = &execmem_cache.free_areas; - struct maple_tree *busy_areas = &execmem_cache.busy_areas; - MA_STATE(mas_free, free_areas, 0, ULONG_MAX); - MA_STATE(mas_busy, busy_areas, 0, ULONG_MAX); - struct mutex *mutex = &execmem_cache.mutex; - void *area; - - execmem_cache_rox = true; - - mutex_lock(mutex); - - mas_for_each(&mas_free, area, ULONG_MAX) { - unsigned long pages = mas_range_len(&mas_free) >> PAGE_SHIFT; - set_memory_ro(mas_free.index, pages); - } - - mas_for_each(&mas_busy, area, ULONG_MAX) { - unsigned long pages = mas_range_len(&mas_busy) >> PAGE_SHIFT; - set_memory_ro(mas_busy.index, pages); - } - - mutex_unlock(mutex); -} - static int execmem_cache_populate(struct execmem_range *range, size_t size) { unsigned long vm_flags = VM_ALLOW_HUGE_VMAP; @@ -302,15 +274,9 @@ static int execmem_cache_populate(struct /* fill memory with instructions that will trap */ execmem_fill_trapping_insns(p, alloc_size, /* writable = */ true); - if (execmem_cache_rox) { - err = set_memory_rox((unsigned long)p, vm->nr_pages); - if (err) - goto err_free_mem; - } else { - err = set_memory_x((unsigned long)p, vm->nr_pages); - if (err) - goto err_free_mem; - } + err = set_memory_rox((unsigned long)p, vm->nr_pages); + if (err) + goto err_free_mem; err = execmem_cache_add(p, alloc_size); if (err)