From nobody Sat Jul 25 03:20:51 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (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 40A3F39446B for ; Mon, 20 Jul 2026 03:23:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784517839; cv=none; b=A0QDeLGF74THmHllMc+iOHxpq+f5N+o6mnqtU9ZWD8k3RJASNpjnSB4Y5DT5ntFLp9V9ln9BdCbbpTmofyaCxoP11RUHH2E9J2u4dd5a1qQi4L4HNERGVLNaLVixh7Ycu4cCIrQGdT4RedA+d9cy+cT6QbbF7KxCqW181HxJzvg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784517839; c=relaxed/simple; bh=0FStFLpRem1qEC/2/F+ynKkdHaKvyc/nHKBpxtlWsAo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=n4lrquOrGThjnQxkxOK11BPr0tu1bKJvf1h8nnIeVKa/gdMHCTjAbxdo/4/VFBvdLBj1i1BS0keVmap+3grq6QEz0Q1pW+TFow2m6BKNp6SzFbiJidpseymUB058B7cvGmZ10NhQ4jsRiyktz/vV+4XoDEqGPFr+5f7Wjc5QLe0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=J2Mzkjz/; arc=none smtp.client-ip=220.197.31.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="J2Mzkjz/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=CQ bEMG8C6NQudrZtH6JGNGhbxssqV+FTapBCimwsn+Q=; b=J2Mzkjz/31UW6MGAf0 5uv8veLaUDyDenbNUovT/xUqMzwiYoIqg1EnK5N96yV1GZbYWBJc/y7VO1GtvZfy NmkTGPIWEE4IZKCsUW9ypTudj881tdAj+OcSOPkhxvLqGz55psvWJqBJ0dHeoRQN i+s1wFnPOtoXryP7b45XnpTTM= Received: from Ubuntu.. (unknown []) by gzsmtp3 (Coremail) with SMTP id PigvCgBH+wKTlF1qrd2XIg--.2654S3; Mon, 20 Jul 2026 11:23:01 +0800 (CST) From: Xiaofeng Yuan To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Alexandre Ghiti , Nam Cao , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, xiaofengmian@163.com Subject: [PATCH v4 1/2] riscv: mm: make EXECMEM_KPROBES writable without CONFIG_STRICT_MODULE_RWX Date: Mon, 20 Jul 2026 03:22:56 +0000 Message-ID: <20260720032258.5188-2-xiaofengmian@163.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260720032258.5188-1-xiaofengmian@163.com> References: <20260720032258.5188-1-xiaofengmian@163.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-CM-TRANSID: PigvCgBH+wKTlF1qrd2XIg--.2654S3 X-Coremail-Antispam: 1Uf129KBjvJXoW7Xw43Cw1DJF43uF15XrWrZrb_yoW8JrW5pr ZrAr45ZFZ7Xr4Yk3y7u3y8ur4DAanIya13Jw1jyryYq3yjy390qr95Zr1xXry8WF1Uuayx ZFna9r93Aayjka7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pi7UUUUUUUU= X-CM-SenderInfo: p0ld0w5hqjzxldq6il2tof0z/xtbDARU8P2pdlJU6HwAA3E Content-Type: text/plain; charset="utf-8" When CONFIG_STRICT_MODULE_RWX is not set, execmem cannot create temporary writable mappings for read-only executable pages. In this case, the execmem ranges must already have writable permissions. Currently EXECMEM_KPROBES unconditionally uses PAGE_KERNEL_READ_EXEC, which causes kprobe instruction slot writes to trigger page faults on systems where CONFIG_STRICT_MODULE_RWX is not enabled. Fix this by using PAGE_KERNEL_EXEC when CONFIG_STRICT_MODULE_RWX is not available. Signed-off-by: Xiaofeng Yuan Reviewed-by: Nam Cao --- v2: use CONFIG_STRICT_MODULE_RWX instead of CONFIG_ARCH_HAS_EXECMEM_ROX (pe= r Nam Cao's review) v3: add commit description v4: fix indent alignment (per Nam Cao's review) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 5b1b3c88b4..7951d72a12 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1457,7 +1457,9 @@ struct execmem_info __init *execmem_arch_setup(void) [EXECMEM_KPROBES] =3D { .start =3D VMALLOC_START, .end =3D VMALLOC_END, - .pgprot =3D PAGE_KERNEL_READ_EXEC, + .pgprot =3D IS_ENABLED(CONFIG_STRICT_MODULE_RWX) ? + PAGE_KERNEL_READ_EXEC : + PAGE_KERNEL_EXEC, .alignment =3D 1, }, [EXECMEM_BPF] =3D { --=20 2.43.0 From nobody Sat Jul 25 03:20:51 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.3]) (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 325B7299923 for ; Mon, 20 Jul 2026 03:23:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784517825; cv=none; b=Ijx0PovGU6A9EVWt4gDJ/cjPpZDwH1vTqRzIYa7IyoHpoueD6EjEHf4Qnp+PRR2cBPgY0vCzsro8QGYhKf7Xkbohau80yfUEG7c+7dKx7VrdnLfn4kJIDtWU8Qej5zj9pTv3CqgUGclgAX7WTt+U5nLQ7wgQL2511p8MVTrvDGc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784517825; c=relaxed/simple; bh=4H//D7t0+mrgrXpIFbvvRS0N05zA3G0FWaAANvcXJIQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UKhSlZGrRCUTdJszQbhjp3ajAhKBlAZy4lF+2mS1s17Dx5KrBdAOELFBHfukV82UuphDuMfbyxxFBxhqBfGetOk+7viND4bNPfqi25/JyG0wQFFnwFnR8Aj12BacbYO/fCuxQEiV9Nz18bENxVyuked9gofXWYWdMbKcI2UTzRM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=IIYkWQwC; arc=none smtp.client-ip=117.135.210.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="IIYkWQwC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=5U kUr8RuelSHMMnVvP5mpx/Yb4/yO3VgsdZyG7QnLwM=; b=IIYkWQwCO4Ls5jXYrP Tb4+oj96r5TjsaL2NszGZnvrvRbFbUN/oockCbz2LzJn83LXI6t6Q3/lYmdS7h47 uA7OseJCf2ZmtCEsjUKlsj85/G9limsmke6BPxDbkWQAG6rUF4Hlj6DOnO+Lt6XH qrwLnI8zIESwvBRorobmuHZLo= Received: from Ubuntu.. (unknown []) by gzsmtp3 (Coremail) with SMTP id PigvCgBH+wKTlF1qrd2XIg--.2654S4; Mon, 20 Jul 2026 11:23:02 +0800 (CST) From: Xiaofeng Yuan To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Alexandre Ghiti , Nam Cao , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, xiaofengmian@163.com Subject: [PATCH v4 2/2] riscv: patch: skip fixmap mapping when kernel text is already writable Date: Mon, 20 Jul 2026 03:22:57 +0000 Message-ID: <20260720032258.5188-3-xiaofengmian@163.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260720032258.5188-1-xiaofengmian@163.com> References: <20260720032258.5188-1-xiaofengmian@163.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-CM-TRANSID: PigvCgBH+wKTlF1qrd2XIg--.2654S4 X-Coremail-Antispam: 1Uf129KBjvJXoW7CF1xuw4UGF43Kr17ZFWxtFb_yoW8GFyDpF s7JF1rZFW5JF4Fv39Fkw1kuryYywnxtrsxGFnrXFyavwsIq34rXwn3W3y2qF10gr1j9w47 uFsxArZI9a4UG37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziebyZUUUUU= X-CM-SenderInfo: p0ld0w5hqjzxldq6il2tof0z/xtbC5RY8P2pdlJaH-wAA39 Content-Type: text/plain; charset="utf-8" Currently patch_map() always creates a temporary writable mapping via fixmap for kernel text addresses, even when CONFIG_STRICT_MODULE_RWX is disabled and the kernel text is already mapped with _PAGE_WRITE. This is unnecessary overhead at best, and on minimal configurations it can cause page faults. Skip the fixmap path for kernel text when CONFIG_STRICT_MODULE_RWX is not enabled, since the text pages are already writable in this case. Signed-off-by: Xiaofeng Yuan Reviewed-by: Nam Cao --- v2: add commit description v3: early return when !CONFIG_STRICT_MODULE_RWX (per Nam Cao's suggestion) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 16b243376f..caef41d5ef 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -44,15 +44,16 @@ static __always_inline void *patch_map(void *addr, cons= t unsigned int fixmap) uintptr_t uintaddr =3D (uintptr_t) addr; phys_addr_t phys; =20 + if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + return addr; + if (core_kernel_text(uintaddr) || is_kernel_exittext(uintaddr)) { phys =3D __pa_symbol(addr); - } else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) { + } else { struct page *page =3D vmalloc_to_page(addr); =20 BUG_ON(!page); phys =3D page_to_phys(page) + offset_in_page(addr); - } else { - return addr; } =20 return (void *)set_fixmap_offset(fixmap, phys); --=20 2.43.0