From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh
---
kernel/arch/x86/mm/pkeys.c | 32 +++++++++-----------------------
1 files changed, 9 insertions(+), 23 deletions(-)
diff --git a/kernel/arch/x86/mm/pkeys.c b/kernel/arch/x86/mm/pkeys.c
index 6e98e0a..8873ed1 100644
--- a/kernel/arch/x86/mm/pkeys.c
+++ b/kernel/arch/x86/mm/pkeys.c
@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel Memory Protection Keys management
* Copyright (c) 2015, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
*/
#include <linux/debugfs.h> /* debugfs_create_u32() */
#include <linux/mm_types.h> /* mm_struct, vma, etc... */
@@ -18,6 +10,7 @@
#include <asm/cpufeature.h> /* boot_cpu_has, ... */
#include <asm/mmu_context.h> /* vma_pkey() */
+#include <asm/fpu/internal.h> /* init_fpstate */
int __execute_only_pkey(struct mm_struct *mm)
{
@@ -39,17 +32,12 @@
* dance to set PKRU if we do not need to. Check it
* first and assume that if the execute-only pkey is
* write-disabled that we do not have to set it
- * ourselves. We need preempt off so that nobody
- * can make fpregs inactive.
+ * ourselves.
*/
- preempt_disable();
if (!need_to_set_mm_pkey &&
- current->thread.fpu.initialized &&
!__pkru_allows_read(read_pkru(), execute_only_pkey)) {
- preempt_enable();
return execute_only_pkey;
}
- preempt_enable();
/*
* Set up PKRU so that it denies access for everything
@@ -75,7 +63,7 @@
static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
{
/* Do this check first since the vm_flags should be hot */
- if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
return false;
if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey)
return false;
@@ -147,13 +135,6 @@
{
u32 init_pkru_value_snapshot = READ_ONCE(init_pkru_value);
/*
- * Any write to PKRU takes it out of the XSAVE 'init
- * state' which increases context switch cost. Avoid
- * writing 0 when PKRU was already 0.
- */
- if (!init_pkru_value_snapshot && !read_pkru())
- return;
- /*
* Override the PKRU state that came from 'init_fpstate'
* with the baseline from the process.
*/
@@ -173,6 +154,7 @@
static ssize_t init_pkru_write_file(struct file *file,
const char __user *user_buf, size_t count, loff_t *ppos)
{
+ struct pkru_state *pk;
char buf[32];
ssize_t len;
u32 new_init_pkru;
@@ -195,6 +177,10 @@
return -EINVAL;
WRITE_ONCE(init_pkru_value, new_init_pkru);
+ pk = get_xsave_addr(&init_fpstate.xsave, XFEATURE_PKRU);
+ if (!pk)
+ return -EINVAL;
+ pk->pkru = new_init_pkru;
return count;
}
--
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