From 9999e48639b3cecb08ffb37358bcba3b48161b29 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 08:50:17 +0000
Subject: [PATCH] add ax88772_rst
---
kernel/arch/x86/entry/vdso/vma.c | 169 +++++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 141 insertions(+), 28 deletions(-)
diff --git a/kernel/arch/x86/entry/vdso/vma.c b/kernel/arch/x86/entry/vdso/vma.c
index 3f9d43f..2b5e04c 100644
--- a/kernel/arch/x86/entry/vdso/vma.c
+++ b/kernel/arch/x86/entry/vdso/vma.c
@@ -1,6 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2007 Andi Kleen, SUSE Labs.
- * Subject to the GPL, v.2
*
* This contains most of the x86 vDSO kernel-side code.
*/
@@ -14,15 +14,31 @@
#include <linux/elf.h>
#include <linux/cpu.h>
#include <linux/ptrace.h>
+#include <linux/time_namespace.h>
+
#include <asm/pvclock.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/vvar.h>
+#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
+
+#undef _ASM_X86_VVAR_H
+#define EMIT_VVAR(name, offset) \
+ const size_t name ## _offset = offset;
+#include <asm/vvar.h>
+
+struct vdso_data *arch_get_vdso_data(void *vvar_page)
+{
+ return (struct vdso_data *)(vvar_page + _vdso_data_offset);
+}
+#undef EMIT_VVAR
+
+unsigned int vclocks_used __read_mostly;
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
@@ -37,9 +53,10 @@
image->alt_len));
}
+static const struct vm_special_mapping vvar_mapping;
struct linux_binprm;
-static int vdso_fault(const struct vm_special_mapping *sm,
+static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
const struct vdso_image *image = vma->vm_mm->context.vdso_image;
@@ -84,12 +101,74 @@
return 0;
}
-static int vvar_fault(const struct vm_special_mapping *sm,
+static int vvar_mremap(const struct vm_special_mapping *sm,
+ struct vm_area_struct *new_vma)
+{
+ const struct vdso_image *image = new_vma->vm_mm->context.vdso_image;
+ unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
+
+ if (new_size != -image->sym_vvar_start)
+ return -EINVAL;
+
+ return 0;
+}
+
+#ifdef CONFIG_TIME_NS
+static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+ if (likely(vma->vm_mm == current->mm))
+ return current->nsproxy->time_ns->vvar_page;
+
+ /*
+ * VM_PFNMAP | VM_IO protect .fault() handler from being called
+ * through interfaces like /proc/$pid/mem or
+ * process_vm_{readv,writev}() as long as there's no .access()
+ * in special_mapping_vmops().
+ * For more details check_vma_flags() and __access_remote_vm()
+ */
+
+ WARN(1, "vvar_page accessed remotely");
+
+ return NULL;
+}
+
+/*
+ * The vvar page layout depends on whether a task belongs to the root or
+ * non-root time namespace. Whenever a task changes its namespace, the VVAR
+ * page tables are cleared and then they will re-faulted with a
+ * corresponding layout.
+ * See also the comment near timens_setup_vdso_data() for details.
+ */
+int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
+{
+ struct mm_struct *mm = task->mm;
+ struct vm_area_struct *vma;
+
+ mmap_read_lock(mm);
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ unsigned long size = vma->vm_end - vma->vm_start;
+
+ if (vma_is_special_mapping(vma, &vvar_mapping))
+ zap_page_range(vma, vma->vm_start, size);
+ }
+
+ mmap_read_unlock(mm);
+ return 0;
+}
+#else
+static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+ return NULL;
+}
+#endif
+
+static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
const struct vdso_image *image = vma->vm_mm->context.vdso_image;
+ unsigned long pfn;
long sym_offset;
- int ret = -EFAULT;
if (!image)
return VM_FAULT_SIGBUS;
@@ -108,28 +187,59 @@
return VM_FAULT_SIGBUS;
if (sym_offset == image->sym_vvar_page) {
- ret = vm_insert_pfn(vma, vmf->address,
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT);
+ struct page *timens_page = find_timens_vvar_page(vma);
+
+ pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+
+ /*
+ * If a task belongs to a time namespace then a namespace
+ * specific VVAR is mapped with the sym_vvar_page offset and
+ * the real VVAR page is mapped with the sym_timens_page
+ * offset.
+ * See also the comment near timens_setup_vdso_data().
+ */
+ if (timens_page) {
+ unsigned long addr;
+ vm_fault_t err;
+
+ /*
+ * Optimization: inside time namespace pre-fault
+ * VVAR page too. As on timens page there are only
+ * offsets for clocks on VVAR, it'll be faulted
+ * shortly by VDSO code.
+ */
+ addr = vmf->address + (image->sym_timens_page - sym_offset);
+ err = vmf_insert_pfn(vma, addr, pfn);
+ if (unlikely(err & VM_FAULT_ERROR))
+ return err;
+
+ pfn = page_to_pfn(timens_page);
+ }
+
+ return vmf_insert_pfn(vma, vmf->address, pfn);
} else if (sym_offset == image->sym_pvclock_page) {
struct pvclock_vsyscall_time_info *pvti =
pvclock_get_pvti_cpu0_va();
- if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
- ret = vm_insert_pfn_prot(
- vma,
- vmf->address,
- __pa(pvti) >> PAGE_SHIFT,
- pgprot_decrypted(vma->vm_page_prot));
+ if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) {
+ return vmf_insert_pfn_prot(vma, vmf->address,
+ __pa(pvti) >> PAGE_SHIFT,
+ pgprot_decrypted(vma->vm_page_prot));
}
} else if (sym_offset == image->sym_hvclock_page) {
struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
- if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
- ret = vm_insert_pfn(vma, vmf->address,
- vmalloc_to_pfn(tsc_pg));
- }
+ if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
+ return vmf_insert_pfn(vma, vmf->address,
+ virt_to_phys(tsc_pg) >> PAGE_SHIFT);
+ } else if (sym_offset == image->sym_timens_page) {
+ struct page *timens_page = find_timens_vvar_page(vma);
- if (ret == 0 || ret == -EBUSY)
- return VM_FAULT_NOPAGE;
+ if (!timens_page)
+ return VM_FAULT_SIGBUS;
+
+ pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+ return vmf_insert_pfn(vma, vmf->address, pfn);
+ }
return VM_FAULT_SIGBUS;
}
@@ -142,6 +252,7 @@
static const struct vm_special_mapping vvar_mapping = {
.name = "[vvar]",
.fault = vvar_fault,
+ .mremap = vvar_mremap,
};
/*
@@ -156,7 +267,7 @@
unsigned long text_start;
int ret = 0;
- if (down_write_killable(&mm->mmap_sem))
+ if (mmap_write_lock_killable(mm))
return -EINTR;
addr = get_unmapped_area(NULL, addr,
@@ -199,7 +310,7 @@
}
up_fail:
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
return ret;
}
@@ -228,8 +339,8 @@
/* Round the lowest possible end address up to a PMD boundary. */
end = (start + len + PMD_SIZE - 1) & PMD_MASK;
- if (end >= TASK_SIZE_MAX)
- end = TASK_SIZE_MAX;
+ if (end >= DEFAULT_MAP_WINDOW)
+ end = DEFAULT_MAP_WINDOW;
end -= len;
if (end > start) {
@@ -261,22 +372,22 @@
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- down_write(&mm->mmap_sem);
+ mmap_write_lock(mm);
/*
* Check if we have already mapped vdso blob - fail to prevent
* abusing from userspace install_speciall_mapping, which may
* not do accounting and rlimit right.
* We could search vma near context.vdso, but it's a slowpath,
- * so let's explicitely check all VMAs to be completely sure.
+ * so let's explicitly check all VMAs to be completely sure.
*/
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma_is_special_mapping(vma, &vdso_mapping) ||
vma_is_special_mapping(vma, &vvar_mapping)) {
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
return -EEXIST;
}
}
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
return map_vdso(image, addr);
}
@@ -329,12 +440,14 @@
static __init int vdso_setup(char *s)
{
vdso64_enabled = simple_strtoul(s, NULL, 0);
- return 0;
+ return 1;
}
__setup("vdso=", vdso_setup);
static int __init init_vdso(void)
{
+ BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
+
init_vdso_image(&vdso_image_64);
#ifdef CONFIG_X86_X32_ABI
--
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