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authorTiwei Bie <tiwei.btw@antgroup.com>2025-02-12 12:57:56 +0800
committerJohannes Berg <johannes.berg@intel.com>2025-03-18 11:04:00 +0100
commit1fc350eed627762f4f6db3f35776d481e7f02c5c (patch)
tree9cef51a1f2579562d4527a3b37f5eb2ccdb01beb
parent84a6fc378471fbeaf48f8604566a5a33a3d63c18 (diff)
um: Allocate vdso page pointer statically
Instead of dynamically allocating the pointer to the vdso page during boot, we can just allocate it statically. Doing so will reduce error handling and make the code slightly more readable. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250212045756.164977-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--arch/x86/um/vdso/vma.c17
1 files changed, 3 insertions, 14 deletions
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index f238f7b33cdd..dc8dfb2abd80 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -12,33 +12,22 @@
static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;
+static struct page *um_vdso;
extern unsigned long task_size;
extern char vdso_start[], vdso_end[];
-static struct page **vdsop;
-
static int __init init_vdso(void)
{
- struct page *um_vdso;
-
BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
um_vdso_addr = task_size - PAGE_SIZE;
- vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
- if (!vdsop)
- goto oom;
-
um_vdso = alloc_page(GFP_KERNEL);
- if (!um_vdso) {
- kfree(vdsop);
-
+ if (!um_vdso)
goto oom;
- }
copy_page(page_address(um_vdso), vdso_start);
- *vdsop = um_vdso;
return 0;
@@ -56,6 +45,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
struct mm_struct *mm = current->mm;
static struct vm_special_mapping vdso_mapping = {
.name = "[vdso]",
+ .pages = &um_vdso,
};
if (!vdso_enabled)
@@ -64,7 +54,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (mmap_write_lock_killable(mm))
return -EINTR;
- vdso_mapping.pages = vdsop;
vma = _install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,