From 1fc350eed627762f4f6db3f35776d481e7f02c5c Mon Sep 17 00:00:00 2001 From: Tiwei Bie Date: Wed, 12 Feb 2025 12:57:56 +0800 Subject: [PATCH] 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 Link: https://patch.msgid.link/20250212045756.164977-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg --- arch/x86/um/vdso/vma.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c index f238f7b33cdd9..dc8dfb2abd809 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, -- 2.39.5