[PATCH v1 5/9] powerpc/vdso: move to _install_special_mapping() and remove arch_vma_name()

From: Christophe Leroy
Date: Tue Aug 25 2020 - 09:54:35 EST


>From commit 2fea7f6c98f5 ("arm64: vdso: move to
_install_special_mapping and remove arch_vma_name").

Use the new _install_special_mapping() API added by
commit a62c34bd2a8a ("x86, mm: Improve _install_special_mapping
and fix x86 vdso naming") which obsolete install_special_mapping().

And remove arch_vma_name() as the name is handled by the new API.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/vdso.c | 59 +++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index bbb69832fd46..4ccfc0dc96b5 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -47,7 +47,6 @@

static unsigned int vdso32_pages;
static void *vdso32_kbase;
-static struct page **vdso32_pagelist;
unsigned long vdso32_sigtramp;
unsigned long vdso32_rt_sigtramp;

@@ -56,7 +55,6 @@ extern char vdso32_start, vdso32_end;
extern char vdso64_start, vdso64_end;
static void *vdso64_kbase = &vdso64_start;
static unsigned int vdso64_pages;
-static struct page **vdso64_pagelist;
#ifdef CONFIG_PPC64
unsigned long vdso64_rt_sigtramp;
#endif /* CONFIG_PPC64 */
@@ -117,6 +115,14 @@ struct lib64_elfinfo
};


+static struct vm_special_mapping vdso32_spec __ro_after_init = {
+ .name = "[vdso]",
+};
+
+static struct vm_special_mapping vdso64_spec __ro_after_init = {
+ .name = "[vdso]",
+};
+
/*
* This is called from binfmt_elf, we create the special vma for the
* vDSO and insert it into the mm struct tree
@@ -124,7 +130,8 @@ struct lib64_elfinfo
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
- struct page **vdso_pagelist;
+ struct vm_special_mapping *vdso_spec;
+ struct vm_area_struct *vma;
unsigned long vdso_pages;
unsigned long vdso_base;
int rc;
@@ -133,11 +140,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return 0;

if (is_32bit_task()) {
- vdso_pagelist = vdso32_pagelist;
+ vdso_spec = &vdso32_spec;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
} else {
- vdso_pagelist = vdso64_pagelist;
+ vdso_spec = &vdso64_spec;
vdso_pages = vdso64_pages;
/*
* On 64bit we don't have a preferred map address. This
@@ -194,12 +201,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
* It's fine to use that for setting breakpoints in the vDSO code
* pages though.
*/
- rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso_pagelist);
- if (rc) {
+ vma = _install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
+ VM_READ | VM_EXEC | VM_MAYREAD |
+ VM_MAYWRITE | VM_MAYEXEC, vdso_spec);
+ if (IS_ERR(vma)) {
current->mm->context.vdso_base = 0;
+ rc = PTR_ERR(vma);
goto fail_mmapsem;
}

@@ -211,15 +218,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return rc;
}

-const char *arch_vma_name(struct vm_area_struct *vma)
-{
- if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
- return "[vdso]";
- return NULL;
-}
-
-
-
#ifdef CONFIG_VDSO32
static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
unsigned long *size)
@@ -685,6 +683,7 @@ early_initcall(vdso_getcpu_init);
static int __init vdso_init(void)
{
int i;
+ struct page **pagelist;

#ifdef CONFIG_PPC64
/*
@@ -740,27 +739,29 @@ static int __init vdso_init(void)

if (IS_ENABLED(CONFIG_VDSO32)) {
/* Make sure pages are in the correct state */
- vdso32_pagelist = kcalloc(vdso32_pages + 1, sizeof(struct page *),
- GFP_KERNEL);
- if (!vdso32_pagelist)
+ pagelist = kcalloc(vdso32_pages + 1, sizeof(struct page *), GFP_KERNEL);
+ if (!pagelist)
goto alloc_failed;

for (i = 0; i < vdso32_pages; i++)
- vdso32_pagelist[i] = virt_to_page(vdso32_kbase + i * PAGE_SIZE);
+ pagelist[i] = virt_to_page(vdso32_kbase + i * PAGE_SIZE);
+
+ pagelist[i++] = virt_to_page(vdso_data);

- vdso32_pagelist[i] = virt_to_page(vdso_data);
+ vdso32_spec.pages = pagelist;
}

if (IS_ENABLED(CONFIG_PPC64)) {
- vdso64_pagelist = kcalloc(vdso64_pages + 1, sizeof(struct page *),
- GFP_KERNEL);
- if (!vdso64_pagelist)
+ pagelist = kcalloc(vdso64_pages + 1, sizeof(struct page *), GFP_KERNEL);
+ if (!pagelist)
goto alloc_failed;

for (i = 0; i < vdso64_pages; i++)
- vdso64_pagelist[i] = virt_to_page(vdso64_kbase + i * PAGE_SIZE);
+ pagelist[i] = virt_to_page(vdso64_kbase + i * PAGE_SIZE);
+
+ pagelist[i++] = virt_to_page(vdso_data);

- vdso64_pagelist[i] = virt_to_page(vdso_data);
+ vdso64_spec.pages = pagelist;
}

smp_wmb();
--
2.25.0