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arm64: vdso: Use only one single vvar mapping

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The vvar mapping is the same for all processes. Use a single mapping to
simplify the logic and align it with the other architectures.

In addition this will enable the move of the vvar handling into generic code.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-5-b64f0842d512@linutronix.de
This commit is contained in:
Thomas Weißschuh 2024-10-10 09:01:07 +02:00 • committed by Thomas Gleixner
parent 0973fed6a5
commit 461c966866
1 changed files with 13 additions and 30 deletions
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43
arch/arm64/kernel/vdso.c
View file

@ -38,8 +38,6 @@ struct vdso_abi_info {
const char *vdso_code_start;
const char *vdso_code_end;
unsigned long vdso_pages;
/* Data Mapping */
struct vm_special_mapping *dm;
/* Code Mapping */
struct vm_special_mapping *cm;
};
@ -112,6 +110,8 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
return (struct vdso_data *)(vvar_page);
}
static const struct vm_special_mapping vvar_map;
/*
* The vvar mapping contains data for a specific time namespace, so when a task
* changes namespace we must unmap its vvar data for the old namespace.
@ -128,12 +128,8 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm))
if (vma_is_special_mapping(vma, &vvar_map))
zap_vma_pages(vma);
#ifdef CONFIG_COMPAT_VDSO
if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm))
zap_vma_pages(vma);
#endif
}
mmap_read_unlock(mm);
@ -175,6 +171,11 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
return vmf_insert_pfn(vma, vmf->address, pfn);
}
static const struct vm_special_mapping vvar_map = {
.name = "[vvar]",
.fault = vvar_fault,
};
static int __setup_additional_pages(enum vdso_abi abi,
struct mm_struct *mm,
struct linux_binprm *bprm,
@ -198,7 +199,7 @@ static int __setup_additional_pages(enum vdso_abi abi,
ret = _install_special_mapping(mm, vdso_base, VVAR_NR_PAGES * PAGE_SIZE,
VM_READ|VM_MAYREAD|VM_PFNMAP,
vdso_info[abi].dm);
&vvar_map);
if (IS_ERR(ret))
goto up_fail;
@ -228,7 +229,6 @@ up_fail:
enum aarch32_map {
AA32_MAP_VECTORS, /* kuser helpers */
AA32_MAP_SIGPAGE,
AA32_MAP_VVAR,
AA32_MAP_VDSO,
};
@ -253,10 +253,6 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
.pages = &aarch32_sig_page,
.mremap = aarch32_sigpage_mremap,
},
[AA32_MAP_VVAR] = {
.name = "[vvar]",
.fault = vvar_fault,
},
[AA32_MAP_VDSO] = {
.name = "[vdso]",
.mremap = vdso_mremap,
@ -306,7 +302,6 @@ static int __init __aarch32_alloc_vdso_pages(void)
if (!IS_ENABLED(CONFIG_COMPAT_VDSO))
return 0;
vdso_info[VDSO_ABI_AA32].dm = &aarch32_vdso_maps[AA32_MAP_VVAR];
vdso_info[VDSO_ABI_AA32].cm = &aarch32_vdso_maps[AA32_MAP_VDSO];
return __vdso_init(VDSO_ABI_AA32);
@ -401,26 +396,14 @@ out:
}
#endif /* CONFIG_COMPAT */
enum aarch64_map {
AA64_MAP_VVAR,
AA64_MAP_VDSO,
};
static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = {
[AA64_MAP_VVAR] = {
.name = "[vvar]",
.fault = vvar_fault,
},
[AA64_MAP_VDSO] = {
.name = "[vdso]",
.mremap = vdso_mremap,
},
static struct vm_special_mapping aarch64_vdso_map __ro_after_init = {
.name = "[vdso]",
.mremap = vdso_mremap,
};
static int __init vdso_init(void)
{
vdso_info[VDSO_ABI_AA64].dm = &aarch64_vdso_maps[AA64_MAP_VVAR];
vdso_info[VDSO_ABI_AA64].cm = &aarch64_vdso_maps[AA64_MAP_VDSO];
vdso_info[VDSO_ABI_AA64].cm = &aarch64_vdso_map;
return __vdso_init(VDSO_ABI_AA64);
}