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riscv: 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>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-6-b64f0842d512@linutronix.de
This commit is contained in:
Thomas Weißschuh 2024-10-10 09:01:08 +02:00 committed by Thomas Gleixner
parent 461c966866
commit d34b60752f
1 changed files with 17 additions and 35 deletions
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52
arch/riscv/kernel/vdso.c
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@ -23,11 +23,6 @@ enum vvar_pages {
VVAR_NR_PAGES,
};
enum rv_vdso_map {
RV_VDSO_MAP_VVAR,
RV_VDSO_MAP_VDSO,
};
#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
static union vdso_data_store vdso_data_store __page_aligned_data;
@ -38,8 +33,6 @@ struct __vdso_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;
};
@ -92,6 +85,8 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
return (struct vdso_data *)(vvar_page);
}
static const struct vm_special_mapping rv_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.
@ -108,12 +103,8 @@ 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.dm))
if (vma_is_special_mapping(vma, &rv_vvar_map))
zap_vma_pages(vma);
#ifdef CONFIG_COMPAT
if (vma_is_special_mapping(vma, compat_vdso_info.dm))
zap_vma_pages(vma);
#endif
}
mmap_read_unlock(mm);
@ -155,43 +146,34 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
return vmf_insert_pfn(vma, vmf->address, pfn);
}
static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
[RV_VDSO_MAP_VVAR] = {
.name = "[vvar]",
.fault = vvar_fault,
},
[RV_VDSO_MAP_VDSO] = {
.name = "[vdso]",
.mremap = vdso_mremap,
},
static const struct vm_special_mapping rv_vvar_map = {
.name = "[vvar]",
.fault = vvar_fault,
};
static struct vm_special_mapping rv_vdso_map __ro_after_init = {
.name = "[vdso]",
.mremap = vdso_mremap,
};
static struct __vdso_info vdso_info __ro_after_init = {
.name = "vdso",
.vdso_code_start = vdso_start,
.vdso_code_end = vdso_end,
.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
.cm = &rv_vdso_map,
};
#ifdef CONFIG_COMPAT
static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = {
[RV_VDSO_MAP_VVAR] = {
.name = "[vvar]",
.fault = vvar_fault,
},
[RV_VDSO_MAP_VDSO] = {
.name = "[vdso]",
.mremap = vdso_mremap,
},
static struct vm_special_mapping rv_compat_vdso_map __ro_after_init = {
.name = "[vdso]",
.mremap = vdso_mremap,
};
static struct __vdso_info compat_vdso_info __ro_after_init = {
.name = "compat_vdso",
.vdso_code_start = compat_vdso_start,
.vdso_code_end = compat_vdso_end,
.dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR],
.cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO],
.cm = &rv_compat_vdso_map,
};
#endif
@ -227,7 +209,7 @@ static int __setup_additional_pages(struct mm_struct *mm,
}
ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
(VM_READ | VM_MAYREAD | VM_PFNMAP), &rv_vvar_map);
if (IS_ERR(ret))
goto up_fail;