Commit d34b6075 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Thomas Gleixner
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riscv: vdso: Use only one single vvar mapping 



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: default avatarThomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-6-b64f0842d512@linutronix.de
parent 461c9668

arch/riscv/kernel/vdso.c

+17 −35
Original line number Diff line number Diff line
@@ -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))

			zap_vma_pages(vma);

#ifdef CONFIG_COMPAT

		if (vma_is_special_mapping(vma, compat_vdso_info.dm))

		if (vma_is_special_mapping(vma, &rv_vvar_map))

			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] = {

static const struct vm_special_mapping rv_vvar_map = {

	.name   = "[vvar]",

	.fault = vvar_fault,

	},

	[RV_VDSO_MAP_VDSO] = {

};



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] = {

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;