Commit 7175126a authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Thomas Gleixner
Browse files

x86/vdso: Allocate vvar page from C code 



Allocate the vvar page through the standard union vdso_data_store
and remove the custom linker script logic.

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-v1-14-b64f0842d512@linutronix.de
parent 7821571b

arch/x86/entry/vdso/vma.c

+5 −11
Original line number Diff line number Diff line
@@ -20,25 +20,19 @@ 
#include <asm/vgtod.h>

#include <asm/proto.h>

#include <asm/vdso.h>

#include <asm/vvar.h>

#include <asm/tlb.h>

#include <asm/page.h>

#include <asm/desc.h>

#include <asm/cpufeature.h>

#include <clocksource/hyperv_timer.h>



#undef _ASM_X86_VVAR_H

#define EMIT_VVAR(name, offset)	\

	const size_t name ## _offset = offset;

#include <asm/vvar.h>



struct vdso_data *arch_get_vdso_data(void *vvar_page)

{

	return (struct vdso_data *)(vvar_page + _vdso_data_offset);

	return (struct vdso_data *)vvar_page;

}

#undef EMIT_VVAR



DEFINE_VVAR(struct vdso_data, _vdso_data);

static union vdso_data_store vdso_data_store __page_aligned_data;

struct vdso_data *vdso_data = vdso_data_store.data;



unsigned int vclocks_used __read_mostly;
@@ -153,7 +147,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, 
	if (sym_offset == image->sym_vvar_page) {

		struct page *timens_page = find_timens_vvar_page(vma);



		pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;

		pfn = __pa_symbol(vdso_data) >> PAGE_SHIFT;



		/*

		 * If a task belongs to a time namespace then a namespace
@@ -200,7 +194,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, 
		if (!timens_page)

			return VM_FAULT_SIGBUS;



		pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;

		pfn = __pa_symbol(vdso_data) >> PAGE_SHIFT;

		return vmf_insert_pfn(vma, vmf->address, pfn);

	}

arch/x86/include/asm/vdso/vsyscall.h

+4 −2
Original line number Diff line number Diff line
@@ -8,20 +8,22 @@ 
#include <asm/vgtod.h>

#include <asm/vvar.h>



extern struct vdso_data *vdso_data;



/*

 * Update the vDSO data page to keep in sync with kernel timekeeping.

 */

static __always_inline

struct vdso_data *__x86_get_k_vdso_data(void)

{

	return _vdso_data;

	return vdso_data;

}

#define __arch_get_k_vdso_data __x86_get_k_vdso_data



static __always_inline

struct vdso_rng_data *__x86_get_k_vdso_rng_data(void)

{

	return (void *)&__vvar_page + __VDSO_RND_DATA_OFFSET;

	return (void *)vdso_data + __VDSO_RND_DATA_OFFSET;

}

#define __arch_get_k_vdso_rng_data __x86_get_k_vdso_rng_data

arch/x86/kernel/vmlinux.lds.S

+0 −23
Original line number Diff line number Diff line
@@ -193,29 +193,6 @@ SECTIONS 


	ORC_UNWIND_TABLE



	. = ALIGN(PAGE_SIZE);

	__vvar_page = .;



	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {

		/* work around gold bug 13023 */

		__vvar_beginning_hack = .;



		/* Place all vvars at the offsets in asm/vvar.h. */

#define EMIT_VVAR(name, offset)				\

		. = __vvar_beginning_hack + offset;	\

		*(.vvar_ ## name)

#include <asm/vvar.h>

#undef EMIT_VVAR



		/*

		 * Pad the rest of the page with zeros.  Otherwise the loader

		 * can leave garbage here.

		 */

		. = __vvar_beginning_hack + PAGE_SIZE;

	} :data



	. = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);



	/* Init code and data - will be freed after init */

	. = ALIGN(PAGE_SIZE);

	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {

arch/x86/tools/relocs.c

+0 −1
Original line number Diff line number Diff line
@@ -89,7 +89,6 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = { 
	"init_per_cpu__.*|"

	"__end_rodata_hpage_align|"

#endif

	"__vvar_page|"

	"_end)$"

};