Commit ac1a42f4 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Thomas Gleixner
Browse files

vdso: Remove remnants of architecture-specific time storage 



All users of the time releated parts of the vDSO are now using the generic
storage implementation. Remove the therefore unnecessary compatibility
accessor functions and symbols.

Co-developed-by: default avatarNam Cao <namcao@linutronix.de>
Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
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/20250204-vdso-store-rng-v3-18-13a4669dfc8c@linutronix.de
parent 998a8a26

include/asm-generic/vdso/vsyscall.h

+4 −16
Original line number Diff line number Diff line
@@ -20,31 +20,19 @@ static __always_inline const struct vdso_rng_data *__arch_get_vdso_u_rng_data(vo 
}

#endif



#else  /* !CONFIG_GENERIC_VDSO_DATA_STORE */



#ifndef __arch_get_k_vdso_data

static __always_inline struct vdso_data *__arch_get_k_vdso_data(void)

{

	return NULL;

}

#endif /* __arch_get_k_vdso_data */

#define vdso_k_time_data __arch_get_k_vdso_data()



#define __arch_get_vdso_u_time_data __arch_get_vdso_data



#endif /* CONFIG_GENERIC_VDSO_DATA_STORE */



#ifndef __arch_update_vsyscall

static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata)

static __always_inline void __arch_update_vsyscall(struct vdso_time_data *vdata)

{

}

#endif /* __arch_update_vsyscall */



#ifndef __arch_sync_vdso_data

static __always_inline void __arch_sync_vdso_data(struct vdso_data *vdata)

#ifndef __arch_sync_vdso_time_data

static __always_inline void __arch_sync_vdso_time_data(struct vdso_time_data *vdata)

{

}

#endif /* __arch_sync_vdso_data */

#endif /* __arch_sync_vdso_time_data */



#endif /* !__ASSEMBLY__ */

include/linux/time_namespace.h

+0 −3
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
#include <linux/ns_common.h>

#include <linux/err.h>

#include <linux/time64.h>

#include <vdso/datapage.h>



struct user_namespace;

extern struct user_namespace init_user_ns;
@@ -166,6 +165,4 @@ static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) 
}

#endif



struct vdso_data *arch_get_vdso_data(void *vvar_page);



#endif /* _LINUX_TIMENS_H */

include/vdso/datapage.h

+1 −18
Original line number Diff line number Diff line
@@ -128,8 +128,6 @@ struct vdso_time_data { 
	struct arch_vdso_time_data arch_data;

};



#define vdso_data vdso_time_data



/**

 * struct vdso_rng_data - vdso RNG state information

 * @generation:	counter representing the number of RNG reseeds
@@ -149,10 +147,7 @@ struct vdso_rng_data { 
 * With the hidden visibility, the compiler simply generates a PC-relative

 * relocation, and this is what we need.

 */

#ifndef CONFIG_GENERIC_VDSO_DATA_STORE

extern struct vdso_time_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));

extern struct vdso_time_data _timens_data[CS_BASES] __attribute__((visibility("hidden")));

#else

#ifdef CONFIG_GENERIC_VDSO_DATA_STORE

extern struct vdso_time_data vdso_u_time_data[CS_BASES] __attribute__((visibility("hidden")));

extern struct vdso_rng_data vdso_u_rng_data __attribute__((visibility("hidden")));

extern struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden")));
@@ -160,17 +155,6 @@ extern struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden" 
extern struct vdso_time_data *vdso_k_time_data;

extern struct vdso_rng_data *vdso_k_rng_data;

extern struct vdso_arch_data *vdso_k_arch_data;

#endif



/**

 * union vdso_data_store - Generic vDSO data page

 */

union vdso_data_store {

	struct vdso_time_data	data[CS_BASES];

	u8			page[1U << CONFIG_PAGE_SHIFT];

};



#ifdef CONFIG_GENERIC_VDSO_DATA_STORE



#define VDSO_ARCH_DATA_SIZE ALIGN(sizeof(struct vdso_arch_data), PAGE_SIZE)

#define VDSO_ARCH_DATA_PAGES (VDSO_ARCH_DATA_SIZE >> PAGE_SHIFT)
@@ -189,7 +173,6 @@ enum vdso_pages { 
/*

 * The generic vDSO implementation requires that gettimeofday.h

 * provides:

 * - __arch_get_vdso_data(): to get the vdso datapage.

 * - __arch_get_hw_counter(): to get the hw counter based on the

 *   clock_mode.

 * - gettimeofday_fallback(): fallback for gettimeofday.

include/vdso/helpers.h

+4 −4
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
#include <asm/barrier.h>

#include <vdso/datapage.h>



static __always_inline u32 vdso_read_begin(const struct vdso_data *vd)

static __always_inline u32 vdso_read_begin(const struct vdso_time_data *vd)

{

	u32 seq;
@@ -18,7 +18,7 @@ static __always_inline u32 vdso_read_begin(const struct vdso_data *vd) 
	return seq;

}



static __always_inline u32 vdso_read_retry(const struct vdso_data *vd,

static __always_inline u32 vdso_read_retry(const struct vdso_time_data *vd,

					   u32 start)

{

	u32 seq;
@@ -28,7 +28,7 @@ static __always_inline u32 vdso_read_retry(const struct vdso_data *vd, 
	return seq != start;

}



static __always_inline void vdso_write_begin(struct vdso_data *vd)

static __always_inline void vdso_write_begin(struct vdso_time_data *vd)

{

	/*

	 * WRITE_ONCE() is required otherwise the compiler can validly tear
@@ -40,7 +40,7 @@ static __always_inline void vdso_write_begin(struct vdso_data *vd) 
	smp_wmb();

}



static __always_inline void vdso_write_end(struct vdso_data *vd)

static __always_inline void vdso_write_end(struct vdso_time_data *vd)

{

	smp_wmb();

	/*

kernel/time/namespace.c

+6 −6
Original line number Diff line number Diff line
@@ -165,18 +165,18 @@ static struct timens_offset offset_from_ts(struct timespec64 off) 
 *     HVCLOCK

 *     VVAR

 *

 * The check for vdso_data->clock_mode is in the unlikely path of

 * The check for vdso_time_data->clock_mode is in the unlikely path of

 * the seq begin magic. So for the non-timens case most of the time

 * 'seq' is even, so the branch is not taken.

 *

 * If 'seq' is odd, i.e. a concurrent update is in progress, the extra check

 * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the

 * for vdso_time_data->clock_mode is a non-issue. The task is spin waiting for the

 * update to finish and for 'seq' to become even anyway.

 *

 * Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which

 * Timens page has vdso_time_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which

 * enforces the time namespace handling path.

 */

static void timens_setup_vdso_data(struct vdso_data *vdata,

static void timens_setup_vdso_data(struct vdso_time_data *vdata,

				   struct time_namespace *ns)

{

	struct timens_offset *offset = vdata->offset;
@@ -219,7 +219,7 @@ static DEFINE_MUTEX(offset_lock); 
static void timens_set_vvar_page(struct task_struct *task,

				struct time_namespace *ns)

{

	struct vdso_data *vdata;

	struct vdso_time_data *vdata;

	unsigned int i;



	if (ns == &init_time_ns)
@@ -235,7 +235,7 @@ static void timens_set_vvar_page(struct task_struct *task, 
		goto out;



	ns->frozen_offsets = true;

	vdata = arch_get_vdso_data(page_address(ns->vvar_page));

	vdata = page_address(ns->vvar_page);



	for (i = 0; i < CS_BASES; i++)

		timens_setup_vdso_data(&vdata[i], ns);