linux/include/vdso/datapage.h
Anna-Maria Behnsen 8b3843ae36 vdso/datapage: Quick fix - use asm/page-def.h for ARM64
The vdso rework for the generic union vdso_data_store broke compat VDSO on
arm64:

In file included from arch/arm64/include/asm/lse.h:5,
		 from arch/arm64/include/asm/cmpxchg.h:14,
		 from arch/arm64/include/asm/atomic.h:16,
		 from include/linux/atomic.h:7,
		 from include/asm-generic/bitops/atomic.h:5,
		 from arch/arm64/include/asm/bitops.h:25,
		 from include/linux/bitops.h:68,
		 from arch/arm64/include/asm/memory.h:209,
		 from arch/arm64/include/asm/page.h:46,
		 from include/vdso/datapage.h:22,
		 from lib/vdso/gettimeofday.c:5,
		 from <command-line>:
arch/arm64/include/asm/atomic_ll_sc.h:298:9: error: unknown type name 'u128'
  298 |         u128 full;
      |         ^~~~
arch/arm64/include/asm/atomic_ll_sc.h:305:24: error: unknown type name 'u128'
  305 | static __always_inline u128
	 \
      |

The reason is the include of asm/page.h which in turn includes headers
which are outside the scope of compat VDSO. The only reason for the
asm/page.h include is the required definition of PAGE_SIZE. But as arm64
defines PAGE_SIZE in asm/page-def.h without extra header includes, this
could be used instead.

Caution: this is a quick fix only! The final fix is an upcoming cleanup of
Arnd which consolidates PAGE_SIZE definition. After the cleanup, the
include of asm/page.h to access PAGE_SIZE is no longer required.

Fixes: a0d2fcd62a ("vdso/ARM: Make union vdso_data_store available for all architectures")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240226175023.56679-1-anna-maria@linutronix.de
Link: https://lore.kernel.org/lkml/CA+G9fYtrXXm_KO9fNPz3XaRxHV7UD_yQp-TEuPQrNRHU+_0W_Q@mail.gmail.com/
2024-02-26 23:13:41 +01:00

157 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __VDSO_DATAPAGE_H
#define __VDSO_DATAPAGE_H
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <uapi/linux/time.h>
#include <uapi/linux/types.h>
#include <uapi/asm-generic/errno-base.h>
#include <vdso/bits.h>
#include <vdso/clocksource.h>
#include <vdso/ktime.h>
#include <vdso/limits.h>
#include <vdso/math64.h>
#include <vdso/processor.h>
#include <vdso/time.h>
#include <vdso/time32.h>
#include <vdso/time64.h>
#ifdef CONFIG_ARM64
#include <asm/page-def.h>
#else
#include <asm/page.h>
#endif
#ifdef CONFIG_ARCH_HAS_VDSO_DATA
#include <asm/vdso/data.h>
#else
struct arch_vdso_data {};
#endif
#define VDSO_BASES (CLOCK_TAI + 1)
#define VDSO_HRES (BIT(CLOCK_REALTIME) | \
BIT(CLOCK_MONOTONIC) | \
BIT(CLOCK_BOOTTIME) | \
BIT(CLOCK_TAI))
#define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \
BIT(CLOCK_MONOTONIC_COARSE))
#define VDSO_RAW (BIT(CLOCK_MONOTONIC_RAW))
#define CS_HRES_COARSE 0
#define CS_RAW 1
#define CS_BASES (CS_RAW + 1)
/**
* struct vdso_timestamp - basetime per clock_id
* @sec: seconds
* @nsec: nanoseconds
*
* There is one vdso_timestamp object in vvar for each vDSO-accelerated
* clock_id. For high-resolution clocks, this encodes the time
* corresponding to vdso_data.cycle_last. For coarse clocks this encodes
* the actual time.
*
* To be noticed that for highres clocks nsec is left-shifted by
* vdso_data.cs[x].shift.
*/
struct vdso_timestamp {
u64 sec;
u64 nsec;
};
/**
* struct vdso_data - vdso datapage representation
* @seq: timebase sequence counter
* @clock_mode: clock mode
* @cycle_last: timebase at clocksource init
* @mask: clocksource mask
* @mult: clocksource multiplier
* @shift: clocksource shift
* @basetime[clock_id]: basetime per clock_id
* @offset[clock_id]: time namespace offset per clock_id
* @tz_minuteswest: minutes west of Greenwich
* @tz_dsttime: type of DST correction
* @hrtimer_res: hrtimer resolution
* @__unused: unused
* @arch_data: architecture specific data (optional, defaults
* to an empty struct)
*
* vdso_data will be accessed by 64 bit and compat code at the same time
* so we should be careful before modifying this structure.
*
* @basetime is used to store the base time for the system wide time getter
* VVAR page.
*
* @offset is used by the special time namespace VVAR pages which are
* installed instead of the real VVAR page. These namespace pages must set
* @seq to 1 and @clock_mode to VDSO_CLOCKMODE_TIMENS to force the code into
* the time namespace slow path. The namespace aware functions retrieve the
* real system wide VVAR page, read host time and add the per clock offset.
* For clocks which are not affected by time namespace adjustment the
* offset must be zero.
*/
struct vdso_data {
u32 seq;
s32 clock_mode;
u64 cycle_last;
u64 mask;
u32 mult;
u32 shift;
union {
struct vdso_timestamp basetime[VDSO_BASES];
struct timens_offset offset[VDSO_BASES];
};
s32 tz_minuteswest;
s32 tz_dsttime;
u32 hrtimer_res;
u32 __unused;
struct arch_vdso_data arch_data;
};
/*
* We use the hidden visibility to prevent the compiler from generating a GOT
* relocation. Not only is going through a GOT useless (the entry couldn't and
* must not be overridden by another library), it does not even work: the linker
* cannot generate an absolute address to the data page.
*
* With the hidden visibility, the compiler simply generates a PC-relative
* relocation, and this is what we need.
*/
extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));
extern struct vdso_data _timens_data[CS_BASES] __attribute__((visibility("hidden")));
/**
* union vdso_data_store - Generic vDSO data page
*/
union vdso_data_store {
struct vdso_data data[CS_BASES];
u8 page[PAGE_SIZE];
};
/*
* 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.
* - clock_gettime_fallback(): fallback for clock_gettime.
* - clock_getres_fallback(): fallback for clock_getres.
*/
#ifdef ENABLE_COMPAT_VDSO
#include <asm/vdso/compat_gettimeofday.h>
#else
#include <asm/vdso/gettimeofday.h>
#endif /* ENABLE_COMPAT_VDSO */
#endif /* !__ASSEMBLY__ */
#endif /* __VDSO_DATAPAGE_H */