1713ce7c43
Define the layout of the data structure shared between kernel and userspace. Track the vdso address in the mm_context; needed for communicating AT_SYSINFO_EHDR to the ELF loader. Add declarations for arm_install_vdso; implementation is in a following patch. Define AT_SYSINFO_EHDR, and, if CONFIG_VDSO=y, report the vdso shared object address via the ELF auxiliary vector. Note - this adds the AT_SYSINFO_EHDR in a new user-visible header asm/auxvec.h; this is consistent with other architectures. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/*
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* Adapted from arm64 version.
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*
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* Copyright (C) 2012 ARM Limited
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_VDSO_DATAPAGE_H
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#define __ASM_VDSO_DATAPAGE_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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#include <asm/page.h>
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/* Try to be cache-friendly on systems that don't implement the
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* generic timer: fit the unconditionally updated fields in the first
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* 32 bytes.
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*/
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struct vdso_data {
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u32 seq_count; /* sequence count - odd during updates */
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u16 tk_is_cntvct; /* fall back to syscall if false */
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u16 cs_shift; /* clocksource shift */
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u32 xtime_coarse_sec; /* coarse time */
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u32 xtime_coarse_nsec;
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u32 wtm_clock_sec; /* wall to monotonic offset */
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u32 wtm_clock_nsec;
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u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */
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u32 cs_mult; /* clocksource multiplier */
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u64 cs_cycle_last; /* last cycle value */
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u64 cs_mask; /* clocksource mask */
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u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */
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u32 tz_minuteswest; /* timezone info for gettimeofday(2) */
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u32 tz_dsttime;
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};
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union vdso_data_store {
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struct vdso_data data;
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u8 page[PAGE_SIZE];
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};
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#endif /* !__ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* __ASM_VDSO_DATAPAGE_H */
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