ARM: 8329/1: miscellaneous vdso infrastructure, preparation

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>
This commit is contained in:
Nathan Lynch 2015-03-25 19:13:16 +01:00 коммит произвёл Russell King
Родитель c517d838eb
Коммит 1713ce7c43
8 изменённых файлов: 113 добавлений и 1 удалений

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@ -1,6 +1,5 @@
generic-y += auxvec.h
generic-y += bitsperlong.h
generic-y += cputime.h
generic-y += current.h

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@ -0,0 +1 @@
#include <uapi/asm/auxvec.h>

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@ -1,7 +1,9 @@
#ifndef __ASMARM_ELF_H
#define __ASMARM_ELF_H
#include <asm/auxvec.h>
#include <asm/hwcap.h>
#include <asm/vdso_datapage.h>
/*
* ELF register definitions..
@ -130,6 +132,13 @@ extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk
#ifdef CONFIG_MMU
#ifdef CONFIG_VDSO
#define ARCH_DLINFO \
do { \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(elf_addr_t)current->mm->context.vdso); \
} while (0)
#endif
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
struct linux_binprm;
int arch_setup_additional_pages(struct linux_binprm *, int);

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@ -11,6 +11,9 @@ typedef struct {
#endif
unsigned int vmalloc_seq;
unsigned long sigpage;
#ifdef CONFIG_VDSO
unsigned long vdso;
#endif
} mm_context_t;
#ifdef CONFIG_CPU_HAS_ASID

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@ -0,0 +1,32 @@
#ifndef __ASM_VDSO_H
#define __ASM_VDSO_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
struct mm_struct;
#ifdef CONFIG_VDSO
void arm_install_vdso(struct mm_struct *mm, unsigned long addr);
extern char vdso_start, vdso_end;
extern unsigned int vdso_total_pages;
#else /* CONFIG_VDSO */
static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
{
}
#define vdso_total_pages 0
#endif /* CONFIG_VDSO */
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* __ASM_VDSO_H */

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@ -0,0 +1,60 @@
/*
* Adapted from arm64 version.
*
* Copyright (C) 2012 ARM Limited
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_VDSO_DATAPAGE_H
#define __ASM_VDSO_DATAPAGE_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <asm/page.h>
/* Try to be cache-friendly on systems that don't implement the
* generic timer: fit the unconditionally updated fields in the first
* 32 bytes.
*/
struct vdso_data {
u32 seq_count; /* sequence count - odd during updates */
u16 tk_is_cntvct; /* fall back to syscall if false */
u16 cs_shift; /* clocksource shift */
u32 xtime_coarse_sec; /* coarse time */
u32 xtime_coarse_nsec;
u32 wtm_clock_sec; /* wall to monotonic offset */
u32 wtm_clock_nsec;
u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */
u32 cs_mult; /* clocksource multiplier */
u64 cs_cycle_last; /* last cycle value */
u64 cs_mask; /* clocksource mask */
u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */
u32 tz_minuteswest; /* timezone info for gettimeofday(2) */
u32 tz_dsttime;
};
union vdso_data_store {
struct vdso_data data;
u8 page[PAGE_SIZE];
};
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* __ASM_VDSO_DATAPAGE_H */

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@ -1,6 +1,7 @@
# UAPI Header export list
include include/uapi/asm-generic/Kbuild.asm
header-y += auxvec.h
header-y += byteorder.h
header-y += fcntl.h
header-y += hwcap.h

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@ -0,0 +1,7 @@
#ifndef __ASM_AUXVEC_H
#define __ASM_AUXVEC_H
/* VDSO location */
#define AT_SYSINFO_EHDR 33
#endif