mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
c39b1dcf05
The page containing VDSO time data is swapped with the one containing TIME namespace data when a process uses a non-root time namespace. For other data like powerpc specific data and RNG data, it means tracking whether time namespace is the root one or not to know which page to use. Simplify the logic behind by moving time data out of first data page so that the first data page which contains everything else always remains the first page. Time data is in the second or third page depending on selected time namespace. While we are playing with get_datapage macro, directly take into account the data offset inside the macro instead of adding that offset afterwards. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/0557d3ec898c1d0ea2fc59fa8757618e524c5d94.1727858295.git.christophe.leroy@csgroup.eu
65 lines
1.4 KiB
ArmAsm
65 lines
1.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* Access to the shared data page by the vDSO & syscall map
|
|
*
|
|
* Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
|
|
*/
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/ppc_asm.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/unistd.h>
|
|
#include <asm/vdso.h>
|
|
#include <asm/vdso_datapage.h>
|
|
|
|
.text
|
|
|
|
/*
|
|
* void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
|
|
*
|
|
* returns a pointer to the syscall map. the map is agnostic to the
|
|
* size of "long", unlike kernel bitops, it stores bits from top to
|
|
* bottom so that memory actually contains a linear bitmap
|
|
* check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
|
|
* 32 bits int at N >> 5.
|
|
*/
|
|
V_FUNCTION_BEGIN(__kernel_get_syscall_map)
|
|
.cfi_startproc
|
|
mflr r12
|
|
.cfi_register lr,r12
|
|
mr. r4,r3
|
|
get_datapage r3
|
|
mtlr r12
|
|
#ifdef __powerpc64__
|
|
addi r3,r3,CFG_SYSCALL_MAP64
|
|
#else
|
|
addi r3,r3,CFG_SYSCALL_MAP32
|
|
#endif
|
|
crclr cr0*4+so
|
|
beqlr
|
|
li r0,NR_syscalls
|
|
stw r0,0(r4)
|
|
blr
|
|
.cfi_endproc
|
|
V_FUNCTION_END(__kernel_get_syscall_map)
|
|
|
|
/*
|
|
* void unsigned long long __kernel_get_tbfreq(void);
|
|
*
|
|
* returns the timebase frequency in HZ
|
|
*/
|
|
V_FUNCTION_BEGIN(__kernel_get_tbfreq)
|
|
.cfi_startproc
|
|
mflr r12
|
|
.cfi_register lr,r12
|
|
get_datapage r3
|
|
#ifndef __powerpc64__
|
|
lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
|
|
#endif
|
|
PPC_LL r3,CFG_TB_TICKS_PER_SEC(r3)
|
|
mtlr r12
|
|
crclr cr0*4+so
|
|
blr
|
|
.cfi_endproc
|
|
V_FUNCTION_END(__kernel_get_tbfreq)
|