mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-29 05:55:02 +08:00
ce3dc44749
With virtually mapped kernel stacks the kernel stack overflow detection is now fault based, every stack has a guard page in the vmalloc space. The panic_stack is renamed to nodat_stack and is used for all function that need to run without DAT, e.g. memcpy_real or do_start_kdump. The main effect is a reduction in the kernel image size as with vmap stacks the old style overflow checking that adds two instructions per function is not needed anymore. Result from bloat-o-meter: add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042) In regard to performance the micro-benchmark for fork has a hit of a few microseconds, allocating 4 pages in vmalloc space is more expensive compare to an order-2 page allocation. But with real workload I could not find a noticeable difference. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
150 lines
3.2 KiB
ArmAsm
150 lines
3.2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* arch/s390/kernel/base.S
|
|
*
|
|
* Copyright IBM Corp. 2006, 2007
|
|
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
|
|
* Michael Holzheu <holzheu@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/nospec-insn.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/sigp.h>
|
|
|
|
GEN_BR_THUNK %r9
|
|
GEN_BR_THUNK %r14
|
|
|
|
ENTRY(s390_base_mcck_handler)
|
|
basr %r13,0
|
|
0: lg %r15,__LC_NODAT_STACK # load panic stack
|
|
aghi %r15,-STACK_FRAME_OVERHEAD
|
|
larl %r1,s390_base_mcck_handler_fn
|
|
lg %r9,0(%r1)
|
|
ltgr %r9,%r9
|
|
jz 1f
|
|
BASR_EX %r14,%r9
|
|
1: la %r1,4095
|
|
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)
|
|
lpswe __LC_MCK_OLD_PSW
|
|
|
|
.section .bss
|
|
.align 8
|
|
.globl s390_base_mcck_handler_fn
|
|
s390_base_mcck_handler_fn:
|
|
.quad 0
|
|
.previous
|
|
|
|
ENTRY(s390_base_ext_handler)
|
|
stmg %r0,%r15,__LC_SAVE_AREA_ASYNC
|
|
basr %r13,0
|
|
0: aghi %r15,-STACK_FRAME_OVERHEAD
|
|
larl %r1,s390_base_ext_handler_fn
|
|
lg %r9,0(%r1)
|
|
ltgr %r9,%r9
|
|
jz 1f
|
|
BASR_EX %r14,%r9
|
|
1: lmg %r0,%r15,__LC_SAVE_AREA_ASYNC
|
|
ni __LC_EXT_OLD_PSW+1,0xfd # clear wait state bit
|
|
lpswe __LC_EXT_OLD_PSW
|
|
|
|
.section .bss
|
|
.align 8
|
|
.globl s390_base_ext_handler_fn
|
|
s390_base_ext_handler_fn:
|
|
.quad 0
|
|
.previous
|
|
|
|
ENTRY(s390_base_pgm_handler)
|
|
stmg %r0,%r15,__LC_SAVE_AREA_SYNC
|
|
basr %r13,0
|
|
0: aghi %r15,-STACK_FRAME_OVERHEAD
|
|
larl %r1,s390_base_pgm_handler_fn
|
|
lg %r9,0(%r1)
|
|
ltgr %r9,%r9
|
|
jz 1f
|
|
BASR_EX %r14,%r9
|
|
lmg %r0,%r15,__LC_SAVE_AREA_SYNC
|
|
lpswe __LC_PGM_OLD_PSW
|
|
1: lpswe disabled_wait_psw-0b(%r13)
|
|
|
|
.align 8
|
|
disabled_wait_psw:
|
|
.quad 0x0002000180000000,0x0000000000000000 + s390_base_pgm_handler
|
|
|
|
.section .bss
|
|
.align 8
|
|
.globl s390_base_pgm_handler_fn
|
|
s390_base_pgm_handler_fn:
|
|
.quad 0
|
|
.previous
|
|
|
|
#
|
|
# Calls diag 308 subcode 1 and continues execution
|
|
#
|
|
ENTRY(diag308_reset)
|
|
larl %r4,.Lctlregs # Save control registers
|
|
stctg %c0,%c15,0(%r4)
|
|
lg %r2,0(%r4) # Disable lowcore protection
|
|
nilh %r2,0xefff
|
|
larl %r4,.Lctlreg0
|
|
stg %r2,0(%r4)
|
|
lctlg %c0,%c0,0(%r4)
|
|
larl %r4,.Lfpctl # Floating point control register
|
|
stfpc 0(%r4)
|
|
larl %r4,.Lprefix # Save prefix register
|
|
stpx 0(%r4)
|
|
larl %r4,.Lprefix_zero # Set prefix register to 0
|
|
spx 0(%r4)
|
|
larl %r4,.Lcontinue_psw # Save PSW flags
|
|
epsw %r2,%r3
|
|
stm %r2,%r3,0(%r4)
|
|
larl %r4,.Lrestart_psw # Setup restart PSW at absolute 0
|
|
lghi %r3,0
|
|
lg %r4,0(%r4) # Save PSW
|
|
sturg %r4,%r3 # Use sturg, because of large pages
|
|
lghi %r1,1
|
|
lghi %r0,0
|
|
diag %r0,%r1,0x308
|
|
.Lrestart_part2:
|
|
lhi %r0,0 # Load r0 with zero
|
|
lhi %r1,2 # Use mode 2 = ESAME (dump)
|
|
sigp %r1,%r0,SIGP_SET_ARCHITECTURE # Switch to ESAME mode
|
|
sam64 # Switch to 64 bit addressing mode
|
|
larl %r4,.Lctlregs # Restore control registers
|
|
lctlg %c0,%c15,0(%r4)
|
|
larl %r4,.Lfpctl # Restore floating point ctl register
|
|
lfpc 0(%r4)
|
|
larl %r4,.Lprefix # Restore prefix register
|
|
spx 0(%r4)
|
|
larl %r4,.Lcontinue_psw # Restore PSW flags
|
|
lpswe 0(%r4)
|
|
.Lcontinue:
|
|
BR_EX %r14
|
|
.align 16
|
|
.Lrestart_psw:
|
|
.long 0x00080000,0x80000000 + .Lrestart_part2
|
|
|
|
.section .data..nosave,"aw",@progbits
|
|
.align 8
|
|
.Lcontinue_psw:
|
|
.quad 0,.Lcontinue
|
|
.previous
|
|
|
|
.section .bss
|
|
.align 8
|
|
.Lctlreg0:
|
|
.quad 0
|
|
.Lctlregs:
|
|
.rept 16
|
|
.quad 0
|
|
.endr
|
|
.Lfpctl:
|
|
.long 0
|
|
.Lprefix:
|
|
.long 0
|
|
.Lprefix_zero:
|
|
.long 0
|
|
.previous
|