iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sh: Rearrange blocks in entry-common.S

Browse Source 
This avoids out-of-range jumps that get auto-replaced by the assembler
and prepares for the changes needed to implement SECCOMP_FILTER cleanly.

Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>
This commit is contained in:
Michael Karcher 2020-07-23 01:13:20 +02:00 committed by Rich Felker
parent e1cc9d8d59
commit 9d2ec8f68e
1 changed files with 29 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
arch/sh/kernel/entry-common.S
View File

@ -178,34 +178,6 @@ syscall_exit_work:
bra resume_userspace
nop
.align 2
syscall_trace_entry:
! Yes it is traced.
mov r15, r4
mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
mov.l r0, @(OFF_R0,r15) ! Save return value
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
! reloaded from the kernel stack by syscall_call
! below, so don't need to be reloaded here.)
! This allows the parent to rewrite system calls
! and args on the fly.
mov.l @(OFF_R4,r15), r4 ! arg0
mov.l @(OFF_R5,r15), r5
mov.l @(OFF_R6,r15), r6
mov.l @(OFF_R7,r15), r7 ! arg3
mov.l @(OFF_R3,r15), r3 ! syscall_nr
!
mov.l 6f, r10 ! Number of syscalls
cmp/hs r10, r3
bf syscall_call
mov #-ENOSYS, r0
bra syscall_exit
mov.l r0, @(OFF_R0,r15) ! Return value
__restore_all:
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
@ -388,6 +360,35 @@ syscall_exit:
bf syscall_exit_work
bra __restore_all
nop
.align 2
syscall_trace_entry:
! Yes it is traced.
mov r15, r4
mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
mov.l r0, @(OFF_R0,r15) ! Save return value
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
! reloaded from the kernel stack by syscall_call
! below, so don't need to be reloaded here.)
! This allows the parent to rewrite system calls
! and args on the fly.
mov.l @(OFF_R4,r15), r4 ! arg0
mov.l @(OFF_R5,r15), r5
mov.l @(OFF_R6,r15), r6
mov.l @(OFF_R7,r15), r7 ! arg3
mov.l @(OFF_R3,r15), r3 ! syscall_nr
!
mov.l 6f, r10 ! Number of syscalls
cmp/hs r10, r3
bf syscall_call
mov #-ENOSYS, r0
bra syscall_exit
mov.l r0, @(OFF_R0,r15) ! Return value
.align 2
#if !defined(CONFIG_CPU_SH2)
1: .long TRA