diff options
| author | Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de> | 2020-07-23 02:13:20 +0300 |
|---|---|---|
| committer | Rich Felker <dalias@libc.org> | 2020-08-15 05:05:19 +0300 |
| commit | 9d2ec8f68e9dfbdd9ae9bdc79cc4deedc0ad4e6b (patch) | |
| tree | e0992fc47c59338d0f514814bf87f1bd63a08570 /arch | |
| parent | e1cc9d8d596e233538a3ecaffea665185751db35 (diff) | |
| download | linux-9d2ec8f68e9dfbdd9ae9bdc79cc4deedc0ad4e6b.tar.xz | |
sh: Rearrange blocks in entry-common.S
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sh/kernel/entry-common.S | 57 |
1 files changed, 29 insertions, 28 deletions
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index 9bac5bbb67f3..c4d88d61890d 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -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 |