The LT instruction was added in the extended immediate facility
introduced with the z9-109 processor.
Cc: Riku Voipio <riku.voipio@iki.fi>
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Fixes: c9bc3437a9
Suggested-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
91 lines
2.9 KiB
ArmAsm
91 lines
2.9 KiB
ArmAsm
/*
|
|
* safe-syscall.inc.S : host-specific assembly fragment
|
|
* to handle signals occurring at the same time as system calls.
|
|
* This is intended to be included by linux-user/safe-syscall.S
|
|
*
|
|
* Written by Richard Henderson <rth@twiddle.net>
|
|
* Copyright (C) 2016 Red Hat, Inc.
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2 or later.
|
|
* See the COPYING file in the top-level directory.
|
|
*/
|
|
|
|
.global safe_syscall_base
|
|
.global safe_syscall_start
|
|
.global safe_syscall_end
|
|
.type safe_syscall_base, @function
|
|
|
|
/* This is the entry point for making a system call. The calling
|
|
* convention here is that of a C varargs function with the
|
|
* first argument an 'int *' to the signal_pending flag, the
|
|
* second one the system call number (as a 'long'), and all further
|
|
* arguments being syscall arguments (also 'long').
|
|
* We return a long which is the syscall's return value, which
|
|
* may be negative-errno on failure. Conversion to the
|
|
* -1-and-errno-set convention is done by the calling wrapper.
|
|
*/
|
|
safe_syscall_base:
|
|
.cfi_startproc
|
|
stmg %r6,%r15,48(%r15) /* save all call-saved registers */
|
|
.cfi_offset %r15,-40
|
|
.cfi_offset %r14,-48
|
|
.cfi_offset %r13,-56
|
|
.cfi_offset %r12,-64
|
|
.cfi_offset %r11,-72
|
|
.cfi_offset %r10,-80
|
|
.cfi_offset %r9,-88
|
|
.cfi_offset %r8,-96
|
|
.cfi_offset %r7,-104
|
|
.cfi_offset %r6,-112
|
|
lgr %r1,%r15
|
|
lg %r0,8(%r15) /* load eos */
|
|
aghi %r15,-160
|
|
.cfi_adjust_cfa_offset 160
|
|
stg %r1,0(%r15) /* store back chain */
|
|
stg %r0,8(%r15) /* store eos */
|
|
|
|
/* The syscall calling convention isn't the same as the
|
|
* C one:
|
|
* we enter with r2 == *signal_pending
|
|
* r3 == syscall number
|
|
* r4, r5, r6, (stack) == syscall arguments
|
|
* and return the result in r2
|
|
* and the syscall instruction needs
|
|
* r1 == syscall number
|
|
* r2 ... r7 == syscall arguments
|
|
* and returns the result in r2
|
|
* Shuffle everything around appropriately.
|
|
*/
|
|
lgr %r8,%r2 /* signal_pending pointer */
|
|
lgr %r1,%r3 /* syscall number */
|
|
lgr %r2,%r4 /* syscall args */
|
|
lgr %r3,%r5
|
|
lgr %r4,%r6
|
|
lmg %r5,%r7,320(%r15)
|
|
|
|
/* This next sequence of code works in conjunction with the
|
|
* rewind_if_safe_syscall_function(). If a signal is taken
|
|
* and the interrupted PC is anywhere between 'safe_syscall_start'
|
|
* and 'safe_syscall_end' then we rewind it to 'safe_syscall_start'.
|
|
* The code sequence must therefore be able to cope with this, and
|
|
* the syscall instruction must be the final one in the sequence.
|
|
*/
|
|
safe_syscall_start:
|
|
/* if signal_pending is non-zero, don't do the call */
|
|
icm %r0,15,0(%r8)
|
|
jne 2f
|
|
svc 0
|
|
safe_syscall_end:
|
|
|
|
1: lg %r15,0(%r15) /* load back chain */
|
|
.cfi_remember_state
|
|
.cfi_adjust_cfa_offset -160
|
|
lmg %r6,%r15,48(%r15) /* load saved registers */
|
|
br %r14
|
|
.cfi_restore_state
|
|
2: lghi %r2, -TARGET_ERESTARTSYS
|
|
j 1b
|
|
.cfi_endproc
|
|
|
|
.size safe_syscall_base, .-safe_syscall_base
|