diff options
Diffstat (limited to 'linux-user/host/s390x/safe-syscall.inc.S')
| -rw-r--r-- | linux-user/host/s390x/safe-syscall.inc.S | 98 |
1 files changed, 0 insertions, 98 deletions
diff --git a/linux-user/host/s390x/safe-syscall.inc.S b/linux-user/host/s390x/safe-syscall.inc.S deleted file mode 100644 index 66f84385a2..0000000000 --- a/linux-user/host/s390x/safe-syscall.inc.S +++ /dev/null @@ -1,98 +0,0 @@ -/* - * 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'). - */ -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: - - /* code path for having successfully executed the syscall */ - lg %r15,0(%r15) /* load back chain */ - .cfi_remember_state - .cfi_adjust_cfa_offset -160 - lmg %r6,%r15,48(%r15) /* load saved registers */ - - lghi %r0, -4095 /* check for syscall error */ - clgr %r2, %r0 - blr %r14 /* return on success */ - lcr %r2, %r2 /* create positive errno */ - jg safe_syscall_set_errno_tail - .cfi_restore_state - - /* code path when we didn't execute the syscall */ -2: lg %r15,0(%r15) /* load back chain */ - .cfi_adjust_cfa_offset -160 - lmg %r6,%r15,48(%r15) /* load saved registers */ - lghi %r2, QEMU_ERESTARTSYS - jg safe_syscall_set_errno_tail - - .cfi_endproc - .size safe_syscall_base, .-safe_syscall_base |