diff options
Diffstat (limited to 'linux-user/host/aarch64/safe-syscall.inc.S')
| -rw-r--r-- | linux-user/host/aarch64/safe-syscall.inc.S | 76 |
1 files changed, 0 insertions, 76 deletions
diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S deleted file mode 100644 index 87c9580faa..0000000000 --- a/linux-user/host/aarch64/safe-syscall.inc.S +++ /dev/null @@ -1,76 +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 - .type safe_syscall_start, #function - .type safe_syscall_end, #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 - /* The syscall calling convention isn't the same as the - * C one: - * we enter with x0 == &signal_pending - * x1 == syscall number - * x2 ... x7, (stack) == syscall arguments - * and return the result in x0 - * and the syscall instruction needs - * x8 == syscall number - * x0 ... x6 == syscall arguments - * and returns the result in x0 - * Shuffle everything around appropriately. - */ - mov x9, x0 /* signal_pending pointer */ - mov x8, x1 /* syscall number */ - mov x0, x2 /* syscall arguments */ - mov x1, x3 - mov x2, x4 - mov x3, x5 - mov x4, x6 - mov x5, x7 - ldr x6, [sp] - - /* 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 */ - ldr w10, [x9] - cbnz w10, 2f - svc 0x0 -safe_syscall_end: - /* code path for having successfully executed the syscall */ - cmp x0, #-4096 - b.hi 0f - ret - - /* code path setting errno */ -0: neg w0, w0 - b safe_syscall_set_errno_tail - - /* code path when we didn't execute the syscall */ -2: mov w0, #QEMU_ERESTARTSYS - b safe_syscall_set_errno_tail - .cfi_endproc - .size safe_syscall_base, .-safe_syscall_base |