diff options
Diffstat (limited to 'linux-user/host/riscv')
| -rw-r--r-- | linux-user/host/riscv/safe-syscall.inc.S | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/linux-user/host/riscv/safe-syscall.inc.S b/linux-user/host/riscv/safe-syscall.inc.S deleted file mode 100644 index ca456d8a46..0000000000 --- a/linux-user/host/riscv/safe-syscall.inc.S +++ /dev/null @@ -1,79 +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) 2018 Linaro, 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 is nearly the same as C: - * we enter with a0 == &signal_pending - * a1 == syscall number - * a2 ... a7 == syscall arguments - * and return the result in a0 - * and the syscall instruction needs - * a7 == syscall number - * a0 ... a5 == syscall arguments - * and returns the result in a0 - * Shuffle everything around appropriately. - */ - mv t0, a0 /* signal_pending pointer */ - mv t1, a1 /* syscall number */ - mv a0, a2 /* syscall arguments */ - mv a1, a3 - mv a2, a4 - mv a3, a5 - mv a4, a6 - mv a5, a7 - mv a7, t1 - - /* - * 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 */ - lw t1, 0(t0) - bnez t1, 2f - scall -safe_syscall_end: - /* code path for having successfully executed the syscall */ - li t2, -4096 - bgtu a0, t2, 0f - ret - - /* code path setting errno */ -0: neg a0, a0 - j safe_syscall_set_errno_tail - - /* code path when we didn't execute the syscall */ -2: li a0, QEMU_ERESTARTSYS - j safe_syscall_set_errno_tail - - .cfi_endproc - .size safe_syscall_base, .-safe_syscall_base |