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5eadbbfca6
Split out the non-ARM specific portions of SYS_CLOSE to a reusable function. This handles all GuestFD. Note that gdb_do_syscall %x reads target_ulong, not int. Reviewed-by: Luc Michel <lmichel@kalray.eu> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
129 lines
3.1 KiB
C
129 lines
3.1 KiB
C
/*
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* Hosted file support for semihosting syscalls.
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*
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* Copyright (c) 2005, 2007 CodeSourcery.
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* Copyright (c) 2019 Linaro
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* Copyright © 2020 by Keith Packard <keithp@keithp.com>
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "qemu/osdep.h"
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#include "exec/gdbstub.h"
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#include "semihosting/guestfd.h"
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#ifdef CONFIG_USER_ONLY
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#include "qemu.h"
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#else
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#include "semihosting/softmmu-uaccess.h"
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#endif
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static GArray *guestfd_array;
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/*
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* Allocate a new guest file descriptor and return it; if we
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* couldn't allocate a new fd then return -1.
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* This is a fairly simplistic implementation because we don't
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* expect that most semihosting guest programs will make very
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* heavy use of opening and closing fds.
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*/
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int alloc_guestfd(void)
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{
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guint i;
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if (!guestfd_array) {
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/* New entries zero-initialized, i.e. type GuestFDUnused */
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guestfd_array = g_array_new(FALSE, TRUE, sizeof(GuestFD));
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}
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/* SYS_OPEN should return nonzero handle on success. Start guestfd from 1 */
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for (i = 1; i < guestfd_array->len; i++) {
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GuestFD *gf = &g_array_index(guestfd_array, GuestFD, i);
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if (gf->type == GuestFDUnused) {
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return i;
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}
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}
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/* All elements already in use: expand the array */
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g_array_set_size(guestfd_array, i + 1);
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return i;
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}
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static void do_dealloc_guestfd(GuestFD *gf)
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{
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gf->type = GuestFDUnused;
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}
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/*
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* Look up the guestfd in the data structure; return NULL
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* for out of bounds, but don't check whether the slot is unused.
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* This is used internally by the other guestfd functions.
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*/
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static GuestFD *do_get_guestfd(int guestfd)
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{
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if (!guestfd_array) {
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return NULL;
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}
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if (guestfd <= 0 || guestfd >= guestfd_array->len) {
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return NULL;
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}
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return &g_array_index(guestfd_array, GuestFD, guestfd);
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}
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/*
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* Given a guest file descriptor, get the associated struct.
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* If the fd is not valid, return NULL. This is the function
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* used by the various semihosting calls to validate a handle
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* from the guest.
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* Note: calling alloc_guestfd() or dealloc_guestfd() will
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* invalidate any GuestFD* obtained by calling this function.
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*/
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GuestFD *get_guestfd(int guestfd)
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{
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GuestFD *gf = do_get_guestfd(guestfd);
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if (!gf || gf->type == GuestFDUnused) {
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return NULL;
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}
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return gf;
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}
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/*
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* Associate the specified guest fd (which must have been
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* allocated via alloc_fd() and not previously used) with
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* the specified host/gdb fd.
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*/
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void associate_guestfd(int guestfd, int hostfd)
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{
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GuestFD *gf = do_get_guestfd(guestfd);
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assert(gf);
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gf->type = use_gdb_syscalls() ? GuestFDGDB : GuestFDHost;
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gf->hostfd = hostfd;
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}
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void staticfile_guestfd(int guestfd, const uint8_t *data, size_t len)
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{
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GuestFD *gf = do_get_guestfd(guestfd);
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assert(gf);
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gf->type = GuestFDStatic;
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gf->staticfile.data = data;
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gf->staticfile.len = len;
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gf->staticfile.off = 0;
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}
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/*
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* Deallocate the specified guest file descriptor. This doesn't
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* close the host fd, it merely undoes the work of alloc_fd().
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*/
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void dealloc_guestfd(int guestfd)
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{
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GuestFD *gf = do_get_guestfd(guestfd);
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assert(gf);
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do_dealloc_guestfd(gf);
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}
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