qemu/hw/semihosting/console.c
Alex Bennée 78e24848f6 semihosting: split console_out into string and char versions
This is ostensibly to avoid the weirdness of len looking like it might
come from a guest and sometimes being used. While we are at it fix up
the error checking for the arm-linux-user implementation of the API
which got flagged up by Coverity (CID 1401700).

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-06-12 17:53:22 +01:00

101 lines
2.8 KiB
C

/*
* Semihosting Console Support
*
* Copyright (c) 2015 Imagination Technologies
* Copyright (c) 2019 Linaro Ltd
*
* This provides support for outputting to a semihosting console.
*
* While most semihosting implementations support reading and writing
* to arbitrary file descriptors we treat the console as something
* specifically for debugging interaction. This means messages can be
* re-directed to gdb (if currently being used to debug) or even
* re-directed elsewhere.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "hw/semihosting/semihost.h"
#include "hw/semihosting/console.h"
#include "exec/gdbstub.h"
#include "qemu/log.h"
#include "chardev/char.h"
int qemu_semihosting_log_out(const char *s, int len)
{
Chardev *chardev = semihosting_get_chardev();
if (chardev) {
return qemu_chr_write_all(chardev, (uint8_t *) s, len);
} else {
return write(STDERR_FILENO, s, len);
}
}
/*
* A re-implementation of lock_user_string that we can use locally
* instead of relying on softmmu-semi. Hopefully we can deprecate that
* in time. Copy string until we find a 0 or address error.
*/
static GString *copy_user_string(CPUArchState *env, target_ulong addr)
{
CPUState *cpu = env_cpu(env);
GString *s = g_string_sized_new(128);
uint8_t c;
do {
if (cpu_memory_rw_debug(cpu, addr++, &c, 1, 0) == 0) {
s = g_string_append_c(s, c);
} else {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: passed inaccessible address " TARGET_FMT_lx,
__func__, addr);
break;
}
} while (c!=0);
return s;
}
static void semihosting_cb(CPUState *cs, target_ulong ret, target_ulong err)
{
if (ret == (target_ulong) -1) {
qemu_log("%s: gdb console output failed ("TARGET_FMT_ld")",
__func__, err);
}
}
int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr)
{
GString *s = copy_user_string(env, addr);
int out = s->len;
if (use_gdb_syscalls()) {
gdb_do_syscall(semihosting_cb, "write,2,%x,%x", addr, s->len);
} else {
out = qemu_semihosting_log_out(s->str, s->len);
}
g_string_free(s, true);
return out;
}
void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr)
{
CPUState *cpu = env_cpu(env);
uint8_t c;
if (cpu_memory_rw_debug(cpu, addr, &c, 1, 0) == 0) {
if (use_gdb_syscalls()) {
gdb_do_syscall(semihosting_cb, "write,2,%x,%x", addr, 1);
} else {
qemu_semihosting_log_out((const char *) &c, 1);
}
} else {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: passed inaccessible address " TARGET_FMT_lx,
__func__, addr);
}
}