target-m68k/m68k-semi.c: Log when put_user for returning values fails

Abstract out the use of put_user for returning semihosting call results,
so that we can log when a guest erroneously attempts a semihosting call
with an unwritable argument block.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Peter Maydell 2012-10-29 12:05:11 +00:00 committed by Blue Swirl
parent 7ba6c10490
commit 1073bfd8c0

View File

@ -133,24 +133,44 @@ static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
}
static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
{
target_ulong args = env->dregs[1];
if (put_user_u32(ret, args) ||
put_user_u32(err, args + 4)) {
/* The m68k semihosting ABI does not provide any way to report this
* error to the guest, so the best we can do is log it in qemu.
* It is always a guest error not to pass us a valid argument block.
*/
qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
"discarded because argument block not writable\n");
}
}
static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err)
{
target_ulong args = env->dregs[1];
if (put_user_u32(ret >> 32, args) ||
put_user_u32(ret, args + 4) ||
put_user_u32(err, args + 8)) {
/* No way to report this via m68k semihosting ABI; just log it */
qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
"discarded because argument block not writable\n");
}
}
static int m68k_semi_is_fseek;
static void m68k_semi_cb(CPUM68KState *env, target_ulong ret, target_ulong err)
{
target_ulong args;
args = env->dregs[1];
if (m68k_semi_is_fseek) {
/* FIXME: We've already lost the high bits of the fseek
return value. */
/* FIXME - handle put_user() failure */
put_user_u32(0, args);
args += 4;
m68k_semi_return_u64(env, ret, err);
m68k_semi_is_fseek = 0;
} else {
m68k_semi_return_u32(env, ret, err);
}
/* FIXME - handle put_user() failure */
put_user_u32(ret, args);
put_user_u32(err, args + 4);
}
/* Read the input value from the argument block; fail the semihosting
@ -269,10 +289,7 @@ void do_m68k_semihosting(CPUM68KState *env, int nr)
arg0, off, arg3);
} else {
off = lseek(arg0, off, arg3);
/* FIXME - handle put_user() failure */
put_user_u32(off >> 32, args);
put_user_u32(off, args + 4);
put_user_u32(errno, args + 8);
m68k_semi_return_u64(env, off, errno);
}
return;
}
@ -444,7 +461,5 @@ void do_m68k_semihosting(CPUM68KState *env, int nr)
result = 0;
}
failed:
/* FIXME - handle put_user() failure */
put_user_u32(result, args);
put_user_u32(errno, args + 4);
m68k_semi_return_u32(env, result, errno);
}