bsd-user/signal.c: host_to_target_siginfo_noswap

Implement conversion of host to target siginfo.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@freebsd.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Warner Losh 2022-01-08 17:50:38 -07:00
parent 6ddc1abe0f
commit c34f2aaff6
1 changed files with 113 additions and 0 deletions

View File

@ -48,6 +48,119 @@ int target_to_host_signal(int sig)
return sig;
}
static bool has_trapno(int tsig)
{
return tsig == TARGET_SIGILL ||
tsig == TARGET_SIGFPE ||
tsig == TARGET_SIGSEGV ||
tsig == TARGET_SIGBUS ||
tsig == TARGET_SIGTRAP;
}
/* Siginfo conversion. */
/*
* Populate tinfo w/o swapping based on guessing which fields are valid.
*/
static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
const siginfo_t *info)
{
int sig = host_to_target_signal(info->si_signo);
int si_code = info->si_code;
int si_type;
/*
* Make sure we that the variable portion of the target siginfo is zeroed
* out so we don't leak anything into that.
*/
memset(&tinfo->_reason, 0, sizeof(tinfo->_reason));
/*
* This is awkward, because we have to use a combination of the si_code and
* si_signo to figure out which of the union's members are valid.o We
* therefore make our best guess.
*
* Once we have made our guess, we record it in the top 16 bits of
* the si_code, so that tswap_siginfo() later can use it.
* tswap_siginfo() will strip these top bits out before writing
* si_code to the guest (sign-extending the lower bits).
*/
tinfo->si_signo = sig;
tinfo->si_errno = info->si_errno;
tinfo->si_code = info->si_code;
tinfo->si_pid = info->si_pid;
tinfo->si_uid = info->si_uid;
tinfo->si_status = info->si_status;
tinfo->si_addr = (abi_ulong)(unsigned long)info->si_addr;
/*
* si_value is opaque to kernel. On all FreeBSD platforms,
* sizeof(sival_ptr) >= sizeof(sival_int) so the following
* always will copy the larger element.
*/
tinfo->si_value.sival_ptr =
(abi_ulong)(unsigned long)info->si_value.sival_ptr;
switch (si_code) {
/*
* All the SI_xxx codes that are defined here are global to
* all the signals (they have values that none of the other,
* more specific signal info will set).
*/
case SI_USER:
case SI_LWP:
case SI_KERNEL:
case SI_QUEUE:
case SI_ASYNCIO:
/*
* Only the fixed parts are valid (though FreeBSD doesn't always
* set all the fields to non-zero values.
*/
si_type = QEMU_SI_NOINFO;
break;
case SI_TIMER:
tinfo->_reason._timer._timerid = info->_reason._timer._timerid;
tinfo->_reason._timer._overrun = info->_reason._timer._overrun;
si_type = QEMU_SI_TIMER;
break;
case SI_MESGQ:
tinfo->_reason._mesgq._mqd = info->_reason._mesgq._mqd;
si_type = QEMU_SI_MESGQ;
break;
default:
/*
* We have to go based on the signal number now to figure out
* what's valid.
*/
if (has_trapno(sig)) {
tinfo->_reason._fault._trapno = info->_reason._fault._trapno;
si_type = QEMU_SI_FAULT;
}
#ifdef TARGET_SIGPOLL
/*
* FreeBSD never had SIGPOLL, but emulates it for Linux so there's
* a chance it may popup in the future.
*/
if (sig == TARGET_SIGPOLL) {
tinfo->_reason._poll._band = info->_reason._poll._band;
si_type = QEMU_SI_POLL;
}
#endif
/*
* Unsure that this can actually be generated, and our support for
* capsicum is somewhere between weak and non-existant, but if we get
* one, then we know what to save.
*/
if (sig == TARGET_SIGTRAP) {
tinfo->_reason._capsicum._syscall =
info->_reason._capsicum._syscall;
si_type = QEMU_SI_CAPSICUM;
}
break;
}
tinfo->si_code = deposit32(si_code, 24, 8, si_type);
}
/*
* Queue a signal so that it will be send to the virtual CPU as soon as
* possible.