Message ID | 20200201122746.1478003-4-laurent@vivier.eu |
---|---|
State | New |
Headers | show |
Series | linux-user: fix use of SIGRTMIN | expand |
> -----Original Message----- > From: Laurent Vivier <laurent@vivier.eu> > Sent: Saturday, February 1, 2020 6:28 AM > To: qemu-devel@nongnu.org > Cc: Josh Kunz <jkz@google.com>; milos.stojanovic@rt-rk.com; Matus Kysel > <mkysel@tachyum.com>; Aleksandar Markovic <aleksandar.markovic@rt- > rk.com>; Marlies Ruck <marlies.ruck@gmail.com>; Laurent Vivier > <laurent@vivier.eu>; Peter Maydell <peter.maydell@linaro.org>; Taylor > Simpson <tsimpson@quicinc.com>; Riku Voipio <riku.voipio@iki.fi> > Subject: [PATCH 3/4] linux-user: fix TARGET_NSIG and _NSIG uses > > Valid signal numbers are between 1 (SIGHUP) and SIGRTMAX. > > System includes define _NSIG to SIGRTMAX + 1, but QEMU (like kernel) > defines TARGET_NSIG to TARGET_SIGRTMAX. > > Fix all the checks involving the signal range. > > Signed-off-by: Laurent Vivier <laurent@vivier.eu> > --- > linux-user/signal.c | 51 ++++++++++++++++++++++++++++++++------------- > 1 file changed, 37 insertions(+), 14 deletions(-) > > diff --git a/linux-user/signal.c b/linux-user/signal.c index > f42a2e1a82a5..3491f0a7ecb1 100644 > --- a/linux-user/signal.c > +++ b/linux-user/signal.c > @@ -30,6 +30,15 @@ static struct target_sigaction > sigact_table[TARGET_NSIG]; static void host_signal_handler(int > host_signum, siginfo_t *info, > void *puc); > > + > +/* > + * System includes define _NSIG as SIGRTMAX + 1, > + * but qemu (like the kernel) defines TARGET_NSIG as TARGET_SIGRTMAX > + * and the first signal is SIGHUP defined as 1 > + * Signal number 0 is reserved for use as kill(pid, 0), to test whether > + * a process exists without sending it a signal. > + */ > +QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG); > static uint8_t host_to_target_signal_table[_NSIG] = { > [SIGHUP] = TARGET_SIGHUP, > [SIGINT] = TARGET_SIGINT, > @@ -67,19 +76,24 @@ static uint8_t host_to_target_signal_table[_NSIG] = { > [SIGSYS] = TARGET_SIGSYS, > /* next signals stay the same */ > }; > -static uint8_t target_to_host_signal_table[_NSIG]; > > +static uint8_t target_to_host_signal_table[TARGET_NSIG + 1]; > + > +/* valid sig is between 1 and _NSIG - 1 */ > int host_to_target_signal(int sig) > { > - if (sig < 0 || sig >= _NSIG) > + if (sig < 1 || sig >= _NSIG) { > return sig; > + } > return host_to_target_signal_table[sig]; } > > +/* valid sig is between 1 and TARGET_NSIG */ > int target_to_host_signal(int sig) > { > - if (sig < 0 || sig >= _NSIG) > + if (sig < 1 || sig > TARGET_NSIG) { > return sig; > + } > return target_to_host_signal_table[sig]; } > > @@ -100,11 +114,15 @@ static inline int target_sigismember(const > target_sigset_t *set, int signum) void > host_to_target_sigset_internal(target_sigset_t *d, > const sigset_t *s) { > - int i; > + int i, j; > target_sigemptyset(d); > - for (i = 1; i <= TARGET_NSIG; i++) { > + for (i = 1; i < _NSIG; i++) { > + j = host_to_target_signal(i); More descriptive name - target_sig > + if (j < 1 || j > TARGET_NSIG) { > + continue; > + } > if (sigismember(s, i)) { > - target_sigaddset(d, host_to_target_signal(i)); > + target_sigaddset(d, j); > } > } > } > @@ -122,11 +140,15 @@ void host_to_target_sigset(target_sigset_t *d, > const sigset_t *s) void target_to_host_sigset_internal(sigset_t *d, > const target_sigset_t *s) { > - int i; > + int i, j; > sigemptyset(d); > for (i = 1; i <= TARGET_NSIG; i++) { > + j = target_to_host_signal(i); More descriptive name - host_sig > + if (j < 1 || j >= _NSIG) { > + continue; > + } > if (target_sigismember(s, i)) { > - sigaddset(d, target_to_host_signal(i)); > + sigaddset(d, j); > } > } > } > @@ -488,13 +510,14 @@ static void signal_table_init(void) > host_to_target_signal_table[__SIGRTMAX] = __SIGRTMIN; > > /* generate signal conversion tables */ > - for(i = 1; i < _NSIG; i++) { > - if (host_to_target_signal_table[i] == 0) > + for (i = 1; i < _NSIG; i++) { > + if (host_to_target_signal_table[i] == 0) { > host_to_target_signal_table[i] = i; > - } > - for(i = 1; i < _NSIG; i++) { > + } > j = host_to_target_signal_table[i]; More descriptive name - target_sig > - target_to_host_signal_table[j] = i; > + if (j <= TARGET_NSIG) { > + target_to_host_signal_table[j] = i; > + } > } > } > > @@ -517,7 +540,7 @@ void signal_init(void) > act.sa_sigaction = host_signal_handler; > for(i = 1; i <= TARGET_NSIG; i++) { #ifdef TARGET_GPROF > - if (i == SIGPROF) { > + if (i == TARGET_SIGPROF) { > continue; > } > #endif > -- > 2.24.1 >
diff --git a/linux-user/signal.c b/linux-user/signal.c index f42a2e1a82a5..3491f0a7ecb1 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -30,6 +30,15 @@ static struct target_sigaction sigact_table[TARGET_NSIG]; static void host_signal_handler(int host_signum, siginfo_t *info, void *puc); + +/* + * System includes define _NSIG as SIGRTMAX + 1, + * but qemu (like the kernel) defines TARGET_NSIG as TARGET_SIGRTMAX + * and the first signal is SIGHUP defined as 1 + * Signal number 0 is reserved for use as kill(pid, 0), to test whether + * a process exists without sending it a signal. + */ +QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG); static uint8_t host_to_target_signal_table[_NSIG] = { [SIGHUP] = TARGET_SIGHUP, [SIGINT] = TARGET_SIGINT, @@ -67,19 +76,24 @@ static uint8_t host_to_target_signal_table[_NSIG] = { [SIGSYS] = TARGET_SIGSYS, /* next signals stay the same */ }; -static uint8_t target_to_host_signal_table[_NSIG]; +static uint8_t target_to_host_signal_table[TARGET_NSIG + 1]; + +/* valid sig is between 1 and _NSIG - 1 */ int host_to_target_signal(int sig) { - if (sig < 0 || sig >= _NSIG) + if (sig < 1 || sig >= _NSIG) { return sig; + } return host_to_target_signal_table[sig]; } +/* valid sig is between 1 and TARGET_NSIG */ int target_to_host_signal(int sig) { - if (sig < 0 || sig >= _NSIG) + if (sig < 1 || sig > TARGET_NSIG) { return sig; + } return target_to_host_signal_table[sig]; } @@ -100,11 +114,15 @@ static inline int target_sigismember(const target_sigset_t *set, int signum) void host_to_target_sigset_internal(target_sigset_t *d, const sigset_t *s) { - int i; + int i, j; target_sigemptyset(d); - for (i = 1; i <= TARGET_NSIG; i++) { + for (i = 1; i < _NSIG; i++) { + j = host_to_target_signal(i); + if (j < 1 || j > TARGET_NSIG) { + continue; + } if (sigismember(s, i)) { - target_sigaddset(d, host_to_target_signal(i)); + target_sigaddset(d, j); } } } @@ -122,11 +140,15 @@ void host_to_target_sigset(target_sigset_t *d, const sigset_t *s) void target_to_host_sigset_internal(sigset_t *d, const target_sigset_t *s) { - int i; + int i, j; sigemptyset(d); for (i = 1; i <= TARGET_NSIG; i++) { + j = target_to_host_signal(i); + if (j < 1 || j >= _NSIG) { + continue; + } if (target_sigismember(s, i)) { - sigaddset(d, target_to_host_signal(i)); + sigaddset(d, j); } } } @@ -488,13 +510,14 @@ static void signal_table_init(void) host_to_target_signal_table[__SIGRTMAX] = __SIGRTMIN; /* generate signal conversion tables */ - for(i = 1; i < _NSIG; i++) { - if (host_to_target_signal_table[i] == 0) + for (i = 1; i < _NSIG; i++) { + if (host_to_target_signal_table[i] == 0) { host_to_target_signal_table[i] = i; - } - for(i = 1; i < _NSIG; i++) { + } j = host_to_target_signal_table[i]; - target_to_host_signal_table[j] = i; + if (j <= TARGET_NSIG) { + target_to_host_signal_table[j] = i; + } } } @@ -517,7 +540,7 @@ void signal_init(void) act.sa_sigaction = host_signal_handler; for(i = 1; i <= TARGET_NSIG; i++) { #ifdef TARGET_GPROF - if (i == SIGPROF) { + if (i == TARGET_SIGPROF) { continue; } #endif
Valid signal numbers are between 1 (SIGHUP) and SIGRTMAX. System includes define _NSIG to SIGRTMAX + 1, but QEMU (like kernel) defines TARGET_NSIG to TARGET_SIGRTMAX. Fix all the checks involving the signal range. Signed-off-by: Laurent Vivier <laurent@vivier.eu> --- linux-user/signal.c | 51 ++++++++++++++++++++++++++++++++------------- 1 file changed, 37 insertions(+), 14 deletions(-)