diff options
Diffstat (limited to 'arch/um/os-Linux/signal.c')
| -rw-r--r-- | arch/um/os-Linux/signal.c | 78 |
1 files changed, 26 insertions, 52 deletions
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index b11ed66c8bb0..11f07f498270 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -21,14 +21,15 @@ #include <sys/ucontext.h> #include <timetravel.h> -void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { +void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *, void *mc) = { [SIGTRAP] = relay_signal, [SIGFPE] = relay_signal, [SIGILL] = relay_signal, [SIGWINCH] = winch, - [SIGBUS] = bus_handler, + [SIGBUS] = relay_signal, [SIGSEGV] = segv_handler, [SIGIO] = sigio_handler, + [SIGCHLD] = sigchld_handler, }; static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) @@ -44,10 +45,10 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) } /* enable signals if sig isn't IRQ signal */ - if ((sig != SIGIO) && (sig != SIGWINCH)) + if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGCHLD)) unblock_signals_trace(); - (*sig_info[sig])(sig, si, &r); + (*sig_info[sig])(sig, si, &r, mc); errno = save_errno; } @@ -64,8 +65,11 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) #define SIGALRM_BIT 1 #define SIGALRM_MASK (1 << SIGALRM_BIT) +#define SIGCHLD_BIT 2 +#define SIGCHLD_MASK (1 << SIGCHLD_BIT) + int signals_enabled; -#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT +#if IS_ENABLED(CONFIG_UML_TIME_TRAVEL_SUPPORT) static int signals_blocked, signals_blocked_pending; #endif static unsigned int signals_pending; @@ -75,7 +79,7 @@ static void sig_handler(int sig, struct siginfo *si, mcontext_t *mc) { int enabled = signals_enabled; -#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT +#if IS_ENABLED(CONFIG_UML_TIME_TRAVEL_SUPPORT) if ((signals_blocked || __atomic_load_n(&signals_blocked_pending, __ATOMIC_SEQ_CST)) && (sig == SIGIO)) { @@ -102,6 +106,11 @@ static void sig_handler(int sig, struct siginfo *si, mcontext_t *mc) return; } + if (!enabled && (sig == SIGCHLD)) { + signals_pending |= SIGCHLD_MASK; + return; + } + block_signals_trace(); sig_handler_common(sig, si, mc); @@ -181,6 +190,8 @@ static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { [SIGIO] = sig_handler, [SIGWINCH] = sig_handler, + /* SIGCHLD is only actually registered in seccomp mode. */ + [SIGCHLD] = sig_handler, [SIGALRM] = timer_alarm_handler, [SIGUSR1] = sigusr1_handler, @@ -190,43 +201,8 @@ static void hard_handler(int sig, siginfo_t *si, void *p) { ucontext_t *uc = p; mcontext_t *mc = &uc->uc_mcontext; - unsigned long pending = 1UL << sig; - - do { - int nested, bail; - /* - * pending comes back with one bit set for each - * interrupt that arrived while setting up the stack, - * plus a bit for this interrupt, plus the zero bit is - * set if this is a nested interrupt. - * If bail is true, then we interrupted another - * handler setting up the stack. In this case, we - * have to return, and the upper handler will deal - * with this interrupt. - */ - bail = to_irq_stack(&pending); - if (bail) - return; - - nested = pending & 1; - pending &= ~1; - - while ((sig = ffs(pending)) != 0){ - sig--; - pending &= ~(1 << sig); - (*handlers[sig])(sig, (struct siginfo *)si, mc); - } - - /* - * Again, pending comes back with a mask of signals - * that arrived while tearing down the stack. If this - * is non-zero, we just go back, set up the stack - * again, and handle the new interrupts. - */ - if (!nested) - pending = from_irq_stack(nested); - } while (pending); + (*handlers[sig])(sig, (struct siginfo *)si, mc); } void set_handler(int sig) @@ -297,7 +273,7 @@ void unblock_signals(void) return; signals_enabled = 1; -#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT +#if IS_ENABLED(CONFIG_UML_TIME_TRAVEL_SUPPORT) deliver_time_travel_irqs(); #endif @@ -344,6 +320,12 @@ void unblock_signals(void) if (save_pending & SIGIO_MASK) sig_handler_common(SIGIO, NULL, NULL); + if (save_pending & SIGCHLD_MASK) { + struct uml_pt_regs regs = {}; + + sigchld_handler(SIGCHLD, NULL, ®s, NULL); + } + /* Do not reenter the handler */ if ((save_pending & SIGALRM_MASK) && (!(signals_active & SIGALRM_MASK))) @@ -389,7 +371,7 @@ int um_set_signals_trace(int enable) return ret; } -#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT +#if IS_ENABLED(CONFIG_UML_TIME_TRAVEL_SUPPORT) void mark_sigio_pending(void) { /* @@ -487,11 +469,3 @@ void unblock_signals_hard(void) unblocking = false; } #endif - -int os_is_signal_stack(void) -{ - stack_t ss; - sigaltstack(NULL, &ss); - - return ss.ss_flags & SS_ONSTACK; -} |