Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2004 PathScale, Inc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <stdarg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <strings.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <as-layout.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <kern_util.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <sysdep/mcontext.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <um_malloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <sys/ucontext.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	[SIGTRAP]	= relay_signal,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	[SIGFPE]	= relay_signal,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	[SIGILL]	= relay_signal,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	[SIGWINCH]	= winch,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	[SIGBUS]	= bus_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	[SIGSEGV]	= segv_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	[SIGIO]		= sigio_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	struct uml_pt_regs r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	int save_errno = errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	r.is_user = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	if (sig == SIGSEGV) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 		/* For segfaults, we want the data from the sigcontext. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		get_regs_from_mc(&r, mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	/* enable signals if sig isn't IRQ signal */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	if ((sig != SIGIO) && (sig != SIGWINCH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		unblock_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	(*sig_info[sig])(sig, si, &r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	errno = save_errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  * These are the asynchronous signals.  SIGPROF is excluded because we want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)  * be able to profile all of UML, not just the non-critical sections.  If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56)  * profiling is not thread-safe, then that is not my problem.  We can disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57)  * profiling when SMP is enabled in that case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) #define SIGIO_BIT 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) #define SIGIO_MASK (1 << SIGIO_BIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) #define SIGALRM_BIT 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) #define SIGALRM_MASK (1 << SIGALRM_BIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) static int signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) static unsigned int signals_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) static unsigned int signals_active = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) void sig_handler(int sig, struct siginfo *si, mcontext_t *mc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	int enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	enabled = signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	if (!enabled && (sig == SIGIO)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		signals_pending |= SIGIO_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	block_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	sig_handler_common(sig, si, mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	set_signals_trace(enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) static void timer_real_alarm_handler(mcontext_t *mc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	struct uml_pt_regs regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	if (mc != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		get_regs_from_mc(&regs, mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		memset(&regs, 0, sizeof(regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	timer_handler(SIGALRM, NULL, &regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	int enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	enabled = signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	if (!signals_enabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		signals_pending |= SIGALRM_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	block_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	signals_active |= SIGALRM_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	timer_real_alarm_handler(mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	signals_active &= ~SIGALRM_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	set_signals_trace(enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) void deliver_alarm(void) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)     timer_alarm_handler(SIGALRM, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) void timer_set_signal_handler(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	set_handler(SIGALRM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) void set_sigstack(void *sig_stack, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	stack_t stack = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		.ss_flags = 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		.ss_sp = sig_stack,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		.ss_size = size - sizeof(void *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	if (sigaltstack(&stack, NULL) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		panic("enabling signal stack failed, errno = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	[SIGSEGV] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	[SIGBUS] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	[SIGILL] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	[SIGFPE] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	[SIGTRAP] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	[SIGIO] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	[SIGWINCH] = sig_handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	[SIGALRM] = timer_alarm_handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) static void hard_handler(int sig, siginfo_t *si, void *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	ucontext_t *uc = p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	mcontext_t *mc = &uc->uc_mcontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	unsigned long pending = 1UL << sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		int nested, bail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		 * pending comes back with one bit set for each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		 * interrupt that arrived while setting up the stack,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		 * plus a bit for this interrupt, plus the zero bit is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 		 * set if this is a nested interrupt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		 * If bail is true, then we interrupted another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		 * handler setting up the stack.  In this case, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		 * have to return, and the upper handler will deal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		 * with this interrupt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		bail = to_irq_stack(&pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		if (bail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		nested = pending & 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		pending &= ~1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		while ((sig = ffs(pending)) != 0){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 			sig--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 			pending &= ~(1 << sig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 			(*handlers[sig])(sig, (struct siginfo *)si, mc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		 * Again, pending comes back with a mask of signals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		 * that arrived while tearing down the stack.  If this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		 * is non-zero, we just go back, set up the stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		 * again, and handle the new interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		if (!nested)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			pending = from_irq_stack(nested);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	} while (pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) void set_handler(int sig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	struct sigaction action;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	int flags = SA_SIGINFO | SA_ONSTACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	sigset_t sig_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	action.sa_sigaction = hard_handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	/* block irq ones */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	sigemptyset(&action.sa_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	sigaddset(&action.sa_mask, SIGIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	sigaddset(&action.sa_mask, SIGWINCH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	sigaddset(&action.sa_mask, SIGALRM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	if (sig == SIGSEGV)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		flags |= SA_NODEFER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (sigismember(&action.sa_mask, sig))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		flags |= SA_RESTART; /* if it's an irq signal */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	action.sa_flags = flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	action.sa_restorer = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	if (sigaction(sig, &action, NULL) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		panic("sigaction failed - errno = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	sigemptyset(&sig_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	sigaddset(&sig_mask, sig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	if (sigprocmask(SIG_UNBLOCK, &sig_mask, NULL) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		panic("sigprocmask failed - errno = %d\n", errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) int change_sig(int signal, int on)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	sigset_t sigset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	sigemptyset(&sigset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	sigaddset(&sigset, signal);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	if (sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, NULL) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 		return -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) void block_signals(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	signals_enabled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	 * This must return with signals disabled, so this barrier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	 * ensures that writes are flushed out before the return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	 * This might matter if gcc figures out how to inline this and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	 * decides to shuffle this code into the caller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	barrier();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) void unblock_signals(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	int save_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	if (signals_enabled == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	signals_enabled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	 * We loop because the IRQ handler returns with interrupts off.  So,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	 * interrupts may have arrived and we need to re-enable them and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	 * recheck signals_pending.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 		 * Save and reset save_pending after enabling signals.  This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		 * way, signals_pending won't be changed while we're reading it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		 * Setting signals_enabled and reading signals_pending must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		 * happen in this order, so have the barrier here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		barrier();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		save_pending = signals_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		if (save_pending == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		signals_pending = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		 * We have pending interrupts, so disable signals, as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 		 * handlers expect them off when they are called.  They will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		 * be enabled again above. We need to trace this, as we're
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		 * expected to be enabling interrupts already, but any more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		 * tracing that happens inside the handlers we call for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		 * pending signals will mess up the tracing state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		signals_enabled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		um_trace_signals_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		 * Deal with SIGIO first because the alarm handler might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		 * schedule, leaving the pending SIGIO stranded until we come
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		 * back here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 		 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		 * SIGIO's handler doesn't use siginfo or mcontext,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 		 * so they can be NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		if (save_pending & SIGIO_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 			sig_handler_common(SIGIO, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 		/* Do not reenter the handler */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		if ((save_pending & SIGALRM_MASK) && (!(signals_active & SIGALRM_MASK)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 			timer_real_alarm_handler(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 		/* Rerun the loop only if there is still pending SIGIO and not in TIMER handler */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 		if (!(signals_pending & SIGIO_MASK) && (signals_active & SIGALRM_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 		/* Re-enable signals and trace that we're doing so. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 		um_trace_signals_on();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 		signals_enabled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) int get_signals(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	return signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) int set_signals(int enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	if (signals_enabled == enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 		return enable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 	ret = signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	if (enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		unblock_signals();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	else block_signals();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) int set_signals_trace(int enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 	if (signals_enabled == enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 		return enable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	ret = signals_enabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	if (enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 		unblock_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 		block_signals_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) int os_is_signal_stack(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	stack_t ss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	sigaltstack(NULL, &ss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	return ss.ss_flags & SS_ONSTACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) }