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)  *  fs/signalfd.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *  Copyright (C) 2003  Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *  Mon Mar 5, 2007: Davide Libenzi <davidel@xmailserver.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *      Changed ->read() to return a siginfo strcture instead of signal number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *      Fixed locking in ->poll().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *      Added sighand-detach notification.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *      Added fd re-use in sys_signalfd() syscall.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *      Now using anonymous inode source.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *      Thanks to Oleg Nesterov for useful code review and suggestions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *      More comments and suggestions from Arnd Bergmann.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *  Sat May 19, 2007: Davi E. M. Arnaut <davi@haxent.com.br>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *      Retrieve multiple signals with one read() call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *  Sun Jul 15, 2007: Davide Libenzi <davidel@xmailserver.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *      Attach to the sighand only during read() and poll().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/poll.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #include <linux/anon_inodes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #include <linux/signalfd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #include <linux/compat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) void signalfd_cleanup(struct sighand_struct *sighand)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	wake_up_pollfree(&sighand->signalfd_wqh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) struct signalfd_ctx {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	sigset_t sigmask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) static int signalfd_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	kfree(file->private_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) static __poll_t signalfd_poll(struct file *file, poll_table *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	struct signalfd_ctx *ctx = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	__poll_t events = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	poll_wait(file, &current->sighand->signalfd_wqh, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	spin_lock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	if (next_signal(&current->pending, &ctx->sigmask) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	    next_signal(&current->signal->shared_pending,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 			&ctx->sigmask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		events |= EPOLLIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	spin_unlock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	return events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69)  * Copied from copy_siginfo_to_user() in kernel/signal.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 			     kernel_siginfo_t const *kinfo)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	struct signalfd_siginfo new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	BUILD_BUG_ON(sizeof(struct signalfd_siginfo) != 128);
^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) 	 * Unused members should be zero ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	memset(&new, 0, sizeof(new));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	 * If you change siginfo_t structure, please be sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	 * this code is fixed accordingly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	new.ssi_signo = kinfo->si_signo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	new.ssi_errno = kinfo->si_errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	new.ssi_code  = kinfo->si_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	switch (siginfo_layout(kinfo->si_signo, kinfo->si_code)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	case SIL_KILL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		new.ssi_pid = kinfo->si_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		new.ssi_uid = kinfo->si_uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	case SIL_TIMER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		new.ssi_tid = kinfo->si_tid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		new.ssi_overrun = kinfo->si_overrun;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		new.ssi_ptr = (long) kinfo->si_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		new.ssi_int = kinfo->si_int;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	case SIL_POLL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		new.ssi_band = kinfo->si_band;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		new.ssi_fd   = kinfo->si_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	case SIL_FAULT_BNDERR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	case SIL_FAULT_PKUERR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		 * Fall through to the SIL_FAULT case.  Both SIL_FAULT_BNDERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		 * and SIL_FAULT_PKUERR are only generated by faults that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		 * deliver them synchronously to userspace.  In case someone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		 * injects one of these signals and signalfd catches it treat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		 * it as SIL_FAULT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	case SIL_FAULT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		new.ssi_addr = (long) kinfo->si_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) #ifdef __ARCH_SI_TRAPNO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 		new.ssi_trapno = kinfo->si_trapno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	case SIL_FAULT_MCEERR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		new.ssi_addr = (long) kinfo->si_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) #ifdef __ARCH_SI_TRAPNO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 		new.ssi_trapno = kinfo->si_trapno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	case SIL_CHLD:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		new.ssi_pid    = kinfo->si_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		new.ssi_uid    = kinfo->si_uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		new.ssi_status = kinfo->si_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		new.ssi_utime  = kinfo->si_utime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		new.ssi_stime  = kinfo->si_stime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	case SIL_RT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		 * This case catches also the signals queued by sigqueue().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		new.ssi_pid = kinfo->si_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		new.ssi_uid = kinfo->si_uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		new.ssi_ptr = (long) kinfo->si_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		new.ssi_int = kinfo->si_int;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	case SIL_SYS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		new.ssi_call_addr = (long) kinfo->si_call_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		new.ssi_syscall   = kinfo->si_syscall;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		new.ssi_arch      = kinfo->si_arch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	if (copy_to_user(uinfo, &new, sizeof(struct signalfd_siginfo)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	return sizeof(*uinfo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 				int nonblock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	DECLARE_WAITQUEUE(wait, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	spin_lock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	ret = dequeue_signal(current, &ctx->sigmask, info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	switch (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	case 0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		if (!nonblock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		ret = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		spin_unlock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	add_wait_queue(&current->sighand->signalfd_wqh, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		set_current_state(TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		ret = dequeue_signal(current, &ctx->sigmask, info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		if (ret != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		if (signal_pending(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 			ret = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		spin_unlock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		spin_lock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	spin_unlock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	remove_wait_queue(&current->sighand->signalfd_wqh, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	__set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)  * Returns a multiple of the size of a "struct signalfd_siginfo", or a negative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)  * error code. The "count" parameter must be at least the size of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)  * "struct signalfd_siginfo".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) static ssize_t signalfd_read(struct file *file, char __user *buf, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 			     loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	struct signalfd_ctx *ctx = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	struct signalfd_siginfo __user *siginfo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	int nonblock = file->f_flags & O_NONBLOCK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	ssize_t ret, total = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	kernel_siginfo_t info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	count /= sizeof(struct signalfd_siginfo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	if (!count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	siginfo = (struct signalfd_siginfo __user *) buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		ret = signalfd_dequeue(ctx, &info, nonblock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		if (unlikely(ret <= 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		ret = signalfd_copyinfo(siginfo, &info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		siginfo++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		total += ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		nonblock = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	} while (--count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	return total ? total: ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) #ifdef CONFIG_PROC_FS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) static void signalfd_show_fdinfo(struct seq_file *m, struct file *f)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	struct signalfd_ctx *ctx = f->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	sigset_t sigmask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	sigmask = ctx->sigmask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	signotset(&sigmask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	render_sigset_t(m, "sigmask:\t", &sigmask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) static const struct file_operations signalfd_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) #ifdef CONFIG_PROC_FS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	.show_fdinfo	= signalfd_show_fdinfo,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	.release	= signalfd_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	.poll		= signalfd_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	.read		= signalfd_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	.llseek		= noop_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) static int do_signalfd4(int ufd, sigset_t *mask, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	struct signalfd_ctx *ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	/* Check the SFD_* constants for consistency.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	BUILD_BUG_ON(SFD_CLOEXEC != O_CLOEXEC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	BUILD_BUG_ON(SFD_NONBLOCK != O_NONBLOCK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	if (flags & ~(SFD_CLOEXEC | SFD_NONBLOCK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	sigdelsetmask(mask, sigmask(SIGKILL) | sigmask(SIGSTOP));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	signotset(mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	if (ufd == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		if (!ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 			return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		ctx->sigmask = *mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 		 * When we call this, the initialization must be complete, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 		 * anon_inode_getfd() will install the fd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		ufd = anon_inode_getfd("[signalfd]", &signalfd_fops, ctx,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 				       O_RDWR | (flags & (O_CLOEXEC | O_NONBLOCK)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		if (ufd < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 			kfree(ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		struct fd f = fdget(ufd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		if (!f.file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 			return -EBADF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 		ctx = f.file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		if (f.file->f_op != &signalfd_fops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 			fdput(f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		spin_lock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		ctx->sigmask = *mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		spin_unlock_irq(&current->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		wake_up(&current->sighand->signalfd_wqh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 		fdput(f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 	return ufd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) SYSCALL_DEFINE4(signalfd4, int, ufd, sigset_t __user *, user_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		size_t, sizemask, int, flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	sigset_t mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	if (sizemask != sizeof(sigset_t))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	if (copy_from_user(&mask, user_mask, sizeof(mask)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	return do_signalfd4(ufd, &mask, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) SYSCALL_DEFINE3(signalfd, int, ufd, sigset_t __user *, user_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 		size_t, sizemask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 	sigset_t mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	if (sizemask != sizeof(sigset_t))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	if (copy_from_user(&mask, user_mask, sizeof(mask)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	return do_signalfd4(ufd, &mask, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) static long do_compat_signalfd4(int ufd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 			const compat_sigset_t __user *user_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 			compat_size_t sigsetsize, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	sigset_t mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	if (sigsetsize != sizeof(compat_sigset_t))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	if (get_compat_sigset(&mask, user_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	return do_signalfd4(ufd, &mask, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) COMPAT_SYSCALL_DEFINE4(signalfd4, int, ufd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 		     const compat_sigset_t __user *, user_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 		     compat_size_t, sigsetsize,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 		     int, flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	return do_compat_signalfd4(ufd, user_mask, sigsetsize, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) COMPAT_SYSCALL_DEFINE3(signalfd, int, ufd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 		     const compat_sigset_t __user *, user_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 		     compat_size_t, sigsetsize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	return do_compat_signalfd4(ufd, user_mask, sigsetsize, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) #endif