This pull request contains the following changes for UML:

- Kconfig cleanups
 - Fix cpu_all_mask() usage
 - Various bug fixes
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Merge tag 'for-linus-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Kconfig cleanups

 - Fix cpu_all_mask() usage

 - Various bug fixes

* tag 'for-linus-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: irq: don't set the chip for all irqs
  um: define set_pte_at() as a static inline function, not a macro
  um: remove uses of variable length arrays
  um: remove unused variable
  uml: fix a boot splat wrt use of cpu_all_mask
  um: Do not unlock mutex that is not hold.
  hostfs: fix mismatch between link_file definition and declaration
  arch: um: drivers: Kconfig: pedantic formatting
  arch: um: Kconfig: pedantic indention cleanups
  um: Revert to using stack for pt_regs in signal handling

arch/um/Kconfig

@@ -142,13 +142,17 @@ config MAGIC_SYSRQ
 
 config KERNEL_STACK_ORDER
 	int "Kernel stack size order"
-	default 1 if 64BIT
-	range 1 10 if 64BIT
-	default 0 if !64BIT
+	default 2 if 64BIT
+	range 2 10 if 64BIT
+	default 1 if !64BIT
 	help
 	  This option determines the size of UML kernel stacks.  They will
 	  be 1 << order pages.  The default is OK unless you're running Valgrind
 	  on UML, in which case, set this to 3.
+	  It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
+	  older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
+	  increase in the size of the state which needs to be saved when handling
+          signals.
 
 config MMAPPER
 	tristate "iomem emulation driver"

arch/um/drivers/Kconfig

@@ -315,7 +315,7 @@ config UML_NET_SLIRP
 	  to network by invoking a program that can handle SLIP encapsulated
 	  packets.  This is commonly (but not limited to) the application
 	  known as SLiRP, a program that can re-socket IP packets back onto
-        the host on which it is run.  Only IP packets are supported,
+	  he host on which it is run.  Only IP packets are supported,
 	  unlike other network transports that can handle all Ethernet
 	  frames.  In general, slirp allows the UML the same IP connectivity
 	  to the outside world that the host user is permitted, and unlike

arch/um/drivers/ubd_kern.c

@@ -276,14 +276,14 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out)
 		str++;
 		if(!strcmp(str, "sync")){
 			global_openflags = of_sync(global_openflags);
-			goto out1;
+			return err;
 		}
 
 		err = -EINVAL;
 		major = simple_strtoul(str, &end, 0);
 		if((*end != '\0') || (end == str)){
 			*error_out = "Didn't parse major number";
-			goto out1;
+			return err;
 		}
 
 		mutex_lock(&ubd_lock);

arch/um/include/asm/pgtable.h

@@ -263,7 +263,12 @@ static inline void set_pte(pte_t *pteptr, pte_t pteval)
 	*pteptr = pte_mknewpage(*pteptr);
 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 }
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *pteptr, pte_t pteval)
+{
+	set_pte(pteptr, pteval);
+}
 
 #define __HAVE_ARCH_PTE_SAME
 static inline int pte_same(pte_t pte_a, pte_t pte_b)

arch/um/kernel/irq.c

@@ -479,7 +479,7 @@ void __init init_IRQ(void)
 	irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq);
 
 
-	for (i = 1; i < NR_IRQS; i++)
+	for (i = 1; i < LAST_IRQ; i++)
 		irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq);
 	/* Initialize EPOLL Loop */
 	os_setup_epoll();

arch/um/kernel/skas/uaccess.c

@@ -59,7 +59,6 @@ static pte_t *maybe_map(unsigned long virt, int is_write)
 static int do_op_one_page(unsigned long addr, int len, int is_write,
 		 int (*op)(unsigned long addr, int len, void *arg), void *arg)
 {
-	jmp_buf buf;
 	struct page *page;
 	pte_t *pte;
 	int n;

arch/um/kernel/time.c

@@ -56,7 +56,7 @@ static int itimer_one_shot(struct clock_event_device *evt)
 static struct clock_event_device timer_clockevent = {
 	.name			= "posix-timer",
 	.rating			= 250,
-	.cpumask		= cpu_all_mask,
+	.cpumask		= cpu_possible_mask,
 	.features		= CLOCK_EVT_FEAT_PERIODIC |
 				  CLOCK_EVT_FEAT_ONESHOT,
 	.set_state_shutdown	= itimer_shutdown,

arch/um/os-Linux/signal.c

@@ -31,29 +31,23 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
 
 static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
 {
-	struct uml_pt_regs *r;
+	struct uml_pt_regs r;
 	int save_errno = errno;
 
-	r = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
-	if (!r)
-		panic("out of memory");
-
-	r->is_user = 0;
+	r.is_user = 0;
 	if (sig == SIGSEGV) {
 		/* For segfaults, we want the data from the sigcontext. */
-		get_regs_from_mc(r, mc);
-		GET_FAULTINFO_FROM_MC(r->faultinfo, mc);
+		get_regs_from_mc(&r, mc);
+		GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
 	}
 
 	/* enable signals if sig isn't IRQ signal */
 	if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGALRM))
 		unblock_signals();
 
-	(*sig_info[sig])(sig, si, r);
+	(*sig_info[sig])(sig, si, &r);
 
 	errno = save_errno;
-
-	free(r);
 }
 
 /*
@@ -91,17 +85,11 @@ void sig_handler(int sig, struct siginfo *si, mcontext_t *mc)
 
 static void timer_real_alarm_handler(mcontext_t *mc)
 {
-	struct uml_pt_regs *regs;
-
-	regs = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
-	if (!regs)
-		panic("out of memory");
+	struct uml_pt_regs regs;
 
 	if (mc != NULL)
-		get_regs_from_mc(regs, mc);
-	timer_handler(SIGALRM, NULL, regs);
-
-	free(regs);
+		get_regs_from_mc(&regs, mc);
+	timer_handler(SIGALRM, NULL, &regs);
 }
 
 void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)

arch/um/os-Linux/umid.c

@@ -135,12 +135,18 @@ out:
  */
 static inline int is_umdir_used(char *dir)
 {
-	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
-	char pid[sizeof("nnnnn\0")], *end;
+	char pid[sizeof("nnnnn\0")], *end, *file;
 	int dead, fd, p, n, err;
+	size_t filelen;
 
-	n = snprintf(file, sizeof(file), "%s/pid", dir);
-	if (n >= sizeof(file)) {
+	err = asprintf(&file, "%s/pid", dir);
+	if (err < 0)
+		return 0;
+
+	filelen = strlen(file);
+
+	n = snprintf(file, filelen, "%s/pid", dir);
+	if (n >= filelen) {
 		printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n");
 		err = -E2BIG;
 		goto out;
@@ -185,6 +191,7 @@ static inline int is_umdir_used(char *dir)
 out_close:
 	close(fd);
 out:
+	free(file);
 	return 0;
 }
 
@@ -210,18 +217,21 @@ static int umdir_take_if_dead(char *dir)
 
 static void __init create_pid_file(void)
 {
-	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
-	char pid[sizeof("nnnnn\0")];
+	char pid[sizeof("nnnnn\0")], *file;
 	int fd, n;
 
-	if (umid_file_name("pid", file, sizeof(file)))
+	file = malloc(strlen(uml_dir) + UMID_LEN + sizeof("/pid\0"));
+	if (!file)
 		return;
 
+	if (umid_file_name("pid", file, sizeof(file)))
+		goto out;
+
 	fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
 	if (fd < 0) {
 		printk(UM_KERN_ERR "Open of machine pid file \"%s\" failed: "
 		       "%s\n", file, strerror(errno));
-		return;
+		goto out;
 	}
 
 	snprintf(pid, sizeof(pid), "%d\n", getpid());
@@ -231,6 +241,8 @@ static void __init create_pid_file(void)
 		       errno);
 
 	close(fd);
+out:
+	free(file);
 }
 
 int __init set_umid(char *name)
@@ -385,13 +397,19 @@ __uml_setup("uml_dir=", set_uml_dir,
 
 static void remove_umid_dir(void)
 {
-	char dir[strlen(uml_dir) + UMID_LEN + 1], err;
+	char *dir, err;
+
+	dir = malloc(strlen(uml_dir) + UMID_LEN + 1);
+	if (!dir)
+		return;
 
 	sprintf(dir, "%s%s", uml_dir, umid);
 	err = remove_files_and_dir(dir);
 	if (err)
 		os_warn("%s - remove_files_and_dir failed with err = %d\n",
 			__func__, err);
+
+	free(dir);
 }
 
 __uml_exitcall(remove_umid_dir);

fs/hostfs/hostfs.h

@@ -87,7 +87,7 @@ extern int do_mkdir(const char *file, int mode);
 extern int hostfs_do_rmdir(const char *file);
 extern int do_mknod(const char *file, int mode, unsigned int major,
 		    unsigned int minor);
-extern int link_file(const char *from, const char *to);
+extern int link_file(const char *to, const char *from);
 extern int hostfs_do_readlink(char *file, char *buf, int size);
 extern int rename_file(char *from, char *to);
 extern int rename2_file(char *from, char *to, unsigned int flags);