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

@@ -80,46 +80,46 @@ config LD_SCRIPT_DYN
 	bool
 	default y
 	depends on !LD_SCRIPT_STATIC
-        select MODULE_REL_CRCS if MODVERSIONS
+	select MODULE_REL_CRCS if MODVERSIONS
 
 config HOSTFS
 	tristate "Host filesystem"
 	help
-          While the User-Mode Linux port uses its own root file system for
-          booting and normal file access, this module lets the UML user
-          access files stored on the host.  It does not require any
-          network connection between the Host and UML.  An example use of
-          this might be:
+	  While the User-Mode Linux port uses its own root file system for
+	  booting and normal file access, this module lets the UML user
+	  access files stored on the host.  It does not require any
+	  network connection between the Host and UML.  An example use of
+	  this might be:
 
-          mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
+	  mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 
-          where /tmp/fromhost is an empty directory inside UML and
-          /tmp/umlshare is a directory on the host with files the UML user
-          wishes to access.
+	  where /tmp/fromhost is an empty directory inside UML and
+	  /tmp/umlshare is a directory on the host with files the UML user
+	  wishes to access.
 
-          For more information, see
-          <http://user-mode-linux.sourceforge.net/hostfs.html>.
+	  For more information, see
+	  <http://user-mode-linux.sourceforge.net/hostfs.html>.
 
-          If you'd like to be able to work with files stored on the host,
-          say Y or M here; otherwise say N.
+	  If you'd like to be able to work with files stored on the host,
+	  say Y or M here; otherwise say N.
 
 config MCONSOLE
 	bool "Management console"
 	depends on PROC_FS
 	default y
 	help
-          The user mode linux management console is a low-level interface to
-          the kernel, somewhat like the i386 SysRq interface.  Since there is
-          a full-blown operating system running under every user mode linux
-          instance, there is much greater flexibility possible than with the
-          SysRq mechanism.
+	  The user mode linux management console is a low-level interface to
+	  the kernel, somewhat like the i386 SysRq interface.  Since there is
+	  a full-blown operating system running under every user mode linux
+	  instance, there is much greater flexibility possible than with the
+	  SysRq mechanism.
 
-          If you answer 'Y' to this option, to use this feature, you need the
-          mconsole client (called uml_mconsole) which is present in CVS in
-          2.4.5-9um and later (path /tools/mconsole), and is also in the
-          distribution RPM package in 2.4.6 and later.
+	  If you answer 'Y' to this option, to use this feature, you need the
+	  mconsole client (called uml_mconsole) which is present in CVS in
+	  2.4.5-9um and later (path /tools/mconsole), and is also in the
+	  distribution RPM package in 2.4.6 and later.
 
-          It is safe to say 'Y' here.
+	  It is safe to say 'Y' here.
 
 config MAGIC_SYSRQ
 	bool "Magic SysRq key"
@@ -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/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 @@ static int remove_files_and_dir(char *dir)
  */
 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);