lguest: use bool instead of int

Impact: clean up

Rusty told me, some time ago, that he had become a fan of "bool".
So, here are some replacements.

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/core.c

@@ -152,7 +152,7 @@ static void unmap_switcher(void)
  * code.  We have to check that the range is below the pfn_limit the Launcher
  * gave us.  We have to make sure that addr + len doesn't give us a false
  * positive by overflowing, too. */
-int lguest_address_ok(const struct lguest *lg,
+bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len)
 {
 	return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);

drivers/lguest/interrupts_and_traps.c

@@ -34,7 +34,7 @@ static int idt_type(u32 lo, u32 hi)
 }
 
 /* An IDT entry can't be used unless the "present" bit is set. */
-static int idt_present(u32 lo, u32 hi)
+static bool idt_present(u32 lo, u32 hi)
 {
 	return (hi & 0x8000);
 }
@@ -60,7 +60,8 @@ static void push_guest_stack(struct lg_cpu *cpu, unsigned long *gstack, u32 val)
  * We set up the stack just like the CPU does for a real interrupt, so it's
  * identical for the Guest (and the standard "iret" instruction will undo
  * it). */
-static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
+static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi,
+				bool has_err)
 {
 	unsigned long gstack, origstack;
 	u32 eflags, ss, irq_enable;
@@ -184,7 +185,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
 		/* set_guest_interrupt() takes the interrupt descriptor and a
 		 * flag to say whether this interrupt pushes an error code onto
 		 * the stack as well: virtual interrupts never do. */
-		set_guest_interrupt(cpu, idt->a, idt->b, 0);
+		set_guest_interrupt(cpu, idt->a, idt->b, false);
 	}
 
 	/* Every time we deliver an interrupt, we update the timestamp in the
@@ -244,26 +245,26 @@ void free_interrupts(void)
 /*H:220 Now we've got the routines to deliver interrupts, delivering traps like
  * page fault is easy.  The only trick is that Intel decided that some traps
  * should have error codes: */
-static int has_err(unsigned int trap)
+static bool has_err(unsigned int trap)
 {
 	return (trap == 8 || (trap >= 10 && trap <= 14) || trap == 17);
 }
 
 /* deliver_trap() returns true if it could deliver the trap. */
-int deliver_trap(struct lg_cpu *cpu, unsigned int num)
+bool deliver_trap(struct lg_cpu *cpu, unsigned int num)
 {
 	/* Trap numbers are always 8 bit, but we set an impossible trap number
 	 * for traps inside the Switcher, so check that here. */
 	if (num >= ARRAY_SIZE(cpu->arch.idt))
-		return 0;
+		return false;
 
 	/* Early on the Guest hasn't set the IDT entries (or maybe it put a
 	 * bogus one in): if we fail here, the Guest will be killed. */
 	if (!idt_present(cpu->arch.idt[num].a, cpu->arch.idt[num].b))
-		return 0;
+		return false;
 	set_guest_interrupt(cpu, cpu->arch.idt[num].a,
 			    cpu->arch.idt[num].b, has_err(num));
-	return 1;
+	return true;
 }
 
 /*H:250 Here's the hard part: returning to the Host every time a trap happens
@@ -279,12 +280,12 @@ int deliver_trap(struct lg_cpu *cpu, unsigned int num)
  *
  * This routine indicates if a particular trap number could be delivered
  * directly. */
-static int direct_trap(unsigned int num)
+static bool direct_trap(unsigned int num)
 {
 	/* Hardware interrupts don't go to the Guest at all (except system
 	 * call). */
 	if (num >= FIRST_EXTERNAL_VECTOR && !could_be_syscall(num))
-		return 0;
+		return false;
 
 	/* The Host needs to see page faults (for shadow paging and to save the
 	 * fault address), general protection faults (in/out emulation) and

drivers/lguest/lg.h

@@ -109,7 +109,7 @@ struct lguest
 extern struct mutex lguest_lock;
 
 /* core.c: */
-int lguest_address_ok(const struct lguest *lg,
+bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len);
 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
 void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
@@ -140,7 +140,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 
 /* interrupts_and_traps.c: */
 void maybe_do_interrupt(struct lg_cpu *cpu);
-int deliver_trap(struct lg_cpu *cpu, unsigned int num);
+bool deliver_trap(struct lg_cpu *cpu, unsigned int num);
 void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
 			  u32 low, u32 hi);
 void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
@@ -173,7 +173,7 @@ void guest_pagetable_flush_user(struct lg_cpu *cpu);
 void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 		   unsigned long vaddr, pte_t val);
 void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
-int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
+bool demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
 void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
 unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
 void page_table_guest_data_init(struct lg_cpu *cpu);

drivers/lguest/page_tables.c

@@ -199,7 +199,7 @@ static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
  *
  * If we fixed up the fault (ie. we mapped the address), this routine returns
  * true.  Otherwise, it was a real fault and we need to tell the Guest. */
-int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
+bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 {
 	pgd_t gpgd;
 	pgd_t *spgd;
@@ -211,7 +211,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 	gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
 	/* Toplevel not present?  We can't map it in. */
 	if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
-		return 0;
+		return false;
 
 	/* Now look at the matching shadow entry. */
 	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
@@ -222,7 +222,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 		 * simple for this corner case. */
 		if (!ptepage) {
 			kill_guest(cpu, "out of memory allocating pte page");
-			return 0;
+			return false;
 		}
 		/* We check that the Guest pgd is OK. */
 		check_gpgd(cpu, gpgd);
@@ -238,16 +238,16 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 
 	/* If this page isn't in the Guest page tables, we can't page it in. */
 	if (!(pte_flags(gpte) & _PAGE_PRESENT))
-		return 0;
+		return false;
 
 	/* Check they're not trying to write to a page the Guest wants
 	 * read-only (bit 2 of errcode == write). */
 	if ((errcode & 2) && !(pte_flags(gpte) & _PAGE_RW))
-		return 0;
+		return false;
 
 	/* User access to a kernel-only page? (bit 3 == user access) */
 	if ((errcode & 4) && !(pte_flags(gpte) & _PAGE_USER))
-		return 0;
+		return false;
 
 	/* Check that the Guest PTE flags are OK, and the page number is below
 	 * the pfn_limit (ie. not mapping the Launcher binary). */
@@ -283,7 +283,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 	 * manipulated, the result returned and the code complete.  A small
 	 * delay and a trace of alliteration are the only indications the Guest
 	 * has that a page fault occurred at all. */
-	return 1;
+	return true;
 }
 
 /*H:360
@@ -296,7 +296,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
  *
  * This is a quick version which answers the question: is this virtual address
  * mapped by the shadow page tables, and is it writable? */
-static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
+static bool page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 {
 	pgd_t *spgd;
 	unsigned long flags;
@@ -304,7 +304,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 	/* Look at the current top level entry: is it present? */
 	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
 	if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
-		return 0;
+		return false;
 
 	/* Check the flags on the pte entry itself: it must be present and
 	 * writable. */

drivers/lguest/segments.c

@@ -45,7 +45,7 @@
  * "Task State Segment" which controls all kinds of delicate things.  The
  * LGUEST_CS and LGUEST_DS entries are reserved for the Switcher, and the
  * the Guest can't be trusted to deal with double faults. */
-static int ignored_gdt(unsigned int num)
+static bool ignored_gdt(unsigned int num)
 {
 	return (num == GDT_ENTRY_TSS
 		|| num == GDT_ENTRY_LGUEST_CS