Merge branch 'linus' into tracing/core

Merge reason: tracing/core was on a .30-rc1 base and was missing out on
              on a handful of tracing fixes present in .30-rc5-almost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 16 insertions, 9 deletions

diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index ac8a4a3741b8..af92a176697f 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -158,7 +158,8 @@ void free_interrupts(void);
 /* segments.c: */
 void setup_default_gdt_entries(struct lguest_ro_state *state);
 void setup_guest_gdt(struct lg_cpu *cpu);
-void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
+void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i,
+                          u32 low, u32 hi);
 void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
 void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
 void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
index 4f15439b7f12..7ede64ffeef9 100644
--- a/drivers/lguest/segments.c
+++ b/drivers/lguest/segments.c
@@ -144,18 +144,19 @@ void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
                         gdt[i] = cpu->arch.gdt[i];
 }
 
-/*H:620 This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT).
- * We copy it from the Guest and tweak the entries. */
-void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
+/*H:620 This is where the Guest asks us to load a new GDT entry
+ * (LHCALL_LOAD_GDT_ENTRY).  We tweak the entry and copy it in. */
+void load_guest_gdt_entry(struct lg_cpu *cpu, u32 num, u32 lo, u32 hi)
 {
         /* We assume the Guest has the same number of GDT entries as the
          * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
         if (num > ARRAY_SIZE(cpu->arch.gdt))
                 kill_guest(cpu, "too many gdt entries %i", num);
 
-        /* We read the whole thing in, then fix it up. */
-        __lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
-        fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
+        /* Set it up, then fix it. */
+        cpu->arch.gdt[num].a = lo;
+        cpu->arch.gdt[num].b = hi;
+        fixup_gdt_table(cpu, num, num+1);
         /* Mark that the GDT changed so the core knows it has to copy it again,
          * even if the Guest is run on the same CPU. */
         cpu->changed |= CHANGED_GDT;
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index a6b717644be0..1a83910f674f 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -324,6 +324,11 @@ static void rewrite_hypercall(struct lg_cpu *cpu)
         u8 insn[3] = {0xcd, 0x1f, 0x90};
 
         __lgwrite(cpu, guest_pa(cpu, cpu->regs->eip), insn, sizeof(insn));
+        /* The above write might have caused a copy of that page to be made
+         * (if it was read-only).  We need to make sure the Guest has
+         * up-to-date pagetables.  As this doesn't happen often, we can just
+         * drop them all. */
+        guest_pagetable_clear_all(cpu);
 }
 
 static bool is_hypercall(struct lg_cpu *cpu)
@@ -563,8 +568,8 @@ void __exit lguest_arch_host_fini(void)
 int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
         switch (args->arg0) {
-        case LHCALL_LOAD_GDT:
-                load_guest_gdt(cpu, args->arg1, args->arg2);
+        case LHCALL_LOAD_GDT_ENTRY:
+                load_guest_gdt_entry(cpu, args->arg1, args->arg2, args->arg3);
                 break;
         case LHCALL_LOAD_IDT_ENTRY:
                 load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3);