bitkeeper revision 1.1351 (42677d3b7Caqgw-mG40oawn1nybJ4A)

Fix segment save/restore during context switching on x86/64.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 1cd03bcd47b9c6148dc56a98eef53745df4ad10b..c89b175fe152ed7c55eaec5b66d5df1247ff0b51 100644 (file)
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -632,17 +632,17 @@ static void load_segments(struct exec_domain *p, struct exec_domain *n)
         else
             regs->cs &= ~3;
 
-        if ( put_user(regs->ss,     rsp- 1) |
-             put_user(regs->rsp,    rsp- 2) |
-             put_user(regs->rflags, rsp- 3) |
-             put_user(regs->cs,     rsp- 4) |
-             put_user(regs->rip,    rsp- 5) |
-             put_user(regs->gs,     rsp- 6) |
-             put_user(regs->fs,     rsp- 7) |
-             put_user(regs->es,     rsp- 8) |
-             put_user(regs->ds,     rsp- 9) |
-             put_user(regs->r11,    rsp-10) |
-             put_user(regs->rcx,    rsp-11) )
+        if ( put_user(regs->ss,             rsp- 1) |
+             put_user(regs->rsp,            rsp- 2) |
+             put_user(regs->rflags,         rsp- 3) |
+             put_user(regs->cs,             rsp- 4) |
+             put_user(regs->rip,            rsp- 5) |
+             put_user(n->arch.user_ctxt.gs, rsp- 6) |
+             put_user(n->arch.user_ctxt.fs, rsp- 7) |
+             put_user(n->arch.user_ctxt.es, rsp- 8) |
+             put_user(n->arch.user_ctxt.ds, rsp- 9) |
+             put_user(regs->r11,            rsp-10) |
+             put_user(regs->rcx,            rsp-11) )
         {
             DPRINTK("Error while creating failsafe callback frame.\n");
             domain_crash();
@@ -737,7 +737,7 @@ static void __context_switch(void)
     {
         memcpy(&p->arch.user_ctxt,
                stack_ec, 
-               sizeof(*stack_ec));
+               CTXT_SWITCH_STACK_BYTES);
         unlazy_fpu(p);
         CLEAR_FAST_TRAP(&p->arch);
         save_segments(p);
@@ -747,7 +747,7 @@ static void __context_switch(void)
     {
         memcpy(stack_ec,
                &n->arch.user_ctxt,
-               sizeof(*stack_ec));
+               CTXT_SWITCH_STACK_BYTES);
 
         /* Maybe switch the debug registers. */
         if ( unlikely(n->arch.debugreg[7]) )

diff --git a/xen/include/asm-x86/x86_32/regs.h b/xen/include/asm-x86/x86_32/regs.h
index 865a385b947580fc86fee9d027c00b56ea907864..0e2e8622a4171b6e6eecd5b5da5856987349555f 100644 (file)
--- a/xen/include/asm-x86/x86_32/regs.h
+++ b/xen/include/asm-x86/x86_32/regs.h
@@ -15,4 +15,7 @@
 #define PERMIT_SOFTINT(_dpl, _e, _r) \
     ((_dpl) >= (VM86_MODE(_r) ? 3 : ((_r)->cs & 3)))
 
+/* Number of bytes of on-stack execution state to be context-switched. */
+#define CTXT_SWITCH_STACK_BYTES (sizeof(execution_context_t))
+
 #endif

diff --git a/xen/include/asm-x86/x86_64/regs.h b/xen/include/asm-x86/x86_64/regs.h
index 355e0fa32119ac55e666a8ab6864b3e43e195004..c476282f2d6536143fdec3472a77db2f0cd09994 100644 (file)
--- a/xen/include/asm-x86/x86_64/regs.h
+++ b/xen/include/asm-x86/x86_64/regs.h
@@ -15,4 +15,8 @@
 #define PERMIT_SOFTINT(_dpl, _e, _r) \
     ((_dpl) >= (KERNEL_MODE(_e, _r) ? 1 : 3))
 
+/* Number of bytes of on-stack execution state to be context-switched. */
+/* NB. Segment registers and bases are not saved/restored on x86/64 stack. */
+#define CTXT_SWITCH_STACK_BYTES (offsetof(execution_context_t, es))
+
 #endif