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authorJeremy Fitzhardinge <jeremy@goop.org>2008-06-25 00:19:28 -0400
committerIngo Molnar <mingo@elte.hu>2008-07-08 13:15:52 +0200
commit2be29982a08009c731307f4a39053b70ac4700da (patch)
treef01fcf847f36b9da5cd87cefa7ee6c13d193077d /arch/x86/ia32/ia32entry.S
parentc7245da6ae7e5208504ff027c4e0eec69b788651 (diff)
x86/paravirt: add sysret/sysexit pvops for returning to 32-bit compatibility userspace
In a 64-bit system, we need separate sysret/sysexit operations to return to a 32-bit userspace. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citirx.com> Cc: xen-devel <xen-devel@lists.xensource.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/ia32/ia32entry.S')
-rw-r--r--arch/x86/ia32/ia32entry.S21
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 3aefbce2de4..2a4c42427d9 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -61,6 +61,19 @@
CFI_UNDEFINED r15
.endm
+#ifdef CONFIG_PARAVIRT
+ENTRY(native_usergs_sysret32)
+ swapgs
+ sysretl
+ENDPROC(native_usergs_sysret32)
+
+ENTRY(native_irq_enable_sysexit)
+ swapgs
+ sti
+ sysexit
+ENDPROC(native_irq_enable_sysexit)
+#endif
+
/*
* 32bit SYSENTER instruction entry.
*
@@ -151,10 +164,7 @@ sysenter_do_call:
CFI_ADJUST_CFA_OFFSET -8
CFI_REGISTER rsp,rcx
TRACE_IRQS_ON
- swapgs
- sti /* sti only takes effect after the next instruction */
- /* sysexit */
- .byte 0xf, 0x35
+ ENABLE_INTERRUPTS_SYSEXIT32
sysenter_tracesys:
CFI_RESTORE_STATE
@@ -254,8 +264,7 @@ cstar_do_call:
TRACE_IRQS_ON
movl RSP-ARGOFFSET(%rsp),%esp
CFI_RESTORE rsp
- swapgs
- sysretl
+ USERGS_SYSRET32
cstar_tracesys:
CFI_RESTORE_STATE