diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-06-25 00:19:26 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 13:13:15 +0200 |
| commit | d75cd22fdd5f7d203fb60014d426942df33dd9a6 (patch) | |
| tree | 0613fca9d594eab9a0679f80510fa11b48b31571 /arch/x86/kernel/paravirt_patch_64.c | |
| parent | e04e0a630d8b5c621b3a8e70ff20db737d3a5728 (diff) | |
x86/paravirt: split sysret and sysexit
Don't conflate sysret and sysexit; they're different instructions with
different semantics, and may be in use at the same time (at least
within the same kernel, depending on whether its an Intel or AMD
system).
sysexit - just return to userspace, does no register restoration of
any kind; must explicitly atomically enable interrupts.
sysret - reloads flags from r11, so no need to explicitly enable
interrupts on 64-bit, responsible for restoring usermode %gs
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/kernel/paravirt_patch_64.c')
| -rw-r--r-- | arch/x86/kernel/paravirt_patch_64.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c index 7d904e138d7e..4a170552b852 100644 --- a/arch/x86/kernel/paravirt_patch_64.c +++ b/arch/x86/kernel/paravirt_patch_64.c @@ -15,7 +15,7 @@ DEF_NATIVE(pv_cpu_ops, clts, "clts"); DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd"); /* the three commands give us more control to how to return from a syscall */ -DEF_NATIVE(pv_cpu_ops, irq_enable_syscall_ret, "movq %gs:" __stringify(pda_oldrsp) ", %rsp; swapgs; sysretq;"); +DEF_NATIVE(pv_cpu_ops, usersp_sysret, "movq %gs:" __stringify(pda_oldrsp) ", %rsp; swapgs; sysretq;"); DEF_NATIVE(pv_cpu_ops, swapgs, "swapgs"); unsigned native_patch(u8 type, u16 clobbers, void *ibuf, @@ -35,7 +35,7 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, PATCH_SITE(pv_irq_ops, irq_enable); PATCH_SITE(pv_irq_ops, irq_disable); PATCH_SITE(pv_cpu_ops, iret); - PATCH_SITE(pv_cpu_ops, irq_enable_syscall_ret); + PATCH_SITE(pv_cpu_ops, usersp_sysret); PATCH_SITE(pv_cpu_ops, swapgs); PATCH_SITE(pv_mmu_ops, read_cr2); PATCH_SITE(pv_mmu_ops, read_cr3); |