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| 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.c | |
| parent | e04e0a630d8b5c621b3a8e70ff20db737d3a5728 (diff) | |
| download | op-kernel-dev-d75cd22fdd5f7d203fb60014d426942df33dd9a6.zip op-kernel-dev-d75cd22fdd5f7d203fb60014d426942df33dd9a6.tar.gz | |
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.c')
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 78c9a1b..565ee7a 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -140,7 +140,8 @@ unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, /* If the operation is a nop, then nop the callsite */ ret = paravirt_patch_nop(); else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || - type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_syscall_ret)) + type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || + type == PARAVIRT_PATCH(pv_cpu_ops.usersp_sysret)) /* If operation requires a jmp, then jmp */ ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len); else @@ -191,7 +192,8 @@ static void native_flush_tlb_single(unsigned long addr) /* These are in entry.S */ extern void native_iret(void); -extern void native_irq_enable_syscall_ret(void); +extern void native_irq_enable_sysexit(void); +extern void native_usersp_sysret(void); static int __init print_banner(void) { @@ -327,7 +329,11 @@ struct pv_cpu_ops pv_cpu_ops = { .write_idt_entry = native_write_idt_entry, .load_sp0 = native_load_sp0, - .irq_enable_syscall_ret = native_irq_enable_syscall_ret, +#ifdef CONFIG_X86_32 + .irq_enable_sysexit = native_irq_enable_sysexit, +#else + .usersp_sysret = native_usersp_sysret, +#endif .iret = native_iret, .swapgs = native_swapgs, |
