diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-06-25 00:19:28 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 13:15:52 +0200 |
| commit | 2be29982a08009c731307f4a39053b70ac4700da (patch) | |
| tree | f01fcf847f36b9da5cd87cefa7ee6c13d193077d /include/asm-x86 | |
| parent | c7245da6ae7e5208504ff027c4e0eec69b788651 (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 'include/asm-x86')
| -rw-r--r-- | include/asm-x86/irqflags.h | 14 | ||||
| -rw-r--r-- | include/asm-x86/paravirt.h | 56 |
2 files changed, 56 insertions, 14 deletions
diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h index 544836c96b6..ea9bd2635d5 100644 --- a/include/asm-x86/irqflags.h +++ b/include/asm-x86/irqflags.h @@ -112,9 +112,17 @@ static inline unsigned long __raw_local_irq_save(void) #ifdef CONFIG_X86_64 #define INTERRUPT_RETURN iretq -#define USERGS_SYSRET \ - swapgs; \ - sysretq; +#define USERGS_SYSRET64 \ + swapgs; \ + sysretq; +#define USERGS_SYSRET32 \ + swapgs; \ + sysretl +#define ENABLE_INTERRUPTS_SYSEXIT32 \ + swapgs; \ + sti; \ + sysexit + #else #define INTERRUPT_RETURN iret #define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h index dad5b4186f5..33f72f8fe75 100644 --- a/include/asm-x86/paravirt.h +++ b/include/asm-x86/paravirt.h @@ -141,9 +141,32 @@ struct pv_cpu_ops { u64 (*read_pmc)(int counter); unsigned long long (*read_tscp)(unsigned int *aux); - /* These three are jmp to, not actually called. */ + /* + * Atomically enable interrupts and return to userspace. This + * is only ever used to return to 32-bit processes; in a + * 64-bit kernel, it's used for 32-on-64 compat processes, but + * never native 64-bit processes. (Jump, not call.) + */ void (*irq_enable_sysexit)(void); - void (*usergs_sysret)(void); + + /* + * Switch to usermode gs and return to 64-bit usermode using + * sysret. Only used in 64-bit kernels to return to 64-bit + * processes. Usermode register state, including %rsp, must + * already be restored. + */ + void (*usergs_sysret64)(void); + + /* + * Switch to usermode gs and return to 32-bit usermode using + * sysret. Used to return to 32-on-64 compat processes. + * Other usermode register state, including %esp, must already + * be restored. + */ + void (*usergs_sysret32)(void); + + /* Normal iret. Jump to this with the standard iret stack + frame set up. */ void (*iret)(void); void (*swapgs)(void); @@ -1481,18 +1504,24 @@ static inline unsigned long __raw_local_irq_save(void) call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable); \ PV_RESTORE_REGS;) -#define ENABLE_INTERRUPTS_SYSEXIT \ - PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_sysexit), \ +#define USERGS_SYSRET32 \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret32), \ CLBR_NONE, \ - jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_sysexit)) - + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret32)) #ifdef CONFIG_X86_32 #define GET_CR0_INTO_EAX \ push %ecx; push %edx; \ call PARA_INDIRECT(pv_cpu_ops+PV_CPU_read_cr0); \ pop %edx; pop %ecx -#else + +#define ENABLE_INTERRUPTS_SYSEXIT \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_sysexit), \ + CLBR_NONE, \ + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_sysexit)) + + +#else /* !CONFIG_X86_32 */ #define SWAPGS \ PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE, \ PV_SAVE_REGS; \ @@ -1505,11 +1534,16 @@ static inline unsigned long __raw_local_irq_save(void) movq %rax, %rcx; \ xorq %rax, %rax; -#define USERGS_SYSRET \ - PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret), \ +#define USERGS_SYSRET64 \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64), \ CLBR_NONE, \ - jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret)) -#endif + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret64)) + +#define ENABLE_INTERRUPTS_SYSEXIT32 \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_sysexit), \ + CLBR_NONE, \ + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_sysexit)) +#endif /* CONFIG_X86_32 */ #endif /* __ASSEMBLY__ */ #endif /* CONFIG_PARAVIRT */ |