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| author | Andy Lutomirski <luto@amacapital.net> | 2014-07-23 19:34:11 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-08-07 23:00:11 +0400 |
| commit | 473d8a237b359c41225458f3d7c6aa2e5beb40d5 (patch) | |
| tree | ff4a4bb57f7a64ce1f3c4e7ab4ce207cc7fe4a6b /arch/x86/include/asm/irqflags.h | |
| parent | 4a0db8af65056ec1a60607d4286b782934a2a03b (diff) | |
| download | linux-473d8a237b359c41225458f3d7c6aa2e5beb40d5.tar.xz | |
x86_64/entry/xen: Do not invoke espfix64 on Xen
commit 7209a75d2009dbf7745e2fd354abf25c3deb3ca3 upstream.
This moves the espfix64 logic into native_iret. To make this work,
it gets rid of the native patch for INTERRUPT_RETURN:
INTERRUPT_RETURN on native kernels is now 'jmp native_iret'.
This changes the 16-bit SS behavior on Xen from OOPSing to leaking
some bits of the Xen hypervisor's RSP (I think).
[ hpa: this is a nonzero cost on native, but probably not enough to
measure. Xen needs to fix this in their own code, probably doing
something equivalent to espfix64. ]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/7b8f1d8ef6597cb16ae004a43c56980a7de3cf94.1406129132.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/asm/irqflags.h')
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index bba3cf88e624..0a8b519226b8 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -129,7 +129,7 @@ static inline notrace unsigned long arch_local_irq_save(void) #define PARAVIRT_ADJUST_EXCEPTION_FRAME /* */ -#define INTERRUPT_RETURN iretq +#define INTERRUPT_RETURN jmp native_iret #define USERGS_SYSRET64 \ swapgs; \ sysretq; |