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| author | Andrew Cooper <andrew.cooper3@citrix.com> | 2013-10-22 17:11:16 +0200 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2013-10-22 17:11:16 +0200 |
| commit | e5fc6434d710894b5fc5a676d7f4c41608ab3ae6 (patch) | |
| tree | b6ee9c44b00ec19ed766bbfe0810ca5e4ff5a4ce | |
| parent | e47a90e6dca491c0ceea6ffa18055e7e32565e8e (diff) | |
| download | xen-e5fc6434d710894b5fc5a676d7f4c41608ab3ae6.tar.gz xen-e5fc6434d710894b5fc5a676d7f4c41608ab3ae6.tar.bz2 xen-e5fc6434d710894b5fc5a676d7f4c41608ab3ae6.zip | |
x86/irq: local_irq_restore() should not blindly popf
local_irq_restore() should only be concerned with possibly changing the
interrupt flag. A blind popf could corrupt other system flags.
While playing in this area, fixup an opencoded use of X86_EFLAGS_IF.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
| -rw-r--r-- | xen/include/asm-x86/system.h | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/xen/include/asm-x86/system.h b/xen/include/asm-x86/system.h index 6ab7d56fbd..e9602aa3d8 100644 --- a/xen/include/asm-x86/system.h +++ b/xen/include/asm-x86/system.h @@ -3,6 +3,7 @@ #include <xen/lib.h> #include <xen/bitops.h> +#include <asm/processor.h> #define read_segment_register(name) \ ({ u16 __sel; \ @@ -159,15 +160,19 @@ static always_inline unsigned long __cmpxchg( #define local_irq_restore(x) \ ({ \ BUILD_BUG_ON(sizeof(x) != sizeof(long)); \ - asm volatile ( "push" __OS " %0 ; popf" __OS \ - : : "g" (x) : "memory", "cc" ); \ + asm volatile ( "pushfq\n\t" \ + "andq %0, (%%rsp)\n\t" \ + "orq %1, (%%rsp)\n\t" \ + "popfq" \ + : : "i?r" ( ~X86_EFLAGS_IF ), \ + "ri" ( (x) & X86_EFLAGS_IF ) ); \ }) static inline int local_irq_is_enabled(void) { unsigned long flags; local_save_flags(flags); - return !!(flags & (1<<9)); /* EFLAGS_IF */ + return !!(flags & X86_EFLAGS_IF); } #define BROKEN_ACPI_Sx 0x0001 |