From: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Add 2 macros to set and get debugreg on x86_64. This is useful for Xen
because it will need only to redefine each macro to a hypervisor call.
Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
arch/x86_64/kernel/signal.c | 2 +-
arch/x86_64/kernel/traps.c | 4 ++--
include/asm-x86_64/processor.h | 8 ++++++++
3 files changed, 11 insertions(+), 3 deletions(-)
diff -puN arch/x86_64/kernel/signal.c~xen-x86_64-add-macro-for-debugreg arch/x86_64/kernel/signal.c
--- 25/arch/x86_64/kernel/signal.c~xen-x86_64-add-macro-for-debugreg 2005-05-25 00:52:49.000000000 -0700
+++ 25-akpm/arch/x86_64/kernel/signal.c 2005-05-25 00:52:49.000000000 -0700
@@ -438,7 +438,7 @@ int do_signal(struct pt_regs *regs, sigs
* inside the kernel.
*/
if (current->thread.debugreg7)
- asm volatile("movq %0,%%db7" : : "r" (current->thread.debugreg7));
+ set_debugreg(current->thread.debugreg7, 7);
/* Whee! Actually deliver the signal. */
return handle_signal(signr, &info, &ka, oldset, regs);
diff -puN arch/x86_64/kernel/traps.c~xen-x86_64-add-macro-for-debugreg arch/x86_64/kernel/traps.c
--- 25/arch/x86_64/kernel/traps.c~xen-x86_64-add-macro-for-debugreg 2005-05-25 00:52:49.000000000 -0700
+++ 25-akpm/arch/x86_64/kernel/traps.c 2005-05-25 00:52:49.000000000 -0700
@@ -669,7 +669,7 @@ asmlinkage void do_debug(struct pt_regs
}
#endif
- asm("movq %%db6,%0" : "=r" (condition));
+ get_debugreg(condition, 6);
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
SIGTRAP) == NOTIFY_STOP)
@@ -721,7 +721,7 @@ asmlinkage void do_debug(struct pt_regs
info.si_addr = (void __user *)regs->rip;
force_sig_info(SIGTRAP, &info, tsk);
clear_dr7:
- asm volatile("movq %0,%%db7"::"r"(0UL));
+ set_debugreg(0UL, 7);
return;
clear_TF_reenable:
diff -puN include/asm-x86_64/processor.h~xen-x86_64-add-macro-for-debugreg include/asm-x86_64/processor.h
--- 25/include/asm-x86_64/processor.h~xen-x86_64-add-macro-for-debugreg 2005-05-25 00:52:49.000000000 -0700
+++ 25-akpm/include/asm-x86_64/processor.h 2005-05-25 00:52:49.000000000 -0700
@@ -279,6 +279,14 @@ struct thread_struct {
set_fs(USER_DS); \
} while(0)
+#define get_debugreg(var, register) \
+ __asm__("movq %%db" #register ", %0" \
+ :"=r" (var))
+#define set_debugreg(value, register) \
+ __asm__("movq %0,%%db" #register \
+ : /* no output */ \
+ :"r" (value))
+
struct task_struct;
struct mm_struct;
_