x86:

Added fields for temporary storage of the debug registers dr6 and dr7 to the
arch_cpu_info structure. The actual registers are stored at the beginning of
x86_exit_user_debug_at_kernel_entry() and read in
x86_handle_debug_exception().
The problem was that x86_exit_user_debug_at_kernel_entry() itself overwrote
dr7 and, if kernel breakpoints were enabled, dr6 could be overwritten anytime
after. So x86_handle_debug_exception() would find incorrect values in the
registers (definitely in dr7) and thus interpret the detected debug condition
incorrectly. Usually watchpoints were recognized as breakpoints.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35951 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/x86/arch_cpu.h

@@ -250,6 +250,9 @@ typedef struct arch_cpu_info {
 
 	struct vm_translation_map_arch_info* active_translation_map;
 
+	uint32				dr6;	// temporary storage for debug registers (cf.
+	uint32				dr7;	// x86_exit_user_debug_at_kernel_entry())
+
 	// local TSS for this cpu
 	struct tss			tss;
 	struct tss			double_fault_tss;