x86/debug: Clear reserved bits of DR6 in do_debug()
Clear the reserved bits from the stored copy of debug status register (DR6). This will help easy bitwise operations such as quick testing of a debug event origin. Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20100128111401.GB13935@in.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
parent
1e12a4a7a3
commit
40f9249a73
|
@ -14,6 +14,9 @@
|
|||
which debugging register was responsible for the trap. The other bits
|
||||
are either reserved or not of interest to us. */
|
||||
|
||||
/* Define reserved bits in DR6 which are always set to 1 */
|
||||
#define DR6_RESERVED (0xFFFF0FF0)
|
||||
|
||||
#define DR_TRAP0 (0x1) /* db0 */
|
||||
#define DR_TRAP1 (0x2) /* db1 */
|
||||
#define DR_TRAP2 (0x4) /* db2 */
|
||||
|
|
|
@ -534,6 +534,9 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
|
|||
|
||||
get_debugreg(dr6, 6);
|
||||
|
||||
/* Filter out all the reserved bits which are preset to 1 */
|
||||
dr6 &= ~DR6_RESERVED;
|
||||
|
||||
/* Catch kmemcheck conditions first of all! */
|
||||
if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
|
||||
return;
|
||||
|
|
Loading…
Reference in a new issue