hw-breakpoints: Keep track of user disabled breakpoints
authorFrederic Weisbecker <fweisbec@gmail.com>
Wed, 2 Dec 2009 06:32:16 +0000 (07:32 +0100)
committerIngo Molnar <mingo@elte.hu>
Wed, 2 Dec 2009 08:59:03 +0000 (09:59 +0100)
commit1cedae72904b85462082dbcfd5190309ba37f8bd
tree43c5873e8b8c1d65acd62fd5a609117fdee7c0da
parent6b62fe019e39edfd1dbe3f224ecd0a87d9365223
hw-breakpoints: Keep track of user disabled breakpoints

When we disable a breakpoint through dr7, we unregister it right
away, making us lose track of its corresponding address
register value.

It means that the following sequence would be unsupported:

 - set address in dr0
 - enable it through dr7
 - disable it through dr7
 - enable it through dr7

because we lost the address register value when we disabled the
breakpoint.

Don't unregister the disabled breakpoints but rather disable
them.

Reported-by: "K.Prasad" <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1259735536-9236-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/ptrace.c