[PATCH 24/38] C/R: x86_64 debug registers

From: Alexey Dobriyan
Date: Fri May 22 2009 - 01:01:45 EST


Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
include/linux/kstate-image.h | 7 +++++++
kernel/kstate/kstate-x86_64.c | 26 ++++++++++++++++++++++----
2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/include/linux/kstate-image.h b/include/linux/kstate-image.h
index d697d97..7c54711 100644
--- a/include/linux/kstate-image.h
+++ b/include/linux/kstate-image.h
@@ -143,6 +143,13 @@ struct kstate_image_task_struct_x86_64 {
__u16 gsindex;
__u16 ss;

+ __u64 dr0;
+ __u64 dr1;
+ __u64 dr2;
+ __u64 dr3;
+ __u64 dr6;
+ __u64 dr7;
+
__u64 tls_array[3];
} __packed;

diff --git a/kernel/kstate/kstate-x86_64.c b/kernel/kstate/kstate-x86_64.c
index 0d85704..83ed1b5 100644
--- a/kernel/kstate/kstate-x86_64.c
+++ b/kernel/kstate/kstate-x86_64.c
@@ -109,6 +109,10 @@ static int check_image_task_struct_x86_64(struct kstate_image_task_struct *tsk_i
if (rv < 0)
return rv;

+ rv = ptrace_check_debugreg(0, i->dr0, i->dr1, i->dr2, i->dr3, i->dr6, i->dr7);
+ if (rv < 0)
+ return rv;
+
if (i->tls_array[0]) {
rv = check_tls((struct desc_struct *)&i->tls_array[0]);
if (rv < 0)
@@ -150,10 +154,6 @@ int kstate_arch_check_task_struct(struct task_struct *tsk)
return -EINVAL;
}
#endif
- if (test_tsk_thread_flag(tsk, TIF_DEBUG)) {
- WARN_ON(1);
- return -EINVAL;
- }
if (tsk->thread.xstate) {
WARN_ON(1);
return -EINVAL;
@@ -250,6 +250,13 @@ static int dump_task_struct_x86_64(struct kstate_context *ctx, struct task_struc
i->gsindex = encode_segment(tsk->thread.gsindex);
i->ss = encode_segment(regs->ss);

+ i->dr0 = tsk->thread.debugreg0;
+ i->dr1 = tsk->thread.debugreg1;
+ i->dr2 = tsk->thread.debugreg2;
+ i->dr3 = tsk->thread.debugreg3;
+ i->dr6 = tsk->thread.debugreg6;
+ i->dr7 = tsk->thread.debugreg7;
+
BUILD_BUG_ON(sizeof(tsk->thread.tls_array[0]) != 8);
BUILD_BUG_ON(sizeof(tsk->thread.tls_array) != 3 * 8);
memcpy(i->tls_array, tsk->thread.tls_array, sizeof(i->tls_array));
@@ -299,6 +306,17 @@ static int restore_task_struct_x86_64(struct task_struct *tsk, struct kstate_ima
tsk->thread.gsindex = decode_segment(i->gsindex);
regs->ss = decode_segment(i->ss);

+ tsk->thread.debugreg0 = i->dr0;
+ tsk->thread.debugreg1 = i->dr1;
+ tsk->thread.debugreg2 = i->dr2;
+ tsk->thread.debugreg3 = i->dr3;
+ tsk->thread.debugreg6 = i->dr6;
+ tsk->thread.debugreg7 = i->dr7;
+ if (i->dr7)
+ set_tsk_thread_flag(tsk, TIF_DEBUG);
+ else
+ clear_tsk_thread_flag(tsk, TIF_DEBUG);
+
memcpy(tsk->thread.tls_array, i->tls_array, sizeof(i->tls_array));

set_tsk_thread_flag(tsk, TIF_FORK);
--
1.5.6.5

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