Le 28/01/2021 à 11:38, David Laight a écrit :
From: Christopher M. Riedl
Sent: 28 January 2021 04:04
Reuse the "safe" implementation from signal.c except for calling
unsafe_copy_from_user() to copy into a local buffer.
Signed-off-by: Christopher M. Riedl <c...@codefail.de>
---
arch/powerpc/kernel/signal.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 2559a681536e..c18402d625f1 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -53,6 +53,33 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task,
void __user *from);
&buf[i], label);\
} while (0)
+#define unsafe_copy_fpr_from_user(task, from, label) do { \
+ struct task_struct *__t = task; \
+ u64 __user *__f = (u64 __user *)from; \
+ u64 buf[ELF_NFPREG]; \
How big is that buffer?
#define ELF_NFPREG 33
So that's 264 bytes.
That's a bit big but still reasonable I think.
Christophe
Isn't is likely to be reasonably large compared to a reasonable
kernel stack frame.
Especially since this isn't even a leaf function.
+ int i; \
+ \
+ unsafe_copy_from_user(buf, __f, ELF_NFPREG * sizeof(double), \
That really ought to be sizeof(buf).
David
+ label); \
+ for (i = 0; i < ELF_NFPREG - 1; i++) \
+ __t->thread.TS_FPR(i) = buf[i]; \
+ __t->thread.fp_state.fpscr = buf[i]; \
+} while (0)
+
+#define unsafe_copy_vsx_from_user(task, from, label) do { \
+ struct task_struct *__t = task; \
+ u64 __user *__f = (u64 __user *)from; \
+ u64 buf[ELF_NVSRHALFREG]; \
+ int i; \
+ \
+ unsafe_copy_from_user(buf, __f, \
+ ELF_NVSRHALFREG * sizeof(double), \
+ label); \
+ for (i = 0; i < ELF_NVSRHALFREG ; i++) \
+ __t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i]; \
+} while (0)
+
+
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
#define unsafe_copy_ckfpr_to_user(to, task, label) do { \
struct task_struct *__t = task; \
@@ -80,6 +107,10 @@ unsigned long copy_ckfpr_from_user(struct task_struct
*task, void __user *from);
unsafe_copy_to_user(to, (task)->thread.fp_state.fpr, \
ELF_NFPREG * sizeof(double), label)
+#define unsafe_copy_fpr_from_user(task, from, label) \
+ unsafe_copy_from_user((task)->thread.fp_state.fpr, from, \
+ ELF_NFPREG * sizeof(double), label)
+
static inline unsigned long
copy_fpr_to_user(void __user *to, struct task_struct *task)
{
@@ -115,6 +146,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user
*from)
#else
#define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
+#define unsafe_copy_fpr_from_user(task, from, label) do { } while (0)
+
static inline unsigned long
copy_fpr_to_user(void __user *to, struct task_struct *task)
{
--
2.26.1
-
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