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authorAl Viro <viro@zeniv.linux.org.uk>2020-02-17 20:25:14 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2020-07-27 21:31:07 +0300
commitdc12d7968f9c9540494deb1285854b18ca4465ec (patch)
tree5d62016a11db4117707189853899ee466b5bcafb /kernel/regset.c
parent1e56f6d28954248f01849c359b1b7210bb6c1add (diff)
downloadlinux-dc12d7968f9c9540494deb1285854b18ca4465ec.tar.xz
copy_regset_to_user(): do all copyout at once.
Turn copy_regset_to_user() into regset_get_alloc() + copy_to_user(). Now all ->get() calls have a kernel buffer as destination. Note that we'd already eliminated the callers of copy_regset_to_user() with non-zero offset; now that argument is simply unused. Uninlined, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'kernel/regset.c')
-rw-r--r--kernel/regset.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/regset.c b/kernel/regset.c
index 6b39fa0993ec..0a610983ce43 100644
--- a/kernel/regset.c
+++ b/kernel/regset.c
@@ -52,3 +52,29 @@ int regset_get_alloc(struct task_struct *target,
return __regset_get(target, regset, size, data);
}
EXPORT_SYMBOL(regset_get_alloc);
+
+/**
+ * copy_regset_to_user - fetch a thread's user_regset data into user memory
+ * @target: thread to be examined
+ * @view: &struct user_regset_view describing user thread machine state
+ * @setno: index in @view->regsets
+ * @offset: offset into the regset data, in bytes
+ * @size: amount of data to copy, in bytes
+ * @data: user-mode pointer to copy into
+ */
+int copy_regset_to_user(struct task_struct *target,
+ const struct user_regset_view *view,
+ unsigned int setno,
+ unsigned int offset, unsigned int size,
+ void __user *data)
+{
+ const struct user_regset *regset = &view->regsets[setno];
+ void *buf;
+ int ret;
+
+ ret = regset_get_alloc(target, regset, size, &buf);
+ if (ret > 0)
+ ret = copy_to_user(data, buf, ret) ? -EFAULT : 0;
+ kfree(buf);
+ return ret;
+}