[PATCH NEEDS TEST] synth_direct_store refactor to use synth_write

[Justin Stitt]

I've just copy/pasted Kees' suggestion here [1] and rebased it against
6.5-rc7.

This patch needs testing as it refactors behavior in synth_direct_store.

[1]: https://lore.kernel.org/all/202308251439.36BC33ADB2@keescook/

Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
 drivers/accessibility/speakup/kobjects.c | 25 +++++++++++-------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/accessibility/speakup/kobjects.c
b/drivers/accessibility/speakup/kobjects.c
index a7522d409802..0dfdb6608e02 100644
--- a/drivers/accessibility/speakup/kobjects.c
+++ b/drivers/accessibility/speakup/kobjects.c
@@ -413,27 +413,24 @@ static ssize_t synth_direct_store(struct kobject *kob=
j,
    struct kobj_attribute *attr,
    const char *buf, size_t count)
 {
- u_char tmp[256];
- int len;
- int bytes;
- const char *ptr =3D buf;
+ char *unescaped;
  unsigned long flags;

  if (!synth)
  return -EPERM;

- len =3D strlen(buf);
+ unescaped =3D kstrdup(buf, GFP_KERNEL);
+ if (!unescaped)
+ return -ENOMEM;
+
+ string_unescape_any_inplace(unescaped);
+
  spin_lock_irqsave(&speakup_info.spinlock, flags);
- while (len > 0) {
- bytes =3D min_t(size_t, len, 250);
- strncpy(tmp, ptr, bytes);
- tmp[bytes] =3D '\0';
- string_unescape_any_inplace(tmp);
- synth_printf("%s", tmp);
- ptr +=3D bytes;
- len -=3D bytes;
- }
+ synth_write(unescaped, strlen(unescaped));
  spin_unlock_irqrestore(&speakup_info.spinlock, flags);
+
+ kfree(unescaped);
+
  return count;
 }

--
2.42.0.rc1.204.g551eb34607-goog