This is a note to let you know that I've just added the patch titled
efi/earlycon: Replace open coded strnchrnul()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-earlycon-replace-open-coded-strnchrnul.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6e92a7ec121c7e23afadefc601975ace938df6db
Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Date: Fri Dec 9 00:12:16 2022 +0200
efi/earlycon: Replace open coded strnchrnul()
[ Upstream commit b7a1cd243839cc1459fbc83a7a62e3b57f29f497 ]
strnchrnul() can be called in the early stages. Replace
open coded variant in the EFI early console driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Stable-dep-of: 0e68b5517d37 ("arm64: efi: Make efi_rt_lock a raw_spinlock")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/firmware/efi/earlycon.c b/drivers/firmware/efi/earlycon.c
index a52236e11e5f7..fc233b6f27cb2 100644
--- a/drivers/firmware/efi/earlycon.c
+++ b/drivers/firmware/efi/earlycon.c
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/serial_core.h>
#include <linux/screen_info.h>
+#include <linux/string.h>
#include <asm/early_ioremap.h>
@@ -143,16 +144,10 @@ efi_earlycon_write(struct console *con, const char *str, unsigned int num)
len = si->lfb_linelength;
while (num) {
- unsigned int linemax;
- unsigned int h, count = 0;
+ unsigned int linemax = (si->lfb_width - efi_x) / font->width;
+ unsigned int h, count;
- for (s = str; *s && *s != '\n'; s++) {
- if (count == num)
- break;
- count++;
- }
-
- linemax = (si->lfb_width - efi_x) / font->width;
+ count = strnchrnul(str, num, '\n') - str;
if (count > linemax)
count = linemax;
