forked from pool/grub2
89 lines
3.0 KiB
Diff
89 lines
3.0 KiB
Diff
|
From 47eddcfc6859f269bb3cfaf95d5b33502cafd9ec Mon Sep 17 00:00:00 2001
|
|||
|
|
From: Michael Chang <mchang@suse.com>
|
|||
|
|
Date: Mon, 21 Jun 2021 05:11:18 +0000
|
|||
|
|
Subject: [PATCH] 30_uefi-firmware: fix printf format with null byte
|
|||
|
|
MIME-Version: 1.0
|
|||
|
|
Content-Type: text/plain; charset=UTF-8
|
|||
|
|
Content-Transfer-Encoding: 8bit
|
|||
|
|
|
|||
|
|
On a Raspberry Pi 4, the OsIndications variable is set as following
|
|||
|
|
|
|||
|
|
$ od -An -t u1 /sys/firmware/efi/efivars/OsIndicationsSupported-8be4df61-93ca-11d2-aa0d-00e098032b8c
|
|||
|
|
6 0 0 0 0 0 0 0 0 0 0 0
|
|||
|
|
|
|||
|
|
The fifth byte indicates there's no boot to uefi firmware support as no
|
|||
|
|
bit is set. However the /etc/grub.d/30_uefi-firmware mistakenly detects
|
|||
|
|
that from the grub-mkconfig output.
|
|||
|
|
|
|||
|
|
/etc/grub.d/30_uefi-firmware: line 34: warning: command substitution: ignored null byte in input
|
|||
|
|
Adding boot menu entry for UEFI Firmware Settings ...
|
|||
|
|
|
|||
|
|
The warning has dictated that the null byte is ignored from the printf
|
|||
|
|
input arguments so that the expression of
|
|||
|
|
|
|||
|
|
rintf 0x%x \'"$(cat $OS_INDICATIONS | cut -b5)"\')
|
|||
|
|
|
|||
|
|
becomes
|
|||
|
|
|
|||
|
|
printf 0x%x \'""\'
|
|||
|
|
0x27
|
|||
|
|
|
|||
|
|
The numeric value of trailing character \' is outputted instead of the
|
|||
|
|
null byte.
|
|||
|
|
|
|||
|
|
From the printf manual, there's description to the synax of formatting
|
|||
|
|
the numeric value ouput of a character.
|
|||
|
|
|
|||
|
|
"If the leading character of a numeric argument is ‘"’ or ‘'’ then its
|
|||
|
|
value is the numeric value of the immediately following character. Any
|
|||
|
|
remaining characters are silently ignored if the POSIXLY_CORRECT
|
|||
|
|
environment variable is set; otherwise, a warning is printed. For
|
|||
|
|
example, ‘printf "%d" "'a"’ outputs ‘97’ on hosts that use the ASCII
|
|||
|
|
character set, since ‘a’ has the numeric value 97 in ASCII."
|
|||
|
|
|
|||
|
|
From the descrption the trailing \' appears to be superfluous and should
|
|||
|
|
get removed to have correct output.
|
|||
|
|
|
|||
|
|
printf 0x%x \'""
|
|||
|
|
0x0
|
|||
|
|
|
|||
|
|
In additon to suppress the warning message of ignored null byte in
|
|||
|
|
input, we can delete it so an empty string is used.
|
|||
|
|
|
|||
|
|
To illustrate the problem using echo as example
|
|||
|
|
|
|||
|
|
printf 0x%x \'"$(echo -e '\x00')"
|
|||
|
|
-bash: warning: command substitution: ignored null byte in input
|
|||
|
|
0x0
|
|||
|
|
|
|||
|
|
And here using tr to delete the null character
|
|||
|
|
|
|||
|
|
printf 0x%x \'"$(echo -e '\x00'| tr -d '\000')"
|
|||
|
|
|
|||
|
|
The expression above is substituted to
|
|||
|
|
|
|||
|
|
printf 0x%x \'""
|
|||
|
|
0x0
|
|||
|
|
|
|||
|
|
Signed-off-by: Michael Chang <mchang@suse.com>
|
|||
|
|
---
|
|||
|
|
util/grub.d/30_uefi-firmware.in | 2 +-
|
|||
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|||
|
|
|
|||
|
|
diff --git a/util/grub.d/30_uefi-firmware.in b/util/grub.d/30_uefi-firmware.in
|
|||
|
|
index d344d3883..d069f2727 100644
|
|||
|
|
--- a/util/grub.d/30_uefi-firmware.in
|
|||
|
|
+++ b/util/grub.d/30_uefi-firmware.in
|
|||
|
|
@@ -31,7 +31,7 @@ EFI_GLOBAL_VARIABLE=8be4df61-93ca-11d2-aa0d-00e098032b8c
|
|||
|
|
OS_INDICATIONS="$EFI_VARS_DIR/OsIndicationsSupported-$EFI_GLOBAL_VARIABLE"
|
|||
|
|
|
|||
|
|
if [ -e "$OS_INDICATIONS" ] && \
|
|||
|
|
- [ "$(( $(printf 0x%x \'"$(cat $OS_INDICATIONS | cut -b5)"\') & 1 ))" = 1 ]; then
|
|||
|
|
+ [ "$(( $(printf 0x%x \'"$(cat $OS_INDICATIONS | cut -b5 | tr -d '\000')") & 1 ))" = 1 ]; then
|
|||
|
|
LABEL="UEFI Firmware Settings"
|
|||
|
|
|
|||
|
|
gettext_printf "Adding boot menu entry for UEFI Firmware Settings ...\n" >&2
|
|||
|
|
--
|
|||
|
|
2.26.2
|
|||
|
|
|