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| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 17:05:56 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 18:17:30 -0700 |
| commit | 506ada89629ec7059b96ecfb0dc7d33ece0103ca (patch) | |
| tree | 0b07297409b68d2333fb4f0eae7f3b072eb68d4c /Documentation/admin-guide/lcd-panel-cgram.rst | |
| download | linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.tar.gz linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.zip | |
bpf: mark a NULL kfunc argument precisegrafted
check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.
Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/admin-guide/lcd-panel-cgram.rst')
| -rw-r--r-- | Documentation/admin-guide/lcd-panel-cgram.rst | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/admin-guide/lcd-panel-cgram.rst b/Documentation/admin-guide/lcd-panel-cgram.rst new file mode 100644 index 000000000..a3eb00c62 --- /dev/null +++ b/Documentation/admin-guide/lcd-panel-cgram.rst @@ -0,0 +1,27 @@ +====================================== +Parallel port LCD/Keypad Panel support +====================================== + +Some LCDs allow you to define up to 8 characters, mapped to ASCII +characters 0 to 7. The escape code to define a new character is +'\e[LG' followed by one digit from 0 to 7, representing the character +number, and up to 8 couples of hex digits terminated by a semi-colon +(';'). Each couple of digits represents a line, with 1-bits for each +illuminated pixel with LSB on the right. Lines are numbered from the +top of the character to the bottom. On a 5x7 matrix, only the 5 lower +bits of the 7 first bytes are used for each character. If the string +is incomplete, only complete lines will be redefined. Here are some +examples:: + + printf "\e[LG0010101050D1F0C04;" => 0 = [enter] + printf "\e[LG1040E1F0000000000;" => 1 = [up] + printf "\e[LG2000000001F0E0400;" => 2 = [down] + printf "\e[LG3040E1F001F0E0400;" => 3 = [up-down] + printf "\e[LG40002060E1E0E0602;" => 4 = [left] + printf "\e[LG500080C0E0F0E0C08;" => 5 = [right] + printf "\e[LG60016051516141400;" => 6 = "IP" + + printf "\e[LG00103071F1F070301;" => big speaker + printf "\e[LG00002061E1E060200;" => small speaker + +Willy |