From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise 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 Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- Documentation/fb/efifb.rst | 71 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 Documentation/fb/efifb.rst (limited to 'Documentation/fb/efifb.rst') diff --git a/Documentation/fb/efifb.rst b/Documentation/fb/efifb.rst new file mode 100644 index 000000000..3d4aab406 --- /dev/null +++ b/Documentation/fb/efifb.rst @@ -0,0 +1,71 @@ +=================================== +efifb - Generic EFI platform driver +=================================== + +This is a generic EFI platform driver for systems with UEFI firmware. The +system must be booted via the EFI stub for this to be usable. efifb supports +both firmware with Graphics Output Protocol (GOP) displays as well as older +systems with only Universal Graphics Adapter (UGA) displays. + +Supported Hardware +================== + +- iMac 17"/20" +- Macbook +- Macbook Pro 15"/17" +- MacMini +- ARM/ARM64/X86 systems with UEFI firmware + +How to use it? +============== + +For UGA displays, efifb does not have any kind of autodetection of your +machine. + +You have to add the following kernel parameters in your elilo.conf:: + + Macbook : + video=efifb:macbook + MacMini : + video=efifb:mini + Macbook Pro 15", iMac 17" : + video=efifb:i17 + Macbook Pro 17", iMac 20" : + video=efifb:i20 + +For GOP displays, efifb can autodetect the display's resolution and framebuffer +address, so these should work out of the box without any special parameters. + +Accepted options: + +======= =========================================================== +nowc Don't map the framebuffer write combined. This can be used + to workaround side-effects and slowdowns on other CPU cores + when large amounts of console data are written. +======= =========================================================== + +Options for GOP displays: + +mode=n + The EFI stub will set the mode of the display to mode number n if + possible. + +x[-(rgb|bgr|)] + The EFI stub will search for a display mode that matches the specified + horizontal and vertical resolution, and optionally bit depth, and set + the mode of the display to it if one is found. The bit depth can either + "rgb" or "bgr" to match specifically those pixel formats, or a number + for a mode with matching bits per pixel. + +auto + The EFI stub will choose the mode with the highest resolution (product + of horizontal and vertical resolution). If there are multiple modes + with the highest resolution, it will choose one with the highest color + depth. + +list + The EFI stub will list out all the display modes that are available. A + specific mode can then be chosen using one of the above options for the + next boot. + +Edgar Hucek -- cgit v1.3.1