From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/video/fbdev/sstfb.c | 1544 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1544 insertions(+) create mode 100644 drivers/video/fbdev/sstfb.c (limited to 'drivers/video/fbdev/sstfb.c') diff --git a/drivers/video/fbdev/sstfb.c b/drivers/video/fbdev/sstfb.c new file mode 100644 index 000000000..274555782 --- /dev/null +++ b/drivers/video/fbdev/sstfb.c @@ -0,0 +1,1544 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/video/sstfb.c -- voodoo graphics frame buffer + * + * Copyright (c) 2000-2002 Ghozlane Toumi + * + * Created 15 Jan 2000 by Ghozlane Toumi + * + * Contributions (and many thanks) : + * + * 03/2001 James Simmons + * 04/2001 Paul Mundt + * 05/2001 Urs Ganse + * (initial work on voodoo2 port, interlace) + * 09/2002 Helge Deller + * (enable driver on big-endian machines (hppa), ioctl fixes) + * 12/2002 Helge Deller + * (port driver to new frambuffer infrastructure) + * 01/2003 Helge Deller + * (initial work on fb hardware acceleration for voodoo2) + * 08/2006 Alan Cox + * Remove never finished and bogus 24/32bit support + * Clean up macro abuse + * Minor tidying for format. + * 12/2006 Helge Deller + * add /sys/class/graphics/fbX/vgapass sysfs-interface + * add module option "mode_option" to set initial screen mode + * use fbdev default videomode database + * remove debug functions from ioctl + */ + +/* + * The voodoo1 has the following memory mapped address space: + * 0x000000 - 0x3fffff : registers (4MB) + * 0x400000 - 0x7fffff : linear frame buffer (4MB) + * 0x800000 - 0xffffff : texture memory (8MB) + */ + +/* + * misc notes, TODOs, toASKs, and deep thoughts + +-TODO: at one time or another test that the mode is acceptable by the monitor +-ASK: Can I choose different ordering for the color bitfields (rgba argb ...) + which one should i use ? is there any preferred one ? It seems ARGB is + the one ... +-TODO: in set_var check the validity of timings (hsync vsync)... +-TODO: check and recheck the use of sst_wait_idle : we don't flush the fifo via + a nop command. so it's ok as long as the commands we pass don't go + through the fifo. warning: issuing a nop command seems to need pci_fifo +-FIXME: in case of failure in the init sequence, be sure we return to a safe + state. +- FIXME: Use accelerator for 2D scroll +-FIXME: 4MB boards have banked memory (FbiInit2 bits 1 & 20) + */ + +/* + * debug info + * SST_DEBUG : enable debugging + * SST_DEBUG_REG : debug registers + * 0 : no debug + * 1 : dac calls, [un]set_bits, FbiInit + * 2 : insane debug level (log every register read/write) + * SST_DEBUG_FUNC : functions + * 0 : no debug + * 1 : function call / debug ioctl + * 2 : variables + * 3 : flood . you don't want to do that. trust me. + * SST_DEBUG_VAR : debug display/var structs + * 0 : no debug + * 1 : dumps display, fb_var + * + * sstfb specific ioctls: + * toggle vga (0x46db) : toggle vga_pass_through + */ + +#undef SST_DEBUG + + +/* + * Includes + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include