ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/video/fbdev/carminefb.h b/drivers/video/fbdev/carminefb.h
new file mode 100644
index 000000000..c9825481d
--- /dev/null
+++ b/drivers/video/fbdev/carminefb.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef CARMINE_CARMINE_H
+#define CARMINE_CARMINE_H
+
+#define CARMINE_MEMORY_BAR	2
+#define CARMINE_CONFIG_BAR	3
+
+#define MAX_DISPLAY	2
+#define CARMINE_DISPLAY_MEM	(800 * 600 * 4)
+#define CARMINE_TOTAL_DISPLAY_MEM	(CARMINE_DISPLAY_MEM * MAX_DISPLAY)
+
+#define CARMINE_USE_DISPLAY0	(1 << 0)
+#define CARMINE_USE_DISPLAY1	(1 << 1)
+
+/*
+ * This values work on the eval card. Custom boards may use different timings,
+ * here an example :)
+ */
+
+/* DRAM initialization values */
+#ifdef CONFIG_FB_CARMINE_DRAM_EVAL
+
+#define CARMINE_DFLT_IP_CLOCK_ENABLE		(0x03ff)
+#define CARMINE_DFLT_IP_DCTL_ADD		(0x05c3)
+#define CARMINE_DFLT_IP_DCTL_MODE		(0x0121)
+#define CARMINE_DFLT_IP_DCTL_EMODE		(0x8000)
+#define CARMINE_DFLT_IP_DCTL_SET_TIME1		(0x4749)
+#define CARMINE_DFLT_IP_DCTL_SET_TIME2		(0x2a22)
+#define CARMINE_DFLT_IP_DCTL_REFRESH		(0x0042)
+#define CARMINE_DFLT_IP_DCTL_STATES		(0x0003)
+#define CARMINE_DFLT_IP_DCTL_RESERVE0		(0x0020)
+#define CARMINE_DFLT_IP_DCTL_FIFO_DEPTH		(0x000f)
+#define CARMINE_DFLT_IP_DCTL_RESERVE2		(0x0000)
+#define CARMINE_DFLT_IP_DCTL_DDRIF1		(0x6646)
+#define CARMINE_DFLT_IP_DCTL_DDRIF2		(0x0055)
+#define CARMINE_DFLT_IP_DCTL_MODE_AFT_RST	(0x0021)
+#define CARMINE_DFLT_IP_DCTL_STATES_AFT_RST	(0x0002)
+#define CARMINE_DFLT_IP_DCTL_IO_CONT0		(0x0555)
+#define CARMINE_DFLT_IP_DCTL_IO_CONT1		(0x0555)
+#define CARMINE_DCTL_DLL_RESET			(1)
+#endif
+
+#ifdef CONFIG_CARMINE_DRAM_CUSTOM
+
+#define CARMINE_DFLT_IP_CLOCK_ENABLE		(0x03ff)
+#define CARMINE_DFLT_IP_DCTL_ADD		(0x03b2)
+#define CARMINE_DFLT_IP_DCTL_MODE		(0x0161)
+#define CARMINE_DFLT_IP_DCTL_EMODE		(0x8000)
+#define CARMINE_DFLT_IP_DCTL_SET_TIME1		(0x2628)
+#define CARMINE_DFLT_IP_DCTL_SET_TIME2		(0x1a09)
+#define CARMINE_DFLT_IP_DCTL_REFRESH		(0x00fe)
+#define CARMINE_DFLT_IP_DCTL_STATES		(0x0003)
+#define CARMINE_DFLT_IP_DCTL_RESERVE0		(0x0020)
+#define CARMINE_DFLT_IP_DCTL_FIFO_DEPTH		(0x000f)
+#define CARMINE_DFLT_IP_DCTL_RESERVE2		(0x0000)
+#define CARMINE_DFLT_IP_DCTL_DDRIF1		(0x0646)
+#define CARMINE_DFLT_IP_DCTL_DDRIF2		(0x55aa)
+#define CARMINE_DFLT_IP_DCTL_MODE_AFT_RST	(0x0061)
+#define CARMINE_DFLT_IP_DCTL_STATES_AFT_RST	(0x0002)
+#define CARMINE_DFLT_IP_DCTL_IO_CONT0		(0x0555)
+#define CARMINE_DFLT_IP_DCTL_IO_CONT1		(0x0555)
+#define CARMINE_DCTL_DLL_RESET			(1)
+#endif
+
+#endif