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, 167 insertions, 0 deletions

diff --git a/sound/soc/sof/ops.c b/sound/soc/sof/ops.c
new file mode 100644
index 000000000..74c04dcf4
--- /dev/null
+++ b/sound/soc/sof/ops.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018 Intel Corporation
+//
+// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
+//
+
+#include <linux/pci.h>
+#include "ops.h"
+
+static
+bool snd_sof_pci_update_bits_unlocked(struct snd_sof_dev *sdev, u32 offset,
+				      u32 mask, u32 value)
+{
+	struct pci_dev *pci = to_pci_dev(sdev->dev);
+	unsigned int old, new;
+	u32 ret = 0;
+
+	pci_read_config_dword(pci, offset, &ret);
+	old = ret;
+	dev_dbg(sdev->dev, "Debug PCIR: %8.8x at  %8.8x\n", old & mask, offset);
+
+	new = (old & ~mask) | (value & mask);
+
+	if (old == new)
+		return false;
+
+	pci_write_config_dword(pci, offset, new);
+	dev_dbg(sdev->dev, "Debug PCIW: %8.8x at  %8.8x\n", value,
+		offset);
+
+	return true;
+}
+
+bool snd_sof_pci_update_bits(struct snd_sof_dev *sdev, u32 offset,
+			     u32 mask, u32 value)
+{
+	guard(spinlock_irqsave)(&sdev->hw_lock);
+	return snd_sof_pci_update_bits_unlocked(sdev, offset, mask, value);
+}
+EXPORT_SYMBOL(snd_sof_pci_update_bits);
+
+bool snd_sof_dsp_update_bits_unlocked(struct snd_sof_dev *sdev, u32 bar,
+				      u32 offset, u32 mask, u32 value)
+{
+	unsigned int old, new;
+	u32 ret;
+
+	ret = snd_sof_dsp_read(sdev, bar, offset);
+
+	old = ret;
+	new = (old & ~mask) | (value & mask);
+
+	if (old == new)
+		return false;
+
+	snd_sof_dsp_write(sdev, bar, offset, new);
+
+	return true;
+}
+EXPORT_SYMBOL(snd_sof_dsp_update_bits_unlocked);
+
+bool snd_sof_dsp_update_bits64_unlocked(struct snd_sof_dev *sdev, u32 bar,
+					u32 offset, u64 mask, u64 value)
+{
+	u64 old, new;
+
+	old = snd_sof_dsp_read64(sdev, bar, offset);
+
+	new = (old & ~mask) | (value & mask);
+
+	if (old == new)
+		return false;
+
+	snd_sof_dsp_write64(sdev, bar, offset, new);
+
+	return true;
+}
+EXPORT_SYMBOL(snd_sof_dsp_update_bits64_unlocked);
+
+/* This is for registers bits with attribute RWC */
+bool snd_sof_dsp_update_bits(struct snd_sof_dev *sdev, u32 bar, u32 offset,
+			     u32 mask, u32 value)
+{
+	guard(spinlock_irqsave)(&sdev->hw_lock);
+	return snd_sof_dsp_update_bits_unlocked(sdev, bar, offset, mask, value);
+}
+EXPORT_SYMBOL(snd_sof_dsp_update_bits);
+
+bool snd_sof_dsp_update_bits64(struct snd_sof_dev *sdev, u32 bar, u32 offset,
+			       u64 mask, u64 value)
+{
+	guard(spinlock_irqsave)(&sdev->hw_lock);
+	return snd_sof_dsp_update_bits64_unlocked(sdev, bar, offset, mask, value);
+}
+EXPORT_SYMBOL(snd_sof_dsp_update_bits64);
+
+static
+void snd_sof_dsp_update_bits_forced_unlocked(struct snd_sof_dev *sdev, u32 bar,
+					     u32 offset, u32 mask, u32 value)
+{
+	unsigned int old, new;
+	u32 ret;
+
+	ret = snd_sof_dsp_read(sdev, bar, offset);
+
+	old = ret;
+	new = (old & ~mask) | (value & mask);
+
+	snd_sof_dsp_write(sdev, bar, offset, new);
+}
+
+/* This is for registers bits with attribute RWC */
+void snd_sof_dsp_update_bits_forced(struct snd_sof_dev *sdev, u32 bar,
+				    u32 offset, u32 mask, u32 value)
+{
+	guard(spinlock_irqsave)(&sdev->hw_lock);
+	snd_sof_dsp_update_bits_forced_unlocked(sdev, bar, offset, mask, value);
+}
+EXPORT_SYMBOL(snd_sof_dsp_update_bits_forced);
+
+/**
+ * snd_sof_dsp_panic - handle a received DSP panic message
+ * @sdev: Pointer to the device's sdev
+ * @offset: offset of panic information
+ * @non_recoverable: the panic is fatal, no recovery will be done by the caller
+ */
+void snd_sof_dsp_panic(struct snd_sof_dev *sdev, u32 offset, bool non_recoverable)
+{
+	/*
+	 * if DSP is not ready and the dsp_oops_offset is not yet set, use the
+	 * offset from the panic message.
+	 */
+	if (!sdev->dsp_oops_offset)
+		sdev->dsp_oops_offset = offset;
+
+	/*
+	 * Print warning if the offset from the panic message differs from
+	 * dsp_oops_offset
+	 */
+	if (sdev->dsp_oops_offset != offset)
+		dev_warn(sdev->dev,
+			 "%s: dsp_oops_offset %zu differs from panic offset %u\n",
+			 __func__, sdev->dsp_oops_offset, offset);
+
+	/*
+	 * Set the fw_state to crashed only in case of non recoverable DSP panic
+	 * event.
+	 * Use different message within the snd_sof_dsp_dbg_dump() depending on
+	 * the non_recoverable flag.
+	 */
+	sdev->dbg_dump_printed = false;
+	if (non_recoverable) {
+		snd_sof_dsp_dbg_dump(sdev, "DSP panic!",
+				     SOF_DBG_DUMP_REGS | SOF_DBG_DUMP_MBOX);
+		sof_set_fw_state(sdev, SOF_FW_CRASHED);
+		sof_fw_trace_fw_crashed(sdev);
+	} else {
+		snd_sof_dsp_dbg_dump(sdev,
+				     "DSP panic (recovery will be attempted)",
+				     SOF_DBG_DUMP_REGS | SOF_DBG_DUMP_MBOX);
+	}
+}
+EXPORT_SYMBOL(snd_sof_dsp_panic);