summaryrefslogtreecommitdiffstats
path: root/drivers/misc/sram-exec.c
diff options
context:
space:
mode:
authorFan Wu <fanwu01@zju.edu.cn>2026-08-20 13:53:06 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-09-01 16:50:04 +0200
commit263f7d61a4201cde16849b2d016251806e7418be (patch)
tree861df7c5b878b85741cf319ece81111b4c41c3b1 /drivers/misc/sram-exec.c
downloadlinux-stable-263f7d61a4201cde16849b2d016251806e7418be.tar.gz
linux-stable-263f7d61a4201cde16849b2d016251806e7418be.zip
usb: typec: qcom-pmic-typec: disable cc_debounce_dwork on stopgrafted
cc_debounce_dwork is queued from the set_cc() and start_toggling() callbacks, which run from TCPM's kthread worker. port_stop() returns before tcpm_unregister_port() destroys that worker. Flushing the worker during unregister may therefore run a callback which queues the delayed work after port_stop() has returned. The delayed work can then run after devres has freed pmic_typec_port. Use disable_delayed_work_sync() in port_stop() to cancel a pending instance and prevent the TCPM callbacks from queueing another one. This issue was found by an in-house static analysis tool. Fixes: a4422ff22142 ("usb: typec: qcom: Add Qualcomm PMIC Type-C driver") Cc: stable <stable@kernel.org> # v6.10+ Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu <fanwu01@zju.edu.cn> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://patch.msgid.link/20260820135307.153773-2-fanwu01@zju.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/sram-exec.c')
-rw-r--r--drivers/misc/sram-exec.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/misc/sram-exec.c b/drivers/misc/sram-exec.c
new file mode 100644
index 000000000..b71dbbd73
--- /dev/null
+++ b/drivers/misc/sram-exec.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SRAM protect-exec region helper functions
+ *
+ * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/
+ * Dave Gerlach
+ */
+
+#include <linux/device.h>
+#include <linux/genalloc.h>
+#include <linux/mm.h>
+#include <linux/sram.h>
+#include <linux/set_memory.h>
+
+#include <asm/fncpy.h>
+
+#include "sram.h"
+
+static DEFINE_MUTEX(exec_pool_list_mutex);
+static LIST_HEAD(exec_pool_list);
+
+int sram_check_protect_exec(struct sram_dev *sram, struct sram_reserve *block,
+ struct sram_partition *part)
+{
+ unsigned long base = (unsigned long)part->base;
+ unsigned long end = base + block->size;
+
+ if (!PAGE_ALIGNED(base) || !PAGE_ALIGNED(end)) {
+ dev_err(sram->dev,
+ "SRAM pool marked with 'protect-exec' is not page aligned and will not be created.\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int sram_add_protect_exec(struct sram_partition *part)
+{
+ mutex_lock(&exec_pool_list_mutex);
+ list_add_tail(&part->list, &exec_pool_list);
+ mutex_unlock(&exec_pool_list_mutex);
+
+ return 0;
+}
+
+/**
+ * sram_exec_copy - copy data to a protected executable region of sram
+ *
+ * @pool: struct gen_pool retrieved that is part of this sram
+ * @dst: Destination address for the copy, that must be inside pool
+ * @src: Source address for the data to copy
+ * @size: Size of copy to perform, which starting from dst, must reside in pool
+ *
+ * Return: Address for copied data that can safely be called through function
+ * pointer, or NULL if problem.
+ *
+ * This helper function allows sram driver to act as central control location
+ * of 'protect-exec' pools which are normal sram pools but are always set
+ * read-only and executable except when copying data to them, at which point
+ * they are set to read-write non-executable, to make sure no memory is
+ * writeable and executable at the same time. This region must be page-aligned
+ * and is checked during probe, otherwise page attribute manipulation would
+ * not be possible. Care must be taken to only call the returned address as
+ * dst address is not guaranteed to be safely callable.
+ *
+ * NOTE: This function uses the fncpy macro to move code to the executable
+ * region. Some architectures have strict requirements for relocating
+ * executable code, so fncpy is a macro that must be defined by any arch
+ * making use of this functionality that guarantees a safe copy of exec
+ * data and returns a safe address that can be called as a C function
+ * pointer.
+ */
+void *sram_exec_copy(struct gen_pool *pool, void *dst, void *src,
+ size_t size)
+{
+ struct sram_partition *part = NULL, *p;
+ unsigned long base;
+ int pages;
+ void *dst_cpy;
+ int ret;
+
+ mutex_lock(&exec_pool_list_mutex);
+ list_for_each_entry(p, &exec_pool_list, list) {
+ if (p->pool == pool)
+ part = p;
+ }
+ mutex_unlock(&exec_pool_list_mutex);
+
+ if (!part)
+ return NULL;
+
+ if (!gen_pool_has_addr(pool, (unsigned long)dst, size))
+ return NULL;
+
+ base = (unsigned long)part->base;
+ pages = PAGE_ALIGN(size) / PAGE_SIZE;
+
+ mutex_lock(&part->lock);
+
+ ret = set_memory_nx((unsigned long)base, pages);
+ if (ret)
+ goto error_out;
+ ret = set_memory_rw((unsigned long)base, pages);
+ if (ret)
+ goto error_out;
+
+ dst_cpy = fncpy(dst, src, size);
+
+ ret = set_memory_rox((unsigned long)base, pages);
+ if (ret)
+ goto error_out;
+
+ mutex_unlock(&part->lock);
+
+ return dst_cpy;
+
+error_out:
+ mutex_unlock(&part->lock);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(sram_exec_copy);