Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 328 insertions, 0 deletions

diff --git a/drivers/firmware/google/vpd.c b/drivers/firmware/google/vpd.c
new file mode 100644
index 000000000..fbb5a8d7c
--- /dev/null
+++ b/drivers/firmware/google/vpd.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * vpd.c
+ *
+ * Driver for exporting VPD content to sysfs.
+ *
+ * Copyright 2017 Google Inc.
+ */
+
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/list.h>
+#include <linux/device-id/coreboot.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+#include "coreboot_table.h"
+#include "vpd_decode.h"
+
+#define CB_TAG_VPD      0x2c
+#define VPD_CBMEM_MAGIC 0x43524f53
+
+static struct kobject *vpd_kobj;
+
+struct vpd_cbmem {
+	u32 magic;
+	u32 version;
+	u32 ro_size;
+	u32 rw_size;
+	u8  blob[];
+};
+
+struct vpd_section {
+	bool enabled;
+	const char *name;
+	char *raw_name;                /* the string name_raw */
+	struct kobject *kobj;          /* vpd/name directory */
+	char *baseaddr;
+	struct bin_attribute bin_attr; /* vpd/name_raw bin_attribute */
+	struct list_head attribs;      /* key/value in vpd_attrib_info list */
+};
+
+struct vpd_attrib_info {
+	char *key;
+	const char *value;
+	struct bin_attribute bin_attr;
+	struct list_head list;
+};
+
+static struct vpd_section ro_vpd;
+static struct vpd_section rw_vpd;
+
+static ssize_t vpd_attrib_read(struct file *filp, struct kobject *kobp,
+			       const struct bin_attribute *bin_attr, char *buf,
+			       loff_t pos, size_t count)
+{
+	struct vpd_attrib_info *info = bin_attr->private;
+
+	return memory_read_from_buffer(buf, count, &pos, info->value,
+				       info->bin_attr.size);
+}
+
+/*
+ * vpd_section_check_key_name()
+ *
+ * The VPD specification supports only [a-zA-Z0-9_]+ characters in key names but
+ * old firmware versions may have entries like "S/N" which are problematic when
+ * exporting them as sysfs attributes. These keys present in old firmwares are
+ * ignored.
+ *
+ * Returns VPD_OK for a valid key name, VPD_FAIL otherwise.
+ *
+ * @key: The key name to check
+ * @key_len: key name length
+ */
+static int vpd_section_check_key_name(const u8 *key, s32 key_len)
+{
+	int c;
+
+	while (key_len-- > 0) {
+		c = *key++;
+
+		if (!isalnum(c) && c != '_')
+			return VPD_FAIL;
+	}
+
+	return VPD_OK;
+}
+
+static int vpd_section_attrib_add(const u8 *key, u32 key_len,
+				  const u8 *value, u32 value_len,
+				  void *arg)
+{
+	int ret;
+	struct vpd_section *sec = arg;
+	struct vpd_attrib_info *info;
+
+	/*
+	 * Return VPD_OK immediately to decode next entry if the current key
+	 * name contains invalid characters.
+	 */
+	if (vpd_section_check_key_name(key, key_len) != VPD_OK)
+		return VPD_OK;
+
+	info = kzalloc_obj(*info);
+	if (!info)
+		return -ENOMEM;
+
+	info->key = kstrndup(key, key_len, GFP_KERNEL);
+	if (!info->key) {
+		ret = -ENOMEM;
+		goto free_info;
+	}
+
+	sysfs_bin_attr_init(&info->bin_attr);
+	info->bin_attr.attr.name = info->key;
+	info->bin_attr.attr.mode = 0444;
+	info->bin_attr.size = value_len;
+	info->bin_attr.read = vpd_attrib_read;
+	info->bin_attr.private = info;
+
+	info->value = value;
+
+	INIT_LIST_HEAD(&info->list);
+
+	ret = sysfs_create_bin_file(sec->kobj, &info->bin_attr);
+	if (ret)
+		goto free_info_key;
+
+	list_add_tail(&info->list, &sec->attribs);
+	return 0;
+
+free_info_key:
+	kfree(info->key);
+free_info:
+	kfree(info);
+
+	return ret;
+}
+
+static void vpd_section_attrib_destroy(struct vpd_section *sec)
+{
+	struct vpd_attrib_info *info;
+	struct vpd_attrib_info *temp;
+
+	list_for_each_entry_safe(info, temp, &sec->attribs, list) {
+		sysfs_remove_bin_file(sec->kobj, &info->bin_attr);
+		kfree(info->key);
+		kfree(info);
+	}
+}
+
+static ssize_t vpd_section_read(struct file *filp, struct kobject *kobp,
+				const struct bin_attribute *bin_attr, char *buf,
+				loff_t pos, size_t count)
+{
+	struct vpd_section *sec = bin_attr->private;
+
+	return memory_read_from_buffer(buf, count, &pos, sec->baseaddr,
+				       sec->bin_attr.size);
+}
+
+static int vpd_section_create_attribs(struct vpd_section *sec)
+{
+	s32 consumed;
+	int ret;
+
+	consumed = 0;
+	do {
+		ret = vpd_decode_string(sec->bin_attr.size, sec->baseaddr,
+					&consumed, vpd_section_attrib_add, sec);
+	} while (ret == VPD_OK);
+
+	return 0;
+}
+
+static int vpd_section_init(const char *name, struct vpd_section *sec,
+			    phys_addr_t physaddr, size_t size)
+{
+	int err;
+
+	sec->baseaddr = memremap(physaddr, size, MEMREMAP_WB);
+	if (!sec->baseaddr)
+		return -ENOMEM;
+
+	sec->name = name;
+
+	/* We want to export the raw partition with name ${name}_raw */
+	sec->raw_name = kasprintf(GFP_KERNEL, "%s_raw", name);
+	if (!sec->raw_name) {
+		err = -ENOMEM;
+		goto err_memunmap;
+	}
+
+	sysfs_bin_attr_init(&sec->bin_attr);
+	sec->bin_attr.attr.name = sec->raw_name;
+	sec->bin_attr.attr.mode = 0444;
+	sec->bin_attr.size = size;
+	sec->bin_attr.read = vpd_section_read;
+	sec->bin_attr.private = sec;
+
+	err = sysfs_create_bin_file(vpd_kobj, &sec->bin_attr);
+	if (err)
+		goto err_free_raw_name;
+
+	sec->kobj = kobject_create_and_add(name, vpd_kobj);
+	if (!sec->kobj) {
+		err = -EINVAL;
+		goto err_sysfs_remove;
+	}
+
+	INIT_LIST_HEAD(&sec->attribs);
+	vpd_section_create_attribs(sec);
+
+	sec->enabled = true;
+
+	return 0;
+
+err_sysfs_remove:
+	sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr);
+err_free_raw_name:
+	kfree(sec->raw_name);
+err_memunmap:
+	memunmap(sec->baseaddr);
+	return err;
+}
+
+static int vpd_section_destroy(struct vpd_section *sec)
+{
+	if (sec->enabled) {
+		vpd_section_attrib_destroy(sec);
+		kobject_put(sec->kobj);
+		sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr);
+		kfree(sec->raw_name);
+		memunmap(sec->baseaddr);
+		sec->enabled = false;
+	}
+
+	return 0;
+}
+
+static int vpd_sections_init(phys_addr_t physaddr)
+{
+	struct vpd_cbmem *temp;
+	struct vpd_cbmem header;
+	int ret = 0;
+
+	temp = memremap(physaddr, sizeof(struct vpd_cbmem), MEMREMAP_WB);
+	if (!temp)
+		return -ENOMEM;
+
+	memcpy(&header, temp, sizeof(struct vpd_cbmem));
+	memunmap(temp);
+
+	if (header.magic != VPD_CBMEM_MAGIC)
+		return -ENODEV;
+
+	if (header.ro_size) {
+		ret = vpd_section_init("ro", &ro_vpd,
+				       physaddr + sizeof(struct vpd_cbmem),
+				       header.ro_size);
+		if (ret)
+			return ret;
+	}
+
+	if (header.rw_size) {
+		ret = vpd_section_init("rw", &rw_vpd,
+				       physaddr + sizeof(struct vpd_cbmem) +
+				       header.ro_size, header.rw_size);
+		if (ret) {
+			vpd_section_destroy(&ro_vpd);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int vpd_probe(struct coreboot_device *dev)
+{
+	int ret;
+
+	vpd_kobj = kobject_create_and_add("vpd", firmware_kobj);
+	if (!vpd_kobj)
+		return -ENOMEM;
+
+	ret = vpd_sections_init(dev->cbmem_ref.cbmem_addr);
+	if (ret) {
+		kobject_put(vpd_kobj);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void vpd_remove(struct coreboot_device *dev)
+{
+	vpd_section_destroy(&ro_vpd);
+	vpd_section_destroy(&rw_vpd);
+
+	kobject_put(vpd_kobj);
+}
+
+static const struct coreboot_device_id vpd_ids[] = {
+	{ .tag = CB_TAG_VPD },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(coreboot, vpd_ids);
+
+static struct coreboot_driver vpd_driver = {
+	.probe = vpd_probe,
+	.remove = vpd_remove,
+	.drv = {
+		.name = "vpd",
+	},
+	.id_table = vpd_ids,
+};
+module_coreboot_driver(vpd_driver);
+
+MODULE_AUTHOR("Google, Inc.");
+MODULE_DESCRIPTION("Driver for exporting Vital Product Data content to sysfs");
+MODULE_LICENSE("GPL");