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, 346 insertions, 0 deletions

diff --git a/drivers/mtd/maps/amd76xrom.c b/drivers/mtd/maps/amd76xrom.c
new file mode 100644
index 000000000..457e6ab7f
--- /dev/null
+++ b/drivers/mtd/maps/amd76xrom.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * amd76xrom.c
+ *
+ * Normal mappings of chips in physical memory
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/cfi.h>
+#include <linux/mtd/flashchip.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/list.h>
+
+
+#define xstr(s) str(s)
+#define str(s) #s
+#define MOD_NAME xstr(KBUILD_BASENAME)
+
+#define ADDRESS_NAME_LEN 18
+
+#define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
+
+struct amd76xrom_window {
+	void __iomem *virt;
+	unsigned long phys;
+	unsigned long size;
+	struct list_head maps;
+	struct resource rsrc;
+	struct pci_dev *pdev;
+};
+
+struct amd76xrom_map_info {
+	struct list_head list;
+	struct map_info map;
+	struct mtd_info *mtd;
+	struct resource rsrc;
+	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
+};
+
+/* The 2 bits controlling the window size are often set to allow reading
+ * the BIOS, but too small to allow writing, since the lock registers are
+ * 4MiB lower in the address space than the data.
+ *
+ * This is intended to prevent flashing the bios, perhaps accidentally.
+ *
+ * This parameter allows the normal driver to over-ride the BIOS settings.
+ *
+ * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
+ * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
+ * 64KiB window.
+ *
+ */
+static uint win_size_bits;
+module_param(win_size_bits, uint, 0);
+MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
+
+static struct amd76xrom_window amd76xrom_window = {
+	.maps = LIST_HEAD_INIT(amd76xrom_window.maps),
+};
+
+static void amd76xrom_cleanup(struct amd76xrom_window *window)
+{
+	struct amd76xrom_map_info *map, *scratch;
+	u8 byte;
+
+	if (window->pdev) {
+		/* Disable writes through the rom window */
+		pci_read_config_byte(window->pdev, 0x40, &byte);
+		pci_write_config_byte(window->pdev, 0x40, byte & ~1);
+		pci_dev_put(window->pdev);
+	}
+
+	/* Free all of the mtd devices */
+	list_for_each_entry_safe(map, scratch, &window->maps, list) {
+		if (map->rsrc.parent) {
+			release_resource(&map->rsrc);
+		}
+		mtd_device_unregister(map->mtd);
+		map_destroy(map->mtd);
+		list_del(&map->list);
+		kfree(map);
+	}
+	if (window->rsrc.parent)
+		release_resource(&window->rsrc);
+
+	if (window->virt) {
+		iounmap(window->virt);
+		window->virt = NULL;
+		window->phys = 0;
+		window->size = 0;
+		window->pdev = NULL;
+	}
+}
+
+
+static int amd76xrom_init_one(struct pci_dev *pdev,
+			      const struct pci_device_id *ent)
+{
+	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
+	u8 byte;
+	struct amd76xrom_window *window = &amd76xrom_window;
+	struct amd76xrom_map_info *map = NULL;
+	unsigned long map_top;
+
+	/* Remember the pci dev I find the window in - already have a ref */
+	window->pdev = pdev;
+
+	/* Enable the selected rom window.  This is often incorrectly
+	 * set up by the BIOS, and the 4MiB offset for the lock registers
+	 * requires the full 5MiB of window space.
+	 *
+	 * This 'write, then read' approach leaves the bits for
+	 * other uses of the hardware info.
+	 */
+	pci_read_config_byte(pdev, 0x43, &byte);
+	pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
+
+	/* Assume the rom window is properly setup, and find it's size */
+	pci_read_config_byte(pdev, 0x43, &byte);
+	if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
+		window->phys = 0xffb00000; /* 5MiB */
+	}
+	else if ((byte & (1<<7)) == (1<<7)) {
+		window->phys = 0xffc00000; /* 4MiB */
+	}
+	else {
+		window->phys = 0xffff0000; /* 64KiB */
+	}
+	window->size = 0xffffffffUL - window->phys + 1UL;
+
+	/*
+	 * Try to reserve the window mem region.  If this fails then
+	 * it is likely due to a fragment of the window being
+	 * "reserved" by the BIOS.  In the case that the
+	 * request_mem_region() fails then once the rom size is
+	 * discovered we will try to reserve the unreserved fragment.
+	 */
+	window->rsrc.name = MOD_NAME;
+	window->rsrc.start = window->phys;
+	window->rsrc.end   = window->phys + window->size - 1;
+	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	if (request_resource(&iomem_resource, &window->rsrc)) {
+		window->rsrc.parent = NULL;
+		printk(KERN_ERR MOD_NAME
+		       " %s(): Unable to register resource %pR - kernel bug?\n",
+		       __func__, &window->rsrc);
+		return -EBUSY;
+	}
+
+
+	/* Enable writes through the rom window */
+	pci_read_config_byte(pdev, 0x40, &byte);
+	pci_write_config_byte(pdev, 0x40, byte | 1);
+
+	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
+
+	/* For write accesses caches are useless */
+	window->virt = ioremap(window->phys, window->size);
+	if (!window->virt) {
+		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
+			window->phys, window->size);
+		goto out;
+	}
+
+	/* Get the first address to look for an rom chip at */
+	map_top = window->phys;
+#if 1
+	/* The probe sequence run over the firmware hub lock
+	 * registers sets them to 0x7 (no access).
+	 * Probe at most the last 4M of the address space.
+	 */
+	if (map_top < 0xffc00000) {
+		map_top = 0xffc00000;
+	}
+#endif
+	/* Loop  through and look for rom chips */
+	while((map_top - 1) < 0xffffffffUL) {
+		struct cfi_private *cfi;
+		unsigned long offset;
+		int i;
+
+		if (!map) {
+			map = kmalloc_obj(*map);
+			if (!map)
+				goto out;
+		}
+		memset(map, 0, sizeof(*map));
+		INIT_LIST_HEAD(&map->list);
+		map->map.name = map->map_name;
+		map->map.phys = map_top;
+		offset = map_top - window->phys;
+		map->map.virt = (void __iomem *)
+			(((unsigned long)(window->virt)) + offset);
+		map->map.size = 0xffffffffUL - map_top + 1UL;
+		/* Set the name of the map to the address I am trying */
+		sprintf(map->map_name, "%s @%08Lx",
+			MOD_NAME, (unsigned long long)map->map.phys);
+
+		/* There is no generic VPP support */
+		for(map->map.bankwidth = 32; map->map.bankwidth;
+			map->map.bankwidth >>= 1)
+		{
+			char **probe_type;
+			/* Skip bankwidths that are not supported */
+			if (!map_bankwidth_supported(map->map.bankwidth))
+				continue;
+
+			/* Setup the map methods */
+			simple_map_init(&map->map);
+
+			/* Try all of the probe methods */
+			probe_type = rom_probe_types;
+			for(; *probe_type; probe_type++) {
+				map->mtd = do_map_probe(*probe_type, &map->map);
+				if (map->mtd)
+					goto found;
+			}
+		}
+		map_top += ROM_PROBE_STEP_SIZE;
+		continue;
+	found:
+		/* Trim the size if we are larger than the map */
+		if (map->mtd->size > map->map.size) {
+			printk(KERN_WARNING MOD_NAME
+				" rom(%llu) larger than window(%lu). fixing...\n",
+				(unsigned long long)map->mtd->size, map->map.size);
+			map->mtd->size = map->map.size;
+		}
+		if (window->rsrc.parent) {
+			/*
+			 * Registering the MTD device in iomem may not be possible
+			 * if there is a BIOS "reserved" and BUSY range.  If this
+			 * fails then continue anyway.
+			 */
+			map->rsrc.name  = map->map_name;
+			map->rsrc.start = map->map.phys;
+			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
+			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+			if (request_resource(&window->rsrc, &map->rsrc)) {
+				printk(KERN_ERR MOD_NAME
+					": cannot reserve MTD resource\n");
+				map->rsrc.parent = NULL;
+			}
+		}
+
+		/* Make the whole region visible in the map */
+		map->map.virt = window->virt;
+		map->map.phys = window->phys;
+		cfi = map->map.fldrv_priv;
+		for(i = 0; i < cfi->numchips; i++) {
+			cfi->chips[i].start += offset;
+		}
+
+		/* Now that the mtd devices is complete claim and export it */
+		map->mtd->owner = THIS_MODULE;
+		if (mtd_device_register(map->mtd, NULL, 0)) {
+			map_destroy(map->mtd);
+			map->mtd = NULL;
+			goto out;
+		}
+
+
+		/* Calculate the new value of map_top */
+		map_top += map->mtd->size;
+
+		/* File away the map structure */
+		list_add(&map->list, &window->maps);
+		map = NULL;
+	}
+
+ out:
+	/* Free any left over map structures */
+	kfree(map);
+	/* See if I have any map structures */
+	if (list_empty(&window->maps)) {
+		amd76xrom_cleanup(window);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+
+static void amd76xrom_remove_one(struct pci_dev *pdev)
+{
+	struct amd76xrom_window *window = &amd76xrom_window;
+
+	amd76xrom_cleanup(window);
+}
+
+static const struct pci_device_id amd76xrom_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440) },
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_AMD, 0x7468, 0, 0) }, /* amd8111 support */
+	{ }
+};
+
+MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
+
+#if 0
+static struct pci_driver amd76xrom_driver = {
+	.name =		MOD_NAME,
+	.id_table =	amd76xrom_pci_tbl,
+	.probe =	amd76xrom_init_one,
+	.remove =	amd76xrom_remove_one,
+};
+#endif
+
+static int __init init_amd76xrom(void)
+{
+	struct pci_dev *pdev;
+	const struct pci_device_id *id;
+	pdev = NULL;
+	for(id = amd76xrom_pci_tbl; id->vendor; id++) {
+		pdev = pci_get_device(id->vendor, id->device, NULL);
+		if (pdev) {
+			break;
+		}
+	}
+	if (pdev) {
+		return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
+	}
+	return -ENXIO;
+#if 0
+	return pci_register_driver(&amd76xrom_driver);
+#endif
+}
+
+static void __exit cleanup_amd76xrom(void)
+{
+	amd76xrom_remove_one(amd76xrom_window.pdev);
+}
+
+module_init(init_amd76xrom);
+module_exit(cleanup_amd76xrom);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
+MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");