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, 244 insertions, 0 deletions

diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c
new file mode 100644
index 000000000..07086dbd3
--- /dev/null
+++ b/arch/hexagon/mm/init.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Memory subsystem initialization for Hexagon
+ *
+ * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <asm/atomic.h>
+#include <linux/highmem.h>
+#include <asm/tlb.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/vm_mmu.h>
+
+/*
+ * Define a startpg just past the end of the kernel image and a lastpg
+ * that corresponds to the end of real or simulated platform memory.
+ */
+#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
+
+unsigned long bootmem_lastpg;	/*  Should be set by platform code  */
+unsigned long __phys_offset;	/*  physical kernel offset >> 12  */
+
+/*  Set as variable to limit PMD copies  */
+int max_kernel_seg = 0x303;
+
+/*  indicate pfn's of high memory  */
+unsigned long highstart_pfn, highend_pfn;
+
+/* Default cache attribute for newly created page tables */
+unsigned long _dflt_cache_att = CACHEDEF;
+
+/*
+ * The current "generation" of kernel map, which should not roll
+ * over until Hell freezes over.  Actual bound in years needs to be
+ * calculated to confirm.
+ */
+DEFINE_SPINLOCK(kmap_gen_lock);
+
+/*  checkpatch says don't init this to 0.  */
+unsigned long long kmap_generation;
+
+void sync_icache_dcache(pte_t pte)
+{
+	unsigned long addr;
+	struct page *page;
+
+	page = pte_page(pte);
+	addr = (unsigned long) page_address(page);
+
+	__vmcache_idsync(addr, PAGE_SIZE);
+}
+
+void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
+{
+	/*
+	 *  This is not particularly well documented anywhere, but
+	 *  give ZONE_NORMAL all the memory, including the big holes
+	 *  left by the kernel+bootmem_map which are already left as reserved
+	 *  in the bootmem_map; free_area_init should see those bits and
+	 *  adjust accordingly.
+	 */
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+}
+
+static void __init paging_init(void)
+{
+	/*
+	 * Set the init_mm descriptors "context" value to point to the
+	 * initial kernel segment table's physical address.
+	 */
+	init_mm.context.ptbase = __pa(init_mm.pgd);
+}
+
+#ifndef DMA_RESERVE
+#define DMA_RESERVE		(4)
+#endif
+
+#define DMA_CHUNKSIZE		(1<<22)
+#define DMA_RESERVED_BYTES	(DMA_RESERVE * DMA_CHUNKSIZE)
+
+/*
+ * Pick out the memory size.  We look for mem=size,
+ * where size is "size[KkMm]"
+ */
+static int __init early_mem(char *p)
+{
+	unsigned long size;
+	char *endp;
+
+	size = memparse(p, &endp);
+
+	bootmem_lastpg = PFN_DOWN(size);
+
+	return 0;
+}
+early_param("mem", early_mem);
+
+size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22);
+
+void __init setup_arch_memory(void)
+{
+	/*  XXX Todo: this probably should be cleaned up  */
+	u32 *segtable = (u32 *) &swapper_pg_dir[0];
+	u32 *segtable_end;
+
+	/*
+	 * Set up boot memory allocator
+	 *
+	 * The Gorman book also talks about these functions.
+	 * This needs to change for highmem setups.
+	 */
+
+	/*  Prior to this, bootmem_lastpg is actually mem size  */
+	bootmem_lastpg += ARCH_PFN_OFFSET;
+
+	/* Memory size needs to be a multiple of 16M */
+	bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
+		~((BIG_KERNEL_PAGE_SIZE) - 1));
+
+	memblock_add(PHYS_OFFSET,
+		     (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
+
+	/* Reserve kernel text/data/bss */
+	memblock_reserve(PHYS_OFFSET,
+			 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
+	/*
+	 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
+	 * memory allocation
+	 */
+	max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
+	min_low_pfn = ARCH_PFN_OFFSET;
+	memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES);
+
+	printk(KERN_INFO "bootmem_startpg:  0x%08lx\n", bootmem_startpg);
+	printk(KERN_INFO "bootmem_lastpg:  0x%08lx\n", bootmem_lastpg);
+	printk(KERN_INFO "min_low_pfn:  0x%08lx\n", min_low_pfn);
+	printk(KERN_INFO "max_low_pfn:  0x%08lx\n", max_low_pfn);
+
+	/*
+	 * The default VM page tables (will be) populated with
+	 * VA=PA+PAGE_OFFSET mapping.  We go in and invalidate entries
+	 * higher than what we have memory for.
+	 */
+
+	/*  this is pointer arithmetic; each entry covers 4MB  */
+	segtable = segtable + (PAGE_OFFSET >> 22);
+
+	/*  this actually only goes to the end of the first gig  */
+	segtable_end = segtable + (1<<(30-22));
+
+	/*
+	 * Move forward to the start of empty pages; take into account
+	 * phys_offset shift.
+	 */
+
+	segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
+	{
+		int i;
+
+		for (i = 1 ; i <= DMA_RESERVE ; i++)
+			segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
+				| __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
+				| __HEXAGON_C_UNC << 6
+				| __HVM_PDE_S_4MB);
+	}
+
+	printk(KERN_INFO "clearing segtable from %p to %p\n", segtable,
+		segtable_end);
+	while (segtable < (segtable_end-8))
+		*(segtable++) = __HVM_PDE_S_INVALID;
+	/* stop the pointer at the device I/O 4MB page  */
+
+	printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n",
+		segtable);
+
+#if 0
+	/*  Other half of the early device table from vm_init_segtable. */
+	printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n",
+		(unsigned long) _K_init_devicetable-PAGE_OFFSET);
+	*segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) |
+		__HVM_PDE_S_4KB;
+	printk(KERN_INFO "*segtable = 0x%08x\n", *segtable);
+#endif
+
+	/*
+	 *  The bootmem allocator seemingly just lives to feed memory
+	 *  to the paging system
+	 */
+	printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE);
+	paging_init();  /*  See Gorman Book, 2.3  */
+
+	/*
+	 *  At this point, the page allocator is kind of initialized, but
+	 *  apparently no pages are available (just like with the bootmem
+	 *  allocator), and need to be freed themselves via mem_init(),
+	 *  which is called by start_kernel() later on in the process
+	 */
+}
+
+static const pgprot_t protection_map[16] = {
+	[VM_NONE]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   CACHEDEF),
+	[VM_READ]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_READ | CACHEDEF),
+	[VM_WRITE]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   CACHEDEF),
+	[VM_WRITE | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_READ | CACHEDEF),
+	[VM_EXEC]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | CACHEDEF),
+	[VM_EXEC | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | _PAGE_READ |
+								   CACHEDEF),
+	[VM_EXEC | VM_WRITE]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | CACHEDEF),
+	[VM_EXEC | VM_WRITE | VM_READ]			= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | _PAGE_READ |
+								   CACHEDEF),
+	[VM_SHARED]                                     = __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   CACHEDEF),
+	[VM_SHARED | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_READ | CACHEDEF),
+	[VM_SHARED | VM_WRITE]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_WRITE | CACHEDEF),
+	[VM_SHARED | VM_WRITE | VM_READ]		= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_READ | _PAGE_WRITE |
+								   CACHEDEF),
+	[VM_SHARED | VM_EXEC]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | CACHEDEF),
+	[VM_SHARED | VM_EXEC | VM_READ]			= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | _PAGE_READ |
+								   CACHEDEF),
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_EXECUTE | _PAGE_WRITE |
+								   CACHEDEF),
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= __pgprot(_PAGE_PRESENT | _PAGE_USER |
+								   _PAGE_READ | _PAGE_EXECUTE |
+								   _PAGE_WRITE | CACHEDEF)
+};
+DECLARE_VM_GET_PAGE_PROT