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, 253 insertions, 0 deletions

diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
new file mode 100644
index 000000000..2572fd49a
--- /dev/null
+++ b/arch/mips/bmips/setup.c
@@ -0,0 +1,253 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ * Copyright (C) 2014 Kevin Cernekee <cernekee@gmail.com>
+ */
+
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/memblock.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_clk.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <linux/smp.h>
+#include <asm/addrspace.h>
+#include <asm/bmips.h>
+#include <asm/bootinfo.h>
+#include <asm/cpu-type.h>
+#include <asm/mipsregs.h>
+#include <asm/prom.h>
+#include <asm/smp-ops.h>
+#include <asm/time.h>
+#include <asm/traps.h>
+#include <asm/fw/cfe/cfe_api.h>
+
+#define RELO_NORMAL_VEC		BIT(18)
+
+#define REG_BCM6328_OTP		((void __iomem *)CKSEG1ADDR(0x1000062c))
+#define BCM6328_TP1_DISABLED	BIT(9)
+
+/*
+ * CBR addr doesn't change and we can cache it.
+ * For broken SoC/Bootloader CBR addr might also be provided via DT
+ * with "brcm,bmips-cbr-reg" in the "cpus" node.
+ */
+void __iomem *bmips_cbr_addr __read_mostly;
+
+extern bool bmips_rac_flush_disable;
+
+static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
+
+struct bmips_quirk {
+	const char		*compatible;
+	void			(*quirk_fn)(void);
+};
+
+static void kbase_setup(void)
+{
+	__raw_writel(kbase | RELO_NORMAL_VEC,
+		     BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
+	ebase = kbase;
+}
+
+static void bcm3384_viper_quirks(void)
+{
+	/*
+	 * Some experimental CM boxes are set up to let CM own the Viper TP0
+	 * and let Linux own TP1.  This requires moving the kernel
+	 * load address to a non-conflicting region (e.g. via
+	 * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
+	 * If we detect this condition, we need to move the MIPS exception
+	 * vectors up to an area that we own.
+	 *
+	 * This is distinct from the OTHER special case mentioned in
+	 * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
+	 * logical CPU#1).  For the Viper TP1 case, SMP is off limits.
+	 *
+	 * Also note that many BMIPS435x CPUs do not have a
+	 * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
+	 * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
+	 */
+	board_ebase_setup = &kbase_setup;
+	bmips_smp_enabled = 0;
+}
+
+static void bcm63xx_fixup_cpu1(void)
+{
+	/*
+	 * The bootloader has set up the CPU1 reset vector at
+	 * 0xa000_0200.
+	 * This conflicts with the special interrupt vector (IV).
+	 * The bootloader has also set up CPU1 to respond to the wrong
+	 * IPI interrupt.
+	 * Here we will start up CPU1 in the background and ask it to
+	 * reconfigure itself then go back to sleep.
+	 */
+	memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
+	__sync();
+	set_c0_cause(C_SW0);
+	cpumask_set_cpu(1, &bmips_booted_mask);
+}
+
+static void bcm6328_quirks(void)
+{
+	/* Check CPU1 status in OTP (it is usually disabled) */
+	if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
+		bmips_smp_enabled = 0;
+	else
+		bcm63xx_fixup_cpu1();
+}
+
+static void bcm6358_quirks(void)
+{
+	/*
+	 * BCM3368/BCM6358 need special handling for their shared TLB, so
+	 * disable SMP for now
+	 */
+	bmips_smp_enabled = 0;
+
+	/*
+	 * RAC flush causes kernel panics on BCM6358 when booting from TP1
+	 * because the bootloader is not initializing it properly.
+	 */
+	bmips_rac_flush_disable = !!(read_c0_brcm_cmt_local() & (1 << 31)) ||
+				  !!bmips_cbr_addr;
+}
+
+static void bcm6368_quirks(void)
+{
+	bcm63xx_fixup_cpu1();
+}
+
+static const struct bmips_quirk bmips_quirk_list[] = {
+	{ "brcm,bcm3368",		&bcm6358_quirks			},
+	{ "brcm,bcm3384-viper",		&bcm3384_viper_quirks		},
+	{ "brcm,bcm33843-viper",	&bcm3384_viper_quirks		},
+	{ "brcm,bcm6328",		&bcm6328_quirks			},
+	{ "brcm,bcm6358",		&bcm6358_quirks			},
+	{ "brcm,bcm6362",		&bcm6368_quirks			},
+	{ "brcm,bcm6368",		&bcm6368_quirks			},
+	{ "brcm,bcm63168",		&bcm6368_quirks			},
+	{ "brcm,bcm63268",		&bcm6368_quirks			},
+	{ },
+};
+
+static void __init bmips_init_cfe(void)
+{
+	cfe_seal = fw_arg3;
+
+	if (cfe_seal != CFE_EPTSEAL)
+		return;
+
+	cfe_init(fw_arg0, fw_arg2);
+}
+
+void __init prom_init(void)
+{
+	/* Cache CBR addr before CPU/DMA setup */
+	bmips_cbr_addr = BMIPS_GET_CBR();
+	bmips_init_cfe();
+	bmips_cpu_setup();
+	register_bmips_smp_ops();
+}
+
+const char *get_system_type(void)
+{
+	return "Generic BMIPS kernel";
+}
+
+void __init plat_time_init(void)
+{
+	struct device_node *np;
+	u32 freq;
+
+	np = of_find_node_by_name(NULL, "cpus");
+	if (!np)
+		panic("missing 'cpus' DT node");
+	if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
+		panic("missing 'mips-hpt-frequency' property");
+	of_node_put(np);
+
+	mips_hpt_frequency = freq;
+}
+
+void __init plat_mem_setup(void)
+{
+	void *dtb;
+	const struct bmips_quirk *q;
+
+	set_io_port_base(0);
+	ioport_resource.start = 0;
+	ioport_resource.end = ~0;
+
+	/*
+	 * intended to somewhat resemble ARM; see
+	 * Documentation/arch/arm/booting.rst
+	 */
+	if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
+		dtb = phys_to_virt(fw_arg2);
+	else
+		dtb = get_fdt();
+
+	if (!dtb)
+		cfe_die("no dtb found");
+
+	__dt_setup_arch(dtb);
+
+	for (q = bmips_quirk_list; q->quirk_fn; q++) {
+		if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
+					     q->compatible)) {
+			q->quirk_fn();
+		}
+	}
+}
+
+void __init device_tree_init(void)
+{
+	struct device_node *np;
+	u32 addr;
+
+	unflatten_and_copy_device_tree();
+
+	/* Disable SMP boot unless both CPUs are listed in DT and !disabled */
+	np = of_find_node_by_name(NULL, "cpus");
+	if (!np)
+		return;
+
+	if (of_get_available_child_count(np) <= 1)
+		bmips_smp_enabled = 0;
+
+	/* Check if DT provide a CBR address */
+	if (of_property_read_u32(np, "brcm,bmips-cbr-reg", &addr))
+		goto exit;
+
+	/* Make sure CBR address is outside DRAM window */
+	if (addr >= (u32)memblock_start_of_DRAM() &&
+	    addr < (u32)memblock_end_of_DRAM()) {
+		WARN(1, "DT CBR %x inside DRAM window. Ignoring DT CBR.\n",
+		     addr);
+		goto exit;
+	}
+
+	bmips_cbr_addr = (void __iomem *)addr;
+	/* Since CBR is provided by DT, enable RAC flush */
+	bmips_rac_flush_disable = false;
+
+exit:
+	of_node_put(np);
+}
+
+static int __init plat_dev_init(void)
+{
+	of_clk_init(NULL);
+	return 0;
+}
+
+arch_initcall(plat_dev_init);