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

12 files changed, 291 insertions, 0 deletions

diff --git a/arch/arc/include/uapi/asm/Kbuild b/arch/arc/include/uapi/asm/Kbuild
new file mode 100644
index 000000000..2501e82a1
--- /dev/null
+++ b/arch/arc/include/uapi/asm/Kbuild
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+syscall-y += unistd_32.h
+
+generic-y += ucontext.h
diff --git a/arch/arc/include/uapi/asm/bpf_perf_event.h b/arch/arc/include/uapi/asm/bpf_perf_event.h
new file mode 100644
index 000000000..6cb1c2823
--- /dev/null
+++ b/arch/arc/include/uapi/asm/bpf_perf_event.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
+#define _UAPI__ASM_BPF_PERF_EVENT_H__
+
+#include <asm/ptrace.h>
+
+typedef struct user_regs_struct bpf_user_pt_regs_t;
+
+#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */
diff --git a/arch/arc/include/uapi/asm/byteorder.h b/arch/arc/include/uapi/asm/byteorder.h
new file mode 100644
index 000000000..554011153
--- /dev/null
+++ b/arch/arc/include/uapi/asm/byteorder.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_ARC_BYTEORDER_H
+#define __ASM_ARC_BYTEORDER_H
+
+#ifdef __BIG_ENDIAN__
+#include <linux/byteorder/big_endian.h>
+#else
+#include <linux/byteorder/little_endian.h>
+#endif
+
+#endif /* ASM_ARC_BYTEORDER_H */
diff --git a/arch/arc/include/uapi/asm/cachectl.h b/arch/arc/include/uapi/asm/cachectl.h
new file mode 100644
index 000000000..0e4f2affc
--- /dev/null
+++ b/arch/arc/include/uapi/asm/cachectl.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ARC_ASM_CACHECTL_H
+#define __ARC_ASM_CACHECTL_H
+
+/*
+ * ARC ABI flags defined for Android's finegrained cacheflush requirements
+ */
+#define CF_I_INV	0x0002
+#define CF_D_FLUSH	0x0010
+#define CF_D_FLUSH_INV	0x0020
+
+#define CF_DEFAULT	(CF_I_INV | CF_D_FLUSH)
+
+/*
+ * Standard flags expected by cacheflush system call users
+ */
+#define ICACHE	CF_I_INV
+#define DCACHE	CF_D_FLUSH
+#define BCACHE	(CF_I_INV | CF_D_FLUSH)
+
+#endif
diff --git a/arch/arc/include/uapi/asm/elf.h b/arch/arc/include/uapi/asm/elf.h
new file mode 100644
index 000000000..3c1dae4e5
--- /dev/null
+++ b/arch/arc/include/uapi/asm/elf.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _UAPI__ASM_ARC_ELF_H
+#define _UAPI__ASM_ARC_ELF_H
+
+#include <asm/ptrace.h>		/* for user_regs_struct */
+
+/* Machine specific ELF Hdr flags */
+#define EF_ARC_OSABI_MSK	0x00000f00
+
+#define EF_ARC_OSABI_V3		0x00000300   /* v3 (no legacy syscalls) */
+#define EF_ARC_OSABI_V4		0x00000400   /* v4 (64bit data any reg align) */
+
+#if __GNUC__ < 6
+#define EF_ARC_OSABI_CURRENT	EF_ARC_OSABI_V3
+#else
+#define EF_ARC_OSABI_CURRENT	EF_ARC_OSABI_V4
+#endif
+
+typedef unsigned long elf_greg_t;
+typedef unsigned long elf_fpregset_t;
+
+#define ELF_NGREG	(sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
+#define ELF_ARCV2REG	(sizeof(struct user_regs_arcv2) / sizeof(elf_greg_t))
+
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+#endif
diff --git a/arch/arc/include/uapi/asm/page.h b/arch/arc/include/uapi/asm/page.h
new file mode 100644
index 000000000..4606a326a
--- /dev/null
+++ b/arch/arc/include/uapi/asm/page.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _UAPI__ASM_ARC_PAGE_H
+#define _UAPI__ASM_ARC_PAGE_H
+
+#include <linux/const.h>
+
+/* PAGE_SHIFT determines the page size */
+#ifdef __KERNEL__
+#include <vdso/page.h>
+#else
+/*
+ * Default 8k
+ * done this way (instead of under CONFIG_ARC_PAGE_SIZE_8K) because adhoc
+ * user code (busybox appletlib.h) expects PAGE_SHIFT to be defined w/o
+ * using the correct uClibc header and in their build our autoconf.h is
+ * not available
+ */
+#define PAGE_SHIFT 13
+#define PAGE_SIZE	_BITUL(PAGE_SHIFT)	/* Default 8K */
+#define PAGE_MASK	(~(PAGE_SIZE-1))
+#endif
+
+#define PAGE_OFFSET	_AC(0x80000000, UL)	/* Kernel starts at 2G onwrds */
+
+#endif /* _UAPI__ASM_ARC_PAGE_H */
diff --git a/arch/arc/include/uapi/asm/ptrace.h b/arch/arc/include/uapi/asm/ptrace.h
new file mode 100644
index 000000000..3ae832db2
--- /dev/null
+++ b/arch/arc/include/uapi/asm/ptrace.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
+ */
+
+#ifndef _UAPI__ASM_ARC_PTRACE_H
+#define _UAPI__ASM_ARC_PTRACE_H
+
+#define PTRACE_GET_THREAD_AREA	25
+
+#ifndef __ASSEMBLER__
+/*
+ * Userspace ABI: Register state needed by
+ *  -ptrace (gdbserver)
+ *  -sigcontext (SA_SIGNINFO signal frame)
+ *
+ * This is to decouple pt_regs from user-space ABI, to be able to change it
+ * w/o affecting the ABI.
+ *
+ * The intermediate pad,pad2 are relics of initial layout based on pt_regs
+ * for optimizations when copying pt_regs to/from user_regs_struct.
+ * We no longer need them, but can't be changed as they are part of ABI now.
+ *
+ * Also, sigcontext only care about the scratch regs as that is what we really
+ * save/restore for signal handling. However gdb also uses the same struct
+ * hence callee regs need to be in there too.
+*/
+struct user_regs_struct {
+
+	unsigned long pad;
+	struct {
+		unsigned long bta, lp_start, lp_end, lp_count;
+		unsigned long status32, ret, blink, fp, gp;
+		unsigned long r12, r11, r10, r9, r8, r7, r6, r5, r4, r3, r2, r1, r0;
+		unsigned long sp;
+	} scratch;
+	unsigned long pad2;
+	struct {
+		unsigned long r25, r24, r23, r22, r21, r20;
+		unsigned long r19, r18, r17, r16, r15, r14, r13;
+	} callee;
+	unsigned long efa;	/* break pt addr, for break points in delay slots */
+	unsigned long stop_pc;	/* give dbg stop_pc after ensuring brkpt trap */
+};
+
+struct user_regs_arcv2 {
+	unsigned long r30, r58, r59;
+};
+
+#endif /* !__ASSEMBLER__ */
+
+#endif /* _UAPI__ASM_ARC_PTRACE_H */
diff --git a/arch/arc/include/uapi/asm/setup.h b/arch/arc/include/uapi/asm/setup.h
new file mode 100644
index 000000000..a6d4e4493
--- /dev/null
+++ b/arch/arc/include/uapi/asm/setup.h
@@ -0,0 +1,6 @@
+/*
+ * setup.h is part of userspace header ABI so UAPI scripts have to generate it
+ * even if there's nothing to export - causing empty <uapi/asm/setup.h>
+ * However to prevent "patch" from discarding it we add this placeholder
+ * comment
+ */
diff --git a/arch/arc/include/uapi/asm/sigcontext.h b/arch/arc/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000..7a5449dfc
--- /dev/null
+++ b/arch/arc/include/uapi/asm/sigcontext.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_SIGCONTEXT_H
+#define _ASM_ARC_SIGCONTEXT_H
+
+#include <asm/ptrace.h>
+
+/*
+ * Signal context structure - contains all info to do with the state
+ * before the signal handler was invoked.
+ */
+struct sigcontext {
+	struct user_regs_struct regs;
+	struct user_regs_arcv2 v2abi;
+};
+
+#endif /* _ASM_ARC_SIGCONTEXT_H */
diff --git a/arch/arc/include/uapi/asm/signal.h b/arch/arc/include/uapi/asm/signal.h
new file mode 100644
index 000000000..ba3143a1b
--- /dev/null
+++ b/arch/arc/include/uapi/asm/signal.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
+ */
+
+#ifndef _ASM_ARC_SIGNAL_H
+#define _ASM_ARC_SIGNAL_H
+
+/*
+ * This is much needed for ARC sigreturn optimization.
+ * This allows uClibc to piggback the addr of a sigreturn stub in sigaction,
+ * which allows sigreturn based re-entry into kernel after handling signal.
+ * W/o this kernel needs to "synthesize" the sigreturn trampoline on user
+ * mode stack which in turn forces the following:
+ * -TLB Flush (after making the stack page executable)
+ * -Cache line Flush (to make I/D Cache lines coherent)
+ */
+#define SA_RESTORER	0x04000000
+
+#include <asm-generic/signal.h>
+
+#endif /* _ASM_ARC_SIGNAL_H */
diff --git a/arch/arc/include/uapi/asm/swab.h b/arch/arc/include/uapi/asm/swab.h
new file mode 100644
index 000000000..417ea30f2
--- /dev/null
+++ b/arch/arc/include/uapi/asm/swab.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * vineetg: May 2011
+ *  -Support single cycle endian-swap insn in ARC700 4.10
+ *
+ * vineetg: June 2009
+ *  -Better htonl implementation (5 instead of 9 ALU instructions)
+ *  -Hardware assisted single cycle bswap (Use Case of ARC custom instrn)
+ */
+
+#ifndef __ASM_ARC_SWAB_H
+#define __ASM_ARC_SWAB_H
+
+#include <linux/types.h>
+
+#define __arch_swab32(x)		\
+({					\
+	unsigned int tmp = x;		\
+	__asm__(			\
+	"	swape	%0, %1	\n"	\
+	: "=r" (tmp)			\
+	: "r" (tmp));			\
+	tmp;				\
+})
+
+#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
+#define __SWAB_64_THRU_32__
+#endif
+
+#endif
diff --git a/arch/arc/include/uapi/asm/unistd.h b/arch/arc/include/uapi/asm/unistd.h
new file mode 100644
index 000000000..cb2905c7c
--- /dev/null
+++ b/arch/arc/include/uapi/asm/unistd.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm/unistd_32.h>