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/arch/mips/kvm/trace.h b/arch/mips/kvm/trace.h
new file mode 100644
index 000000000..136c3535a
--- /dev/null
+++ b/arch/mips/kvm/trace.h
@@ -0,0 +1,346 @@
+/*
+ * 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) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ */
+
+#if !defined(_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+
+/*
+ * arch/mips/kvm/mips.c
+ */
+extern bool kvm_trace_guest_mode_change;
+int kvm_guest_mode_change_trace_reg(void);
+void kvm_guest_mode_change_trace_unreg(void);
+
+/*
+ * Tracepoints for VM enters
+ */
+DECLARE_EVENT_CLASS(kvm_transition,
+	TP_PROTO(struct kvm_vcpu *vcpu),
+	TP_ARGS(vcpu),
+	TP_STRUCT__entry(
+		__field(unsigned long, pc)
+	),
+
+	TP_fast_assign(
+		__entry->pc = vcpu->arch.pc;
+	),
+
+	TP_printk("PC: 0x%08lx",
+		  __entry->pc)
+);
+
+DEFINE_EVENT(kvm_transition, kvm_enter,
+	     TP_PROTO(struct kvm_vcpu *vcpu),
+	     TP_ARGS(vcpu));
+
+DEFINE_EVENT(kvm_transition, kvm_reenter,
+	     TP_PROTO(struct kvm_vcpu *vcpu),
+	     TP_ARGS(vcpu));
+
+DEFINE_EVENT(kvm_transition, kvm_out,
+	     TP_PROTO(struct kvm_vcpu *vcpu),
+	     TP_ARGS(vcpu));
+
+/* The first 32 exit reasons correspond to Cause.ExcCode */
+#define KVM_TRACE_EXIT_INT		 0
+#define KVM_TRACE_EXIT_TLBMOD		 1
+#define KVM_TRACE_EXIT_TLBMISS_LD	 2
+#define KVM_TRACE_EXIT_TLBMISS_ST	 3
+#define KVM_TRACE_EXIT_ADDRERR_LD	 4
+#define KVM_TRACE_EXIT_ADDRERR_ST	 5
+#define KVM_TRACE_EXIT_SYSCALL		 8
+#define KVM_TRACE_EXIT_BREAK_INST	 9
+#define KVM_TRACE_EXIT_RESVD_INST	10
+#define KVM_TRACE_EXIT_COP_UNUSABLE	11
+#define KVM_TRACE_EXIT_TRAP_INST	13
+#define KVM_TRACE_EXIT_MSA_FPE		14
+#define KVM_TRACE_EXIT_FPE		15
+#define KVM_TRACE_EXIT_MSA_DISABLED	21
+#define KVM_TRACE_EXIT_GUEST_EXIT	27
+/* Further exit reasons */
+#define KVM_TRACE_EXIT_WAIT		32
+#define KVM_TRACE_EXIT_CACHE		33
+#define KVM_TRACE_EXIT_SIGNAL		34
+/* 32 exit reasons correspond to GuestCtl0.GExcCode (VZ) */
+#define KVM_TRACE_EXIT_GEXCCODE_BASE	64
+#define KVM_TRACE_EXIT_GPSI		64	/*  0 */
+#define KVM_TRACE_EXIT_GSFC		65	/*  1 */
+#define KVM_TRACE_EXIT_HC		66	/*  2 */
+#define KVM_TRACE_EXIT_GRR		67	/*  3 */
+#define KVM_TRACE_EXIT_GVA		72	/*  8 */
+#define KVM_TRACE_EXIT_GHFC		73	/*  9 */
+#define KVM_TRACE_EXIT_GPA		74	/* 10 */
+
+/* Tracepoints for VM exits */
+#define kvm_trace_symbol_exit_types				\
+	{ KVM_TRACE_EXIT_INT,		"Interrupt" },		\
+	{ KVM_TRACE_EXIT_TLBMOD,	"TLB Mod" },		\
+	{ KVM_TRACE_EXIT_TLBMISS_LD,	"TLB Miss (LD)" },	\
+	{ KVM_TRACE_EXIT_TLBMISS_ST,	"TLB Miss (ST)" },	\
+	{ KVM_TRACE_EXIT_ADDRERR_LD,	"Address Error (LD)" },	\
+	{ KVM_TRACE_EXIT_ADDRERR_ST,	"Address Err (ST)" },	\
+	{ KVM_TRACE_EXIT_SYSCALL,	"System Call" },	\
+	{ KVM_TRACE_EXIT_BREAK_INST,	"Break Inst" },		\
+	{ KVM_TRACE_EXIT_RESVD_INST,	"Reserved Inst" },	\
+	{ KVM_TRACE_EXIT_COP_UNUSABLE,	"COP0/1 Unusable" },	\
+	{ KVM_TRACE_EXIT_TRAP_INST,	"Trap Inst" },		\
+	{ KVM_TRACE_EXIT_MSA_FPE,	"MSA FPE" },		\
+	{ KVM_TRACE_EXIT_FPE,		"FPE" },		\
+	{ KVM_TRACE_EXIT_MSA_DISABLED,	"MSA Disabled" },	\
+	{ KVM_TRACE_EXIT_GUEST_EXIT,	"Guest Exit" },		\
+	{ KVM_TRACE_EXIT_WAIT,		"WAIT" },		\
+	{ KVM_TRACE_EXIT_CACHE,		"CACHE" },		\
+	{ KVM_TRACE_EXIT_SIGNAL,	"Signal" },		\
+	{ KVM_TRACE_EXIT_GPSI,		"GPSI" },		\
+	{ KVM_TRACE_EXIT_GSFC,		"GSFC" },		\
+	{ KVM_TRACE_EXIT_HC,		"HC" },			\
+	{ KVM_TRACE_EXIT_GRR,		"GRR" },		\
+	{ KVM_TRACE_EXIT_GVA,		"GVA" },		\
+	{ KVM_TRACE_EXIT_GHFC,		"GHFC" },		\
+	{ KVM_TRACE_EXIT_GPA,		"GPA" }
+
+TRACE_EVENT(kvm_exit,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
+	    TP_ARGS(vcpu, reason),
+	    TP_STRUCT__entry(
+			__field(unsigned long, pc)
+			__field(unsigned int, reason)
+	    ),
+
+	    TP_fast_assign(
+			__entry->pc = vcpu->arch.pc;
+			__entry->reason = reason;
+	    ),
+
+	    TP_printk("[%s]PC: 0x%08lx",
+		      __print_symbolic(__entry->reason,
+				       kvm_trace_symbol_exit_types),
+		      __entry->pc)
+);
+
+#define KVM_TRACE_MFC0		0
+#define KVM_TRACE_MTC0		1
+#define KVM_TRACE_DMFC0		2
+#define KVM_TRACE_DMTC0		3
+#define KVM_TRACE_RDHWR		4
+
+#define KVM_TRACE_HWR_COP0	0
+#define KVM_TRACE_HWR_HWR	1
+
+#define KVM_TRACE_COP0(REG, SEL)	((KVM_TRACE_HWR_COP0 << 8) |	\
+					 ((REG) << 3) | (SEL))
+#define KVM_TRACE_HWR(REG, SEL)		((KVM_TRACE_HWR_HWR  << 8) |	\
+					 ((REG) << 3) | (SEL))
+
+#define kvm_trace_symbol_hwr_ops				\
+	{ KVM_TRACE_MFC0,		"MFC0" },		\
+	{ KVM_TRACE_MTC0,		"MTC0" },		\
+	{ KVM_TRACE_DMFC0,		"DMFC0" },		\
+	{ KVM_TRACE_DMTC0,		"DMTC0" },		\
+	{ KVM_TRACE_RDHWR,		"RDHWR" }
+
+#define kvm_trace_symbol_hwr_cop				\
+	{ KVM_TRACE_HWR_COP0,		"COP0" },		\
+	{ KVM_TRACE_HWR_HWR,		"HWR" }
+
+#define kvm_trace_symbol_hwr_regs				\
+	{ KVM_TRACE_COP0( 0, 0),	"Index" },		\
+	{ KVM_TRACE_COP0( 2, 0),	"EntryLo0" },		\
+	{ KVM_TRACE_COP0( 3, 0),	"EntryLo1" },		\
+	{ KVM_TRACE_COP0( 4, 0),	"Context" },		\
+	{ KVM_TRACE_COP0( 4, 2),	"UserLocal" },		\
+	{ KVM_TRACE_COP0( 5, 0),	"PageMask" },		\
+	{ KVM_TRACE_COP0( 6, 0),	"Wired" },		\
+	{ KVM_TRACE_COP0( 7, 0),	"HWREna" },		\
+	{ KVM_TRACE_COP0( 8, 0),	"BadVAddr" },		\
+	{ KVM_TRACE_COP0( 9, 0),	"Count" },		\
+	{ KVM_TRACE_COP0(10, 0),	"EntryHi" },		\
+	{ KVM_TRACE_COP0(11, 0),	"Compare" },		\
+	{ KVM_TRACE_COP0(12, 0),	"Status" },		\
+	{ KVM_TRACE_COP0(12, 1),	"IntCtl" },		\
+	{ KVM_TRACE_COP0(12, 2),	"SRSCtl" },		\
+	{ KVM_TRACE_COP0(13, 0),	"Cause" },		\
+	{ KVM_TRACE_COP0(14, 0),	"EPC" },		\
+	{ KVM_TRACE_COP0(15, 0),	"PRId" },		\
+	{ KVM_TRACE_COP0(15, 1),	"EBase" },		\
+	{ KVM_TRACE_COP0(16, 0),	"Config" },		\
+	{ KVM_TRACE_COP0(16, 1),	"Config1" },		\
+	{ KVM_TRACE_COP0(16, 2),	"Config2" },		\
+	{ KVM_TRACE_COP0(16, 3),	"Config3" },		\
+	{ KVM_TRACE_COP0(16, 4),	"Config4" },		\
+	{ KVM_TRACE_COP0(16, 5),	"Config5" },		\
+	{ KVM_TRACE_COP0(16, 7),	"Config7" },		\
+	{ KVM_TRACE_COP0(17, 1),	"MAAR" },		\
+	{ KVM_TRACE_COP0(17, 2),	"MAARI" },		\
+	{ KVM_TRACE_COP0(26, 0),	"ECC" },		\
+	{ KVM_TRACE_COP0(30, 0),	"ErrorEPC" },		\
+	{ KVM_TRACE_COP0(31, 2),	"KScratch1" },		\
+	{ KVM_TRACE_COP0(31, 3),	"KScratch2" },		\
+	{ KVM_TRACE_COP0(31, 4),	"KScratch3" },		\
+	{ KVM_TRACE_COP0(31, 5),	"KScratch4" },		\
+	{ KVM_TRACE_COP0(31, 6),	"KScratch5" },		\
+	{ KVM_TRACE_COP0(31, 7),	"KScratch6" },		\
+	{ KVM_TRACE_HWR( 0, 0),		"CPUNum" },		\
+	{ KVM_TRACE_HWR( 1, 0),		"SYNCI_Step" },		\
+	{ KVM_TRACE_HWR( 2, 0),		"CC" },			\
+	{ KVM_TRACE_HWR( 3, 0),		"CCRes" },		\
+	{ KVM_TRACE_HWR(29, 0),		"ULR" }
+
+TRACE_EVENT(kvm_hwr,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int op, unsigned int reg,
+		     unsigned long val),
+	    TP_ARGS(vcpu, op, reg, val),
+	    TP_STRUCT__entry(
+			__field(unsigned long, val)
+			__field(u16, reg)
+			__field(u8, op)
+	    ),
+
+	    TP_fast_assign(
+			__entry->val = val;
+			__entry->reg = reg;
+			__entry->op = op;
+	    ),
+
+	    TP_printk("%s %s (%s:%u:%u) 0x%08lx",
+		      __print_symbolic(__entry->op,
+				       kvm_trace_symbol_hwr_ops),
+		      __print_symbolic(__entry->reg,
+				       kvm_trace_symbol_hwr_regs),
+		      __print_symbolic(__entry->reg >> 8,
+				       kvm_trace_symbol_hwr_cop),
+		      (__entry->reg >> 3) & 0x1f,
+		      __entry->reg & 0x7,
+		      __entry->val)
+);
+
+#define KVM_TRACE_AUX_RESTORE		0
+#define KVM_TRACE_AUX_SAVE		1
+#define KVM_TRACE_AUX_ENABLE		2
+#define KVM_TRACE_AUX_DISABLE		3
+#define KVM_TRACE_AUX_DISCARD		4
+
+#define KVM_TRACE_AUX_FPU		1
+#define KVM_TRACE_AUX_MSA		2
+#define KVM_TRACE_AUX_FPU_MSA		3
+
+#define kvm_trace_symbol_aux_op		\
+	{ KVM_TRACE_AUX_RESTORE, "restore" },	\
+	{ KVM_TRACE_AUX_SAVE,    "save" },	\
+	{ KVM_TRACE_AUX_ENABLE,  "enable" },	\
+	{ KVM_TRACE_AUX_DISABLE, "disable" },	\
+	{ KVM_TRACE_AUX_DISCARD, "discard" }
+
+#define kvm_trace_symbol_aux_state		\
+	{ KVM_TRACE_AUX_FPU,     "FPU" },	\
+	{ KVM_TRACE_AUX_MSA,     "MSA" },	\
+	{ KVM_TRACE_AUX_FPU_MSA, "FPU & MSA" }
+
+TRACE_EVENT(kvm_aux,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int op,
+		     unsigned int state),
+	    TP_ARGS(vcpu, op, state),
+	    TP_STRUCT__entry(
+			__field(unsigned long, pc)
+			__field(u8, op)
+			__field(u8, state)
+	    ),
+
+	    TP_fast_assign(
+			__entry->pc = vcpu->arch.pc;
+			__entry->op = op;
+			__entry->state = state;
+	    ),
+
+	    TP_printk("%s %s PC: 0x%08lx",
+		      __print_symbolic(__entry->op,
+				       kvm_trace_symbol_aux_op),
+		      __print_symbolic(__entry->state,
+				       kvm_trace_symbol_aux_state),
+		      __entry->pc)
+);
+
+TRACE_EVENT(kvm_asid_change,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int old_asid,
+		     unsigned int new_asid),
+	    TP_ARGS(vcpu, old_asid, new_asid),
+	    TP_STRUCT__entry(
+			__field(unsigned long, pc)
+			__field(u8, old_asid)
+			__field(u8, new_asid)
+	    ),
+
+	    TP_fast_assign(
+			__entry->pc = vcpu->arch.pc;
+			__entry->old_asid = old_asid;
+			__entry->new_asid = new_asid;
+	    ),
+
+	    TP_printk("PC: 0x%08lx old: 0x%02x new: 0x%02x",
+		      __entry->pc,
+		      __entry->old_asid,
+		      __entry->new_asid)
+);
+
+TRACE_EVENT(kvm_guestid_change,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int guestid),
+	    TP_ARGS(vcpu, guestid),
+	    TP_STRUCT__entry(
+			__field(unsigned int, guestid)
+	    ),
+
+	    TP_fast_assign(
+			__entry->guestid = guestid;
+	    ),
+
+	    TP_printk("GuestID: 0x%02x",
+		      __entry->guestid)
+);
+
+TRACE_EVENT_FN(kvm_guest_mode_change,
+	    TP_PROTO(struct kvm_vcpu *vcpu),
+	    TP_ARGS(vcpu),
+	    TP_STRUCT__entry(
+			__field(unsigned long, epc)
+			__field(unsigned long, pc)
+			__field(unsigned long, badvaddr)
+			__field(unsigned int, status)
+			__field(unsigned int, cause)
+	    ),
+
+	    TP_fast_assign(
+			__entry->epc = kvm_read_c0_guest_epc(&vcpu->arch.cop0);
+			__entry->pc = vcpu->arch.pc;
+			__entry->badvaddr = kvm_read_c0_guest_badvaddr(&vcpu->arch.cop0);
+			__entry->status = kvm_read_c0_guest_status(&vcpu->arch.cop0);
+			__entry->cause = kvm_read_c0_guest_cause(&vcpu->arch.cop0);
+	    ),
+
+	    TP_printk("EPC: 0x%08lx PC: 0x%08lx Status: 0x%08x Cause: 0x%08x BadVAddr: 0x%08lx",
+		      __entry->epc,
+		      __entry->pc,
+		      __entry->status,
+		      __entry->cause,
+		      __entry->badvaddr),
+
+	    kvm_guest_mode_change_trace_reg,
+	    kvm_guest_mode_change_trace_unreg
+);
+
+#endif /* _TRACE_KVM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>