Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - kprobes: Restructured stack unwinder to show properly on x86 when a
   stack dump happens from a kretprobe callback.

 - Fix to bootconfig parsing

 - Have tracefs allow owner and group permissions by default (only
   denying others). There's been pressure to allow non root to tracefs
   in a controlled fashion, and using groups is probably the safest.

 - Bootconfig memory managament updates.

 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.

 - Allow perf to be traced by function tracer.

 - Rewrite of function graph tracer to be a callback from the function
   tracer instead of having its own trampoline (this change will happen
   on an arch by arch basis, and currently only x86_64 implements it).

 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.

 - Allow histogram triggers to add variables that can perform
   calculations against the event's fields.

 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent
   warnings from the compiler.

 - Extend histogram triggers to key off of variables.

 - Have trace recursion use bit magic to determine preempt context over
   if branches.

 - Have trace recursion disable preemption as all use cases do anyway.

 - Added testing for verification of tracing utilities.

 - Various small clean ups and fixes.

* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
  tracing/histogram: Fix semicolon.cocci warnings
  tracing/histogram: Fix documentation inline emphasis warning
  tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
  tracing: Show size of requested perf buffer
  bootconfig: Initialize ret in xbc_parse_tree()
  ftrace: do CPU checking after preemption disabled
  ftrace: disable preemption when recursion locked
  tracing/histogram: Document expression arithmetic and constants
  tracing/histogram: Optimize division by a power of 2
  tracing/histogram: Covert expr to const if both operands are constants
  tracing/histogram: Simplify handling of .sym-offset in expressions
  tracing: Fix operator precedence for hist triggers expression
  tracing: Add division and multiplication support for hist triggers
  tracing: Add support for creating hist trigger variables from literal
  selftests/ftrace: Stop tracing while reading the trace file by default
  MAINTAINERS: Update KPROBES and TRACING entries
  test_kprobes: Move it from kernel/ to lib/
  docs, kprobes: Remove invalid URL and add new reference
  samples/kretprobes: Fix return value if register_kretprobe() failed
  lib/bootconfig: Fix the xbc_get_info kerneldoc
  ...

1 files changed, 12 insertions, 14 deletions

diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c
index 75bff0f77319..6c7f3b143fdc 100644
--- a/arch/mips/kernel/kprobes.c
+++ b/arch/mips/kernel/kprobes.c
@@ -11,6 +11,8 @@
  *   Copyright (C) IBM Corporation, 2002, 2004
  */
 
+#define pr_fmt(fmt) "kprobes: " fmt
+
 #include <linux/kprobes.h>
 #include <linux/preempt.h>
 #include <linux/uaccess.h>
@@ -80,8 +82,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	insn = p->addr[0];
 
 	if (insn_has_ll_or_sc(insn)) {
-		pr_notice("Kprobes for ll and sc instructions are not"
-			  "supported\n");
+		pr_notice("Kprobes for ll and sc instructions are not supported\n");
 		ret = -EINVAL;
 		goto out;
 	}
@@ -219,7 +220,7 @@ static int evaluate_branch_instruction(struct kprobe *p, struct pt_regs *regs,
 	return 0;
 
 unaligned:
-	pr_notice("%s: unaligned epc - sending SIGBUS.\n", current->comm);
+	pr_notice("Failed to emulate branch instruction because of unaligned epc - sending SIGBUS to %s.\n", current->comm);
 	force_sig(SIGBUS);
 	return -EFAULT;
 
@@ -238,10 +239,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs,
 		regs->cp0_epc = (unsigned long)p->addr;
 	else if (insn_has_delayslot(p->opcode)) {
 		ret = evaluate_branch_instruction(p, regs, kcb);
-		if (ret < 0) {
-			pr_notice("Kprobes: Error in evaluating branch\n");
+		if (ret < 0)
 			return;
-		}
 	}
 	regs->cp0_epc = (unsigned long)&p->ainsn.insn[0];
 }
@@ -461,14 +460,14 @@ static void __used kretprobe_trampoline_holder(void)
 		/* Keep the assembler from reordering and placing JR here. */
 		".set noreorder\n\t"
 		"nop\n\t"
-		".global kretprobe_trampoline\n"
-		"kretprobe_trampoline:\n\t"
+		".global __kretprobe_trampoline\n"
+		"__kretprobe_trampoline:\n\t"
 		"nop\n\t"
 		".set pop"
 		: : : "memory");
 }
 
-void kretprobe_trampoline(void);
+void __kretprobe_trampoline(void);
 
 void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 				      struct pt_regs *regs)
@@ -477,7 +476,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 	ri->fp = NULL;
 
 	/* Replace the return addr with trampoline addr */
-	regs->regs[31] = (unsigned long)kretprobe_trampoline;
+	regs->regs[31] = (unsigned long)__kretprobe_trampoline;
 }
 
 /*
@@ -486,8 +485,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
 static int __kprobes trampoline_probe_handler(struct kprobe *p,
 						struct pt_regs *regs)
 {
-	instruction_pointer(regs) = __kretprobe_trampoline_handler(regs,
-						kretprobe_trampoline, NULL);
+	instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL);
 	/*
 	 * By returning a non-zero value, we are telling
 	 * kprobe_handler() that we don't want the post_handler
@@ -498,14 +496,14 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 
 int __kprobes arch_trampoline_kprobe(struct kprobe *p)
 {
-	if (p->addr == (kprobe_opcode_t *)kretprobe_trampoline)
+	if (p->addr == (kprobe_opcode_t *)__kretprobe_trampoline)
 		return 1;
 
 	return 0;
 }
 
 static struct kprobe trampoline_p = {
-	.addr = (kprobe_opcode_t *)kretprobe_trampoline,
+	.addr = (kprobe_opcode_t *)__kretprobe_trampoline,
 	.pre_handler = trampoline_probe_handler
 };