Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

5 files changed, 509 insertions, 0 deletions

diff --git a/arch/mips/tools/.gitignore b/arch/mips/tools/.gitignore
new file mode 100644
index 000000000..794817dfb
--- /dev/null
+++ b/arch/mips/tools/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+elf-entry
+loongson3-llsc-check
diff --git a/arch/mips/tools/Makefile b/arch/mips/tools/Makefile
new file mode 100644
index 000000000..b851e5dcc
--- /dev/null
+++ b/arch/mips/tools/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+hostprogs := elf-entry
+PHONY += elf-entry
+elf-entry: $(obj)/elf-entry
+	@:
+
+hostprogs += loongson3-llsc-check
+PHONY += loongson3-llsc-check
+loongson3-llsc-check: $(obj)/loongson3-llsc-check
+	@:
diff --git a/arch/mips/tools/elf-entry.c b/arch/mips/tools/elf-entry.c
new file mode 100644
index 000000000..dbd14ff05
--- /dev/null
+++ b/arch/mips/tools/elf-entry.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <byteswap.h>
+#include <elf.h>
+#include <endian.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef be32toh
+/* If libc provides [bl]e{32,64}toh() then we'll use them */
+#elif BYTE_ORDER == LITTLE_ENDIAN
+# define be32toh(x)	bswap_32(x)
+# define le32toh(x)	(x)
+# define be64toh(x)	bswap_64(x)
+# define le64toh(x)	(x)
+#elif BYTE_ORDER == BIG_ENDIAN
+# define be32toh(x)	(x)
+# define le32toh(x)	bswap_32(x)
+# define be64toh(x)	(x)
+# define le64toh(x)	bswap_64(x)
+#endif
+
+__attribute__((noreturn))
+static void die(const char *msg)
+{
+	fputs(msg, stderr);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, const char *argv[])
+{
+	uint64_t entry;
+	size_t nread;
+	FILE *file;
+	union {
+		Elf32_Ehdr ehdr32;
+		Elf64_Ehdr ehdr64;
+	} hdr;
+
+	if (argc != 2)
+		die("Usage: elf-entry <elf-file>\n");
+
+	file = fopen(argv[1], "r");
+	if (!file) {
+		perror("Unable to open input file");
+		return EXIT_FAILURE;
+	}
+
+	nread = fread(&hdr, 1, sizeof(hdr), file);
+	if (nread != sizeof(hdr)) {
+		perror("Unable to read input file");
+		fclose(file);
+		return EXIT_FAILURE;
+	}
+
+	if (memcmp(hdr.ehdr32.e_ident, ELFMAG, SELFMAG)) {
+		fclose(file);
+		die("Input is not an ELF\n");
+	}
+
+	switch (hdr.ehdr32.e_ident[EI_CLASS]) {
+	case ELFCLASS32:
+		switch (hdr.ehdr32.e_ident[EI_DATA]) {
+		case ELFDATA2LSB:
+			entry = le32toh(hdr.ehdr32.e_entry);
+			break;
+		case ELFDATA2MSB:
+			entry = be32toh(hdr.ehdr32.e_entry);
+			break;
+		default:
+			fclose(file);
+			die("Invalid ELF encoding\n");
+		}
+
+		/* Sign extend to form a canonical address */
+		entry = (int64_t)(int32_t)entry;
+		break;
+
+	case ELFCLASS64:
+		switch (hdr.ehdr32.e_ident[EI_DATA]) {
+		case ELFDATA2LSB:
+			entry = le64toh(hdr.ehdr64.e_entry);
+			break;
+		case ELFDATA2MSB:
+			entry = be64toh(hdr.ehdr64.e_entry);
+			break;
+		default:
+			fclose(file);
+			die("Invalid ELF encoding\n");
+		}
+		break;
+
+	default:
+		fclose(file);
+		die("Invalid ELF class\n");
+	}
+
+	printf("0x%016" PRIx64 "\n", entry);
+	fclose(file);
+	return EXIT_SUCCESS;
+}
diff --git a/arch/mips/tools/generic-board-config.sh b/arch/mips/tools/generic-board-config.sh
new file mode 100755
index 000000000..dfa5f31f5
--- /dev/null
+++ b/arch/mips/tools/generic-board-config.sh
@@ -0,0 +1,84 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2017 Imagination Technologies
+# Author: Paul Burton <paul.burton@mips.com>
+#
+# This script merges configuration fragments for boards supported by the
+# generic MIPS kernel. It checks each for requirements specified using
+# formatted comments, and then calls merge_config.sh to merge those
+# fragments which have no unmet requirements.
+#
+# An example of requirements in your board config fragment might be:
+#
+# # require CONFIG_CPU_MIPS32_R2=y
+# # require CONFIG_CPU_LITTLE_ENDIAN=y
+#
+# This would mean that your board is only included in kernels which are
+# configured for little endian MIPS32r2 CPUs, and not for example in kernels
+# configured for 64 bit or big endian systems.
+#
+
+srctree="$1"
+objtree="$2"
+ref_cfg="$3"
+cfg="$4"
+boards_origin="$5"
+shift 5
+
+# Only print Skipping... lines if the user explicitly specified BOARDS=. In the
+# general case it only serves to obscure the useful output about what actually
+# was included.
+case ${boards_origin} in
+"command line")
+	print_skipped=1
+	;;
+environment*)
+	print_skipped=1
+	;;
+*)
+	print_skipped=0
+	;;
+esac
+
+for board in $@; do
+	board_cfg="${srctree}/arch/mips/configs/generic/board-${board}.config"
+	if [ ! -f "${board_cfg}" ]; then
+		echo "WARNING: Board config '${board_cfg}' not found"
+		continue
+	fi
+
+	# For each line beginning with # require, cut out the field following
+	# it & search for that in the reference config file. If the requirement
+	# is not found then the subshell will exit with code 1, and we'll
+	# continue on to the next board.
+	grep -E '^# require ' "${board_cfg}" | \
+	    cut -d' ' -f 3- | \
+	    while read req; do
+		case ${req} in
+		*=y)
+			# If we require something =y then we check that a line
+			# containing it is present in the reference config.
+			grep -Eq "^${req}\$" "${ref_cfg}" && continue
+			;;
+		*=n)
+			# If we require something =n then we just invert that
+			# check, considering the requirement met if there isn't
+			# a line containing the value =y in the reference
+			# config.
+			grep -Eq "^${req/%=n/=y}\$" "${ref_cfg}" || continue
+			;;
+		*)
+			echo "WARNING: Unhandled requirement '${req}'"
+			;;
+		esac
+
+		[ ${print_skipped} -eq 1 ] && echo "Skipping ${board_cfg}"
+		exit 1
+	done || continue
+
+	# Merge this board config fragment into our final config file
+	${srctree}/scripts/kconfig/merge_config.sh \
+		-m -O ${objtree} ${cfg} ${board_cfg} \
+		| grep -Ev '^(#|Using)'
+done
diff --git a/arch/mips/tools/loongson3-llsc-check.c b/arch/mips/tools/loongson3-llsc-check.c
new file mode 100644
index 000000000..5f68a4fa8
--- /dev/null
+++ b/arch/mips/tools/loongson3-llsc-check.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <byteswap.h>
+#include <elf.h>
+#include <endian.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#ifdef be32toh
+/* If libc provides le{16,32,64}toh() then we'll use them */
+#elif BYTE_ORDER == LITTLE_ENDIAN
+# define le16toh(x)	(x)
+# define le32toh(x)	(x)
+# define le64toh(x)	(x)
+#elif BYTE_ORDER == BIG_ENDIAN
+# define le16toh(x)	bswap_16(x)
+# define le32toh(x)	bswap_32(x)
+# define le64toh(x)	bswap_64(x)
+#endif
+
+/* MIPS opcodes, in bits 31:26 of an instruction */
+#define OP_SPECIAL	0x00
+#define OP_REGIMM	0x01
+#define OP_BEQ		0x04
+#define OP_BNE		0x05
+#define OP_BLEZ		0x06
+#define OP_BGTZ		0x07
+#define OP_BEQL		0x14
+#define OP_BNEL		0x15
+#define OP_BLEZL	0x16
+#define OP_BGTZL	0x17
+#define OP_LL		0x30
+#define OP_LLD		0x34
+#define OP_SC		0x38
+#define OP_SCD		0x3c
+
+/* Bits 20:16 of OP_REGIMM instructions */
+#define REGIMM_BLTZ	0x00
+#define REGIMM_BGEZ	0x01
+#define REGIMM_BLTZL	0x02
+#define REGIMM_BGEZL	0x03
+#define REGIMM_BLTZAL	0x10
+#define REGIMM_BGEZAL	0x11
+#define REGIMM_BLTZALL	0x12
+#define REGIMM_BGEZALL	0x13
+
+/* Bits 5:0 of OP_SPECIAL instructions */
+#define SPECIAL_SYNC	0x0f
+
+static void usage(FILE *f)
+{
+	fprintf(f, "Usage: loongson3-llsc-check /path/to/vmlinux\n");
+}
+
+static int se16(uint16_t x)
+{
+	return (int16_t)x;
+}
+
+static bool is_ll(uint32_t insn)
+{
+	switch (insn >> 26) {
+	case OP_LL:
+	case OP_LLD:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static bool is_sc(uint32_t insn)
+{
+	switch (insn >> 26) {
+	case OP_SC:
+	case OP_SCD:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static bool is_sync(uint32_t insn)
+{
+	/* Bits 31:11 should all be zeroes */
+	if (insn >> 11)
+		return false;
+
+	/* Bits 5:0 specify the SYNC special encoding */
+	if ((insn & 0x3f) != SPECIAL_SYNC)
+		return false;
+
+	return true;
+}
+
+static bool is_branch(uint32_t insn, int *off)
+{
+	switch (insn >> 26) {
+	case OP_BEQ:
+	case OP_BEQL:
+	case OP_BNE:
+	case OP_BNEL:
+	case OP_BGTZ:
+	case OP_BGTZL:
+	case OP_BLEZ:
+	case OP_BLEZL:
+		*off = se16(insn) + 1;
+		return true;
+
+	case OP_REGIMM:
+		switch ((insn >> 16) & 0x1f) {
+		case REGIMM_BGEZ:
+		case REGIMM_BGEZL:
+		case REGIMM_BGEZAL:
+		case REGIMM_BGEZALL:
+		case REGIMM_BLTZ:
+		case REGIMM_BLTZL:
+		case REGIMM_BLTZAL:
+		case REGIMM_BLTZALL:
+			*off = se16(insn) + 1;
+			return true;
+
+		default:
+			return false;
+		}
+
+	default:
+		return false;
+	}
+}
+
+static int check_ll(uint64_t pc, uint32_t *code, size_t sz)
+{
+	ssize_t i, max, sc_pos;
+	int off;
+
+	/*
+	 * Every LL must be preceded by a sync instruction in order to ensure
+	 * that instruction reordering doesn't allow a prior memory access to
+	 * execute after the LL & cause erroneous results.
+	 */
+	if (!is_sync(le32toh(code[-1]))) {
+		fprintf(stderr, "%" PRIx64 ": LL not preceded by sync\n", pc);
+		return -EINVAL;
+	}
+
+	/* Find the matching SC instruction */
+	max = sz / 4;
+	for (sc_pos = 0; sc_pos < max; sc_pos++) {
+		if (is_sc(le32toh(code[sc_pos])))
+			break;
+	}
+	if (sc_pos >= max) {
+		fprintf(stderr, "%" PRIx64 ": LL has no matching SC\n", pc);
+		return -EINVAL;
+	}
+
+	/*
+	 * Check branches within the LL/SC loop target sync instructions,
+	 * ensuring that speculative execution can't generate memory accesses
+	 * due to instructions outside of the loop.
+	 */
+	for (i = 0; i < sc_pos; i++) {
+		if (!is_branch(le32toh(code[i]), &off))
+			continue;
+
+		/*
+		 * If the branch target is within the LL/SC loop then we don't
+		 * need to worry about it.
+		 */
+		if ((off >= -i) && (off <= sc_pos))
+			continue;
+
+		/* If the branch targets a sync instruction we're all good... */
+		if (is_sync(le32toh(code[i + off])))
+			continue;
+
+		/* ...but if not, we have a problem */
+		fprintf(stderr, "%" PRIx64 ": Branch target not a sync\n",
+			pc + (i * 4));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int check_code(uint64_t pc, uint32_t *code, size_t sz)
+{
+	int err = 0;
+
+	if (sz % 4) {
+		fprintf(stderr, "%" PRIx64 ": Section size not a multiple of 4\n",
+			pc);
+		err = -EINVAL;
+		sz -= (sz % 4);
+	}
+
+	if (is_ll(le32toh(code[0]))) {
+		fprintf(stderr, "%" PRIx64 ": First instruction in section is an LL\n",
+			pc);
+		err = -EINVAL;
+	}
+
+#define advance() (	\
+	code++,		\
+	pc += 4,	\
+	sz -= 4		\
+)
+
+	/*
+	 * Skip the first instruction, allowing check_ll to look backwards
+	 * unconditionally.
+	 */
+	advance();
+
+	/* Now scan through the code looking for LL instructions */
+	for (; sz; advance()) {
+		if (is_ll(le32toh(code[0])))
+			err |= check_ll(pc, code, sz);
+	}
+
+	return err;
+}
+
+int main(int argc, char *argv[])
+{
+	int vmlinux_fd, status, err, i;
+	const char *vmlinux_path;
+	struct stat st;
+	Elf64_Ehdr *eh;
+	Elf64_Shdr *sh;
+	void *vmlinux;
+
+	status = EXIT_FAILURE;
+
+	if (argc < 2) {
+		usage(stderr);
+		goto out_ret;
+	}
+
+	vmlinux_path = argv[1];
+	vmlinux_fd = open(vmlinux_path, O_RDONLY);
+	if (vmlinux_fd == -1) {
+		perror("Unable to open vmlinux");
+		goto out_ret;
+	}
+
+	err = fstat(vmlinux_fd, &st);
+	if (err) {
+		perror("Unable to stat vmlinux");
+		goto out_close;
+	}
+
+	vmlinux = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, vmlinux_fd, 0);
+	if (vmlinux == MAP_FAILED) {
+		perror("Unable to mmap vmlinux");
+		goto out_close;
+	}
+
+	eh = vmlinux;
+	if (memcmp(eh->e_ident, ELFMAG, SELFMAG)) {
+		fprintf(stderr, "vmlinux is not an ELF?\n");
+		goto out_munmap;
+	}
+
+	if (eh->e_ident[EI_CLASS] != ELFCLASS64) {
+		fprintf(stderr, "vmlinux is not 64b?\n");
+		goto out_munmap;
+	}
+
+	if (eh->e_ident[EI_DATA] != ELFDATA2LSB) {
+		fprintf(stderr, "vmlinux is not little endian?\n");
+		goto out_munmap;
+	}
+
+	for (i = 0; i < le16toh(eh->e_shnum); i++) {
+		sh = vmlinux + le64toh(eh->e_shoff) + (i * le16toh(eh->e_shentsize));
+
+		if (sh->sh_type != SHT_PROGBITS)
+			continue;
+		if (!(sh->sh_flags & SHF_EXECINSTR))
+			continue;
+
+		err = check_code(le64toh(sh->sh_addr),
+				 vmlinux + le64toh(sh->sh_offset),
+				 le64toh(sh->sh_size));
+		if (err)
+			goto out_munmap;
+	}
+
+	status = EXIT_SUCCESS;
+out_munmap:
+	munmap(vmlinux, st.st_size);
+out_close:
+	close(vmlinux_fd);
+out_ret:
+	fprintf(stdout, "loongson3-llsc-check returns %s\n",
+		status ? "failure" : "success");
+	return status;
+}