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, 244 insertions, 0 deletions

diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
new file mode 100644
index 000000000..d5f6d8283
--- /dev/null
+++ b/scripts/mod/modpost.h
@@ -0,0 +1,244 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <byteswap.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <elf.h>
+#include "../../include/linux/module_symbol.h"
+
+#include <list_types.h>
+#include "elfconfig.h"
+
+/* On BSD-alike OSes elf.h defines these according to host's word size */
+#undef ELF_ST_BIND
+#undef ELF_ST_TYPE
+#undef ELF_R_SYM
+#undef ELF_R_TYPE
+
+#if KERNEL_ELFCLASS == ELFCLASS32
+
+#define Elf_Ehdr    Elf32_Ehdr
+#define Elf_Shdr    Elf32_Shdr
+#define Elf_Sym     Elf32_Sym
+#define Elf_Addr    Elf32_Addr
+#define Elf_Section Elf32_Half
+#define ELF_ST_BIND ELF32_ST_BIND
+#define ELF_ST_TYPE ELF32_ST_TYPE
+
+#define Elf_Rel     Elf32_Rel
+#define Elf_Rela    Elf32_Rela
+#define ELF_R_SYM   ELF32_R_SYM
+#define ELF_R_TYPE  ELF32_R_TYPE
+#else
+
+#define Elf_Ehdr    Elf64_Ehdr
+#define Elf_Shdr    Elf64_Shdr
+#define Elf_Sym     Elf64_Sym
+#define Elf_Addr    Elf64_Addr
+#define Elf_Section Elf64_Half
+#define ELF_ST_BIND ELF64_ST_BIND
+#define ELF_ST_TYPE ELF64_ST_TYPE
+
+#define Elf_Rel     Elf64_Rel
+#define Elf_Rela    Elf64_Rela
+#define ELF_R_SYM   ELF64_R_SYM
+#define ELF_R_TYPE  ELF64_R_TYPE
+#endif
+
+#define bswap(x) \
+({ \
+	_Static_assert(sizeof(x) == 1 || sizeof(x) == 2 || \
+		       sizeof(x) == 4 || sizeof(x) == 8, "bug"); \
+	(typeof(x))(sizeof(x) == 2 ? bswap_16(x) : \
+		    sizeof(x) == 4 ? bswap_32(x) : \
+		    sizeof(x) == 8 ? bswap_64(x) : \
+		    x); \
+})
+
+#define TO_NATIVE(x)	\
+	(target_is_big_endian == host_is_big_endian ? x : bswap(x))
+
+#define __get_unaligned_t(type, ptr) ({					\
+	const struct { type x; } __attribute__((__packed__)) *__pptr =	\
+						(typeof(__pptr))(ptr);	\
+	__pptr->x;							\
+})
+
+#define get_unaligned(ptr)	__get_unaligned_t(typeof(*(ptr)), (ptr))
+
+#define get_unaligned_native(ptr) \
+({ \
+	typeof(*(ptr)) _val = get_unaligned(ptr); \
+	TO_NATIVE(_val); \
+})
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
+
+struct buffer {
+	char *p;
+	int pos;
+	int size;
+};
+
+void __attribute__((format(printf, 2, 3)))
+buf_printf(struct buffer *buf, const char *fmt, ...);
+
+void
+buf_write(struct buffer *buf, const char *s, int len);
+
+/**
+ * struct module_alias - auto-generated MODULE_ALIAS()
+ *
+ * @node: linked to module::aliases
+ * @modname: name of the builtin module (only for vmlinux)
+ * @str: a string for MODULE_ALIAS()
+ */
+struct module_alias {
+	struct list_head node;
+	char *builtin_modname;
+	char str[];
+};
+
+/**
+ * struct module - represent a module (vmlinux or *.ko)
+ *
+ * @dump_file: path to the .symvers file if loaded from a file
+ * @aliases: list head for module_aliases
+ * @no_trim_symbol: .no_trim_symbol section data
+ * @no_trim_symbol_len: length of the .no_trim_symbol section
+ */
+struct module {
+	struct list_head list;
+	struct list_head exported_symbols;
+	struct list_head unresolved_symbols;
+	const char *dump_file;
+	bool is_gpl_compatible;
+	bool is_vmlinux;
+	bool seen;
+	bool has_init;
+	bool has_cleanup;
+	char	     srcversion[25];
+	// Missing namespace dependencies
+	struct list_head missing_namespaces;
+	// Actual imported namespaces
+	struct list_head imported_namespaces;
+	struct list_head aliases;
+	char *no_trim_symbol;
+	unsigned int no_trim_symbol_len;
+	char name[];
+};
+
+struct elf_info {
+	size_t size;
+	Elf_Ehdr     *hdr;
+	Elf_Shdr     *sechdrs;
+	Elf_Sym      *symtab_start;
+	Elf_Sym      *symtab_stop;
+	unsigned int export_symbol_secndx;	/* .export_symbol section */
+	char         *strtab;
+	char	     *modinfo;
+	unsigned int modinfo_len;
+	char         *no_trim_symbol;
+	unsigned int no_trim_symbol_len;
+
+	/* support for 32bit section numbers */
+
+	unsigned int num_sections; /* max_secindex + 1 */
+	unsigned int secindex_strings;
+	/* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
+	 * take shndx from symtab_shndx_start[N] instead */
+	Elf32_Word   *symtab_shndx_start;
+	Elf32_Word   *symtab_shndx_stop;
+
+	struct symsearch *symsearch;
+};
+
+/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
+static inline unsigned int get_secindex(const struct elf_info *info,
+					const Elf_Sym *sym)
+{
+	unsigned int index = sym->st_shndx;
+
+	/*
+	 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
+	 * in the .symtab_shndx section.
+	 */
+	if (index == SHN_XINDEX)
+		return info->symtab_shndx_start[sym - info->symtab_start];
+
+	/*
+	 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
+	 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
+	 * section indices.
+	 */
+	if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
+		return index - SHN_HIRESERVE - 1;
+
+	return index;
+}
+
+/*
+ * If there's no name there, ignore it; likewise, ignore it if it's
+ * one of the magic symbols emitted used by current tools.
+ *
+ * Internal symbols created by tools should be ignored by modpost.
+ */
+static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym)
+{
+	const char *name = elf->strtab + sym->st_name;
+
+	if (!name || !strlen(name))
+		return false;
+	return !is_mapping_symbol(name);
+}
+
+/* symsearch.c */
+void symsearch_init(struct elf_info *elf);
+void symsearch_finish(struct elf_info *elf);
+Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr,
+				unsigned int secndx, bool allow_negative,
+				Elf_Addr min_distance);
+
+/* file2alias.c */
+void handle_moddevtable(struct module *mod, struct elf_info *info,
+			Elf_Sym *sym, const char *symname);
+
+/* sumversion.c */
+void get_src_version(const char *modname, char sum[], unsigned sumlen);
+
+/* from modpost.c */
+extern bool target_is_big_endian;
+extern bool host_is_big_endian;
+const char *get_basename(const char *path);
+char *read_text_file(const char *filename);
+char *get_line(char **stringp);
+void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
+
+void __attribute__((format(printf, 3, 4)))
+modpost_log(bool is_error, struct module *mod, const char *fmt, ...);
+
+/*
+ * warn - show the given message, then let modpost continue running, still
+ *        allowing modpost to exit successfully. This should be used when
+ *        we still allow to generate vmlinux and modules.
+ *
+ * error - show the given message, then let modpost continue running, but fail
+ *         in the end. This should be used when we should stop building vmlinux
+ *         or modules, but we can continue running modpost to catch as many
+ *         issues as possible.
+ *
+ * fatal - show the given message, and bail out immediately. This should be
+ *         used when there is no point to continue running modpost.
+ */
+#define warn(fmt, args...)	modpost_log(false, NULL, fmt, ##args)
+#define error(fmt, args...)	modpost_log(true, NULL, fmt, ##args)
+#define fatal(fmt, args...)	do { error(fmt, ##args); exit(1); } while (1)