Commit 67bfce0e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull ftrace fix from Steven Rostedt:
 "Fix s390 breakage from sorting mcount tables.

  The latest merge of the tracing tree sorts the mcount table at build
  time. But s390 appears to do things differently (like always) and
  replaces the sorted table back to the original unsorted one. As the
  ftrace algorithm depends on it being sorted, bad things happen when it
  is not, and s390 experienced those bad things.

  Add a new config to tell the boot if the mcount table is sorted or
  not, and allow s390 to opt out of it"

* tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix assuming build time sort works for s390
parents 473aec0e 6b9b6413

kernel/trace/Kconfig

+8 −1
Original line number Diff line number Diff line
@@ -70,6 +70,13 @@ config HAVE_C_RECORDMCOUNT 
	help

	  C version of recordmcount available?



config BUILDTIME_MCOUNT_SORT

       bool

       default y

       depends on BUILDTIME_TABLE_SORT && !S390

       help

         Sort the mcount_loc section at build time.



config TRACER_MAX_TRACE

	bool
@@ -918,7 +925,7 @@ config EVENT_TRACE_TEST_SYSCALLS 
config FTRACE_SORT_STARTUP_TEST

       bool "Verify compile time sorting of ftrace functions"

       depends on DYNAMIC_FTRACE

       depends on BUILDTIME_TABLE_SORT

       depends on BUILDTIME_MCOUNT_SORT

       help

	 Sorting of the mcount_loc sections that is used to find the

	 where the ftrace knows where to patch functions for tracing

kernel/trace/ftrace.c

+2 −2
Original line number Diff line number Diff line
@@ -6435,10 +6435,10 @@ static int ftrace_process_locs(struct module *mod, 


	/*

	 * Sorting mcount in vmlinux at build time depend on

	 * CONFIG_BUILDTIME_TABLE_SORT, while mcount loc in

	 * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in

	 * modules can not be sorted at build time.

	 */

	if (!IS_ENABLED(CONFIG_BUILDTIME_TABLE_SORT) || mod) {

	if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {

		sort(start, count, sizeof(*start),

		     ftrace_cmp_ips, NULL);

	} else {