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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-23 08:07:02 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-23 08:07:02 +0200
commit67bfce0e01927859618b76ff5a36a7f23b412cef (patch)
tree0608ca6cc9c35059acd10454704346edcfdfbd7e /kernel/trace
parent473aec0e1f84be97c7ea52c4266b7ef13ce36af3 (diff)
parent6b9b6413700e104934734b72a3be622a76923b98 (diff)
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
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/Kconfig9
-rw-r--r--kernel/trace/ftrace.c4
2 files changed, 10 insertions, 3 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index f468767bc287..752ed89a293b 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -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
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6163b6f762f7..f9feb197b2da 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -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 {