path: root/kernel/trace
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authorLinus Torvalds <>2016-05-17 17:11:27 -0700
committerLinus Torvalds <>2016-05-17 17:11:27 -0700
commit0b86c75db6e7f68c22ac5d0dae0f551c4897cdf5 (patch)
treed1be280c331fbd85c021b5686914d2cc21475f54 /kernel/trace
parent16bf8348055fe4615bd08ef50f9874f5dcc10268 (diff)
parentbe69f70e6395a4ba9c178b2531433547e1955195 (diff)
Merge branch 'for-linus' of git://
Pull livepatching updates from Jiri Kosina: - remove of our own implementation of architecture-specific relocation code and leveraging existing code in the module loader to perform arch-dependent work, from Jessica Yu. The relevant patches have been acked by Rusty (for module.c) and Heiko (for s390). - live patching support for ppc64le, which is a joint work of Michael Ellerman and Torsten Duwe. This is coming from topic branch that is share between livepatching.git and ppc tree. - addition of livepatching documentation from Petr Mladek * 'for-linus' of git:// livepatch: make object/func-walking helpers more robust livepatch: Add some basic livepatch documentation powerpc/livepatch: Add live patching support on ppc64le powerpc/livepatch: Add livepatch stack to struct thread_info powerpc/livepatch: Add livepatch header livepatch: Allow architectures to specify an alternate ftrace location ftrace: Make ftrace_location_range() global livepatch: robustify klp_register_patch() API error checking Documentation: livepatch: outline Elf format and requirements for patch modules livepatch: reuse module loader code to write relocations module: s390: keep mod_arch_specific for livepatch modules module: preserve Elf information for livepatch modules Elf: add livepatch-specific Elf constants
Diffstat (limited to 'kernel/trace')
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b1870fbd2b67..7e8d792da963 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1530,7 +1530,19 @@ static int ftrace_cmp_recs(const void *a, const void *b)
return 0;
-static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
+ * ftrace_location_range - return the first address of a traced location
+ * if it touches the given ip range
+ * @start: start of range to search.
+ * @end: end of range to search (inclusive). @end points to the last byte
+ * to check.
+ *
+ * Returns rec->ip if the related ftrace location is a least partly within
+ * the given address range. That is, the first address of the instruction
+ * that is either a NOP or call to the function tracer. It checks the ftrace
+ * internal tables to determine if the address belongs or not.
+ */
+unsigned long ftrace_location_range(unsigned long start, unsigned long end)
struct ftrace_page *pg;
struct dyn_ftrace *rec;