This is needed for kgr to find fentry location to be "ftraced". We use this to find a place where to jump to a new/old code location.
Signed-off-by: Jiri Slaby <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> --- include/linux/ftrace.h | 1 + kernel/trace/ftrace.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ae9504b4b67d..8b447493b6a5 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -299,6 +299,7 @@ extern void unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops); extern void unregister_ftrace_function_probe_all(char *glob); +extern unsigned long ftrace_function_to_fentry(unsigned long addr); extern int ftrace_text_reserved(const void *start, const void *end); extern int ftrace_nr_registered_ops(void); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4a54a25afa2f..9968695cdcf9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1495,6 +1495,35 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) } \ } +/** + * ftrace_function_to_fentry -- lookup fentry location for a function + * @addr: function address to find a fentry in + * + * Perform a lookup in a list of fentry callsites to find one that fits a + * specified function @addr. It returns the corresponding fentry callsite or + * zero on failure. + */ +unsigned long ftrace_function_to_fentry(unsigned long addr) +{ + const struct dyn_ftrace *rec; + const struct ftrace_page *pg; + unsigned long ret = 0; + + mutex_lock(&ftrace_lock); + do_for_each_ftrace_rec(pg, rec) { + unsigned long off; + if (!kallsyms_lookup_size_offset(rec->ip, NULL, &off)) + continue; + if (addr + off == rec->ip) { + ret = rec->ip; + goto end; + } + } while_for_each_ftrace_rec() +end: + mutex_unlock(&ftrace_lock); + + return ret; +} static int ftrace_cmp_recs(const void *a, const void *b) { -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
