When ftrace_call_adjust() returns 0 for a patch site,
ftrace_process_locs() does not skip the site. The NULL test runs before
the adjustment since commit 6eeca746fa5f ("ftrace: Test mcount_loc
addr before calling ftrace_call_addr()"), so the 0 is stored as the
record's ip and ftrace_init_nop() later hits the BUG_ON() in arm64's
patch_map(). Test the adjusted address too and count the site as
skipped.Reviewed-by: Ben Cressey <[email protected]> Reviewed-by: Florent Revest (Anthropic) <[email protected]> Assisted-by: LLM Signed-off-by: Jose Fernandez (Anthropic) <[email protected]> --- kernel/trace/ftrace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2cc2d41353c10..fa541d3e8784a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7676,6 +7676,11 @@ static int ftrace_process_locs(struct module *mod, } addr = ftrace_call_adjust(addr); + /* The architecture may return 0 to reject a patch site */ + if (!addr) { + skipped++; + continue; + } end_offset = (pg->index+1) * sizeof(pg->records[0]); if (end_offset > PAGE_SIZE << pg->order) { -- 2.52.0
