[PATCH 11/13] ftrace: Add swap_func to ftrace_process_locs()
From: Mike Rapoport <rppt@kernel.org>
Date: 2023-06-01 10:18:13
Also in:
bpf, linux-arm-kernel, linux-mips, linux-modules, linux-riscv, linux-s390, linux-trace-kernel, lkml, loongarch, netdev, sparclinux
Subsystem:
function hooks (ftrace), the rest, tracing · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds
From: Song Liu <song@kernel.org> ftrace_process_locs sorts module mcount, which is inside RO memory. Add a ftrace_swap_func so that archs can use RO-memory-poke function to do the sorting. Signed-off-by: Song Liu <song@kernel.org> --- include/linux/ftrace.h | 2 ++ kernel/trace/ftrace.c | 13 ++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index b23bdd414394..fe443b8ed32c 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h@@ -1166,4 +1166,6 @@ unsigned long arch_syscall_addr(int nr); #endif /* CONFIG_FTRACE_SYSCALLS */ +void ftrace_swap_func(void *a, void *b, int n); + #endif /* _LINUX_FTRACE_H */
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 764668467155..f5ddc9d4cfb6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c@@ -6430,6 +6430,17 @@ static void test_is_sorted(unsigned long *start, unsigned long count) } #endif +void __weak ftrace_swap_func(void *a, void *b, int n) +{ + unsigned long t; + + WARN_ON_ONCE(n != sizeof(t)); + + t = *((unsigned long *)a); + *(unsigned long *)a = *(unsigned long *)b; + *(unsigned long *)b = t; +} + static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end)
@@ -6455,7 +6466,7 @@ static int ftrace_process_locs(struct module *mod, */ if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { sort(start, count, sizeof(*start), - ftrace_cmp_ips, NULL); + ftrace_cmp_ips, ftrace_swap_func); } else { test_is_sorted(start, count); }
--
2.35.1