diff mbox series

[11/13] ftrace: Add swap_func to ftrace_process_locs()

Message ID 20230601101257.530867-12-rppt@kernel.org (mailing list archive)
State Superseded
Headers show
Series mm: jit/text allocator | expand

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conchuod/cover_letter success Series has a cover letter
conchuod/tree_selection success Guessed tree name to be for-next at HEAD ac9a78681b92
conchuod/fixes_present success Fixes tag not required for -next series
conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 29 this patch: 29
conchuod/build_rv64_clang_allmodconfig success Errors and warnings before: 269 this patch: 269
conchuod/module_param success Was 0 now: 0
conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 5107 this patch: 5107
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch success total: 0 errors, 0 warnings, 0 checks, 31 lines checked
conchuod/build_rv64_nommu_k210_defconfig success Build OK
conchuod/verify_fixes success No Fixes tag
conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

Mike Rapoport June 1, 2023, 10:12 a.m. UTC 
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 mbox series

Patch

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);
 	}