Commit 9440155c authored by Peter Zijlstra (Intel)'s avatar Peter Zijlstra (Intel) Committed by Daniel Borkmann
Browse files

ftrace: Add HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 



x86 will shortly start using -fpatchable-function-entry for purposes
other than ftrace, make sure the __patchable_function_entry section
isn't merged in the mcount_loc section.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220903131154.420467-2-jolsa@kernel.org
parent bfeb7e39

include/asm-generic/vmlinux.lds.h

+10 −1
Original line number Diff line number Diff line
@@ -154,6 +154,14 @@ 
#define MEM_DISCARD(sec) *(.mem##sec)

#endif



#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE

#define KEEP_PATCHABLE		KEEP(*(__patchable_function_entries))

#define PATCHABLE_DISCARDS

#else

#define KEEP_PATCHABLE

#define PATCHABLE_DISCARDS	*(__patchable_function_entries)

#endif



#ifdef CONFIG_FTRACE_MCOUNT_RECORD

/*

 * The ftrace call sites are logged to a section whose name depends on the
@@ -172,7 +180,7 @@ 
#define MCOUNT_REC()	. = ALIGN(8);				\

			__start_mcount_loc = .;			\

			KEEP(*(__mcount_loc))			\

			KEEP(*(__patchable_function_entries))	\

			KEEP_PATCHABLE				\

			__stop_mcount_loc = .;			\

			ftrace_stub_graph = ftrace_stub;	\

			ftrace_ops_list_func = arch_ftrace_ops_list_func;
@@ -1024,6 +1032,7 @@ 


#define COMMON_DISCARDS							\

	SANITIZER_DISCARDS						\

	PATCHABLE_DISCARDS						\

	*(.discard)							\

	*(.discard.*)							\

	*(.modinfo)							\

kernel/trace/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -51,6 +51,12 @@ config HAVE_DYNAMIC_FTRACE_WITH_ARGS 
	 This allows for use of regs_get_kernel_argument() and

	 kernel_stack_pointer().



config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE

	bool

	help

	  If the architecture generates __patchable_function_entries sections

	  but does not want them included in the ftrace locations.



config HAVE_FTRACE_MCOUNT_RECORD

	bool

	help

tools/objtool/check.c

+2 −1
Original line number Diff line number Diff line
@@ -4113,7 +4113,8 @@ static int validate_ibt(struct objtool_file *file) 
		    !strcmp(sec->name, "__bug_table")			||

		    !strcmp(sec->name, "__ex_table")			||

		    !strcmp(sec->name, "__jump_table")			||

		    !strcmp(sec->name, "__mcount_loc"))

		    !strcmp(sec->name, "__mcount_loc")			||

		    strstr(sec->name, "__patchable_function_entries"))

			continue;



		list_for_each_entry(reloc, &sec->reloc->reloc_list, list)