From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, "Martin KaFai Lau" <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"KP Singh" <kpsingh@chromium.org>,
"Stanislav Fomichev" <sdf@google.com>,
"Hao Luo" <haoluo@google.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Björn Töpel" <bjorn@kernel.org>,
"Steven Rostedt" <rostedt@goodmis.org>
Subject: [PATCHv2 bpf-next 1/2] ftrace: Add HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
Date: Thu, 1 Sep 2022 15:41:49 +0200 [thread overview]
Message-ID: <20220901134150.418203-2-jolsa@kernel.org> (raw)
In-Reply-To: <20220901134150.418203-1-jolsa@kernel.org>
From: "Peter Zijlstra (Intel)" <peterz@infradead.org>
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: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/asm-generic/vmlinux.lds.h | 11 ++++++++++-
kernel/trace/Kconfig | 6 ++++++
tools/objtool/check.c | 3 ++-
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 7515a465ec03..13b197ef0d63 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -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) \
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 1052126bdca2..e9e95c790b8e 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -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
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0cec74da7ffe..f23e8d11f6d4 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4110,7 +4110,8 @@ 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)
--
2.37.2
next prev parent reply other threads:[~2022-09-01 13:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 13:41 [PATCHv2 bpf-next 0/2] bpf,ftrace: bpf dispatcher function fix Jiri Olsa
2022-09-01 13:41 ` Jiri Olsa [this message]
2022-09-01 13:41 ` [PATCHv2 bpf-next 2/2] bpf: Move bpf_dispatcher function out of ftrace locations Jiri Olsa
2022-09-02 11:14 ` Peter Zijlstra
2022-09-02 16:53 ` Jiri Olsa
2022-09-02 17:20 ` Peter Zijlstra
2022-09-03 13:11 ` Jiri Olsa
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