From: duwe@lst.de (Torsten Duwe)
To: Mark Rutland <mark.rutland@arm.com>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Julien Thierry <julien.thierry@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Arnd Bergmann <arnd@arndb.de>,
AKASHI Takahiro <takahiro.akashi@linaro.org>,
Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, live-patching@vger.kernel.org
Subject: [PATCH v8 5/5] arm64: use -fpatchable-function-entry if available
Date: Fri, 8 Feb 2019 16:10:24 +0100 (CET) [thread overview]
Message-ID: <20190208151024.676A168DEE@newverein.lst.de> (raw)
In-Reply-To: <20190208150826.44EBC68DD2@newverein.lst.de>
Test whether gcc supports -fpatchable-function-entry and use it to promote
DYNAMIC_FTRACE to DYNAMIC_FTRACE_WITH_REGS. Amend support for the new
object section that holds the locations (__patchable_function_entries) and
define a proper "notrace" attribute to switch it off.
Signed-off-by: Torsten Duwe <duwe@suse.de>
---
arch/arm64/Kconfig | 2 ++
arch/arm64/Makefile | 5 +++++
include/asm-generic/vmlinux.lds.h | 1 +
include/linux/compiler_types.h | 2 ++
kernel/module.c | 7 ++++++-
5 files changed, 16 insertions(+), 1 deletion(-)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -132,6 +132,8 @@ config ARM64
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS \
+ if $(cc-option,-fpatchable-function-entry=2)
select HAVE_EFFICIENT_UNALIGNED_ACCESS
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_TRACER
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -89,6 +89,11 @@ ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds
endif
+ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
+ KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FENTRY
+ CC_FLAGS_FTRACE := -fpatchable-function-entry=2
+endif
+
# Default value
head-y := arch/arm64/kernel/head.o
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -113,6 +113,7 @@
#define MCOUNT_REC() . = ALIGN(8); \
__start_mcount_loc = .; \
KEEP(*(__mcount_loc)) \
+ KEEP(*(__patchable_function_entries)) \
__stop_mcount_loc = .;
#else
#define MCOUNT_REC()
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -112,6 +112,8 @@ struct ftrace_likely_data {
#if defined(CC_USING_HOTPATCH)
#define notrace __attribute__((hotpatch(0, 0)))
+#elif defined(CC_USING_PATCHABLE_FENTRY)
+#define notrace __attribute__((patchable_function_entry(0)))
#else
#define notrace __attribute__((__no_instrument_function__))
#endif
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3122,7 +3122,12 @@ static int find_module_sections(struct m
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
/* sechdrs[0].sh_size is always zero */
- mod->ftrace_callsites = section_objs(info, "__mcount_loc",
+ mod->ftrace_callsites = section_objs(info,
+#ifdef CC_USING_PATCHABLE_FENTRY
+ "__patchable_function_entries",
+#else
+ "__mcount_loc",
+#endif
sizeof(*mod->ftrace_callsites),
&mod->num_ftrace_callsites);
#endif
next prev parent reply other threads:[~2019-02-08 15:10 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-08 15:08 [PATCH v8 0/5] arm64: ftrace with regs Torsten Duwe
2019-02-08 15:10 ` [PATCH v8 1/5] arm64: replace -pg with CC_FLAGS_FTRACE in arm64 Makefiles Torsten Duwe
2019-02-11 11:53 ` Mark Rutland
2019-02-08 15:10 ` [PATCH v8 2/5] arm64: replace -pg with CC_FLAGS_FTRACE in efi Makefiles Torsten Duwe
2019-02-11 11:59 ` Mark Rutland
2019-04-08 15:23 ` Mark Rutland
2019-04-08 20:49 ` Ard Biesheuvel
2019-02-08 15:10 ` [PATCH v8 3/5] arm64: replace -pg with CC_FLAGS_FTRACE in mm/kasan Makefile Torsten Duwe
2019-02-11 11:55 ` Mark Rutland
2019-02-11 11:56 ` Mark Rutland
2019-04-08 15:25 ` Mark Rutland
2019-04-08 15:35 ` Andrey Ryabinin
2019-02-08 15:10 ` [PATCH v8 4/5] arm64: implement ftrace with regs Torsten Duwe
2019-02-13 10:30 ` Julien Thierry
2019-02-08 15:10 ` Torsten Duwe [this message]
2019-02-13 11:11 ` [PATCH v8 0/5] arm64: " Julien Thierry
2019-03-11 11:49 ` Torsten Duwe
2019-03-11 12:18 ` Mark Rutland
2019-03-29 10:18 ` Torsten Duwe
2019-04-08 15:36 ` Mark Rutland
2019-04-09 17:52 ` Will Deacon
2019-07-10 12:27 ` Ruslan Bilovol
2019-07-24 16:15 ` Mark Rutland
2019-10-16 11:42 ` Jiri Kosina
2019-10-16 17:58 ` Mark Rutland
2019-10-18 17:41 ` Mark Rutland
2019-10-19 11:01 ` Torsten Duwe
2019-10-21 11:37 ` Mark Rutland
2019-10-21 13:20 ` Josh Poimboeuf
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