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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-07-24 18:36:57 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-26 13:18:20 +0200 |
| commit | ee9f8fce99640811b2b8e79d0d1dbe8bab69ba67 (patch) | |
| tree | be03fe86edb9ebd70b4d29ca2bc8a4d972ff6644 /scripts | |
| parent | 1ee6f00d1164955b7bdadd36fc0f2736754784d9 (diff) | |
| download | linux-ee9f8fce99640811b2b8e79d0d1dbe8bab69ba67.tar.bz2 | |
x86/unwind: Add the ORC unwinder
Add the new ORC unwinder which is enabled by CONFIG_ORC_UNWINDER=y.
It plugs into the existing x86 unwinder framework.
It relies on objtool to generate the needed .orc_unwind and
.orc_unwind_ip sections.
For more details on why ORC is used instead of DWARF, see
Documentation/x86/orc-unwinder.txt - but the short version is
that it's a simplified, fundamentally more robust debugninfo
data structure, which also allows up to two orders of magnitude
faster lookups than the DWARF unwinder - which matters to
profiling workloads like perf.
Thanks to Andy Lutomirski for the performance improvement ideas:
splitting the ORC unwind table into two parallel arrays and creating a
fast lookup table to search a subset of the unwind table.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/0a6cbfb40f8da99b7a45a1a8302dc6aef16ec812.1500938583.git.jpoimboe@redhat.com
[ Extended the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.build | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 854608d42e85..80ed14809a05 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -258,7 +258,8 @@ ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool -objtool_args = check +objtool_args = $(if $(CONFIG_ORC_UNWINDER),orc generate,check) + ifndef CONFIG_FRAME_POINTER objtool_args += --no-fp endif @@ -279,6 +280,11 @@ objtool_obj = $(if $(patsubst y%,, \ endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION +# Rebuild all objects when objtool changes, or is enabled/disabled. +objtool_dep = $(objtool_obj) \ + $(wildcard include/config/orc/unwinder.h \ + include/config/stack/validation.h) + define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ $(call cmd_and_fixdep,cc_o_c) \ @@ -301,13 +307,13 @@ cmd_undef_syms = echo endif # Built-in and composite module parts -$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE +$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE $(call cmd,force_checksrc) $(call if_changed_rule,cc_o_c) # Single-part modules are special since we need to mark them in $(MODVERDIR) -$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE +$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE $(call cmd,force_checksrc) $(call if_changed_rule,cc_o_c) @{ echo $(@:.o=.ko); echo $@; \ @@ -402,7 +408,7 @@ cmd_modversions_S = \ endif endif -$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE +$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE $(call if_changed_rule,as_o_S) targets += $(real-objs-y) $(real-objs-m) $(lib-y) |