Hi Matt,
On 6/2/20 8:49 PM, Matt Helsley wrote:
Move recordmcount into the objtool directory. We keep this step separate
so changes which turn recordmcount into a subcommand of objtool don't
get obscured.
Signed-off-by: Matt Helsley <mhels...@vmware.com>
---
Documentation/trace/ftrace-design.rst | 4 ++--
Documentation/trace/ftrace.rst | 2 +-
Makefile | 15 +++++++++------
scripts/.gitignore | 1 -
scripts/Makefile | 1 -
scripts/Makefile.build | 11 ++++++-----
tools/objtool/.gitignore | 1 +
tools/objtool/Build | 2 ++
tools/objtool/Makefile | 13 ++++++++++++-
{scripts => tools/objtool}/recordmcount.c | 0
{scripts => tools/objtool}/recordmcount.h | 0
{scripts => tools/objtool}/recordmcount.pl | 0
12 files changed, 33 insertions(+), 17 deletions(-)
rename {scripts => tools/objtool}/recordmcount.c (100%)
rename {scripts => tools/objtool}/recordmcount.h (100%)
rename {scripts => tools/objtool}/recordmcount.pl (100%)
diff --git a/Documentation/trace/ftrace-design.rst
b/Documentation/trace/ftrace-design.rst
index a8e22e0db63c..dea8db5e79d0 100644
--- a/Documentation/trace/ftrace-design.rst
+++ b/Documentation/trace/ftrace-design.rst
@@ -261,7 +261,7 @@ You need very few things to get the syscalls tracing in an
arch.
HAVE_FTRACE_MCOUNT_RECORD
-------------------------
-See scripts/recordmcount.pl for more info. Just fill in the arch-specific
+See tools/objtool/recordmcount.pl for more info. Just fill in the
arch-specific
details for how to locate the addresses of mcount call sites via objdump.
This option doesn't make much sense without also implementing dynamic ftrace.
@@ -379,7 +379,7 @@ linux/ftrace.h for the functions::
ftrace_make_call()
The rec->ip value is the address of the mcount call site that was collected
-by the scripts/recordmcount.pl during build time.
+by the tools/objtool/recordmcount.pl during build time.
The last function is used to do runtime patching of the active tracer. This
will be modifying the assembly code at the location of the ftrace_call symbol
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index 3b5614b1d1a5..9adefcc3c7a8 100644
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -2685,7 +2685,7 @@ starts of pointing to a simple return. (Enabling FTRACE
will
include the -pg switch in the compiling of the kernel.)
At compile time every C file object is run through the
-recordmcount program (located in the scripts directory). This
+recordmcount program (located in the tools/objtool directory). This
program will parse the ELF headers in the C object to find all
the locations in the .text section that call mcount. Starting
with gcc version 4.6, the -mfentry has been added for x86, which
diff --git a/Makefile b/Makefile
index 04f5662ae61a..d353a0a65a71 100644
--- a/Makefile
+++ b/Makefile
@@ -844,6 +844,7 @@ ifdef CONFIG_DYNAMIC_FTRACE
ifdef CONFIG_HAVE_C_RECORDMCOUNT
BUILD_C_RECORDMCOUNT := y
export BUILD_C_RECORDMCOUNT
+ objtool_target := tools/objtool FORCE
endif
endif
endif
@@ -1023,10 +1024,10 @@ endif
export mod_sign_cmd
HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
+has_libelf := $(call try-run,\
+ echo "int main() {}" | $(HOSTCC) -xc -o /dev/null
$(HOST_LIBELF_LIBS) -,1,0)
Maybe there could be some build dependency, e.g. CONFIG_OBJTOOL_SUBCMDS
that sets the "objtool_target" and "has_libelf" when selected.
Then the CONFIG_UNWINDER_ORC, RECORD_MCOUNT and STACK_VALIDATION would
just had to select that config option.
ifdef CONFIG_STACK_VALIDATION
- has_libelf := $(call try-run,\
- echo "int main() {}" | $(HOSTCC) -xc -o /dev/null
$(HOST_LIBELF_LIBS) -,1,0)
ifeq ($(has_libelf),1)
objtool_target := tools/objtool FORCE
else
@@ -1163,13 +1164,15 @@ uapi-asm-generic:
PHONY += prepare-objtool
prepare-objtool: $(objtool_target)
-ifeq ($(SKIP_STACK_VALIDATION),1)
-ifdef CONFIG_UNWINDER_ORC
+ifneq ($(has_libelf),1)
+ ifdef CONFIG_UNWINDER_ORC
@echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please
install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
@false
-else
+ else
+ ifeq ($(SKIP_STACK_VALIDATION),1)
@echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev,
libelf-devel or elfutils-libelf-devel" >&2
I think this would be more readable without the else branch:
ifneq ($(has_libelf),1)
ifdef <some objtool command config>
<warn about unavailability>
endif
ifdef <another objtool command config>
<warn ...>
endif
<...>
endif
Cheers,
--
Julien Thierry
