Recordmcount utility under scripts is run, after compiling each object,
to find out all the locations of calling _mcount() and put them into
specific seciton named __mcount_loc.
Then linker collects all such information into a table in the kernel image
(between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace.
This patch adds arm64 specific definitions to identify such locations.
There are two types of implementation, C and Perl. On arm64, only C version
is used to build the kernel now that CONFIG_HAVE_C_RECORDMCOUNT is on.
But Perl version is also maintained.
This patch also contains a workaround just in case where a header file,
elf.h, on host machine doesn't have definitions of EM_AARCH64 nor
R_AARCH64_ABS64. Without them, compiling C version of recordmcount will
fail.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit af64d2aa87)
Signed-off-by: David Riley <davidriley@chromium.org>
Change-Id: I29f5d20de6fe3e79eadf2ba4da879203f87a9093
Reviewed-on: https://chromium-review.googlesource.com/206233
Reviewed-by: Olof Johansson <olofj@chromium.org>
Tested-by: David Riley <davidriley@chromium.org>
79f5851bc3