[PATCH] lkdtm: support llvm-objcopy

[Nick Desaulniers]

With CONFIG_LKDTM=y and make OBJCOPY=llvm-objcopy, llvm-objcopy errors:
llvm-objcopy: error: --set-section-flags=.text conflicts with
--rename-section=.text=.rodata

Rather than support setting flags then renaming sections vs renaming
then setting flags, it's simpler to just change both at the same time
via --rename-section.

This can be verified with:
$ readelf -S drivers/misc/lkdtm/rodata_objcopy.o
...
Section Headers:
  [Nr] Name              Type             Address           Offset
       Size              EntSize          Flags  Link  Info  Align
...
  [ 1] .rodata           PROGBITS         0000000000000000  00000040
       0000000000000004  0000000000000000   A       0     0     4
...

Which shows in the Flags field that .text is now renamed .rodata, the
append flag A is set, and the section is not flagged as writeable W.

Link: https://github.com/ClangBuiltLinux/linux/issues/448
Reported-by: Nathan Chancellor <nathanchance@xxxxxxxxx>
Suggested-by: Jordan Rupprect <rupprecht@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---
 drivers/misc/lkdtm/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile
index 951c984de61a..89dee2a9d88c 100644
--- a/drivers/misc/lkdtm/Makefile
+++ b/drivers/misc/lkdtm/Makefile
@@ -15,8 +15,7 @@ KCOV_INSTRUMENT_rodata.o	:= n
 
 OBJCOPYFLAGS :=
 OBJCOPYFLAGS_rodata_objcopy.o	:= \
-			--set-section-flags .text=alloc,readonly \
-			--rename-section .text=.rodata
+			--rename-section .text=.rodata,alloc,readonly
 targets += rodata.o rodata_objcopy.o
 $(obj)/rodata_objcopy.o: $(obj)/rodata.o FORCE
 	$(call if_changed,objcopy)
-- 
2.21.0.1020.gf2820cf01a-goog