From: Nick Desaulniers <ndesaulniers@google.com>
To: keescook@chromium.org
Cc: clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <nathanchance@gmail.com>,
Jordan Rupprect <rupprecht@google.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] lkdtm: support llvm-objcopy
Date: Mon, 13 May 2019 15:21:09 -0700 [thread overview]
Message-ID: <20190513222109.110020-1-ndesaulniers@google.com> (raw)
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@gmail.com>
Suggested-by: Jordan Rupprect <rupprecht@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
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
next reply other threads:[~2019-05-13 22:21 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-13 22:21 Nick Desaulniers [this message]
2019-05-13 22:26 ` [PATCH] lkdtm: support llvm-objcopy Nick Desaulniers
2019-05-13 23:04 ` Kees Cook
2019-05-13 23:29 ` Nathan Chancellor
2019-05-13 23:38 ` Jordan Rupprecht
2019-05-13 23:47 ` Nathan Chancellor
2019-05-13 23:50 ` Nick Desaulniers
2019-05-14 18:10 ` Kees Cook
2019-05-14 20:24 ` Nick Desaulniers
2019-05-15 16:42 ` Kees Cook
2019-05-15 17:37 ` Nick Desaulniers
2019-05-15 18:12 ` [PATCH v2] " Nick Desaulniers
2019-05-15 18:19 ` Nathan Chancellor
2019-05-15 18:24 ` [PATCH v3] " Nick Desaulniers
[not found] ` <20190517001002.D1A262084A@mail.kernel.org>
2019-05-17 4:06 ` Nathan Chancellor
2019-05-17 4:09 ` Nathan Chancellor
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