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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-10-08 19:58:40 +0300
committerKees Cook <keescook@chromium.org>2021-12-17 02:54:37 +0300
commitbc93a22a19eb2b68a16ecf04cdf4b2ed65aaf398 (patch)
tree5ab422ecde69b7bd598bcceee2546efa47a846aa
parent026c6fa1a525ca3f8a615052e45d766208989597 (diff)
downloadlinux-bc93a22a19eb2b68a16ecf04cdf4b2ed65aaf398.tar.xz
lkdtm: Fix content of section containing lkdtm_rodata_do_nothing()
On a kernel without CONFIG_STRICT_KERNEL_RWX, running EXEC_RODATA test leads to "Illegal instruction" failure. Looking at the content of rodata_objcopy.o, we see that the function content zeroes only: Disassembly of section .rodata: 0000000000000000 <.lkdtm_rodata_do_nothing>: 0: 00 00 00 00 .long 0x0 Add the contents flag in order to keep the content of the section while renaming it. Disassembly of section .rodata: 0000000000000000 <.lkdtm_rodata_do_nothing>: 0: 4e 80 00 20 blr Fixes: e9e08a07385e ("lkdtm: support llvm-objcopy") Cc: stable@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/8900731fbc05fb8b0de18af7133a8fc07c3c53a1.1633712176.git.christophe.leroy@csgroup.eu
-rw-r--r--drivers/misc/lkdtm/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile
index aa12097668d3..e2984ce51fe4 100644
--- a/drivers/misc/lkdtm/Makefile
+++ b/drivers/misc/lkdtm/Makefile
@@ -20,7 +20,7 @@ CFLAGS_REMOVE_rodata.o += $(CC_FLAGS_LTO)
OBJCOPYFLAGS :=
OBJCOPYFLAGS_rodata_objcopy.o := \
- --rename-section .noinstr.text=.rodata,alloc,readonly,load
+ --rename-section .noinstr.text=.rodata,alloc,readonly,load,contents
targets += rodata.o rodata_objcopy.o
$(obj)/rodata_objcopy.o: $(obj)/rodata.o FORCE
$(call if_changed,objcopy)