Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 032/563] lkdtm: Fix content of section containing lkdtm_rodata_do_nothing() | Date | Mon, 24 Jan 2022 19:36:37 +0100 |
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From: Christophe Leroy <christophe.leroy@csgroup.eu>
commit bc93a22a19eb2b68a16ecf04cdf4b2ed65aaf398 upstream.
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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/misc/lkdtm/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -16,7 +16,7 @@ KCOV_INSTRUMENT_rodata.o := n 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)
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