6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook keescook@chromium.org
[ Upstream commit fb28a8862dc4b5bf8e44578338f35d9c6c68339d ]
The EXEC_RODATA test plays a lot of tricks to live in the .rodata section, and once again ran into objtool's (completely reasonable) assumptions that executable code should live in an executable section. However, this manifested only under CONFIG_CFI_CLANG=y, as one of the .cfi_sites was pointing into the .rodata section.
Since we're testing non-CFI execution properties in perms.c (and rodata.c), we can disable CFI for the involved functions, and remove the CFI arguments from rodata.c entirely.
Reported-by: kernel test robot oliver.sang@intel.com Closes: https://lore.kernel.org/oe-lkp/202308301532.d7acf63e-oliver.sang@intel.com Fixes: 6342a20efbd8 ("objtool: Add elf_create_section_pair()") Link: https://lore.kernel.org/r/20240430234953.work.760-kees@kernel.org Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/lkdtm/Makefile | 2 +- drivers/misc/lkdtm/perms.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile index 95ef971b5e1cb..b28701138b4bc 100644 --- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -19,7 +19,7 @@ KASAN_SANITIZE_rodata.o := n KCSAN_SANITIZE_rodata.o := n KCOV_INSTRUMENT_rodata.o := n OBJECT_FILES_NON_STANDARD_rodata.o := y -CFLAGS_REMOVE_rodata.o += $(CC_FLAGS_LTO) $(RETHUNK_CFLAGS) +CFLAGS_REMOVE_rodata.o += $(CC_FLAGS_LTO) $(RETHUNK_CFLAGS) $(CC_FLAGS_CFI)
OBJCOPYFLAGS := OBJCOPYFLAGS_rodata_objcopy.o := \ diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index b93404d656509..5b861dbff27e9 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -61,7 +61,7 @@ static void *setup_function_descriptor(func_desc_t *fdesc, void *dst) return fdesc; }
-static noinline void execute_location(void *dst, bool write) +static noinline __nocfi void execute_location(void *dst, bool write) { void (*func)(void); func_desc_t fdesc;