From: Fangrui Song maskray@google.com
[ Upstream commit 793f49a87aae24e5bcf92ad98d764153fc936570 ]
arm64 references the start address of .builtin_fw (__start_builtin_fw) with a pair of R_AARCH64_ADR_PREL_PG_HI21/R_AARCH64_LDST64_ABS_LO12_NC relocations. The compiler is allowed to emit the R_AARCH64_LDST64_ABS_LO12_NC relocation because struct builtin_fw in include/linux/firmware.h is 8-byte aligned.
The R_AARCH64_LDST64_ABS_LO12_NC relocation requires the address to be a multiple of 8, which may not be the case if .builtin_fw is empty. Unconditionally align .builtin_fw to fix the linker error. 32-bit architectures could use ALIGN(4) but that would add unnecessary complexity, so just use ALIGN(8).
Link: https://lkml.kernel.org/r/20201208054646.2913063-1-maskray@google.com Link: https://github.com/ClangBuiltLinux/linux/issues/1204 Fixes: 5658c76 ("firmware: allow firmware files to be built into kernel image") Signed-off-by: Fangrui Song maskray@google.com Reported-by: kernel test robot lkp@intel.com Acked-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Nick Desaulniers ndesaulniers@google.com Tested-by: Nick Desaulniers ndesaulniers@google.com Tested-by: Douglas Anderson dianders@chromium.org Acked-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/asm-generic/vmlinux.lds.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index f65a924a75abd..e71c97c3c25ef 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -363,7 +363,7 @@ } \ \ /* Built-in firmware blobs */ \ - .builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) { \ + .builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) ALIGN(8) { \ __start_builtin_fw = .; \ KEEP(*(.builtin_fw)) \ __end_builtin_fw = .; \