From 08869deb7efbda6e979886cb67e3d5843f92c2e8 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Sun, 30 Jun 2019 07:39:20 -0500 Subject: add support for powerpc/powerpc64 unaligned relocations R_PPC_UADDR32 (R_PPC64_UADDR64) has the same meaning as R_PPC_ADDR32 (R_PPC64_ADDR64), except that its address need not be aligned. For powerpc64, BFD ld(1) will automatically convert between ADDR<->UADDR relocations when the address is/isn't at its native alignment. This will happen if, for example, there is a pointer in a packed struct. gold and lld do not currently generate R_PPC64_UADDR64, but pass through misaligned R_PPC64_ADDR64 relocations from object files, possibly relaxing them to misaligned R_PPC64_RELATIVE. In both cases (relaxed or not) this violates the PSABI, which defines the relevant field type as "a 64-bit field occupying 8 bytes, the alignment of which is 8 bytes unless otherwise specified." All three linkers violate the PSABI on 32-bit powerpc, where the only difference is that the field is 32 bits wide, aligned to 4 bytes. Currently musl fails to load executables linked by BFD ld containing R_PPC64_UADDR64, with the error "unsupported relocation type 43". This change provides compatibility with BFD ld on powerpc64, and any static linker on either architecture that starts following the PSABI more closely. --- arch/powerpc/reloc.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc') diff --git a/arch/powerpc/reloc.h b/arch/powerpc/reloc.h index 1b4cab36..527b6b7c 100644 --- a/arch/powerpc/reloc.h +++ b/arch/powerpc/reloc.h @@ -9,6 +9,7 @@ #define TPOFF_K (-0x7000) #define REL_SYMBOLIC R_PPC_ADDR32 +#define REL_USYMBOLIC R_PPC_UADDR32 #define REL_GOT R_PPC_GLOB_DAT #define REL_PLT R_PPC_JMP_SLOT #define REL_RELATIVE R_PPC_RELATIVE -- cgit v1.2.1