From: Masahiro Yamada <masahiroy@xxxxxxxxxx>
commit c7acee3d2f128a38b68fb7af85dbbd91bfd0b4ad upstream.
Christophe Leroy reported that commit 7b4537199a4a ("kbuild: link
symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") broke
mpc85xx_defconfig + CONFIG_RELOCATABLE=y.
LD vmlinux
SYSMAP System.map
SORTTAB vmlinux
CHKREL vmlinux
WARNING: 451 bad relocations
c0b312a9 R_PPC_UADDR32 .head.text-0x3ff9ed54
c0b312ad R_PPC_UADDR32 .head.text-0x3ffac224
c0b312b1 R_PPC_UADDR32 .head.text-0x3ffb09f4
c0b312b5 R_PPC_UADDR32 .head.text-0x3fe184dc
c0b312b9 R_PPC_UADDR32 .head.text-0x3fe183a8
...
The compiler emits a bunch of R_PPC_UADDR32, which is not supported by
arch/powerpc/kernel/reloc_32.S.
The reason is there exists an unaligned symbol.
$ powerpc-linux-gnu-nm -n vmlinux
...
c0b31258 d spe_aligninfo
c0b31298 d __func__.0
c0b312a9 D sys_call_table
c0b319b8 d __func__.0
Commit 7b4537199a4a is not the root cause. Even before that, I can
reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y
+ CONFIG_MODVERSIONS=n.
It is just that nobody noticed because when CONFIG_MODVERSIONS is
enabled, a __crc_* symbol inserted before sys_call_table was hiding the
unalignment issue.
Adding alignment to the syscall table for ppc32 fixes the issue.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Tested-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
[mpe: Trim change log discussion, add Cc stable]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@xxxxxxxxxx/
Link: https://lore.kernel.org/r/20220820165129.1147589-1-masahiroy@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/systbl.S | 1 +
1 file changed, 1 insertion(+)
--- a/arch/powerpc/kernel/systbl.S
+++ b/arch/powerpc/kernel/systbl.S
@@ -18,6 +18,7 @@
.p2align 3
#define __SYSCALL(nr, entry) .8byte entry
#else
+ .p2align 2
#define __SYSCALL(nr, entry) .long entry
#endif
