From: Gerald Schaefer gerald.schaefer@de.ibm.com
commit 4c1cbcbd6c56c79de2c07159be4f55386bb0bef2 upstream.
With certain kernel configurations, the R_390_JMP_SLOT relocation type might be generated, which is not expected by the KASLR relocation code, and the kernel stops with the message "Unknown relocation type".
This was found with a zfcpdump kernel config, where CONFIG_MODULES=n and CONFIG_VFIO=n. In that case, symbol_get() is used on undefined __weak symbols in virt/kvm/vfio.c, which results in the generation of R_390_JMP_SLOT relocation types.
Fix this by handling R_390_JMP_SLOT similar to R_390_GLOB_DAT.
Fixes: 805bc0bc238f ("s390/kernel: build a relocatable kernel") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Gerald Schaefer gerald.schaefer@de.ibm.com Reviewed-by: Philipp Rudo prudo@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/kernel/machine_kexec_reloc.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/s390/kernel/machine_kexec_reloc.c b/arch/s390/kernel/machine_kexec_reloc.c index d5035de9020e..b7182cec48dc 100644 --- a/arch/s390/kernel/machine_kexec_reloc.c +++ b/arch/s390/kernel/machine_kexec_reloc.c @@ -28,6 +28,7 @@ int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val, break; case R_390_64: /* Direct 64 bit. */ case R_390_GLOB_DAT: + case R_390_JMP_SLOT: *(u64 *)loc = val; break; case R_390_PC16: /* PC relative 16 bit. */