diff options
| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2019-10-21 19:56:00 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-29 09:22:35 +0100 |
| commit | fa8ef4a0c1c9eea54113eb090c3a3dcda624039d (patch) | |
| tree | d7d94c519ad1fce06a90e39d9253c6d053fa6406 /arch | |
| parent | 65b870d6eb0bf2084c5ce3a4638b44c6f9ccc4c9 (diff) | |
s390/kaslr: add support for R_390_GLOB_DAT relocation type
commit ac49303d9ef0ad98b79867a380ef23480e48870b upstream.
Commit "bpf: Process in-kernel BTF" in linux-next introduced an undefined
__weak symbol, which results in an R_390_GLOB_DAT relocation type. That
is not yet handled by the KASLR relocation code, and the kernel stops with
the message "Unknown relocation type".
Add code to detect and handle R_390_GLOB_DAT relocation types and undefined
symbols.
Fixes: 805bc0bc238f ("s390/kernel: build a relocatable kernel")
Cc: <stable@vger.kernel.org> # v5.2+
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/boot/startup.c | 14 | ||||
| -rw-r--r-- | arch/s390/kernel/machine_kexec_reloc.c | 1 |
2 files changed, 12 insertions, 3 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 7b0d05414618..ceeacbeff600 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -101,10 +101,18 @@ static void handle_relocs(unsigned long offset) dynsym = (Elf64_Sym *) vmlinux.dynsym_start; for (rela = rela_start; rela < rela_end; rela++) { loc = rela->r_offset + offset; - val = rela->r_addend + offset; + val = rela->r_addend; r_sym = ELF64_R_SYM(rela->r_info); - if (r_sym) - val += dynsym[r_sym].st_value; + if (r_sym) { + if (dynsym[r_sym].st_shndx != SHN_UNDEF) + val += dynsym[r_sym].st_value + offset; + } else { + /* + * 0 == undefined symbol table index (STN_UNDEF), + * used for R_390_RELATIVE, only add KASLR offset + */ + val += offset; + } r_type = ELF64_R_TYPE(rela->r_info); rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0); if (rc) diff --git a/arch/s390/kernel/machine_kexec_reloc.c b/arch/s390/kernel/machine_kexec_reloc.c index 3b664cb3ec4d..d5035de9020e 100644 --- a/arch/s390/kernel/machine_kexec_reloc.c +++ b/arch/s390/kernel/machine_kexec_reloc.c @@ -27,6 +27,7 @@ int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val, *(u32 *)loc = val; break; case R_390_64: /* Direct 64 bit. */ + case R_390_GLOB_DAT: *(u64 *)loc = val; break; case R_390_PC16: /* PC relative 16 bit. */ |