s390: add automatic detection of the spectre defense
Automatically decide between nobp vs. expolines if the spectre_v2=auto
kernel parameter is specified or CONFIG_EXPOLINE_AUTO=y is set.
The decision made at boot time due to CONFIG_EXPOLINE_AUTO=y being set
can be overruled with the nobp, nospec and spectre_v2 kernel parameters.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 1fc6d1f..5a83be9 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -159,7 +159,7 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
me->core_layout.size += me->arch.got_size;
me->arch.plt_offset = me->core_layout.size;
if (me->arch.plt_size) {
- if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_call_disable)
+ if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)
me->arch.plt_size += PLT_ENTRY_SIZE;
me->core_layout.size += me->arch.plt_size;
}
@@ -318,8 +318,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
info->plt_offset;
ip[0] = 0x0d10e310; /* basr 1,0 */
ip[1] = 0x100a0004; /* lg 1,10(1) */
- if (IS_ENABLED(CONFIG_EXPOLINE) &&
- !nospec_call_disable) {
+ if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {
unsigned int *ij;
ij = me->core_layout.base +
me->arch.plt_offset +
@@ -440,7 +439,7 @@ int module_finalize(const Elf_Ehdr *hdr,
void *aseg;
if (IS_ENABLED(CONFIG_EXPOLINE) &&
- !nospec_call_disable && me->arch.plt_size) {
+ !nospec_disable && me->arch.plt_size) {
unsigned int *ij;
ij = me->core_layout.base + me->arch.plt_offset +
@@ -467,11 +466,11 @@ int module_finalize(const Elf_Ehdr *hdr,
if (IS_ENABLED(CONFIG_EXPOLINE) &&
(!strcmp(".nospec_call_table", secname)))
- nospec_call_revert(aseg, aseg + s->sh_size);
+ nospec_revert(aseg, aseg + s->sh_size);
if (IS_ENABLED(CONFIG_EXPOLINE) &&
(!strcmp(".nospec_return_table", secname)))
- nospec_return_revert(aseg, aseg + s->sh_size);
+ nospec_revert(aseg, aseg + s->sh_size);
}
jump_label_apply_nops(me);