@@ -76,6 +76,7 @@ extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
struct module;
void alternatives_module_add(struct module *mod, char *name,
+ void *para, void *para_end,
void *locks, void *locks_end,
void *text, void *text_end);
void alternatives_module_del(struct module *mod);
@@ -482,6 +482,12 @@ struct alt_module {
struct module *mod;
char *name;
+#ifdef CONFIG_PARAVIRT_RUNTIME
+ /* ptrs to paravirt sites */
+ struct paravirt_patch_site *para;
+ struct paravirt_patch_site *para_end;
+#endif
+
/* ptrs to lock prefixes */
const s32 *locks;
const s32 *locks_end;
@@ -496,6 +502,7 @@ struct alt_module {
static LIST_HEAD(alt_modules);
void __init_or_module alternatives_module_add(struct module *mod, char *name,
+ void *para, void *para_end,
void *locks, void *locks_end,
void *text, void *text_end)
{
@@ -506,7 +513,7 @@ void __init_or_module alternatives_module_add(struct module *mod, char *name,
if (!noreplace_smp && (num_present_cpus() == 1 || setup_max_cpus <= 1))
uniproc_patched = true;
#endif
- if (!uniproc_patched)
+ if (!IS_ENABLED(CONFIG_PARAVIRT_RUNTIME) && !uniproc_patched)
return;
mutex_lock(&text_mutex);
@@ -516,6 +523,11 @@ void __init_or_module alternatives_module_add(struct module *mod, char *name,
alt->mod = mod;
alt->name = name;
+#ifdef CONFIG_PARAVIRT_RUNTIME
+ alt->para = para;
+ alt->para_end = para_end;
+#endif
+
if (num_possible_cpus() != 1 || uniproc_patched) {
/* Remember only if we'll need to undo it. */
alt->locks = locks;
@@ -733,6 +745,8 @@ void __init alternative_instructions(void)
apply_alternatives(__alt_instructions, __alt_instructions_end);
alternatives_module_add(NULL, "core kernel",
+ __parainstructions_runtime,
+ __parainstructions_runtime_end,
__smp_locks, __smp_locks_end,
_text, _etext);
@@ -248,12 +248,30 @@ int module_finalize(const Elf_Ehdr *hdr,
void *aseg = (void *)alt->sh_addr;
apply_alternatives(aseg, aseg + alt->sh_size);
}
- if (locks && text) {
- void *lseg = (void *)locks->sh_addr;
- void *tseg = (void *)text->sh_addr;
+ if (para_run || (locks && text)) {
+ void *pseg, *pseg_end;
+ void *lseg, *lseg_end;
+ void *tseg, *tseg_end;
+
+ pseg = pseg_end = NULL;
+ lseg = lseg_end = NULL;
+ tseg = tseg_end = NULL;
+ if (para_run) {
+ pseg = (void *)para_run->sh_addr;
+ pseg_end = pseg + para_run->sh_size;
+ }
+
+ if (locks && text) {
+ tseg = (void *)text->sh_addr;
+ tseg_end = tseg + text->sh_size;
+
+ lseg = (void *)locks->sh_addr;
+ lseg_end = lseg + locks->sh_size;
+ }
alternatives_module_add(me, me->name,
- lseg, lseg + locks->sh_size,
- tseg, tseg + text->sh_size);
+ pseg, pseg_end,
+ lseg, lseg_end,
+ tseg, tseg_end);
}
if (para) {
Persist .parainstructions.runtime in memory. We will use it to patch paravirt-ops at runtime. The extra memory footprint depends on chosen config options but the inlined queued_spin_unlock() presents an edge case: $ objdump -h vmlinux|grep .parainstructions Idx Name Size VMA LMA File-off Algn 27 .parainstructions 0001013c ffffffff82895000 0000000002895000 01c95000 2**3 28 .parainstructions.runtime 0000cd2c ffffffff828a5140 00000000028a5140 01ca5140 2**3 (The added footprint is the size of the .parainstructions.runtime section.) $ size vmlinux text data bss dec hex filename 13726196 12302814 14094336 40123346 2643bd2 vmlinux Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> --- arch/x86/include/asm/alternative.h | 1 + arch/x86/kernel/alternative.c | 16 +++++++++++++++- arch/x86/kernel/module.c | 28 +++++++++++++++++++++++----- 3 files changed, 39 insertions(+), 6 deletions(-)