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-rw-r--r--arch/arm64/include/asm/alternative.h7
-rw-r--r--arch/arm64/include/asm/pgtable.h6
-rw-r--r--arch/arm64/kernel/alternative.c51
-rw-r--r--arch/arm64/kernel/module.c5
4 files changed, 53 insertions, 16 deletions
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index a91933b1e2e6..4b650ec1d7dd 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -28,7 +28,12 @@ typedef void (*alternative_cb_t)(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void __init apply_alternatives_all(void);
-void apply_alternatives(void *start, size_t length);
+
+#ifdef CONFIG_MODULES
+void apply_alternatives_module(void *start, size_t length);
+#else
+static inline void apply_alternatives_module(void *start, size_t length) { }
+#endif
#define ALTINSTR_ENTRY(feature,cb) \
" .word 661b - .\n" /* label */ \
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 9f82d6b53851..1bdeca8918a6 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -224,10 +224,8 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
* Only if the new pte is valid and kernel, otherwise TLB maintenance
* or update_mmu_cache() have the necessary barriers.
*/
- if (pte_valid_not_user(pte)) {
+ if (pte_valid_not_user(pte))
dsb(ishst);
- isb();
- }
}
extern void __sync_icache_dcache(pte_t pteval);
@@ -434,7 +432,6 @@ static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
{
WRITE_ONCE(*pmdp, pmd);
dsb(ishst);
- isb();
}
static inline void pmd_clear(pmd_t *pmdp)
@@ -485,7 +482,6 @@ static inline void set_pud(pud_t *pudp, pud_t pud)
{
WRITE_ONCE(*pudp, pud);
dsb(ishst);
- isb();
}
static inline void pud_clear(pud_t *pudp)
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index 5c4bce4ac381..36fb069fd049 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -122,7 +122,30 @@ static void patch_alternative(struct alt_instr *alt,
}
}
-static void __apply_alternatives(void *alt_region, bool use_linear_alias)
+/*
+ * We provide our own, private D-cache cleaning function so that we don't
+ * accidentally call into the cache.S code, which is patched by us at
+ * runtime.
+ */
+static void clean_dcache_range_nopatch(u64 start, u64 end)
+{
+ u64 cur, d_size, ctr_el0;
+
+ ctr_el0 = read_sanitised_ftr_reg(SYS_CTR_EL0);
+ d_size = 4 << cpuid_feature_extract_unsigned_field(ctr_el0,
+ CTR_DMINLINE_SHIFT);
+ cur = start & ~(d_size - 1);
+ do {
+ /*
+ * We must clean+invalidate to the PoC in order to avoid
+ * Cortex-A53 errata 826319, 827319, 824069 and 819472
+ * (this corresponds to ARM64_WORKAROUND_CLEAN_CACHE)
+ */
+ asm volatile("dc civac, %0" : : "r" (cur) : "memory");
+ } while (cur += d_size, cur < end);
+}
+
+static void __apply_alternatives(void *alt_region, bool is_module)
{
struct alt_instr *alt;
struct alt_region *region = alt_region;
@@ -145,7 +168,7 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias)
pr_info_once("patching kernel code\n");
origptr = ALT_ORIG_PTR(alt);
- updptr = use_linear_alias ? lm_alias(origptr) : origptr;
+ updptr = is_module ? origptr : lm_alias(origptr);
nr_inst = alt->orig_len / AARCH64_INSN_SIZE;
if (alt->cpufeature < ARM64_CB_PATCH)
@@ -155,8 +178,20 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias)
alt_cb(alt, origptr, updptr, nr_inst);
- flush_icache_range((uintptr_t)origptr,
- (uintptr_t)(origptr + nr_inst));
+ if (!is_module) {
+ clean_dcache_range_nopatch((u64)origptr,
+ (u64)(origptr + nr_inst));
+ }
+ }
+
+ /*
+ * The core module code takes care of cache maintenance in
+ * flush_module_icache().
+ */
+ if (!is_module) {
+ dsb(ish);
+ __flush_icache_all();
+ isb();
}
}
@@ -178,7 +213,7 @@ static int __apply_alternatives_multi_stop(void *unused)
isb();
} else {
BUG_ON(alternatives_applied);
- __apply_alternatives(&region, true);
+ __apply_alternatives(&region, false);
/* Barriers provided by the cache flushing */
WRITE_ONCE(alternatives_applied, 1);
}
@@ -192,12 +227,14 @@ void __init apply_alternatives_all(void)
stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
}
-void apply_alternatives(void *start, size_t length)
+#ifdef CONFIG_MODULES
+void apply_alternatives_module(void *start, size_t length)
{
struct alt_region region = {
.begin = start,
.end = start + length,
};
- __apply_alternatives(&region, false);
+ __apply_alternatives(&region, true);
}
+#endif
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 155fd91e78f4..f0f27aeefb73 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -448,9 +448,8 @@ int module_finalize(const Elf_Ehdr *hdr,
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
- if (strcmp(".altinstructions", secstrs + s->sh_name) == 0) {
- apply_alternatives((void *)s->sh_addr, s->sh_size);
- }
+ if (strcmp(".altinstructions", secstrs + s->sh_name) == 0)
+ apply_alternatives_module((void *)s->sh_addr, s->sh_size);
#ifdef CONFIG_ARM64_MODULE_PLTS
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) &&
!strcmp(".text.ftrace_trampoline", secstrs + s->sh_name))