diff options
| -rw-r--r-- | arch/arm64/include/asm/cacheflush.h | 27 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/insn.c | 18 | ||||
| -rw-r--r-- | arch/arm64/mm/cache.S | 4 |
4 files changed, 33 insertions, 18 deletions
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index d264a7274811..19844211a4e6 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -19,6 +19,7 @@ #ifndef __ASM_CACHEFLUSH_H #define __ASM_CACHEFLUSH_H +#include <linux/kgdb.h> #include <linux/mm.h> /* @@ -71,7 +72,7 @@ * - kaddr - page address * - size - region size */ -extern void flush_icache_range(unsigned long start, unsigned long end); +extern void __flush_icache_range(unsigned long start, unsigned long end); extern int invalidate_icache_range(unsigned long start, unsigned long end); extern void __flush_dcache_area(void *addr, size_t len); extern void __inval_dcache_area(void *addr, size_t len); @@ -81,6 +82,30 @@ extern void __clean_dcache_area_pou(void *addr, size_t len); extern long __flush_cache_user_range(unsigned long start, unsigned long end); extern void sync_icache_aliases(void *kaddr, unsigned long len); +static inline void flush_icache_range(unsigned long start, unsigned long end) +{ + __flush_icache_range(start, end); + + /* + * IPI all online CPUs so that they undergo a context synchronization + * event and are forced to refetch the new instructions. + */ +#ifdef CONFIG_KGDB + /* + * KGDB performs cache maintenance with interrupts disabled, so we + * will deadlock trying to IPI the secondary CPUs. In theory, we can + * set CACHE_FLUSH_IS_SAFE to 0 to avoid this known issue, but that + * just means that KGDB will elide the maintenance altogether! As it + * turns out, KGDB uses IPIs to round-up the secondary CPUs during + * the patching operation, so we don't need extra IPIs here anyway. + * In which case, add a KGDB-specific bodge and return early. + */ + if (kgdb_connected && irqs_disabled()) + return; +#endif + kick_all_cpus_sync(); +} + static inline void flush_cache_mm(struct mm_struct *mm) { } diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 5d59ff9a8da9..459129712dfa 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -107,7 +107,7 @@ static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, for (i = 0; i < SZ_2K; i += 0x80) memcpy(dst + i, hyp_vecs_start, hyp_vecs_end - hyp_vecs_start); - flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K); + __flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K); } static void __install_bp_hardening_cb(bp_hardening_cb_t fn, diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 816d03c4c913..0f6a2e0cfde0 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -216,8 +216,8 @@ int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) ret = aarch64_insn_write(tp, insn); if (ret == 0) - flush_icache_range((uintptr_t)tp, - (uintptr_t)tp + AARCH64_INSN_SIZE); + __flush_icache_range((uintptr_t)tp, + (uintptr_t)tp + AARCH64_INSN_SIZE); return ret; } @@ -283,18 +283,8 @@ int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt) if (ret) return ret; - if (aarch64_insn_hotpatch_safe(insn, insns[0])) { - /* - * ARMv8 architecture doesn't guarantee all CPUs see - * the new instruction after returning from function - * aarch64_insn_patch_text_nosync(). So send IPIs to - * all other CPUs to achieve instruction - * synchronization. - */ - ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]); - kick_all_cpus_sync(); - return ret; - } + if (aarch64_insn_hotpatch_safe(insn, insns[0])) + return aarch64_insn_patch_text_nosync(addrs[0], insns[0]); } return aarch64_insn_patch_text_sync(addrs, insns, cnt); diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 30334d81b021..0c22ede52f90 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -35,7 +35,7 @@ * - start - virtual start address of region * - end - virtual end address of region */ -ENTRY(flush_icache_range) +ENTRY(__flush_icache_range) /* FALLTHROUGH */ /* @@ -77,7 +77,7 @@ alternative_else_nop_endif 9: mov x0, #-EFAULT b 1b -ENDPROC(flush_icache_range) +ENDPROC(__flush_icache_range) ENDPROC(__flush_cache_user_range) /* |