diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index aa7b155b6173..1797f80c10de 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -5,6 +5,7 @@ #include <linux/types.h> #include <linux/stringify.h> #include <asm/asm.h> +#include <asm/bug.h> #define ALTINSTR_FLAG_INV (1 << 15) #define ALT_NOT(feat) ((feat) | ALTINSTR_FLAG_INV) @@ -84,10 +85,17 @@ struct module; extern void its_init_mod(struct module *mod); extern void its_fini_mod(struct module *mod); extern void its_free_mod(struct module *mod); +extern u8 *its_static_thunk(int reg); #else /* CONFIG_MITIGATION_ITS */ static inline void its_init_mod(struct module *mod) { } static inline void its_fini_mod(struct module *mod) { } static inline void its_free_mod(struct module *mod) { } +static inline u8 *its_static_thunk(int reg) +{ + WARN_ONCE(1, "ITS not compiled in"); + + return NULL; +} #endif #ifdef CONFIG_RETHUNK diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 3c08f0e25df7..43ec73da66d8 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -597,6 +597,14 @@ static bool cpu_wants_indirect_its_thunk_at(unsigned long addr, int reg) /* Lower-half of the cacheline? */ return !(addr & 0x20); } + +u8 *its_static_thunk(int reg) +{ + u8 *thunk = __x86_indirect_its_thunk_array[reg]; + + return thunk; +} + #endif /* diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 8be74c2aa7b8..37a005df0b95 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -449,7 +449,7 @@ static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip) if (IS_ENABLED(CONFIG_MITIGATION_ITS) && cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) { OPTIMIZER_HIDE_VAR(reg); - emit_jump(&prog, &__x86_indirect_its_thunk_array[reg], ip); + emit_jump(&prog, its_static_thunk(reg), ip); } else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) { EMIT_LFENCE(); EMIT2(0xFF, 0xE0 + reg);