diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index a1803a1026..3f9e25fa0c 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -392,27 +392,18 @@ void tb_destroy(TranslationBlock *tb) bool cpu_restore_state(CPUState *cpu, uintptr_t host_pc, bool will_exit) { - TranslationBlock *tb; - bool r = false; - uintptr_t check_offset; - - /* The host_pc has to be in the region of current code buffer. If - * it is not we will not be able to resolve it here. The two cases - * where host_pc will not be correct are: + /* + * The host_pc has to be in the region of the code buffer. + * If it is not we will not be able to resolve it here. + * The two cases where host_pc will not be correct are: * * - fault during translation (instruction fetch) * - fault from helper (not using GETPC() macro) * * Either way we need return early as we can't resolve it here. - * - * We are using unsigned arithmetic so if host_pc < - * tcg_init_ctx.code_gen_buffer check_offset will wrap to way - * above the code_gen_buffer_size */ - check_offset = host_pc - (uintptr_t) tcg_init_ctx.code_gen_buffer; - - if (check_offset < tcg_init_ctx.code_gen_buffer_size) { - tb = tcg_tb_lookup(host_pc); + if (in_code_gen_buffer((const void *)host_pc)) { + TranslationBlock *tb = tcg_tb_lookup(host_pc); if (tb) { cpu_restore_state_from_tb(cpu, tb, host_pc, will_exit); if (tb_cflags(tb) & CF_NOCACHE) { @@ -421,11 +412,10 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t host_pc, bool will_exit) tcg_tb_remove(tb); tb_destroy(tb); } - r = true; + return true; } } - - return r; + return false; } static void page_init(void) diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h index bb1e97b13b..ef571b6f3e 100644 --- a/include/tcg/tcg.h +++ b/include/tcg/tcg.h @@ -680,6 +680,17 @@ extern __thread TCGContext *tcg_ctx; extern void *tcg_code_gen_epilogue; extern TCGv_env cpu_env; +static inline bool in_code_gen_buffer(const void *p) +{ + const TCGContext *s = &tcg_init_ctx; + /* + * Much like it is valid to have a pointer to the byte past the + * end of an array (so long as you don't dereference it), allow + * a pointer to the byte past the end of the code gen buffer. + */ + return (size_t)(p - s->code_gen_buffer) <= s->code_gen_buffer_size; +} + static inline size_t temp_idx(TCGTemp *ts) { ptrdiff_t n = ts - tcg_ctx->temps;