diff options
| -rw-r--r-- | accel/tcg/translate-all.c | 52 | ||||
| -rw-r--r-- | include/exec/exec-all.h | 11 |
2 files changed, 40 insertions, 23 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 34c5e28d07..e7f0329a52 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -352,36 +352,42 @@ static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb, return 0; } -bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr) +bool cpu_restore_state(CPUState *cpu, uintptr_t host_pc) { TranslationBlock *tb; bool r = false; + uintptr_t check_offset; - /* A retaddr of zero is invalid so we really shouldn't have ended - * up here. The target code has likely forgotten to check retaddr - * != 0 before attempting to restore state. We return early to - * avoid blowing up on a recursive tb_lock(). The target must have - * previously survived a failed cpu_restore_state because - * tb_find_pc(0) would have failed anyway. It still should be - * fixed though. + /* 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: + * + * - fault during translation (instruction fetch) + * - fault from helper (not using GETPC() macro) + * + * Either way we need return early to avoid blowing up on a + * recursive tb_lock() 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 */ - - if (!retaddr) { - return r; - } - - tb_lock(); - tb = tb_find_pc(retaddr); - if (tb) { - cpu_restore_state_from_tb(cpu, tb, retaddr); - if (tb->cflags & CF_NOCACHE) { - /* one-shot translation, invalidate it immediately */ - tb_phys_invalidate(tb, -1); - tb_remove(tb); + check_offset = host_pc - (uintptr_t) tcg_init_ctx.code_gen_buffer; + + if (check_offset < tcg_init_ctx.code_gen_buffer_size) { + tb_lock(); + tb = tb_find_pc(host_pc); + if (tb) { + cpu_restore_state_from_tb(cpu, tb, host_pc); + if (tb->cflags & CF_NOCACHE) { + /* one-shot translation, invalidate it immediately */ + tb_phys_invalidate(tb, -1); + tb_remove(tb); + } + r = true; } - r = true; + tb_unlock(); } - tb_unlock(); return r; } diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 923ece3e9b..0f51c92adb 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -45,6 +45,17 @@ void restore_state_to_opc(CPUArchState *env, struct TranslationBlock *tb, target_ulong *data); void cpu_gen_init(void); + +/** + * cpu_restore_state: + * @cpu: the vCPU state is to be restore to + * @searched_pc: the host PC the fault occurred at + * @return: true if state was restored, false otherwise + * + * Attempt to restore the state for a fault occurring in translated + * code. If the searched_pc is not in translated code no state is + * restored and the function returns false. + */ bool cpu_restore_state(CPUState *cpu, uintptr_t searched_pc); void QEMU_NORETURN cpu_loop_exit_noexc(CPUState *cpu); |