| // Copyright 2016 The Fuchsia Authors |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #include <err.h> |
| #include <kernel/stats.h> |
| #include <kernel/thread.h> |
| #include <lib/ktrace.h> |
| #include <lib/vdso.h> |
| #include <object/process_dispatcher.h> |
| #include <platform.h> |
| #include <syscalls/syscalls.h> |
| #include <trace.h> |
| #include <zircon/zx-syscall-numbers.h> |
| |
| #include <inttypes.h> |
| #include <stdint.h> |
| |
| #include "priv.h" |
| #include "vdso-valid-sysret.h" |
| |
| #define LOCAL_TRACE 0 |
| |
| int sys_invalid_syscall(uint64_t num, uint64_t pc, |
| uintptr_t vdso_code_address) { |
| LTRACEF("invalid syscall %lu from PC %#lx vDSO code %#lx\n", |
| num, pc, vdso_code_address); |
| thread_signal_policy_exception(); |
| return ZX_ERR_BAD_SYSCALL; |
| } |
| |
| // N.B. Interrupts must be disabled on entry and they will be disabled on exit. |
| // The reason is the two calls two arch_curr_cpu_num in the ktrace calls: we |
| // don't want the cpu changing during the call. |
| |
| template <typename T> |
| inline syscall_result do_syscall(uint64_t syscall_num, uint64_t pc, |
| bool (*valid_pc)(uintptr_t), T make_call) { |
| ktrace_tiny(TAG_SYSCALL_ENTER, (static_cast<uint32_t>(syscall_num) << 8) | arch_curr_cpu_num()); |
| |
| CPU_STATS_INC(syscalls); |
| |
| /* re-enable interrupts to maintain kernel preemptiveness |
| This must be done after the above ktrace_tiny call, and after the |
| above CPU_STATS_INC call as it also calls arch_curr_cpu_num. */ |
| arch_enable_ints(); |
| |
| LTRACEF_LEVEL(2, "t %p syscall num %" PRIu64 " ip/pc %#" PRIx64 "\n", |
| get_current_thread(), syscall_num, pc); |
| |
| ProcessDispatcher* current_process = ProcessDispatcher::GetCurrent(); |
| const uintptr_t vdso_code_address = current_process->vdso_code_address(); |
| |
| uint64_t ret; |
| if (unlikely(!valid_pc(pc - vdso_code_address))) { |
| ret = sys_invalid_syscall(syscall_num, pc, vdso_code_address); |
| } else { |
| ret = make_call(current_process); |
| } |
| |
| LTRACEF_LEVEL(2, "t %p ret %#" PRIx64 "\n", get_current_thread(), ret); |
| |
| /* re-disable interrupts on the way out |
| This must be done before the below ktrace_tiny call. */ |
| arch_disable_ints(); |
| |
| ktrace_tiny(TAG_SYSCALL_EXIT, (static_cast<uint32_t>(syscall_num << 8)) | arch_curr_cpu_num()); |
| |
| // The assembler caller will re-disable interrupts at the appropriate time. |
| return {ret, thread_is_signaled(get_current_thread())}; |
| } |
| |
| syscall_result unknown_syscall(uint64_t syscall_num, uint64_t pc) { |
| return do_syscall(syscall_num, pc, |
| [](uintptr_t) { return false; }, |
| [&](ProcessDispatcher*) { |
| __builtin_unreachable(); |
| return ZX_ERR_INTERNAL; |
| }); |
| } |
| |
| // Autogenerated per-syscall wrapper functions. |
| #include <zircon/syscall-kernel-wrappers.inc> |